TY - THES A1 - Heuer, Anjana T1 - Aktive Gefäßverschlusssysteme in der interventionellen Radiologie: Sicherheit und Effektivität des neuartigen Doppelclip-basierten Celt ACD® Systems T1 - Active vascular closure devices in interventional radiology: safety and efficacy of a novel double-clip-based Celt ACD® system N2 - Mit steigender Nachfrage an minimal-invasiven Therapieoptionen wächst auch das Interesse an innovativen Alternativen im Bereich des arteriellen Gefäßverschlusses nach PVI. Ziel der vorliegenden Arbeit war es, die Effektivität und Sicherheit eines neu auf dem Markt befindlichen, Doppelclip-basierten aktiven VVS zu prüfen. Eine hohe technische Erfolgsrate von 98,8 % bei einer geringen Komplikationsrate von 3,6 % wurde verzeichnet. Bei Anwesenheit der Komorbiditäten Dm und CNI 5 zeigte sich eine signifikante Assoziation zu einem vermehrten Auftreten von Komplikationen. Ein nachgewiesener signifikanter Zusammenhang bestand zudem zwischen einem erhöhten Kalzifikationsgrad der Punktionsstelle bei Vorliegen einer pAVK und eines Dm. Eine erhöhte Gefäßrigidität aufgrund von Komorbiditäten und vaskulären Kalzifikationen, intrinsische Fremdkörperreaktionen, vasoregulatorische Reaktionen oder Produktversagen bieten hypothetische Erklärungsansätze für die einzelnen komplikativen Fälle. Die Nutzung des VVS in spezifischen, bisher nicht beschriebenen Situationen (Unterdimensionierung, Anwendung nach Gefäßpunktionen mit Zugangsschleusen bis 9F, antegrade Punktionsrichtung, anspruchsvolle Eingriffe multimorbider Patienten mit komplexem vaskulärem Status) erwies sich als suffizient. Zur Prävention schwerwiegender Komplikationen während zukünftiger Interventionen wurden die Empfehlung ausgesprochen, eine Durchleuchtungsaufnahme zur Lagekontrolle vor Implantation des proximalen Clips anzufertigen. Eine speziell für Gefäßverschlüsse nach antegrader Punktion konzipierte Zugangsschleuse könnte das Abknicken von Zugangsschleusen bei VVS Applikation verhindern. Zusammenfassend kann das untersuchte aktive VVS mit einzigartigem Wirkmechanismus und spezifischen Design als effektiv und sicher angesehen werden. N2 - The need of minimally invasive therapy options is constantly growing and so is the need for alternative options of vascular closure after peripheral vascular interventions. The aim of this thesis was to assess the efficacy and safety of the novel double-clip-based vascular closure device (VCD). The overall technical success rate was 98,8% with an overall low complication rate of 3,6 %. The comorbidities diabetes and chronical kidney disease proof to be significant risk factors for the appearance of complications. There was a significant association between an increased degree of calcification of the puncture site in the presence of peripheral artery disease and diabetes. Increased vascular rigidity due to comorbidities and vascular calcifications, intrinsic foreign body reactions, vasoregulatory reactions, or product failure offer hypothetical explanations for the individual complicative cases. The use of the VCD during previously not analyzed settings e.g. undersizing in relation to the introducer sheath, accesses of up to 8 or 9 Fr with a 7 Fr device, antegrade puncture and challenging patient collective, proofed to be sufficient. To prevent major complications during future application, it is recommended to check the position of the VCD fluoroscopically, before implantation of the proximal wing. A specially designed introducer sheath may be helpful to prevent kinking of the introducer sheath during VCD application in antegrad punctures. In conclusion, the novel VCD proved to be effective and safe. KW - Gefäßverschluss KW - Vascular closure devices KW - antegrade puncture KW - femoral access KW - access site complications Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300986 ER - TY - THES A1 - Portmann, Johannes T1 - Accelerated inversion recovery MRI of the myocardium using spiral acquisition T1 - Beschleunigte Inversion-Recovery MR-Bildgebung des Myokards mit spiralen Auslesezügen N2 - This work deals with the acceleration of cardiovascular MRI for the assessment of functional information in steady-state contrast and for viability assessment during the inversion recovery of the magnetization. Two approaches are introduced and discussed in detail. MOCO-MAP uses an exponential model to recover dynamic image data, IR-CRISPI, with its low-rank plus sparse reconstruction, is related to compressed sensing. MOCO-MAP is a successor to model-based acceleration of parametermapping (MAP) for the application in the myocardial region. To this end, it was augmented with a motion correction (MOCO) step to allow exponential fitting the signal of a still object in temporal direction. Iteratively, this introduction of prior physical knowledge together with the enforcement of consistency with the measured data can be used to reconstruct an image series from distinctly shorter sampling time than the standard exam (< 3 s opposed to about 10 s). Results show feasibility of the method as well as detectability of delayed enhancement in the myocardium, but also significant discrepancies when imaging cardiac function and artifacts caused already by minor inaccuracy of the motion correction. IR-CRISPI was developed from CRISPI, which is a real-time protocol specifically designed for functional evaluation of image data in steady-state contrast. With a reconstruction based on the separate calculation of low-rank and sparse part, it employs a softer constraint than the strict exponential model, which was possible due to sufficient temporal sampling density via spiral acquisition. The low-rank plus sparse reconstruction is fit for the use on dynamic and on inversion recovery data. Thus, motion correction is rendered unnecessary with it. IR-CRISPI was equipped with noise suppression via spatial wavelet filtering. A study comprising 10 patients with cardiac disease show medical applicability. A comparison with performed traditional reference exams offer insight into diagnostic benefits. Especially regarding patients with difficulty to hold their breath, the real-time manner of the IR-CRISPI acquisition provides a valuable alternative and an increase in robustness. In conclusion, especially with IR-CRISPI in free breathing, a major acceleration of the cardiovascular MR exam could be realized. In an acquisition of less than 100 s, it not only includes the information of two traditional protocols (cine and LGE), which take up more than 9.6 min, but also allows adjustment of TI in retrospect and yields lower artifact level with similar image quality. N2 - Diese Arbeit behandelt die Beschleunigung der kardiovaskulären MRT zum Erfassen funktioneller Information bei Steady-State-Kontrast und zur Unter- suchung der Vitalität bei Wiederherstellung der Magnetisierung nach ihrer Inversion. Zwei Ansätze werden eingeführt und im Detail diskutiert: MOCO- MAP, welches ein exponentielles Modell nutzt, um dynamische Daten zu rekonstruieren, und IR-CRISPI, welches mit seinem “low-rank plus sparse"- Algorithmus mit Compressed Sensing verwandt ist. MOCO-MAP ist der Nachfolger der modellbasierten Beschleunigung des Parameter-Mappings (MAP) für die Anwendung im Bereich des Myokards. Hierzu wurde es mit einer Bewegungskorrektur (MOCO) versehen, um expo- nentielles Fitten eines unbewegten Objects in Zeitrichtung zu ermöglichen. Das Einbringen dieses physikalischen Vorwissens zusammen mit dem Erzwin- gen von Konsistenz mit den Messdaten wird dazu genutzt, iterativ eine Bildfolge aus Daten einer deutlich kürzeren Messung als herkömmlich zu rekonstruieren (< 3 s gegenüber ca. 10 s). Die Ergebnisse zeigen die Umsetz- barkeit der Methode sowie die Nachweisbarkeit von Delayed Enhancements im Myokard, aber deutliche funktionelle Abweichungen und Artefakte bereits aufgrund von kleinen Ungenauigkeiten der Bewegungskorrektur. IR-CRISPI geht aus CRISPI hervor, welches zur Auswertung von funk- tionellen Echtzeitdaten bei konstantem Kontrast dient. Mit der Rekon- struktion durch getrennte Berechnung von niedrigrangigem und dünnbe- setztem Matrixanteil wird hier bei der Datenrekonstruktion weniger stark eingeschränkt als bei einem strikten exponentiellen Modell. Die pirale Auf- nahmeweise erlaubt hierzu ausreichend effiziente k-Raumabdeckung. Die “low-rank plus sparse"-Rekonstruktion ist kompatibel mit dynamischen und mit Inversion-Recovery-Daten. Eine Bewegungskorrektur ist folglich nicht nötig. IR-CRISPI wurde mit einer Rauschunterdrückung durch räumliche Wavelet- Filterung versehen. Eine Studie, die 10 Patienten einschließt, zeigt die Eignung für die medizinische Anwendung. Der Vergleich mit herkömm- lichen Aufnahmetechniken lässt auf den gewonnenen diagnostischen Nutzen schließen. Besonders für Patienten, die Schwierigkeiten mit dem Luftanhal- ten haben, eröffnet diese Echtzeitaufnahmemethode eine wertvolle Alterna- tive und erhöhte Stabilität. Am Ende konnte gerade mittels IR-CRISPI eine bemerkenswerte Beschleu- nigung der kardiovaskulären MR-Untersuchung verwirklicht werden. Trotz der kurzen Aufnahmezeit von weniger als 100 s für den kompletten linken Ven- trikel schließt es nicht nur die Information zweier herkömmlicher Protokolle mit ein (Cine und LGE), die zusammen mehr als 9,6 min dauern, sondern es erlaubt zusätzlich auch das Einstellen der TI-Zeit im Nachhinein und liefert Ergebnisse mit geringerem Artefaktlevel bei ähnlicher Bildqualität KW - Kernspintomografie KW - Herzfunktion KW - Herzmuskel KW - Bildgebendes Verfahren KW - Echtzeit KW - cine loop KW - late enhancement KW - late gadolinium-enhancement KW - magnetic resonance imaging KW - real-time imaging KW - spiral trajectory Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-302822 ER - TY - THES A1 - Laas, Susanne Franziska T1 - Stellenwert der kontrastmittelverstärkten MRT bei traumatischen Verletzungen und posttraumatischen Veränderungen an der Hand T1 - The importance of contrast-enhanced MRI in traumatic and posttraumatic injuries of the hand N2 - Die vorliegende Arbeit hat zum Ziel, den Stellenwert von kontrastverstärkten MR- Sequenzen in der bildgebenden Diagnostik von Hand und Fingern zu untersuchen. Denn trotz einer breiten empirischen Anwendung von gadoliniumhaltigen Kontrastmitteln im europäischen Raum besteht keine ausreichende wissenschaftliche Datengrundlage zur kontrastverstärkten Hand-MRT nach einem Trauma. Zu diesem Zweck wurden zwischen Januar 2016 und August 2018 am Rhön-Klinikum Campus Bad Neustadt 165 MRT-Untersuchungen von distalem Unterarm, Karpus, Metakarpus und/oder Fingern selektiert. Einschlusskriterien waren eine positive Traumaanamnese, standardisierte MRT-Sequenzen und das Fehlen von Kontraindikationen. Zur Definition eines diagnostischen Referenzstandards wurden alle Fälle vorab durch einen Senior-Investigator mit 36 Jahren Erfahrung in muskuloskelettaler Radiologie analysiert. Für die Bildevaluation wurden aus jeder MRT-Untersuchung zwei Datensätze erstellt, wobei der erste Datensatz nur die nativen Sequenzen (PD / T2 FSE fs und T1 FSE ) und der zweite Datensatz zusätzlich zu eine kontrastverstärkte Sequenz als T1 FSE fs nach Gadolinium-Applikation enthielt. Als Observer fungierten zwei radiologische Fach- bzw. Oberärzte des Universitätsklinikum Würzburgs. In der vorliegenden Studie wurde ein diagnostisch relevantes Kontrastmittelenhancement an Patienten mit traumatischen Handverletzungen nachgewiesen. Der Kontrastmitteleffekt war mit subjektiven und objektiven Messgrößen statistisch signifikant bei Läsionen der Ligamente und an den ligamentähnlichen Insertionen des ulnaren TFCC-Abschnittes. Als Erklärung für das Kontrastmittelenhancement in der MRT dient in erster Linie die bereits früher beschriebene Hyperämie, die posttraumatisch am Traumaort mit Ausgang von der Synovialis entsteht. Anhand der Studienergebnisse kann die Empfehlung ausgesprochen werden, in der MRT-Diagnostik von traumatischen Läsionen der Hand immer dann intravenöses Kontrastmittel auf Gadolinium-Basis zu verabreichen, wenn am vermuteten Läsionsort der T2-Kontrast für eine sichere Diagnose unzureichend ist. N2 - The aim of this study was to examine the impact of contrast-enhanced MRI-sequences in radiological diagnostics of the wrist and fingers. In spite of widespread empirical usage of gadolinium-enhanced contrast agents in Europe, there is insufficient scientific data regarding the contrast-enhanced MRT of the posttraumatic hand. In this study, 165 MRT scans of the distal forearm, carpus, metacarpus and/or fingers were selected at the Rhön-Klinikum Campus Bad Neustadt between January 2016 and August 2018. Inclusion criteria included a positive trauma anamnesis, standardized MRT sequences and the lack of contra-indications. In order to define a diagnostic standard as a reference, each case was analyzed beforehand by a senior-investigator with 36 years of professional experience in musculoskeletal radiology. Two data records were generated from each MRI-Scan, the first data record containing only the native sequences (PD / T2 FSE fs and T1 FSE) and the second record containing an additional contrast-enhanced sequence as T1 FSE fs after gadolinium. Two radiological specialists/assistant medical directors of the Universitätsklinikum Würzburg served as observers. This study succeeded in demonstrating diagnostically relevant contrast enhancement in patients with traumatic hand injuries. It is known that enhancement in MRI scans is linked to posttraumatic synovial hyperemia. The positive diagnostic effect of gadolinium enhancement was demonstrated in ligament lesions and insertions of the ulnar TFCC and proved statistically significant in the subjective and objective radiological examination. Taking these results into account, intravenous application of gadolinium may be beneficial when interpreting traumatic lesions of the hand, especially when T2-contrast is not sufficient for diagnosis. KW - Intravenöse Applikation KW - Kontrastmittel KW - Kernspintomographie KW - Hand KW - Trauma KW - MRT KW - gadoliniumhaltiges Kontrastmittel KW - intravenös KW - traumatisch KW - Karpus KW - TFCC KW - Triangulärer fibrokartilaginärer Komplex KW - SL-Band KW - Hyperämie Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299370 ER - TY - THES A1 - Klinnert Vlachopoulou, Cristina Maria T1 - Comparison between Dual-Energy-CT perfusion imaging and perfusion-weighted SElf-gated Non-Contrast-Enhanced FUnctional MR imaging of the lung in patients with pulmonary artery embolism T1 - Vergleich zwischen Perfusionskarten der Lunge des DECT und "SElf-gated Non-Contrast-Enhanced Functional” MRT bei Patienten mit einer Lungenembolie N2 - Pulmonary artery embolism (PE) is a common condition and an even more common clinical suspect. The computed tomography pulmonary angiogram (CTPA) is the main medical imaging tool used to diagnose a suspected case of PE. To gain a better impression of the effects of a PE on the perfusion and hence the gas exchange, a functional imaging method is beneficial. One approach for functional imaging using radiation exposure is the generation of color-coded iodine perfusion maps acquired by Dual-Energy Computed Tomography (DECT), which enable the detection of perfusion defects in the pulmonary parenchyma. In contrast to the existing approach of DECT with iodine color-coded maps, the SElf-gated Non-Contrast-Enhanced FUnctional Lung (SENCEFUL) MRI technique offers the possibility to interpret perfusion maps without any radiation exposure or application of contrast agents. The measurement in SENCEFUL MRI can be performed during conditions of free breathing and without electrocardiogram triggering. The purpose of this study was to determine whether PE can be diagnosed on the basis of visible perfusion defects in the perfusion maps of SENCEFUL MRI and in the iodine-coded maps of DECT and to compare the diagnostic performance of these methods. Both SENCEFUL-MRI and iodine distribution maps from DECT have been compared with the CTPA of ten patients with PE. Additionally, the functional images were compared with each other on a per-patient basis. The iodine perfusion maps of DECT had a sensitivity of 84.2 % and specificity of 65.2 % for the diagnosis of PE. The SENCEFUL technique in MRI showed a sensitivity of 78.9 % and a specificity of 26.1 %. When comparing the whole lung depicted in both series of functional images, the main perfusion defect location matched in four of ten patients (40 %). In conclusion, this work found that DECT iodine maps have higher sensitivity and specificity in the diagnosis of pulmonary embolism compared with SENCEFUL MRI. N2 - Die Lungenembolie (LE) ist eine häufige Erkrankung und eine noch häufigere Verdachtsdiagnose. Die Computertomographie der Pulmonalarterien (CTPA) ist die Bildgebung erster Wahl für die Diagnose einer LE. Für eine bessere Darstellung der Folgen einer LE dienen Perfusionskarten. Eine existierende Bildgebungstechnik mit ionisierender Strahlung sind die Iodkarten der Dual-Energy-Computertomographie (DECT), welche bei einer LE Perfusionsdefekte im Lungenparenchym wiedergeben. Eine weitere strahlungsfreie und kontrastmittelfreie Methode ist die „SElf-gated Non-Contrast-Enhanced FUnctional Lung” (SENCEFUL) Magnet-Resonanz-Tomographie (MRT). Diese Technik kann ohne Atemhaltemanöver und ohne EKG-Monitoring stattfinden. Ziel der Arbeit war es zu bestimmen, ob eine LE aufgrund eines Perfusionsdefekts in den Iodkarten des DECT und SENCEFUL MRT diagnostiziert werden kann. Beide Bildgebungstechniken wurden mit der CTPA von zehn Patienten mit LE verglichen. Außerdem wurden die Perfusionsbilder untereinander verglichen. Die Iodkarten hatten eine Sensitivität von 84.2 % und eine Spezifizität von 65.2 %. Die SENCEFUL MRT Bilder zeigten eine Sensitivität von 78.9 % und eine Spezifizität von 26.1 %. Der Vergleich beider funktioneller Bildgebungstechniken bezogen auf die gesamte Lunge ergab, dass in vier von zehn Patienten die prädominierende Lokalisation der Minderperfusion übereinstimmte. Zusammenfassend konnte in dieser Arbeit festgestellt werden, dass die Iodkarten des DECTs im Vergleich zum SENCEFUL MRT eine höhere Sensitivität und Spezifizität in der Diagnose einer Lungenembolie aufweisen. KW - Lungenembolie KW - pulmonary embolism KW - perfusion map Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313034 ER - TY - THES A1 - Lucius, Leonie Johanna T1 - Die endovaskuläre Therapie der malignen unteren Einflussstauung mit dem Sinus-XL® Stent T1 - Endovascular therapy of malignant obstruction of the inferior vena cava with the Sinus-XL® stent system N2 - Die interventionelle Radiologie hat sich in den letzten Jahrzehnten zunehmend auf palliativmedizinische sowie onkologische Bereiche ausgeweitet und kann durch minimal-invasive Therapieoptionen gerade in vulnerablen Patientenkollektiven attraktive Behandlungsmöglichkeiten zur Verfügung stellen. Die tumorbedingte untere Einflussstauung ist ein seltenes Krankheitsbild und stellt eine schwere symptomatische Komplikation einer malignen Grunderkrankung dar. Dabei kommt es im Rahmen dieser Grunderkrankung durch die Primärtumormasse oder Metastasen zu extrinsischer Kompression der Vena cava inferior (VCI), Gefäßinvasion oder Thrombusbildung. Ziel der Dissertationsarbeit ist es, den technischen und klinischen Erfolg der Sinus-XL ® Stentimplantation in die Vena cava inferior bei einer tumorbedingten unteren Einflussstauung zu untersuchen. Als technischer Erfolg wurde dabei die problemlose Stentimplantation mit anschließender Aufhebung der VCI-Stenose/Okklusion und Revaskularisation der VCI definiert. Bezüglich des klinischen Erfolges wurde der Frage nachgegangen, inwieweit die Stentimplantation die typischen Symptome einer unteren Einflussstauung (Ödeme der unteren Extremität, Aszites und Anasarka) lindern und bestenfalls eliminieren kann. In der vorliegenden Arbeit sind dazu retrospektiv die Daten von insgesamt 21 Patienten (11 Frauen, 10 Männer) mit einem medianen Alter von 61 Jahren (19-92 Jahre), die zwischen Oktober 2010 und Januar 2021 aufgrund einer tumorbedingten unteren Einflussstauung mit einem Sinus-XL ® Stent endovaskulär versorgt wurden, ausgewertet worden. Zur Quantifizierung der klinischen Symptomatik wurde für das jeweilige Symptom ein Scoring-System entwickelt bzw. modifiziert. Der technische Erfolg belief sich auf 100% (21/21). Postinterventionell konnte zudem eine signifikante Reduktion des transstenotischen Druckgradienten (p = 0,008) und eine signifikante Aufweitung des Stenosendiameters (p < 0,001) erreicht werden. Die primäre und primär-assistierte Stentoffenheit betrug 92,9 % (13/14) und 100% (14/14), die anatomische Stentoffenheit (< 50% Restenose) belief sich auf 53,3 % (8/15). Die Reinterventionsrate lag bei 4,8 % (1/21). Schwerwiegende Komplikationen traten nicht auf. Der klinische Erfolg bezüglich der Ödeme der unteren Extremität belief sich auf 82,4 % (14/17), 93,8 % (15/16) sowie auf 85,7 % (18/21) und zeigte in allen betrachteten Zeitintervallen eine signifikante Scorewertreduktion (p < 0,001). Das klinische Outcome bezüglich der Ödeme war bei kürzeren Stenosen/Obstruktionen signifikant besser (p = 0,025). Bezüglich einer intrahepatischen Segmentbeteiligung, der transstenotischen Druckgradienten, der absoluten Gradientenreduktion sowie der Überlebenszeit nach der Intervention zeigten sich hingegen keine als klinisch relevant einzustufende Ergebnisse. Ein eindeutiger Effekt der Intervention auf die Symptome Anasarka und Aszites konnte nicht nachgewiesen werden. Diesbezüglich zeigten sich klinische Erfolgsraten von 42,9 % (6/14) und 5,3 % (1/19). Im postinterventionellen Verlauf konnten außerdem signifikante Reduktionen der präinterventionellen Harnstoffwerte sowie des Körpergewichtes der Patienten verzeichnet werden. Zusammenfassend zeigt die vorliegende Arbeit, dass die Sinus-XL ® Stentimplantation geeignet ist, eine tumorbedingte Vena cava inferior-Stenose/Obstruktion aufzuheben und eine Revaskularisation der VCI zu erreichen. Die klinischen Symptome einer unteren Einflussstauung – insbesondere bezogen auf die Ödeme der unteren Extremität und mit Einschränkungen bezogen auf die Symptome Aszites und Anasarka – können ebenfalls durch die Stentimplantation gelindert und teilweise sogar langanhaltend eliminiert werden. Die Sinus-XL ® Stentimplantation sollte daher stets als Therapieoption bei tumorbedingten unteren Einflussstauungen in Erwägung gezogen werden. Nicht zuletzt stellt die Stentimplantation auch eine sichere und komplikationsarme Intervention dar. Weitere Studien, bestenfalls multizentrische Studien, sind jedoch notwendig, um die dargestellten Ergebnisse weiter zu untermauern. N2 - In recent decades interventional radiology has increasingly expanded into palliative as well as oncologic settings and can provide attractive treatment options through minimal-invasive therapies, especially in vulnerable patient populations. Malignant obstruction of the inferior vena cava (IVC) is a rare clinical condition and represents a severe symptomatic complication of an underlying malignant disease. Extrinsic compression of the inferior vena cava, vascular invasion or thrombus formation occur as part of the underlying disease. The aim of this work is to investigate the technical and clinical success of Sinus-XL ® stent implantation into the inferior vena cava in case of malignant obstruction of the inferior vena cava. Technical success was defined as the successful stent implantation with subsequent resolution of the stenosis/occlusion and revascularization of the IVC. Regarding clinical success, the question was addressed to what extent stent implantation can alleviate and, at best, eliminate the typical symptoms of malignant IVC obstruction (lower extremity edema, ascites and anasarca). Therefore data from a total of 21 patients (11 women, 10 men) with a median age of 61 years (19-92 years) who underwent endovascular treatment with a Sinus-XL ® stent for malignant IVC obstruction between October 2010 and January 2021 was retrospectively analyzed. In order to quantify the extent of the clinical symptoms a scoring system was developed or modified for each symptom. The technical success was 100% (21/21). After the intervention a significant reduction of the transstenotic pressure gradient (p = 0.008) and a significant widening of the stenotic diameter (p < 0.001) were achieved. Primary and primary-assisted stent patency were 92.9% (13/14) and 100% (14/14), anatomic stent patency (< 50% restenosis) was 53.3% (8/15). The reintervention rate was 4.8% (1/21). No major complications occurred. The clinical outcome regarding lower extremity edema was 82.4% (14/17), 93.8% (15/16), and 85.7% (18/21), showing a significant score reduction in all time intervals considered (p < 0.001). Clinical outcome regarding edema was significantly better with shorter stenosis/obstruction (p = 0.025). In contrast, with regard to intrahepatic segment involvement, transstenotic pressure gradients, absolute gradient reduction, and survival time after the intervention, there were no results that could be classified as clinically relevant. A clear effect of the intervention on the symptoms of anasarca and ascites could not be demonstrated. In this regard, clinical success rates of 42.9% (6/14) and 5.3% (1/19) were shown. In the post-interventional course, significant reductions of the pre-interventional urea levels as well as of the patients´ body weight could also be recorded. In conclusion, the present work shows that Sinus-XL ® stent implantation is suitable to resolve malignant IVC obstruction and to achieve revascularization of the IVC. The clinical symptoms - especially related to lower extremity edema and with limitations related to the symptoms of ascites and anasarca - can be alleviated by stent implantation and in some cases even eliminated. Sinus-XL ® stent implantation should therefore always be considered as a therapeutic option for malignant IVC obstruction. Last but not least, stent implantation also represents a safe and low-complication intervention. However, further studies, at best multicenter studies, are necessary to further substantiate the presented results. KW - Vena cava inferior KW - Stent KW - Interventionsradiologie KW - Onkologie KW - maligne untere Einflussstauung KW - endovaskuläre Therapie Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-326691 ER - TY - THES A1 - Steingrüber, Marcus T1 - Die perkutane transluminale Zangenbiopsie biliärer Strikturen: Eine neuartige Methode T1 - The percutaneous endobiliary forceps biopsy of biliary strictures: An innovative technique N2 - Das Ziel der Studie bestand darin, die Durchführbarkeit, Effizienz und Sicherheit der perkutanen transluminalen Zangenbiopsie bei biliären Strikturen nach „Cross and push“ Technik am Universitätsklinikum Würzburg zu evaluieren. Die Gewinnung der Zangenbiopsie bei den insgesamt 17 Patienten erfolgte an den baugleichen Angiographieeinheiten der interventionellen radiologischen Abteilung. Die Schaffung des biliären Zugangsweges wurde per Feinnadelpunktion oder über einen bereits einliegenden Drainagekatheter durchgeführt. Nach Vordirigieren einer armierten Führungsschleuse bis unmittelbar vor die Stenose wurden die Gewebeproben mittels Biopsiezange entnommen. Auf diese Weise sollte ein Abknicken des Instrumentariums durch die fibrotische Beschaffenheit der Striktur vermieden und so die Gewebegewinnung erleichtert werden. Im Anschluss folgten die PTCD-Neuanlage bzw. der Katheterwechsel sowie die histologische Auswertung der Zangenbiopsie. Die Dokumentation umfasste den technischen Erfolg, die Biopsieanzahl sowie -größe, die Untersuchungs- und die Fluoroskopiezeit, das Dosisflächenprodukt, die Repräsentativität der Biopsien und die Komplikationsrate. Die technische Erfolgsrate lag bei 100 %. Bei zehn Patienten und Patientinnen (58,8 %) wurde in der Zangenbiopsie ein Malignom bestätigt. Bei sieben Betroffenen (41,2 %) ergab die Zangenbiopsie einen benignen Befund, wobei dieser in zwei Fällen (11,8 %) falsch negativ war. Die Kriterien der Repräsentativität wurden bei elf Patienten und Patientinnen (64,7 %) erfüllt. Die mediane Biopsiezahl betrug 4 und die Biopsiegröße war 1 - 2 mm. Bei einer medianen Untersuchungszeit von 24 min bemaß sich die mediane Fluoroskopiezeit auf 7,6 min. Das mediane DAP für alle Interventionen betrug 2.593 μGym2. Zu einer Majorkomplikation kam es bei einer Patientin (5,9 %). Bei der perkutanen transluminalen Zangenbiopsie nach „Cross and push“ Technik handelt es sich um ein effektives und sicheres Verfahren zur histologischen Beurteilung biliärer Strikturen mit einer moderaten Komplikationsrate. Die Anwendung sollte besonders bei proximalen Strikturen in Betracht gezogen werden, wenn die ERCP oder alternative Verfahren nicht erfolgreich waren und parallel eine Entlastung der Cholestase via PTCD intendiert oder bereits vorhanden ist. Zur weiteren Evaluation der Methode ist zukünftig die Betrachtung eines größeren Patientenkollektives nötig. Um das Verfahren mit Alternativmethoden vergleichen zu können, bedarf es randomisierter kontrollierter Studien. N2 - Percutaneous transhepatic biliary drainage-based forceps biopsy in patients with biliary obstruction of unknown origin is an relatively unknown procedure. Nonetheless this method offers the opportunity of tissue sampling and therapy of obstructive jaundice via percutaneous transhepatic biliary drainage (PTBD) simultaneously. In 2015 Patel et al. described the percutaneous endobiliary forceps biopsy (PEFB) using “cross and push” technique. This approach is characterized by using a guiding sheath to push and advance the biopsy forceps into the biliary stricture. By supporting the forceps biopsy catheter with a sheath, a retroflexion of the forceps cup leading to an ineffective biopsy can be prevented. Aim of the following study was to evaluate feasibility, efficiency and safety of this procedure in our institution. Between October 2014 and October 2019 17 patients underwent PEFB in the interventional radiology department. Biliary access was achieved by using a percutaneous access needle or via a preexisting external biliary drainage catheter. After obtaining the specimens for histopathologic evaluation, a new biliary drainage catheter was placed. The primary outcome measures were: evaluation of technical success rate, procedure time and fluoroscopy time, dose area product (DAP), complication rate, number and size of the biopsies as well as the histopathologic results. Technical success rate was 100 %. In ten patients PEFB confirmed a malignant biliary stricture. Seven patients had a benign histopathologic result, although in two cases this proofed to be false negative. In eleven patients the tissue samples proofed to be representative for the underlying disease. The median number of biopsies was 4 with a size between 1 -2 mm. The median procedure time was 24 minutes with a median fluoroscopy time of 7,6 minutes. Median DAP was 2.593 μGym2. Complications occurred in three cases with one major complication and minor complications in two patients. The percutaneous endobiliary forceps biopsy is a feasible and safe technique for histologic evaluation of biliary strictures. The procedure should be considered in cases not allowing an endoscopic approach and when the drainage of obstructive jaundice via PTBD is planned or already present. KW - Zangenbiopsie KW - biliäre Striktur KW - biliäre Stenose KW - Gallengangsstenose KW - PEFB Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-321721 ER - TY - JOUR A1 - Diessner, Joachim A1 - Anders, Laura A1 - Herbert, Saskia A1 - Kiesel, Matthias A1 - Bley, Thorsten A1 - Schlaiss, Tanja A1 - Sauer, Stephanie A1 - Wöckel, Achim A1 - Bartmann, Catharina T1 - Evaluation of different imaging modalities for axillary lymph node staging in breast cancer patients to provide a personalized and optimized therapy algorithm JF - Journal of Cancer Research and Clinical Oncology N2 - Purpose The reliable detection of tumor-infiltrated axillary lymph nodes for breast cancer [BC] patients plays a decisive role in further therapy. We aimed to find out whether cross-sectional imaging techniques could improve sensitivity for pretherapeutic axillary staging in nodal-positive BC patients compared to conventional imaging such as mammography and sonography. Methods Data for breast cancer patients with tumor-infiltrated axillary lymph nodes having received surgery between 2014 and 2020 were included in this study. All examinations (sonography, mammography, computed tomography [CT] and magnetic resonance imaging [MRI]) were interpreted by board-certified specialists in radiology. The sensitivity of different imaging modalities was calculated, and binary logistic regression analyses were performed to detect variables influencing the detection of positive lymph nodes. Results All included 382 breast cancer patients had received conventional imaging, while 52.61% of the patients had received cross-sectional imaging. The sensitivity of the combination of all imaging modalities was 68.89%. The combination of MRI and CT showed 63.83% and the combination of sonography and mammography showed 36.11% sensitivity. Conclusion We could demonstrate that cross-sectional imaging can improve the sensitivity of the detection of tumor-infiltrated axillary lymph nodes in breast cancer patients. Only the safe detection of these lymph nodes at the time of diagnosis enables the evaluation of the response to neoadjuvant therapy, thereby allowing access to prognosis and improving new post-neoadjuvant therapies. KW - breast cancer imaging KW - positive nodal status KW - cross-sectional imaging KW - conventional imaging KW - post-neoadjuvant therapies KW - neoadjuvant therapies Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324047 VL - 149 IS - 7 ER - TY - JOUR A1 - Conrads, Nora A1 - Grunz, Jan-Peter A1 - Huflage, Henner A1 - Luetkens, Karsten Sebastian A1 - Feldle, Philipp A1 - Grunz, Katharina A1 - Köhler, Stefan A1 - Westermaier, Thomas T1 - Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine JF - Archives of Orthopaedic and Trauma Surgery N2 - Introduction In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities. Materials and methods Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded. Results Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5%) and 28 screws (1.6%), while the midline of the vertebral body was crossed in 8 screws (0.5%). Furthermore, 11 screws each (0.6%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1% of patients, whereas neurological deterioration occurred in 8.9% of cases with neurological follow-up. Conclusions Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required. KW - pedicle screws KW - vertebral pedicles KW - fluoroscopy KW - neuronavigation KW - spine Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324966 VL - 143 IS - 6 ER - TY - JOUR A1 - Guggenberger, Konstanze V. A1 - Vogt, Marius L. A1 - Song, Jae W. A1 - Weng, Andreas M. A1 - Fröhlich, Matthias A1 - Schmalzing, Marc A1 - Venhoff, Nils A1 - Hillenkamp, Jost A1 - Pham, Mirko A1 - Meckel, Stephan A1 - Bley, Thorsten A. T1 - Intraorbital findings in giant cell arteritis on black blood MRI JF - European Radiology N2 - Objective Blindness is a feared complication of giant cell arteritis (GCA). However, the spectrum of pathologic orbital imaging findings on magnetic resonance imaging (MRI) in GCA is not well understood. In this study, we assess inflammatory changes of intraorbital structures on black blood MRI (BB-MRI) in patients with GCA compared to age-matched controls. Methods In this multicenter case-control study, 106 subjects underwent BB-MRI. Fifty-six patients with clinically or histologically diagnosed GCA and 50 age-matched controls without clinical or laboratory evidence of vasculitis were included. All individuals were imaged on a 3-T MR scanner with a post-contrast compressed-sensing (CS) T1-weighted sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) BB-MRI sequence. Imaging results were correlated with available clinical symptoms. Results Eighteen of 56 GCA patients (32%) showed inflammatory changes of at least one of the intraorbital structures. The most common finding was enhancement of at least one of the optic nerve sheaths (N = 13, 72%). Vessel wall enhancement of the ophthalmic artery was unilateral in 8 and bilateral in 3 patients. Enhancement of the optic nerve was observed in one patient. There was no significant correlation between imaging features of inflammation and clinically reported orbital symptoms (p = 0.10). None of the age-matched control patients showed any inflammatory changes of intraorbital structures. Conclusions BB-MRI revealed inflammatory findings in the orbits in up to 32% of patients with GCA. Optic nerve sheath enhancement was the most common intraorbital inflammatory change on BB-MRI. MRI findings were independent of clinically reported orbital symptoms. Key Points • Up to 32% of GCA patients shows signs of inflammation of intraorbital structures on BB-MRI. • Enhancement of the optic nerve sheath is the most common intraorbital finding in GCA patients on BB-MRI. • Features of inflammation of intraorbital structures are independent of clinically reported symptoms. KW - giant cell arteritis KW - magnetic resonance imaging KW - orbit KW - ophthalmic artery KW - optic nerve Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324978 VL - 33 IS - 4 ER - TY - JOUR A1 - Laqua, Fabian Christopher A1 - Woznicki, Piotr A1 - Bley, Thorsten A. A1 - Schöneck, Mirjam A1 - Rinneburger, Miriam A1 - Weisthoff, Mathilda A1 - Schmidt, Matthias A1 - Persigehl, Thorsten A1 - Iuga, Andra-Iza A1 - Baeßler, Bettina T1 - Transfer-learning deep radiomics and hand-crafted radiomics for classifying lymph nodes from contrast-enhanced computed tomography in lung cancer JF - Cancers N2 - Objectives: Positron emission tomography (PET) is currently considered the non-invasive reference standard for lymph node (N-)staging in lung cancer. However, not all patients can undergo this diagnostic procedure due to high costs, limited availability, and additional radiation exposure. The purpose of this study was to predict the PET result from traditional contrast-enhanced computed tomography (CT) and to test different feature extraction strategies. Methods: In this study, 100 lung cancer patients underwent a contrast-enhanced \(^{18}\)F-fluorodeoxyglucose (FDG) PET/CT scan between August 2012 and December 2019. We trained machine learning models to predict FDG uptake in the subsequent PET scan. Model inputs were composed of (i) traditional “hand-crafted” radiomics features from the segmented lymph nodes, (ii) deep features derived from a pretrained EfficientNet-CNN, and (iii) a hybrid approach combining (i) and (ii). Results: In total, 2734 lymph nodes [555 (20.3%) PET-positive] from 100 patients [49% female; mean age 65, SD: 14] with lung cancer (60% adenocarcinoma, 21% plate epithelial carcinoma, 8% small-cell lung cancer) were included in this study. The area under the receiver operating characteristic curve (AUC) ranged from 0.79 to 0.87, and the scaled Brier score (SBS) ranged from 16 to 36%. The random forest model (iii) yielded the best results [AUC 0.871 (0.865–0.878), SBS 35.8 (34.2–37.2)] and had significantly higher model performance than both approaches alone (AUC: p < 0.001, z = 8.8 and z = 22.4; SBS: p < 0.001, z = 11.4 and z = 26.6, against (i) and (ii), respectively). Conclusion: Both traditional radiomics features and transfer-learning deep radiomics features provide relevant and complementary information for non-invasive N-staging in lung cancer. KW - computed tomography KW - computational neural networks KW - lymphatic metastasis KW - carcinoma KW - non-small-cell lung KW - small-cell lung Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319231 SN - 2072-6694 VL - 15 IS - 10 ER - TY - JOUR A1 - Vogel, P. A1 - Rückert, M. A. A1 - Greiner, C. A1 - Günther, J. A1 - Reichl, T. A1 - Kampf, T. A1 - Bley, T. A. A1 - Behr, V. C. A1 - Herz, S. T1 - iMPI: portable human-sized magnetic particle imaging scanner for real-time endovascular interventions JF - Scientific Reports N2 - Minimally invasive endovascular interventions have become an important tool for the treatment of cardiovascular diseases such as ischemic heart disease, peripheral artery disease, and stroke. X-ray fluoroscopy and digital subtraction angiography are used to precisely guide these procedures, but they are associated with radiation exposure for patients and clinical staff. Magnetic Particle Imaging (MPI) is an emerging imaging technology using time-varying magnetic fields combined with magnetic nanoparticle tracers for fast and highly sensitive imaging. In recent years, basic experiments have shown that MPI has great potential for cardiovascular applications. However, commercially available MPI scanners were too large and expensive and had a small field of view (FOV) designed for rodents, which limited further translational research. The first human-sized MPI scanner designed specifically for brain imaging showed promising results but had limitations in gradient strength, acquisition time and portability. Here, we present a portable interventional MPI (iMPI) system dedicated for real-time endovascular interventions free of ionizing radiation. It uses a novel field generator approach with a very large FOV and an application-oriented open design enabling hybrid approaches with conventional X-ray-based angiography. The feasibility of a real-time iMPI-guided percutaneous transluminal angioplasty (PTA) is shown in a realistic dynamic human-sized leg model. KW - biomedical engineering KW - electrical and electronic engineering KW - imaging KW - three-dimensional imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357794 VL - 13 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Kleefeldt, Florian A1 - Ergün, Süleyman A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Hendel, Robin A1 - Kunz, Andreas Steven A1 - Pannenbecker, Pauline A1 - Kuhl, Philipp Josef A1 - Augustin, Anne Marie A1 - Bley, Thorsten Alexander A1 - Petritsch, Bernhard A1 - Grunz, Jan-Peter T1 - Standardized assessment of vascular reconstruction kernels in photon-counting CT angiographies of the leg using a continuous extracorporeal perfusion model JF - Scientific Reports N2 - This study evaluated the influence of different vascular reconstruction kernels on the image quality of CT angiographies of the lower extremity runoff using a 1st-generation photon-counting-detector CT (PCD-CT) compared with dose-matched examinations on a 3rd-generation energy-integrating-detector CT (EID-CT). Inducing continuous extracorporeal perfusion in a human cadaveric model, we performed CT angiographies of eight upper leg arterial runoffs with radiation dose-equivalent 120 kVp acquisition protocols (CTDIvol 5 mGy). Reconstructions were executed with different vascular kernels, matching the individual modulation transfer functions between scanners. Signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were computed to assess objective image quality. Six radiologists evaluated image quality subjectively using a forced-choice pairwise comparison tool. Interrater agreement was determined by calculating Kendall’s concordance coefficient (W). The intraluminal attenuation of PCD-CT images was significantly higher than of EID-CT (414.7 ± 27.3 HU vs. 329.3 ± 24.5 HU; p < 0.001). Using comparable kernels, image noise with PCD-CT was significantly lower than with EID-CT (p ≤ 0.044). Correspondingly, SNR and CNR were approximately twofold higher for PCD-CT (p < 0.001). Increasing the spatial frequency for PCD-CT reconstructions by one level resulted in similar metrics compared to EID-CT (CNRfat; EID-CT Bv49: 21.7 ± 3.7 versus PCD-CT Bv60: 21.4 ± 3.5). Overall image quality of PCD-CTA achieved ratings superior to EID-CTA irrespective of the used reconstruction kernels (best: PCD-CT Bv60; worst: EID-CT Bv40; p < 0.001). Interrater agreement was good (W = 0.78). Concluding, PCD-CT offers superior intraluminal attenuation, SNR, and CNR compared to EID-CT in angiographies of the upper leg arterial runoff. Combined with improved subjective image quality, PCD-CT facilitates the use of sharper convolution kernels and ultimately bears the potential of improved vascular structure assessability. KW - experimental models of disease KW - preclinical research KW - translational research Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357912 VL - 13 ER - TY - JOUR A1 - Patzer, Theresa Sophie A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Conrads, Nora A1 - Luetkens, Karsten Sebastian A1 - Pannenbecker, Pauline A1 - Paul, Mila Marie A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Ultrahigh-resolution photon-counting CT in cadaveric fracture models: spatial frequency is not everything JF - Diagnostics N2 - In this study, the impact of reconstruction sharpness on the visualization of the appendicular skeleton in ultrahigh-resolution (UHR) photon-counting detector (PCD) CT was investigated. Sixteen cadaveric extremities (eight fractured) were examined with a standardized 120 kVp scan protocol (CTDI\(_{vol}\) 10 mGy). Images were reconstructed with the sharpest non-UHR kernel (Br76) and all available UHR kernels (Br80 to Br96). Seven radiologists evaluated image quality and fracture assessability. Interrater agreement was assessed with the intraclass correlation coefficient. For quantitative comparisons, signal-to-noise-ratios (SNRs) were calculated. Subjective image quality was best for Br84 (median 1, interquartile range 1–3; p ≤ 0.003). Regarding fracture assessability, no significant difference was ascertained between Br76, Br80 and Br84 (p > 0.999), with inferior ratings for all sharper kernels (p < 0.001). Interrater agreement for image quality (0.795, 0.732–0.848; p < 0.001) and fracture assessability (0.880; 0.842–0.911; p < 0.001) was good. SNR was highest for Br76 (3.4, 3.0–3.9) with no significant difference to Br80 and Br84 (p > 0.999). Br76 and Br80 produced higher SNRs than all kernels sharper than Br84 (p ≤ 0.026). In conclusion, PCD-CT reconstructions with a moderate UHR kernel offer superior image quality for visualizing the appendicular skeleton. Fracture assessability benefits from sharp non-UHR and moderate UHR kernels, while ultra-sharp reconstructions incur augmented image noise. KW - photon-counting KW - tomography KW - X-ray computed KW - fracture KW - cancellous bone KW - convolution kernel Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319281 SN - 2075-4418 VL - 13 IS - 10 ER - TY - JOUR A1 - Huflage, Henner A1 - Kunz, Andreas Steven A1 - Hendel, Robin A1 - Kraft, Johannes A1 - Weick, Stefan A1 - Razinskas, Gary A1 - Sauer, Stephanie Tina A1 - Pennig, Lenhard A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Obesity-related pitfalls of virtual versus true non-contrast imaging — an intraindividual comparison in 253 oncologic patients JF - Diagnostics N2 - Objectives: Dual-source dual-energy CT (DECT) facilitates reconstruction of virtual non-contrast images from contrast-enhanced scans within a limited field of view. This study evaluates the replacement of true non-contrast acquisition with virtual non-contrast reconstructions and investigates the limitations of dual-source DECT in obese patients. Materials and Methods: A total of 253 oncologic patients (153 women; age 64.5 ± 16.2 years; BMI 26.6 ± 5.1 kg/m\(^2\)) received both multi-phase single-energy CT (SECT) and DECT in sequential staging examinations with a third-generation dual-source scanner. Patients were allocated to one of three BMI clusters: non-obese: <25 kg/m\(^2\) (n = 110), pre-obese: 25–29.9 kg/m\(^2\) (n = 73), and obese: >30 kg/m\(^2\) (n = 70). Radiation dose and image quality were compared for each scan. DECT examinations were evaluated regarding liver coverage within the dual-energy field of view. Results: While arterial contrast phases in DECT were associated with a higher CTDI\(_{vol}\) than in SECT (11.1 vs. 8.1 mGy; p < 0.001), replacement of true with virtual non-contrast imaging resulted in a considerably lower overall dose-length product (312.6 vs. 475.3 mGy·cm; p < 0.001). The proportion of DLP variance predictable from patient BMI was substantial in DECT (R\(^2\) = 0.738) and SECT (R\(^2\) = 0.620); however, DLP of SECT showed a stronger increase in obese patients (p < 0.001). Incomplete coverage of the liver within the dual-energy field of view was most common in the obese subgroup (17.1%) compared with non-obese (0%) and pre-obese patients (4.1%). Conclusion: DECT facilitates a 30.8% dose reduction over SECT in abdominal oncologic staging examinations. Employing dual-source scanner architecture, the risk for incomplete liver coverage increases in obese patients. KW - dual-energy CT KW - dual-source CT KW - virtual non-contrast KW - radiation dose KW - spectral CT KW - obesity Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313519 SN - 2075-4418 VL - 13 IS - 9 ER - TY - JOUR A1 - Patzer, Theresa Sophie A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Luetkens, Karsten Sebastian A1 - Conrads, Nora A1 - Gruschwitz, Philipp A1 - Pannenbecker, Pauline A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Quantitative and qualitative image quality assessment in shoulder examinations with a first-generation photon-counting detector CT JF - Scientific Reports N2 - Photon-counting detector (PCD) CT allows for ultra-high-resolution (UHR) examinations of the shoulder without requiring an additional post-patient comb filter to narrow the detector aperture. This study was designed to compare the PCD performance with a high-end energy-integrating detector (EID) CT. Sixteen cadaveric shoulders were examined with both scanners using dose-matched 120 kVp acquisition protocols (low-dose/full-dose: CTDI\(_{vol}\) = 5.0/10.0 mGy). Specimens were scanned in UHR mode with the PCD-CT, whereas EID-CT examinations were conducted in accordance with the clinical standard as “non-UHR”. Reconstruction of EID data employed the sharpest kernel available for standard-resolution scans (ρ\(_{50}\) = 12.3 lp/cm), while PCD data were reconstructed with both a comparable kernel (11.8 lp/cm) and a sharper dedicated bone kernel (16.5 lp/cm). Six radiologists with 2–9 years of experience in musculoskeletal imaging rated image quality subjectively. Interrater agreement was analyzed by calculation of the intraclass correlation coefficient in a two-way random effects model. Quantitative analyses comprised noise recording and calculating signal-to-noise ratios based on attenuation measurements in bone and soft tissue. Subjective image quality was higher in UHR-PCD-CT than in EID-CT and non-UHR-PCD-CT datasets (all p < 0.001). While low-dose UHR-PCD-CT was considered superior to full-dose non-UHR studies on either scanner (all p < 0.001), ratings of low-dose non-UHR-PCD-CT and full-dose EID-CT examinations did not differ (p > 0.99). Interrater reliability was moderate, indicated by a single measures intraclass correlation coefficient of 0.66 (95% confidence interval: 0.58–0.73; p < 0.001). Image noise was lowest and signal-to-noise ratios were highest in non-UHR-PCD-CT reconstructions at either dose level (p < 0.001). This investigation demonstrates that superior depiction of trabecular microstructure and considerable denoising can be realized without additional radiation dose by employing a PCD for shoulder CT imaging. Allowing for UHR scans without dose penalty, PCD-CT appears as a promising alternative to EID-CT for shoulder trauma assessment in clinical routine. KW - bone KW - musculoskeletal system Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357925 VL - 13 ER - TY - JOUR A1 - Schreiber, Laura M. A1 - Lohr, David A1 - Baltes, Steffen A1 - Vogel, Ulrich A1 - Elabyad, Ibrahim A. A1 - Bille, Maya A1 - Reiter, Theresa A1 - Kosmala, Aleksander A1 - Gassenmaier, Tobias A1 - Stefanescu, Maria R. A1 - Kollmann, Alena A1 - Aures, Julia A1 - Schnitter, Florian A1 - Pali, Mihaela A1 - Ueda, Yuichiro A1 - Williams, Tatiana A1 - Christa, Martin A1 - Hofmann, Ulrich A1 - Bauer, Wolfgang A1 - Gerull, Brenda A1 - Zernecke, Alma A1 - Ergün, Süleyman A1 - Terekhov, Maxim T1 - Ultra-high field cardiac MRI in large animals and humans for translational cardiovascular research JF - Frontiers in Cardiovascular Medicine N2 - A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all in-vivo imaging techniques, a reduction of the number of animals per study because of the possibility to scan every animal repeatedly. We present here a solution to the dual use problem of whole-body UHF-MRI systems, which are typically installed in clinical environments, to both UHF-MRI in large animals and humans. Moreover, we provide evidence that in such a research infrastructure UHF-MRI, and ideally combined with a standard small-bore UHF-MRI system, can contribute to a variety of spatial scales in translational cardiovascular research: from cardiac organoids, Zebra fish and rodent hearts to large animal models such as pigs and humans. We present pilot data from serial CINE, late gadolinium enhancement, and susceptibility weighted UHF-MRI in a myocardial infarction model over eight weeks. In 14 pigs which were delivered from a breeding facility in a national SARS-CoV-2 hotspot, we found no infection in the incoming pigs. Human scanning using CINE and phase contrast flow measurements provided good image quality of the left and right ventricle. Agreement of functional analysis between CINE and phase contrast MRI was excellent. MRI in arrested hearts or excised vascular tissue for MRI-based histologic imaging, structural imaging of myofiber and vascular smooth muscle cell architecture using high-resolution diffusion tensor imaging, and UHF-MRI for monitoring free radicals as a surrogate for MRI of reactive oxygen species in studies of oxidative stress are demonstrated. We conclude that UHF-MRI has the potential to become an important precision imaging modality in translational cardiovascular research. KW - ultrahigh-field MRI KW - large animal models KW - translational research KW - research infrastructure KW - heart KW - organoid KW - pig KW - cardiovascular MRI Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-317398 SN - 2297-055X VL - 10 ER - TY - JOUR A1 - Hennes, Jan-Lucca A1 - Huflage, Henner A1 - Grunz, Jan-Peter A1 - Hartung, Viktor A1 - Augustin, Anne Marie A1 - Patzer, Theresa Sophie A1 - Pannenbecker, Pauline A1 - Petritsch, Bernhard A1 - Bley, Thorsten Alexander A1 - Gruschwitz, Philipp T1 - An intra-individual comparison of low-keV photon-counting CT versus energy-integrating-detector CT angiography of the aorta JF - Diagnostics N2 - This retrospective study aims to provide an intra-individual comparison of aortic CT angiographies (CTAs) using first-generation photon-counting-detector CT (PCD-CT) and third-generation energy-integrating-detector CT (EID-CT). High-pitch CTAs were performed with both scanners and equal contrast-agent protocols. EID-CT employed automatic tube voltage selection (90/100 kVp) with reference tube current of 434/350 mAs, whereas multi-energy PCD-CT scans were generated with fixed tube voltage (120 kVp), image quality level of 64, and reconstructed as 55 keV monoenergetic images. For image quality assessment, contrast-to-noise ratios (CNRs) were calculated, and subjective evaluation (overall quality, luminal contrast, vessel sharpness, blooming, and beam hardening) was performed independently by three radiologists. Fifty-seven patients (12 women, 45 men) were included with a median interval between examinations of 12.7 months (interquartile range 11.1 months). Using manufacturer-recommended scan protocols resulted in a substantially lower radiation dose in PCD-CT (size-specific dose estimate: 4.88 ± 0.48 versus 6.28 ± 0.50 mGy, p < 0.001), while CNR was approximately 50% higher (41.11 ± 8.68 versus 27.05 ± 6.73, p < 0.001). Overall image quality and luminal contrast were deemed superior in PCD-CT (p < 0.001). Notably, EID-CT allowed for comparable vessel sharpness (p = 0.439) and less pronounced blooming and beam hardening (p < 0.001). Inter-rater agreement was good to excellent (0.58–0.87). Concluding, aortic PCD-CTAs facilitate increased image quality with significantly lower radiation dose compared to EID-CTAs KW - CT angiography KW - aorta KW - photon-counting-detector CT KW - radiation dose reduction KW - spectral imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-355568 SN - 2075-4418 VL - 13 IS - 24 ER - TY - JOUR A1 - Woznicki, Piotr A1 - Laqua, Fabian Christopher A1 - Al-Haj, Adam A1 - Bley, Thorsten A1 - Baeßler, Bettina T1 - Addressing challenges in radiomics research: systematic review and repository of open-access cancer imaging datasets JF - Insights into Imaging N2 - Objectives Open-access cancer imaging datasets have become integral for evaluating novel AI approaches in radiology. However, their use in quantitative analysis with radiomics features presents unique challenges, such as incomplete documentation, low visibility, non-uniform data formats, data inhomogeneity, and complex preprocessing. These issues may cause problems with reproducibility and standardization in radiomics studies. Methods We systematically reviewed imaging datasets with public copyright licenses, published up to March 2023 across four large online cancer imaging archives. We included only datasets with tomographic images (CT, MRI, or PET), segmentations, and clinical annotations, specifically identifying those suitable for radiomics research. Reproducible preprocessing and feature extraction were performed for each dataset to enable their easy reuse. Results We discovered 29 datasets with corresponding segmentations and labels in the form of health outcomes, tumor pathology, staging, imaging-based scores, genetic markers, or repeated imaging. We compiled a repository encompassing 10,354 patients and 49,515 scans. Of the 29 datasets, 15 were licensed under Creative Commons licenses, allowing both non-commercial and commercial usage and redistribution, while others featured custom or restricted licenses. Studies spanned from the early 1990s to 2021, with the majority concluding after 2013. Seven different formats were used for the imaging data. Preprocessing and feature extraction were successfully performed for each dataset. Conclusion RadiomicsHub is a comprehensive public repository with radiomics features derived from a systematic review of public cancer imaging datasets. By converting all datasets to a standardized format and ensuring reproducible and traceable processing, RadiomicsHub addresses key reproducibility and standardization challenges in radiomics. Critical relevance statement This study critically addresses the challenges associated with locating, preprocessing, and extracting quantitative features from open-access datasets, to facilitate more robust and reliable evaluations of radiomics models. Key points - Through a systematic review, we identified 29 cancer imaging datasets suitable for radiomics research. - A public repository with collection overview and radiomics features, encompassing 10,354 patients and 49,515 scans, was compiled. - Most datasets can be shared, used, and built upon freely under a Creative Commons license. - All 29 identified datasets have been converted into a common format to enable reproducible radiomics feature extraction. KW - radiomics KW - radiology KW - cancer imaging KW - machine learning KW - reproducibility of results Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357936 SN - 1869-4101 VL - 14 ER - TY - JOUR A1 - Heinz, Tizian A1 - Meller, Felix A1 - Luetkens, Karsten Sebastian A1 - Anderson, Philip Mark A1 - Stratos, Ioannis A1 - Horas, Konstantin A1 - Rudert, Maximilian A1 - Reppenhagen, Stephan A1 - Weißenberger, Manuel T1 - The AMADEUS score is not a sufficient predictor for functional outcome after high tibial osteotomy JF - Journal of Experimental Orthopaedics N2 - Purpose The Area Measurement And Depth Underlying Structures (AMADEUS) classification system has been proposed as a valuable tool for magnetic resonance (MR)-based grading of preoperatively encountered chondral defects of the knee joint. However, the potential relationship of this novel score with clinical data was yet to determine. It was the primary intention of this study to assess the correlative relationship of the AMADEUS with patient reported outcome scores in patients undergoing medial open-wedge high tibial valgus osteotomy (HTO). Furthermore, the arthroscopic ICRS (International Cartilage Repair Society) grade evaluation was tested for correlation with the AMADEUS classification system. Methods This retrospective, monocentric study found a total of 70 individuals that were indicated for HTO due to degenerative chondral defects of the medial compartment between 2008 and 2019. A preoperative MR image as well as a pre-osteotomy diagnostic arthroscopy for ICRS grade evaluation was mandatory for all patients. The Knee Osteoarthritis Outcome Score (KOOS) including its five subscale scores (KOOS-ADL, KOOS-QOL, KOOS-Sports, KOOS-Pain, KOOS-Symptoms) was obtained preoperatively and at a mean follow-up of 41.2 ± 26.3 months. Preoperative chondral defects were evaluated using the AMADEUS classification system and the final AMADEUS scores were correlated with the pre- and postoperative KOOS subscale sores. Furthermore, arthroscopic ICRS defect severity was correlated with the AMADEUS classification system. Results There was a statistically significant correlation between the AMADEUS BME (bone marrow edema) subscore and the KOOS Symptoms subscore at the preoperative visit (r = 0.25, p = 0.04). No statistically significant monotonic association between the AMADEUS total score and the AMADEUS grade with pre- and postoperative KOOS subscale scores were found. Intraoperatively obtained ICRS grade did reveal a moderate correlative relation with the AMADEUS total score and the AMADEUS grade (r = 0.28, p = 0.02). Conclusions The novel AMADEUS classification system largely lacks correlative capacity with patient reported outcome measures in patients undergoing HTO. The MR tomographic appearance of bone marrow edema is the only parameter predictive of the clinical outcome at the preoperative visit. KW - cartilage KW - AMADEUS KW - KOOS KW - knee KW - high tibial osteotomy KW - chondral defect KW - osteoarthritis KW - PROM KW - correlation Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357765 VL - 10 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Ergün, Süleyman A1 - Peter, Dominik A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Hendel, Robin A1 - Pannenbecker, Pauline A1 - Augustin, Anne Marie A1 - Kunz, Andreas Steven A1 - Feldle, Philipp A1 - Bley, Thorsten Alexander A1 - Grunz, Jan-Peter T1 - Comparison of ultrahigh and standard resolution photon-counting CT angiography of the femoral arteries in a continuously perfused in vitro model JF - European Radiology Experimental N2 - Background With the emergence of photon-counting CT, ultrahigh-resolution (UHR) imaging can be performed without dose penalty. This study aims to directly compare the image quality of UHR and standard resolution (SR) scan mode in femoral artery angiographies. Methods After establishing continuous extracorporeal perfusion in four fresh-frozen cadaveric specimens, photon-counting CT angiographies were performed with a radiation dose of 5 mGy and tube voltage of 120 kV in both SR and UHR mode. Images were reconstructed with dedicated convolution kernels (soft: Body-vascular (Bv)48; sharp: Bv60; ultrasharp: Bv76). Six radiologists evaluated the image quality by means of a pairwise forced-choice comparison tool. Kendall’s concordance coefficient (W) was calculated to quantify interrater agreement. Image quality was further assessed by measuring intraluminal attenuation and image noise as well as by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR). Results UHR yielded lower noise than SR for identical reconstructions with kernels ≥ Bv60 (p < 0.001). UHR scans exhibited lower intraluminal attenuation compared to SR (Bv60: 406.4 ± 25.1 versus 418.1 ± 30.1 HU; p < 0.001). Irrespective of scan mode, SNR and CNR decreased while noise increased with sharper kernels but UHR scans were objectively superior to SR nonetheless (Bv60: SNR 25.9 ± 6.4 versus 20.9 ± 5.3; CNR 22.7 ± 5.8 versus 18.4 ± 4.8; p < 0.001). Notably, UHR scans were preferred in subjective assessment when images were reconstructed with the ultrasharp Bv76 kernel, whereas SR was rated superior for Bv60. Interrater agreement was high (W = 0.935). Conclusions Combinations of UHR scan mode and ultrasharp convolution kernel are able to exploit the full image quality potential in photon-counting CT angiography of the femoral arteries. Relevance statement The UHR scan mode offers improved image quality and may increase diagnostic accuracy in CT angiography of the peripheral arterial runoff when optimized reconstruction parameters are chosen. Key points • UHR photon-counting CT improves image quality in combination with ultrasharp convolution kernels. • UHR datasets display lower image noise compared with identically reconstructed standard resolution scans. • Scans in UHR mode show decreased intraluminal attenuation compared with standard resolution imaging. KW - CT angiography KW - femoral arteries KW - photon-counting computed tomography (CT) KW - small pixel effect KW - ultrahigh resolution Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357905 VL - 7 ER - TY - JOUR A1 - Gruschwitz, Philipp A1 - Hartung, Viktor A1 - Kleefeldt, Florian A1 - Peter, Dominik A1 - Lichthardt, Sven A1 - Huflage, Henner A1 - Grunz, Jan-Peter A1 - Augustin, Anne Marie A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Petritsch, Bernhard T1 - Continuous extracorporeal femoral perfusion model for intravascular ultrasound, computed tomography and digital subtraction angiography JF - PLoS One N2 - Objectives We developed a novel human cadaveric perfusion model with continuous extracorporeal femoral perfusion suitable for performing intra-individual comparison studies, training of interventional procedures and preclinical testing of endovascular devices. Objective of this study was to introduce the techniques and evaluate the feasibility for realistic computed tomography angiography (CTA), digital subtraction angiography (DSA) including vascular interventions, and intravascular ultrasound (IVUS). Methods The establishment of the extracorporeal perfusion was attempted using one formalin-fixed and five fresh-frozen human cadavers. In all specimens, the common femoral and popliteal arteries were prepared, introducer sheaths inserted, and perfusion established by a peristaltic pump. Subsequently, we performed CTA and bilateral DSA in five cadavers and IVUS on both legs of four donors. Examination time without unintentional interruption was measured both with and without non-contrast planning CT. Percutaneous transluminal angioplasty and stenting was performed by two interventional radiologists on nine extremities (five donors) using a broad spectrum of different intravascular devices. Results The perfusion of the upper leg arteries was successfully established in all fresh-frozen but not in the formalin-fixed cadaver. The experimental setup generated a stable circulation in each procedure (ten upper legs) for a period of more than six hours. Images acquired with CT, DSA and IVUS offered a realistic impression and enabled the sufficient visualization of all examined vessel segments. Arterial cannulating, percutaneous transluminal angioplasty as well as stent deployment were feasible in a way that is comparable to a vascular intervention in vivo. The perfusion model allowed for introduction and testing of previously not used devices. Conclusions The continuous femoral perfusion model can be established with moderate effort, works stable, and is utilizable for medical imaging of the peripheral arterial system using CTA, DSA and IVUS. Therefore, it appears suitable for research studies, developing skills in interventional procedures and testing of new or unfamiliar vascular devices. KW - continuous extracorporeal femoral perfusion model KW - novel human cadaveric perfusion model KW - computed tomography angiography (CTA) KW - digital subtraction angiography (DSA) KW - intravascular ultrasound (IVUS) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350136 SN - 1932-6203 VL - 18 IS - 5 ER - TY - JOUR A1 - Grunz, Jan-Peter A1 - Kunz, Andreas Steven A1 - Baumann, Freerk T. A1 - Hasenclever, Dirk A1 - Sieren, Malte Maria A1 - Heldmann, Stefan A1 - Bley, Thorsten Alexander A1 - Einsele, Hermann A1 - Knop, Stefan A1 - Jundt, Franziska T1 - Assessing osteolytic lesion size on sequential CT scans is a reliable study endpoint for bone remineralization in newly diagnosed multiple myeloma JF - Cancers N2 - Multiple myeloma (MM) frequently induces persisting osteolytic manifestations despite hematologic treatment response. This study aimed to establish a biometrically valid study endpoint for bone remineralization through quantitative and qualitative analyses in sequential CT scans. Twenty patients (seven women, 58 ± 8 years) with newly diagnosed MM received standardized induction therapy comprising the anti-SLAMF7 antibody elotuzumab, carfilzomib, lenalidomide, and dexamethasone (E-KRd). All patients underwent whole-body low-dose CT scans before and after six cycles of E-KRd. Two radiologists independently recorded osteolytic lesion sizes, as well as the presence of cortical destruction, pathologic fractures, rim and trabecular sclerosis. Bland–Altman analyses and Krippendorff’s α were employed to assess inter-reader reliability, which was high for lesion size measurement (standard error 1.2 mm) and all qualitative criteria assessed (α ≥ 0.74). After six cycles of E-KRd induction, osteolytic lesion size decreased by 22% (p < 0.001). While lesion size response did not correlate with the initial lesion size at baseline imaging (Pearson’s r = 0.144), logistic regression analysis revealed that the majority of responding osteolyses exhibited trabecular sclerosis (p < 0.001). The sum of osteolytic lesion sizes on sequential CT scans defines a reliable study endpoint to characterize bone remineralization. Patient level response is strongly associated with the presence of trabecular sclerosis. KW - multiple myeloma KW - bone remineralization KW - computed tomography KW - whole-body imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362526 SN - 2072-6694 VL - 15 IS - 15 ER - TY - JOUR A1 - Luetkens, Karsten Sebastian A1 - Grunz, Jan-Peter A1 - Kunz, Andreas Steven A1 - Huflage, Henner A1 - Weißenberger, Manuel A1 - Hartung, Viktor A1 - Patzer, Theresa Sophie A1 - Gruschwitz, Philipp A1 - Ergün, Süleyman A1 - Bley, Thorsten Alexander A1 - Feldle, Philipp T1 - Ultra-high-resolution photon-counting detector CT arthrography of the ankle: a feasibility study JF - Diagnostics N2 - This study was designed to investigate the image quality of ultra-high-resolution ankle arthrography employing a photon-counting detector CT. Bilateral arthrograms were acquired in four cadaveric specimens with full-dose (10 mGy) and low-dose (3 mGy) scan protocols. Three convolution kernels with different spatial frequencies were utilized for image reconstruction (ρ\(_{50}\); Br98: 39.0, Br84: 22.6, Br76: 16.5 lp/cm). Seven radiologists subjectively assessed the image quality regarding the depiction of bone, hyaline cartilage, and ligaments. An additional quantitative assessment comprised the measurement of noise and the computation of contrast-to-noise ratios (CNR). While an optimal depiction of bone tissue was achieved with the ultra-sharp Br98 kernel (S ≤ 0.043), the visualization of cartilage improved with lower modulation transfer functions at each dose level (p ≤ 0.014). The interrater reliability ranged from good to excellent for all assessed tissues (intraclass correlation coefficient ≥ 0.805). The noise levels in subcutaneous fat decreased with reduced spatial frequency (p < 0.001). Notably, the low-dose Br76 matched the CNR of the full-dose Br84 (p 0.999) and superseded Br98 (p < 0.001) in all tissues. Based on the reported results, a photon-counting detector CT arthrography of the ankle with an ultra-high-resolution collimation offers stellar image quality and tissue assessability, improving the evaluation of miniscule anatomical structures. While bone depiction was superior in combination with an ultra-sharp convolution kernel, soft tissue evaluation benefited from employing a lower spatial frequency. KW - photon-counting CT KW - arthrography KW - ankle KW - cartilage KW - radiation dosage Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362622 SN - 2075-4418 VL - 13 IS - 13 ER - TY - JOUR A1 - Elsner, Clara A1 - Kunz, Andreas Steven A1 - Wagner, Nicole A1 - Huflage, Henner A1 - Hübner, Stefan A1 - Luetkens, Karsten Sebastian A1 - Bley, Thorsten Alexander A1 - Schmitt, Rainer A1 - Ergün, Süleyman A1 - Grunz, Jan-Peter T1 - MRI-based evaluation of the flexor digitorum superficialis anatomy: investigating the prevalence and morphometry of the “chiasma antebrachii” JF - Diagnostics N2 - Recent dissection studies resulted in the introduction of the term “chiasma antebrachii”, which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.3 ± 21.3 years), MRI examinations of the forearm (2010–2021) were reviewed by two radiologists, who evaluated all studies for the presence and length of the chiasma as well as its distance from the distal radioulnar and elbow joint. The chiasma antebrachii was identified in the distal third of the forearm in 88 patients (98.9%), while one intersection was located more proximally in the middle part. The chiasma had a median length of 28 mm (interquartile range: 24–35 mm). Its distances to the distal radioulnar and elbow joint were 16 mm (8–25 mm) and 215 mm (187–227 mm), respectively. T1-weighted post-contrast sequences were found to be superior to T2- or proton-density-weighted sequences in 71 cases (79.8%). To conclude, the chiasma antebrachii is part of the standard FDS anatomy. Knowledge of its morphology is important, e.g., in targeted injections of therapeutics or reconstructive surgery. KW - flexor digitorum superficialis KW - flexor tendon KW - chiasma antebrachii KW - magnetic resonance imaging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362631 SN - 2075-4418 VL - 13 IS - 14 ER - TY - JOUR A1 - Ewald, Andrea A1 - Fuchs, Andreas A1 - Boegelein, Lasse A1 - Grunz, Jan-Peter A1 - Kneist, Karl A1 - Gbureck, Uwe A1 - Hoelscher-Doht, Stefanie T1 - Degradation and bone-contact biocompatibility of two drillable magnesium phosphate bone cements in an in vivo rabbit bone defect model JF - Materials N2 - The use of bone-cement-enforced osteosynthesis is a growing topic in trauma surgery. In this context, drillability is a desirable feature for cements that can improve fracture stability, which most of the available cement systems lack. Therefore, in this study, we evaluated a resorbable and drillable magnesium-phosphate (MgP)-based cement paste considering degradation behavior and biocompatibility in vivo. Two different magnesium-phosphate-based cement (MPC) pastes with different amounts of phytic acid (IP 6) as setting retarder (MPC 22.5 and MPC 25) were implanted in an orthotopic defect model of the lateral femoral condyle of New Zealand white rabbits for 6 weeks. After explantation, their resorption behavior and material characteristics were evaluated by means of X-ray diffraction (XRD), porosimetry measurement, histological staining, peripheral quantitative computed tomography (pQCT), cone-beam computed tomography (CBCT) and biomechanical load-to-failure tests. Both cement pastes displayed comparable results in mechanical strength and resorption kinetics. Bone-contact biocompatibility was excellent without any signs of inflammation. Initial resorption and bone remodeling could be observed. MPC pastes with IP 6 as setting retardant have the potential to be a valuable alternative in distinct fracture patterns. Drillability, promising resorption potential and high mechanical strength confirm their suitability for use in clinical routine. KW - magnesium phosphate cement KW - phytic acid KW - drillability KW - bone replacement material Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-362824 SN - 1996-1944 VL - 16 IS - 13 ER -