Institut für diagnostische und interventionelle Neuroradiologie (ehem. Abteilung für Neuroradiologie)
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- ischemic stroke (6)
- mechanical thrombectomy (4)
- chemotherapy (3)
- cochlear implantation (3)
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- thrombo-inflammation (3)
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- Childhood medulloblastoma (2)
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- Institut für diagnostische und interventionelle Neuroradiologie (ehem. Abteilung für Neuroradiologie) (74) (remove)
Sonstige beteiligte Institutionen
Purpose
By applying diffusor tensor imaging (DTI) in patients with anterior interosseous nerve syndrome (AINS), this proof of principle study aims to quantify the extent of structural damage of a peripheral nerve at the anatomical level of individual fascicles.
Methods
In this institutional review board approved prospective study 13 patients with spontaneous AINS were examined at 3 Tesla including a transversal T2-weighted turbo-spin-echo and a spin-echo echo-planar-imaging pulse sequence of the upper arm level. Calculations of quantitative DTI parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for median nerve lesion and non-lesion fascicles as well as ulnar and radial nerve were obtained. DTI values were compared to each other and to a previously published dataset of 58 healthy controls using one-way Analysis of Variance with Bonferroni correction and p-values <.05 were considered significant. Receiver operating characteristic (ROC) curves were performed to assess diagnostic accuracy.
Results
FA of median nerve lesion fascicles was decreased compared to median nerve non-lesion fascicles, ulnar nerve and radial nerve while MD, RD, and AD was increased (p < .001 for all parameters). Compared to median nerve values of healthy controls, lesion fascicles showed a significant decrease in FA while MD, RD, and AD was increased (p < .001 for all parameters). FA of median nerve non-lesion fascicles showed a weak significant decrease compared to healthy controls (p < .01) while there was no difference in MD, RD, and AD. ROC analyses revealed an excellent diagnostic accuracy of FA, MD and RD in the discrimination of median nerve lesion and non-lesion fascicles in AINS patients as well as in the discrimination of lesion fascicles and normative median nerve values of healthy controls.
Conclusion
By applying this functional MR Neurography technique in patients with AINS, this proof of principle study demonstrates that diffusion tensor imaging is feasible to quantify structural nerve injury at the anatomical level of individual fascicles.
Preclinical studies point to a pivotal role of the orexin 1 (OX1) receptor in arousal and fear learning and therefore suggest the HCRTR1 gene as a prime candidate in panic disorder (PD) with/without agoraphobia (AG), PD/AG treatment response, and PD/AG-related intermediate phenotypes. Here, a multilevel approach was applied to test the non-synonymous HCRTR1 C/T Ile408Val gene variant (rs2271933) for association with PD/AG in two independent case-control samples (total n = 613 cases, 1839 healthy subjects), as an outcome predictor of a six-weeks exposure-based cognitive behavioral therapy (CBT) in PD/AG patients (n = 189), as well as with respect to agoraphobic cognitions (ACQ) (n = 483 patients, n = 2382 healthy subjects), fMRI alerting network activation in healthy subjects (n = 94), and a behavioral avoidance task in PD/AG pre- and post-CBT (n = 271). The HCRTR1 rs2271933 T allele was associated with PD/AG in both samples independently, and in their meta-analysis (p = 4.2 × 10−7), particularly in the female subsample (p = 9.8 × 10−9). T allele carriers displayed a significantly poorer CBT outcome (e.g., Hamilton anxiety rating scale: p = 7.5 × 10−4). The T allele count was linked to higher ACQ sores in PD/AG and healthy subjects, decreased inferior frontal gyrus and increased locus coeruleus activation in the alerting network. Finally, the T allele count was associated with increased pre-CBT exposure avoidance and autonomic arousal as well as decreased post-CBT improvement. In sum, the present results provide converging evidence for an involvement of HCRTR1 gene variation in the etiology of PD/AG and PD/AG-related traits as well as treatment response to CBT, supporting future therapeutic approaches targeting the orexin-related arousal system.
Despite successful recanalization of large-vessel occlusions in acute ischemic stroke, individual patients profit to a varying degree. Dynamic susceptibility-weighted perfusion and dynamic T1-weighted contrast-enhanced blood-brain barrier permeability imaging may help to determine secondary stroke injury and predict clinical outcome. We prospectively performed perfusion and permeability imaging in 38 patients within 24 h after successful mechanical thrombectomy of an occlusion of the middle cerebral artery M1 segment. Perfusion alterations were evaluated on cerebral blood flow maps, blood-brain barrier disruption (BBBD) visually and quantitatively on ktrans maps and hemorrhagic transformation on susceptibility-weighted images. Visual BBBD within the DWI lesion corresponded to a median ktrans elevation (IQR) of 0.77 (0.41–1.4) min−1 and was found in all 7 cases of hypoperfusion (100%), in 10 of 16 cases of hyperperfusion (63%), and in only three of 13 cases with unaffected perfusion (23%). BBBD was significantly associated with hemorrhagic transformation (p < 0.001). While BBBD alone was not a predictor of clinical outcome at 3 months (positive predictive value (PPV) = 0.8 [0.56–0.94]), hypoperfusion occurred more often in patients with unfavorable clinical outcome (PPV = 0.43 [0.10–0.82]) compared to hyperperfusion (PPV = 0.93 [0.68–1.0]) or unaffected perfusion (PPV = 1.0 [0.75–1.0]). We show that combined perfusion and permeability imaging reveals distinct infarct signatures after recanalization, indicating the severity of prior ischemic damage. It assists in predicting clinical outcome and may identify patients at risk of stroke progression.
Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies
(2021)
Purpose
Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN.
Methods
Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated.
Results
Median age at first recurrence was 7.6 years (IQR: 4.0–13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3–20.0) and 36.9 months (CI 29.7–53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74–1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found.
Conclusion
No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation.
Background
Cognitive impairment is a major comorbidity in patients with chronic heart failure (HF) with a wide range of phenotypes. In this study, we aimed to identify and compare different clusters of cognitive deficits.
Methods
The prospective cohort study “Cognition.Matters-HF” recruited 147 chronic HF patients (aged 64.5 ± 10.8 years; 16.2% female) of any etiology. All patients underwent extensive neuropsychological testing. We performed a hierarchical cluster analysis of the cognitive domains, such as intensity of attention, visual/verbal memory, and executive function. Generated clusters were compared exploratively with respect to the results of cardiological, neurological, and neuroradiological examinations without correction for multiple testing.
Results
Dendrogram and the scree plot suggested three distinct cognitive profiles: In the first cluster, 42 patients (28.6%) performed without any deficits in all domains. Exclusively, the intensity of attention deficits was seen in the second cluster, including 55 patients (37.4%). A third cluster with 50 patients (34.0%) was characterized by deficits in all cognitive domains. Age (p = 0.163) and typical clinical markers of chronic HF, such as ejection fraction (p = 0.222), 6-min walking test distance (p = 0.138), NT-proBNP (p = 0.364), and New York Heart Association class (p = 0.868) did not differ between clusters. However, we observed that women (p = 0.012) and patients with previous cardiac valve surgery (p = 0.005) prevailed in the “global deficits” cluster and the “no deficits” group had a lower prevalence of underlying arterial hypertension (p = 0.029). Total brain volume (p = 0.017) was smaller in the global deficit cluster, and serum levels of glial fibrillary acidic protein were increased (p = 0.048).
Conclusion
Apart from cognitively healthy and globally impaired HF patients, we identified a group with deficits only in the intensity of attention. Women and patients with previous cardiac valve surgery are at risk for global cognitive impairment when suffering HF and could benefit from special multimodal treatment addressing the psychosocial condition.
Treating seronegative neuromyelitis optica spectrum disorder with inebilizumab: a case report
(2023)
Background
Neuromyelitis optica spectrum disorder (NMOSD) is a devastating inflammatory disease of the central nervous system that is often severely disabling from the outset. The lack of pathognomonic aquaporin 4 (AQP4) antibodies in seronegative NMOSD not only hinders early diagnosis, but also limits therapeutic options, in contrast to AQP4 antibody-positive NMOSD, where the therapeutic landscape has recently evolved massively.
Case presentation
We report a 56-year-old woman with bilateral optic neuritis and longitudinally extensive myelitis as the index events of a seronegative NMOSD, who was successfully treated with inebilizumab.
Conclusion
Treatment with inebilizumab may be considered in aggressive seronegative NMOSD. Whether broader CD19-directed B cell depletion is more effective than treatment with rituximab remains elusive.
Automated analysis of the inner ear anatomy in radiological data instead of time-consuming manual assessment is a worthwhile goal that could facilitate preoperative planning and clinical research. We propose a framework encompassing joint semantic segmentation of the inner ear and anatomical landmark detection of helicotrema, oval and round window. A fully automated pipeline with a single, dual-headed volumetric 3D U-Net was implemented, trained and evaluated using manually labeled in-house datasets from cadaveric specimen (N = 43) and clinical practice (N = 9). The model robustness was further evaluated on three independent open-source datasets (N = 23 + 7 + 17 scans) consisting of cadaveric specimen scans. For the in-house datasets, Dice scores of 0.97 and 0.94, intersection-over-union scores of 0.94 and 0.89 and average Hausdorf distances of 0.065 and 0.14 voxel units were achieved. The landmark localization task was performed automatically with an average localization error of 3.3 and 5.2 voxel units. A robust, albeit reduced performance could be
attained for the catalogue of three open-source datasets. Results of the ablation studies with 43 mono-parametric variations of the basal architecture and training protocol provided task-optimal parameters for both categories. Ablation studies against single-task variants of the basal architecture showed a clear performance beneft of coupling landmark localization with segmentation and a dataset-dependent performance impact on segmentation ability.
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.
Störungen der Ionen- und Blutgas Homöostase mit Verschiebungen von Na+ und K+ in der regionalen Hypoxie sind ein Kennzeichen der experimentellen zerebralen Ischämie, wurden aber in ihrer Bedeutung für Schlaganfallpatienten noch nicht hinreichend untersucht. Wir berichten über eine prospektive, humane Querschnittsstudie an 366 Schlaganfallpatienten, die mit einer endovaskulären Rekanalisation bei einem akuten LVO der vorderen Zirkulation zwischen dem 18.Dezember 2018 und dem 31.August 2020 behandelt wurden. Im Rahmen der vorliegenden Dissertationsarbeit wurden intraprozedural arterielle Blutgasproben (1ml) aus dem lokal ischämischen Kollateralkreislauf und der intraindividuellen systemischen Referenzlokalisation in 51 Patienten gewonnen. Die Probengewinnung mit Hilfe eines Mikrokatheters erfolgte nach einem bereits veröffentlichten Protokoll.
Diese Arbeit weist in der Perakutphase eines Großgefäßverschlusses signifikant nach, dass der lokal ischämische paO2 (-4,29%, paO2ischämisch=185,3 mmHg vs. paO2systemisch=193,6mmHg; p=0,035) und die Konzentration von K+ (-5,49%, K+ischämisch=3,44mmol/L vs. K+systemisch=3,64mmol/L; p=0,0081) signifikant reduziert war. Wir beobachteten, dass der Na+:K+-Quotient in der Kollateralzirkulation (+3,29%; Na+:K+-Quotientischämisch=41,74 vs. Na+:K+-Quotientsystemisch=40,38; p=0,0048) im Vergleich zur systemischen Zirkulation signifikant erhöht war, während die Na+-Konzentration signifikant positiv mit einer Zunahme des Infarktausmaßes assoziiert war (r=0,42, p=0,0033). Wir fanden eine alkaline Tendenz des zerebralen pH (+0,14%, pHischämisch=7,38 vs. pHsystemisch=7,37, p=0,0019), mit einer zeitabhängigen Verschiebung in den azidotischen Bereich (r=-0,36, p=0,0549).
Schlussfolgernd deuten unsere Ergebnisse darauf hin, dass die durch den Schlaganfall verursachten Veränderungen der zerebralen Sauerstoffversorgung, der Ionenzusammensetzung und des Säure-Basen-Gleichgewichts dynamisch auftreten, während der okklusiven Ischämie fortschreiten und mit der akuten Gewebeschädigung im Zusammenhang stehen. Wünschenswert sind weitere prospektive Studien, um die Ergebnisse valide zu reproduzieren.
In dieser Arbeit wurde einerseits retrospektiv untersucht, wie sich supratentorielle und infratentorielle Ependymome bildmorphologisch unterscheiden, ob Lokalrezidive eines Ependymoms dessen Bildeigenschaften teilen und welche Art von Rezidiven im Verlauf auftreten können. Die von uns beschriebenen Bildcharakteristika der Ependymome decken sich zum größten Teil mit bereits veröffentlichten Studien. Supratentorielle Ependymome unterscheiden sich signifikant in ihrer Bildmorphologie im Vergleich zu Ependymome der hintern Schädelgrube. Alle pädiatrischen Ependymompatienten/innen in unserem Kollektiv erkrankten an mindestens einem Rezidiv. Am häufigsten traten Lokalrezidive gefolgt von Meningeosen im ersten Rezidiv auf. Seltener fanden sich transiente postradiogene Läsionen, Diffuse intrinsische Ponsgliome und extraneurale Metastasen. Der bildmorphologische Vergleich, Primarius versus Lokalrezidiv ergab überwiegend ähnliche bildgebende Eigenschaften vor allem im Signalverhalten, Tumorbegrenzung und KM-Aufnahme sowie KM anreichernder Tumoranteil. Die kranielle Meningeose präsentierte sich zum ersten Rezidivzeitpunkt different zum Primärtumor. Die extraneuralen Metastasen hatten bildcharakteristisch Ähnlichkeiten zum Primärtumor. Bei der Bewertung neuer intraparenchymaler Läsionen sollte immer der zeitliche Zusammenhang zur letzten Therapie und damit mögliche vorübergehende postradiologischen Veränderungen berücksichtigt werden.
Letztlich ist das pädiatrische Ependymom und Ependymomrezidiv ein komplexes und immer noch unvollständiges erfasstes Krankheitsbild. Durch umfangreichere Studien und die Zusammenführung dieser Ergebnisse könnte schlussendlich die Komplexität des Krankheitsbildes und somit die Therapieoptionen verbessert werden. Durch unsere Studie gelang einerseits die Beschreibung und der Vergleich des primären Ependymoms bezüglich supra- und infratentorieller Lokalisation und andererseits gelang eine neuroradiologische Beschreibung von Ependymomrezidiven im Vergleich zum primären Ependymom, wodurch in Zukunft die Nachsorge der Ependymomrezidive und die Therapieoptionen optimiert werden könnten.