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 - 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 - 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 -