RATIONALE AND OBJECTIVES:To train and test an AI-based algorithm for automated detection of focal bone marrow lesions (FL) from MRI. MATERIALS AND METHODS:This retrospective feasibility study included 444 patients with monoclonal plasma cell disorders. For this feasibility study, only FLs in the left pelvis were included. Using the nnDetection framework, the algorithm was trained based on 334 patients with 494 FLs from center 1, and was tested on an internal test set (36 patients, 89 FLs, center 1) and a multicentric external test set (74 patients, 262 FLs, centers 2-11). Mean average precision (mAP), F1-score, sensitivity, positive predictive value (PPV), and Spearman correlation coefficient between automatically determined and actual number of FLs were calculated. RESULTS:On the internal/external test set, the algorithm achieved a mAP of 0.44/0.34, F1-Score of 0.54/0.44, sensitivity of 0.49/0.34, and a PPV of 0.61/0.61, respectively. In two subsets of the external multicentric test set with high imaging quality, the performance nearly matched that of the internal test set, with mAP of 0.45/0.41, F1-Score of 0.50/0.53, sensitivity of 0.44/0.43, and a PPV of 0.60/0.71, respectively. There was a significant correlation between the automatically determined and actual number of FLs on both the internal (r=0.51, p=0.001) and external multicentric test set (r=0.59, p<0.001). CONCLUSION:This study demonstrates that the automated detection of FLs from MRI, and thereby the automated assessment of the number of FLs, is feasible.

This multicenter imaging study aimed to establish and validate automated radiomics models predicting therapy response (TR) and minimal residual response (MRD) in newly diagnosed multiple myeloma (MM) from baseline MRI. Retrospectively, 118 MM patients from the GMMG-HD7 trial (EudraCT: 2017-004768-37) with data on TR and/or MRD after induction therapy and baseline MRI were included. Data were split by center into a training set (center 1–2; n = 79) and a test set (center 3–10; n = 39). TR was classified as very good partial response or better versus other. An in-house developed nnU-Net was used to automatically segment pelvic bone marrow for the subsequent extraction of 245 radiomics features and piriformis muscle for normalization. Random forest classifiers were trained using radiomics features only (I), radiomics features with additional confounders (II) or myeloma-relevant clinical features (III), or only clinical features (IV) to predict TR or MRD status. The area under the receiver operating characteristic curve (AUROC) was calculated to assess prediction performance. The prediction model using only radiomics features (I) showed the highest predictive performance for TR on the test set with an AUROC of 0.70. AUROC values for radiomics-based prediction of the MRD status (I-III) ranged from 0.54 to 0.52. In conclusion, our study demonstrated the potential of automated radiomics models from baseline MRI to non-invasively predict TR in MM on an independent, multicentric test set.

Objectives In multiple myeloma and its precursor stages, plasma cell infiltration (PCI) and cytogenetic aberrations are important for staging, risk stratification, and response assessment. However, invasive bone marrow (BM) biopsies cannot be performed frequently and multifocally to assess the spatially heterogenous tumor tissue. Therefore, the goal of this study was to establish an automated framework to predict local BM biopsy results from magnetic resonance imaging (MRI). Materials and Methods This retrospective multicentric study used data from center 1 for algorithm training and internal testing, and data from center 2 to 8 for external testing. An nnU-Net was trained for automated segmentation of pelvic BM from T1-weighted whole-body MRI. Radiomics features were extracted from these segmentations, and random forest models were trained to predict PCI and the presence or absence of cytogenetic aberrations. Pearson correlation coefficient and the area under the receiver operating characteristic were used to evaluate the prediction performance for PCI and cytogenetic aberrations, respectively. Results A total of 672 MRIs from 512 patients (median age, 61 years; interquartile range, 53–67 years; 307 men) from 8 centers and 370 corresponding BM biopsies were included. The predicted PCI from the best model was significantly correlated (P ≤ 0.01) to the actual PCI from biopsy in all internal and external test sets (internal test set: r = 0.71 [0.51, 0.83]; center 2, high-quality test set: r = 0.45 [0.12, 0.69]; center 2, other test set: r = 0.30 [0.07, 0.49]; multicenter test set: r = 0.57 [0.30, 0.76]). The areas under the receiver operating characteristic of the prediction models for the different cytogenetic aberrations ranged from 0.57 to 0.76 for the internal test set, but no model generalized well to all 3 external test sets. Conclusions The automated image analysis framework established in this study allows for noninvasive prediction of a surrogate parameter for PCI, which is significantly correlated to the actual PCI from BM biopsy.

Background Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience. Methods A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted. Results We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5–20) and 9 (IQR 7–10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis. Conclusion Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

PURPOSE:Despite improved techniques and sophisticated postinterventional care, symptomatic intracranial hemorrhage (sICH) remains the most feared complication of mechanical thrombectomy (MT). Based on peri-interventional parameters, we aimed to discover which patients have a higher risk of sICH. METHODS:From March 2017 until March 2020 consecutive patients with acute ischemic stroke (AIS) and confirmed large-vessel occlusion who underwent MT were analyzed retrospectively. Demographic, clinical, and radiological variables and parameters specific to thrombectomy were reviewed. A univariate analysis was performed and statistically significant variables were included in a logistic regression model to identify independent factors predictive of sICH. RESULTS:A total of 236 patients with confirmed large-vessel occlusion were included and 22 (9.3%) had sICH. Univariate predictors of sICH included diabetes mellitus, glucose > 11.1 mmol/L, creatinine clearance (CrCl) ≤ 30 ml/min/1.73, ASPECTS indicating pretreatment infarct size, acute internal carotid artery (ICA) occlusion, stent implantation, tirofiban use, time from symptom onset to groin puncture > 4.5 h and high contrast medium consumption. In the adjusted analysis, ASPECTS < 6 (OR 3.673, p = 0.041), and amount of contrast injected ≥ 140 ml (OR 5.412, p = 0.003) were independent predictors of sICH, but not any more baseline glucose > 11.1 mmol/L (OR 1.467, p = 0.584), CrCl ≤ 30 ml/min/1.73 (OR 4.177, p = 0.069), acute ICA occlusion (OR 2.079, p = 0.181), stent implantation (OR 0.465, p = 0.512), tirofiban use (OR 5.164, p = 0.167), and time from onset-to-groin puncture (OR 1.453, p = 0.514). CONCLUSION:The amount of contrast medium used is a modifiable factor associated with sICH. This association is novel and may be related to the neurotoxicity of the contrast medium disrupting the blood-brain barrier.

Background The risk of stroke after carotid sinus massage is greater if there is preexisting carotid stenosis or carotid plaques. We present the case of a patient with underlying 40% carotid stenosis, who developed a watershed stroke after a self-neck massage in our stroke unit. We show a well-documented case with magnetic resonance images before and after the neck massage. We report a case of a watershed brain infarct after a self-massage of the carotid sinus, with preexisting carotid artery stenosis. Neck massage continues to be a significant cause of stroke and should therefore not be performed by patients. Clinicians must be aware of the implications of a carotid sinus massage in both the outpatient and inpatient settings. Case presentation We admitted a 58-year-old white male patient, with no relevant medical history, to our department with a brain stem infarct. During his stay at our stroke unit, the patient performed a self-neck massage with consecutive bradycardia and asystole, resulting in left-side hemiparesis. The underlying cause of the hemodynamic stroke is believed to be secondary to this intensive neck massage performed by the patient. The patient also suffered from unknown right internal carotid artery stenosis. Conclusion Clinicians and patients must be aware that neck massage can lead to ischemic stroke. We postulate that repetitive impaired cardiac output can lead to a hemodynamic (watershed-type) stroke.

Background: The present study evaluates the possible prognostic benefits of 7 T susceptibility weighted imaging (SWI) of traumatic cerebral microbleeds (TMBs) over 3 T SWI to predict the acute clinical state and subjective impairments, including health-related quality of life (HRQOL), after closed head injury (CHI). Methods: The study group comprised 10 participants with known TMBs All subjects underwent 3 T magnetic resonance imaging (MRI) and 7 T MRI, respectively. Location and count of TMBs were independently evaluated by two neuroradiologists. The initial Glasgow Coma Scale (GCS), the duration of coma and further clinical data were taken from the patients records. HRQOL was assessed by means of a questionnaire. Memory complaints and neurological symptoms were inquired at the time of the MRI examinations. Results: SWI revealed a total of 485 TMBs at 3 T, 584 TMBs at 7 T with similar spatial resolution, and 684 TMBs at 7 T with a factor of 10 higher spatial resolution. The TMBs depicted by 7 T high-resolution SWI were correlated with the duration of coma (Spearman’s rho of 0.77). The corresponding association with TMBs in 3 T MRI SWI showed a Spearman’s rho of 0.71. The initial GCS score and TMBs correlated with a Spearman’s rho of −0.35 at 3 T SWI MRI and a rho of −0.33 at 7 T high-resolution SWI, respectively. The physical aspect of HRQOL correlated substantially with the count of TMBs (rho = 0.44 for 3 T SWI and rho = 0.35 for both 7 T SWI sequences, respectively). Conclusions: The number of TMBs showed a substantial association with indicators of the acute clinical state and chronic neurobehavioral parameters after CHI, but there was no additional advantage of 7 T MRI. These preliminary findings warrant a larger prospective study for the future.

INTRODUCTION:Emergency department (ED) triage regarding infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is challenging. During the coronavirus disease 2019 (COVID-19) outbreak in Germany, the diagnostic outcomes of critically ill patients admitted to the resuscitation room in the ED of our academic 754-bed hospital should be analyzed.METHODS:All resuscitation room patients between March 1st and April 15th 2020 were included in this retrospective study. Every patient with suspicion of SARS-CoV-2 infection received a pharyngeal swab for real-time polymerase chain reaction (rt-PCR), divided in the clinical subgroups of "highly suspicious for COVID-19" and "COVID-19 as differential diagnosis." All respiratory and infectious symptoms were included as at least "differential diagnosis" as an expanded suspicion strategy.RESULTS:Ninety-five patients were included (trauma n = 14, critically ill n = 81). Of 3 highly suspicious patients, 2 had rt-PCR positive pharyngeal swabs. In 39 patients, COVID-19 was defined as differential diagnosis, and 3 were positive for SARS-CoV-2. Of them, pharyngeal swabs were positive in 1 case, while in 2 cases, only tracheal fluid was rt-PCR positive while the pharyngeal swabs were negative. In one of these 2 cases, chest computed tomography (CT) was also negative for ground-glass opacities but showed a pulmonary abscess and pulmonary embolism.CONCLUSION:We recommend an expanded suspicion strategy for COVID-19 due to unexpected diagnostic outcomes. Personal protective equipment should be used in every resuscitation room operation due to unexpected cases and initial knowledge gaps. Furthermore, tracheal fluid should be tested for SARS-CoV-2 in every intubated patient due to cases with negative pharyngeal swabs and negative chest CT.

Purpose Orbital decompression surgery is performed in patients with Graves’ orbitopathy to treat dysthyroid optical neuropathy (DON) and reduce disfiguring proptosis. The intended proptosis reduction can deviate from the postoperative result and changes of motility with consecutive diplopia can occur. We performed a retrospective study to identify anatomical factors in computed tomography (CT), which influence the surgical effect and postoperative ocular motility and diplopia. Methods Pre- and postoperative CT-scans of 125 eyes of 68 patients, who mainly underwent a balanced orbital decompression for disfiguring proptosis (≥18mm Hertel Index), have been analyzed. Proptosis, ductions, misalignment and diplopia were assessed before and after surgery. Medial and lateral orbital wall length, conus angle, depth of ethmoidal sinus, orbital surface, length of medial and orbital defect, depth of tissue prolapse and horizontal muscle diameters were analyzed in CT scans before and after surgery. With linear regression and multivariate analyses these parameters have been correlated with postoperative proptosis, abduction deficit, deviation and binocular single vision (BSV). Results Proptosis could be reduced by 5.3±2mm. Patients with <5mm proptosis reduction had significantly less often new onset of diplopia compared to patients with >5mm reduction (13% vs. 56%, p = 0.02). Multiple linear regression showed a significant correlation between tissue prolapse and depth of the ethmoidal sinus as well as age (p<0.001, r = 0.71). Proptosis reduction could not be predicted by tissue prolapse, defect length or depth of ethmoidal sinus. The abduction deficit correlated significantly with tissue prolapse and orbital surface area (p<0.001, r = 0.37) but not with the horizontal muscle diameter. Conclusion We were able to show that orbital morphology influences the outcome of balanced orbital decompression surgery in terms of proptosis reduction and motility. However, the rather low coefficients of correlation show that the surgical outcome cannot be predicted with simple CT measurements, although risk factors for postoperative abduction deficit could be found. Therefore, preoperative planning should consider especially the orbital surface area and depth of ethmoidal sinus. Patients should be informed about the higher risk of diplopia with higher proptosis reduction.

Das Ziel der vorliegenden Studie ist der intermodale Vergleich der Strahlendosis während einer Multidetektor Computer Tomografie (MSCT) und einer Cone-Beam Computer Tomografie (CBCT) für die perioperative Cochlea Implantat Evaluation.

To examine radiation dose levels of CT-guided interventional procedures of chest, abdomen, spine and extremities on different CT-scanner generations at a large multicentre institute.

PURPOSE:New software solutions emerged to support radiologists in image interpretation in acute ischemic stroke. This study aimed to validate the performance of computer-aided assessment of the Alberta Stroke Program Early CT score (ASPECTS) for detecting signs of early infarction.METHODS:ASPECT scores were assessed in 119 CT scans of patients with acute middle cerebral artery ischemia. Patient collective was differentiated according to (I) normal brain, (II) leukoencephalopathic changes, (III) infarcts, and (IV) atypical parenchymal defects (multiple sclerosis, etc.). ASPECTS assessments were automatically provided by the software package e-ASPECTS (Brainomix®, UK) (A). Subsequently, three neuroradiologists (B), (C), and (D) examined independently 2380 brain regions. Interrater comparison was performed with the definite infarct core as reference standard after best medical care (thrombolysis and/or thrombectomy).RESULTS:Interrater comparison revealed higher correlation coefficient of (B) 0.71, (C) 0.76, and of (D) 0.80 with definite infarct core compared to (A) 0.59 for ASPECTS assessment in the acute ischemic stroke setting. While (B), (C), and (D) showed a significant correlation for individual patient groups (I), (II), (III), and (IV), except for (D) (II), (A) was not significant in patient groups with pre-existing changes (II), (III), and (IV). The following sensitivities, specificities, PPV, NPV, and accuracies given in percent were achieved: (A) 83, 57, 55, 82, and 67; (B) 74, 76, 69, 83, and 77; (C) 80.8, 85.2, 76, 84, and 80; (D) 63, 90.7, 82, 79, and 80, respectively.CONCLUSION:For ASPECTS assessment, the examined software may provide valid data in case of normal brain. It may enhance the work of neuroradiologists in clinical decision making. A final human check for plausibility is needed, particularly in patient groups with pre-existing cerebral changes.

April 23, 2018April 10, 2018Free AccessPolarity-specific Modulation of Central Pain Processing by Transcranial Direct Current Stimulation (P2.100)Steffen Naegel, Nina Theysohn, Adrian Ringelstein, Christoph Kleinschnitz, H. Diener, Zaza Katsarava, Mark Obermann, and Dagny HolleAuthors Info & AffiliationsApril 10, 2018 issue90 (15_supplement)https://doi.org/10.1212/WNL.90.15_supplement.P2.100 Letters to the Editor

Background The importance of monitoring of the radiation dose received by the human body during computed tomography (CT) examinations is not negligible. Several dose-monitoring software tools emerged in order to monitor and control dose distribution during CT examinations. Some software tools incorporate Monte Carlo Simulation (MCS) and allow calculation of effective dose and organ dose apart from standard dose descriptors. Purpose To verify the results of a dose-monitoring software tool based on MCS in assessment of effective and organ doses in thoracic CT protocols. Material and Methods Phantom measurements were performed with thermoluminescent dosimeters (TLD LiF:Mg,Ti) using two different thoracic CT protocols of the clinical routine: (I) standard CT thorax (CTT); and (II) CTT with high-pitch mode, P = 3.2. Radiation doses estimated with MCS and measured with TLDs were compared. Results Inter-modality comparison showed an excellent correlation between MCS-simulated and TLD-measured doses ((I) after localizer correction r = 0.81; (II) r = 0.87). The following effective and organ doses were determined: (I) (a) effective dose = MCS 1.2 mSv, TLD 1.3 mSv; (b) thyroid gland = MCS 2.8 mGy, TLD 2.5 mGy; (c) thymus = MCS 3.1 mGy, TLD 2.5 mGy; (d) bone marrow = MCS 0.8 mGy, TLD 0.9 mGy; (e) breast = MCS 2.5 mGy, TLD 2.2 mGy; (f) lung = MCS 2.8 mGy, TLD 2.7 mGy; (II) (a) effective dose = MCS 0.6 mSv, TLD 0.7 mSv; (b) thyroid gland = MCS 1.4 mGy, TLD 1.8 mGy; (c) thymus = MCS 1.4 mGy, TLD 1.8 mGy; (d) bone marrow = MCS 0.4 mGy, TLD 0.5 mGy; (e) breast = MCS 1.1 mGy, TLD 1.1 mGy; (f) lung = MCS 1.2 mGy, TLD 1.3 mGy. Conclusion Overall, in thoracic CT protocols, organ doses simulated by the dose-monitoring software tool were coherent to those measured by TLDs. Despite some challenges, the dose-monitoring software was capable of an accurate dose calculation.

Untersuchung der Strahlenexposition von Säuglingen und Kleinkindern mit Retinoblastom bei der intraarteriellen Melphalantherapie im neurointerventionellen Setting.

Background A neurointerventional examination of intracranial aneurysms often involves the eye lens in the primary beam of radiation. Objective To assess and compare eye-lens doses imparted during interventional and non-interventional imaging techniques for the examination of intracranial aneurysms. Methods We performed a phantom study on an anthropomorphic phantom (ATOM dosimetry phantom 702-D; CIRS, Norfolk, Virginia, USA) and assessed eye-lens doses with thermoluminescent dosimeters (TLDs) type 100 (LiF:Mg, Ti) during (1) interventional (depiction of all cerebral arteries with triple 3D-rotational angiography and twice 2-plane DSA anteroposterior and lateral projections) and (2) non-interventional (CT angiography (CTA)) diagnosis of intracranial aneurysms. Eye-lens doses were calculated following recommendations of the ICRP 103. Image quality was analysed in retrospective by two experienced radiologists on the basis of non-interventional and interventional pan-angiography examinations of patients with incidental aneurysms (n=50) on a five-point Likert scale. Results The following eye-lens doses were assessed: (1) interventional setting (triple 3D-rotational angiography and twice 2-plane DSA anteroposterior and lateral projections) 12mGy; (2) non-interventional setting (CTA) 4.1mGy. Image quality for depiction of intracranial aneurysms (>3mm) was evaluated as good by both readers for both imaging techniques. Conclusions Eye-lens doses are markedly higher during the interventional than during the non-interventional diagnosis of intracranial aneurysms. For the eye-lens dose, CTA offers considerable radiation dose savings in the diagnosis of intracranial aneurysms.

Die bildgebende Darstellung der hirnversorgenden Gefäße ist in der Akutphase des Schlaganfalls besonders wichtig. Spezielles Augenmerk wird in diesem Beitrag auf die Selektionskraft der MRT-Bildgebung hinsichtlich der Indikationsstellung für eine Thrombektomie oder i. v. Lysetherapie gelegt. Außerdem gibt der Text einen Einblick in zukünftige Entwicklungen bildgebender Verfahren, die das Potenzial haben, die Schlaganfallversorgung zu verändern.

Gemäß den Leitlinien der Deutschen Gesellschaft für Neurologie [1] ist die Anwendung eines schnittbildgebenden Verfahrens in der Akutphase eines ischämischen Schlaganfalls vor Einleitung einer Lysetherapie obligat. In der Regel wird heute eine CT des Schädels durchgeführt, häufig kombiniert mit einer CTA (computertomografische Angiografie) und gelegentlich auch in Kombination mit einer PCT (computertomografische Perfusionsmessung).