Structured Reporting in Multiple Sclerosis - Consensus-Based Reporting Templates for Magnetic Resonance Imaging of the Brain and Spinal Cord. / Strukturierte Befundung bei Multipler Sklerose ­ Konsensbasierte Befundvorlagen für die magnetresonanztomografische Untersuchung des Gehirns und des Rückenmarks.

As a result of technical developments and greater availability of imaging equipment, the number of neuroradiological examinations is steadily increasing [1]. Due to improved image quality and sensitivity, more details can be detected making reporting more complex and time-intensive. At the same time, reliable algorithms increasingly allow quantitative image analysis that should be integrated in reports in a standardized manner. Moreover, increasing digitalization is resulting in a decrease in the personal exchange between neuroradiologists and referring disciplines, thereby making communication more difficult. The introduction of structured reporting tailored to the specific disease and medical issue [2, 3] and corresponding to at least the second reporting level as defined by the German Radiological Society (https://www.befundung.drg.de/de-DE/2908/strukturierte-befundung/) is therefore desirable to ensure that the quality standards of neuroradiological reports continue to be met.The advantages of structured reporting include a reduced workload for neuroradiologists and an information gain for referring physicians. A complete and standardized list with relevant details for image reporting is provided to neuroradiologists in accordance with the current state of knowledge, thereby ensuring that important points are not forgotten [4]. A time savings and increase in efficiency during reporting were also seen [5]. Further advantages include report clarity and consistency and better comparability in follow-up examinations regardless of the neuroradiologist's particular reporting style. This results in better communication with the referring disciplines and makes clinical decision significantly easier [6, 7]. Although the advantages are significant, any potential disadvantages like the reduction of autonomy in reporting and inadequate coverage of all relevant details and any incidental findings not associated with the main pathology in complex cases or in rare diseases should be taken into consideration [4]. Therefore, studies examining the advantages of structured reporting, promoting the introduction of this system in the clinical routine, and increasing the acceptance among neuroradiologists are still needed.Numerous specific templates for structured reporting, e. g., regarding diseases in cardiology and oncology, are already available on the website www.befundung.drg.de . Multiple sclerosis (MS) is an idiopathic chronic inflammatory and neurodegenerative disease of the central nervous system and is the most common non-trauma-based inflammatory neurological disease in young adults. Therefore, it has significant individual and socioeconomic relevance [8]. Magnetic resonance imaging (MRI) plays an important role in the diagnosis, prognosis evaluation, and follow-up of this disease. MRI is established as the central diagnostic method in the diagnostic criteria. Therefore, specific changes are seen on MRI in almost all patients with a verified MS diagnosis [9]. Reporting of MRI datasets regarding the brain and spinal cord of patients with MS includes examination of the images with respect to the relevant medical issue in order to determine whether the McDonald criteria, which were revised in 2017 [10] and define dissemination in time and space clinically as well as with respect to MRI based on the recommendations of the MAGNIMS groups [11, 12], are fulfilled. A more precise definition of lesion types and locations according to the recommendations of an international expert group [13] is discussed in the supplementary material. Spinal cord signal abnormalities are seen in up to 92 % of MS patients [14-16] and are primarily located in the cervical spine [15]. The recommendations of the MAGNIMS-CMSC-NAIMS working group published in 2021 [11] explicitly recommend the use of structured reporting for MS patients.Therefore, a reporting template for evaluating MRI examinations of the brain and spinal cord of patients with MS was created as part of the BMBF-funded DIFUTURE consortium in consensus with neuroradiological and neurological experts in concordance with the recommendations mentioned above [11] and was made available for broad use (https://github.com/DRGagit/ak_befundung). The goal is to facilitate efficient and comprehensive evaluation of patients with MS in the primary diagnostic workup and follow-up imaging. These reporting templates are consensus-based recommendations and do not make any claim to general validity or completeness. The information technology working group (@GIT) of the German Radiological Society and the German Society for Neuroradiology strive to keep the reporting templates presented here up-to-date with respect to new research data and recommendations of the MAGNIMS-CMSC-NAIMS group [11]. KEY POINTS:: · consensus-based reporting templates. · template for the structured reporting of MRI examinations of patients with multiple sclerosis. · structured reporting might facilitate communication between neuroradiologists and referring disciplines. CITATION FORMAT: · Riederer I, Mühlau M, Wiestler B et al. Structured Reporting in Multiple Sclerosis - Consensus-Based Reporting Templates for Magnetic Resonance Imaging of the Brain and Spinal Cord. Fortschr Röntgenstr 2023; 195: 135 - 138.

Diagnosis and follow-up evaluation of central nervous system vasculitis: an evaluation of vessel-wall MRI findings.

OBJECTIVE: To approach the clinical value of MRI with vessel wall imaging (VWI) in patients with central nervous system vasculitis (CNSV), we analyzed patterns of VWI findings both at the time of initial presentation and during follow-up. METHODS: Stenoocclusive lesions, vessel-wall contrast enhancement (VW-CE) and diffusion-restricted lesions were analyzed in patients with a diagnosis of CNSV. On available VWI follow-up, progression, regression or stability of VW-CE were evaluated and correlated with the clinical status. RESULTS: Of the 45 patients included, 28 exhibited stenoses visible on MR angiography (MRA-positive) while 17 had no stenosis (MRA-negative). VW-CE was found in 2/17 MRA-negative and all MRA-positive patients (p < 0.05). 79.1% (53/67) of stenoses showed VW-CE. VW-CE was concentric in 88.3% and eccentric in 11.7% of cases. Diffusion-restricted lesions were found more frequently in relation to stenoses with VW-CE than without VW-CE (p < 0.05). 48 VW-CE lesions in 23 patients were followed over a median time of 239.5 days. 13 VW-CE lesions (27.1%) resolved completely, 14 (29.2%) showed partial regression, 17 (35.4%) remained stable and 4 (8.3%) progressed. 22/23 patients received immunosuppressive therapy for the duration of follow-up. Patients with stable or progressive VW-CE were more likely (p < 0.05) to have a relapse (14/30 cases) than patients with partial or complete regression of VW-CE (5/25 cases). CONCLUSION: Concentric VW-CE is a common finding in medium/large-sized vessel CNSV. VW-CE might represent active inflammation in certain situations. However, follow-up VWI findings proved ambiguous as persisting VW-CE despite immunosuppressive therapy and clinical remission was a frequent finding.

TSPO PET imaging of natalizumab-associated progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a severe infection of the CNS caused by the polyomavirus JC that can occur in multiple sclerosis patients treated with natalizumab. Clinical management of patients with natalizumab-associated PML is challenging not least because current imaging tools for the early detection, longitudinal monitoring and differential diagnosis of PML lesions are limited. Here we evaluate whether translocator protein (TSPO) PET imaging can be applied to monitor the inflammatory activity of PML lesions over time and differentiate them from multiple sclerosis lesions. For this monocentre pilot study we followed eight patients with natalizumab-associated PML with PET imaging using the TSPO radioligand 18F-GE-180 combined with frequent 3 T MRI. In addition we compared TSPO PET signals in PML lesions with the signal pattern of multiple sclerosis lesions from 17 independent multiple sclerosis patients. We evaluated the standardized uptake value ratio as well as the morphometry of the TSPO uptake for putative PML and multiple sclerosis lesions areas compared to a radiologically unaffected pseudo-reference region in the cerebrum. Furthermore, TSPO expression in situ was immunohistochemically verified by determining the density and cellular identity of TSPO-expressing cells in brain sections from four patients with early natalizumab-associated PML as well as five patients with other forms of PML and six patients with inflammatory demyelinating CNS lesions (clinically isolated syndrome/multiple sclerosis). Histological analysis revealed a reticular accumulation of TSPO expressing phagocytes in PML lesions, while such phagocytes showed a more homogeneous distribution in putative multiple sclerosis lesions. TSPO PET imaging showed an enhanced tracer uptake in natalizumab-associated PML lesions that was present from the early to the chronic stages (up to 52 months after PML diagnosis). While gadolinium enhancement on MRI rapidly declined to baseline levels, TSPO tracer uptake followed a slow one phase decay curve. A TSPO-based 3D diagnostic matrix taking into account the uptake levels as well as the shape and texture of the TSPO signal differentiated >96% of PML and multiple sclerosis lesions. Indeed, treatment with rituximab after natalizumab-associated PML in three patients did not affect tracer uptake in the assigned PML lesions but reverted tracer uptake to baseline in the assigned active multiple sclerosis lesions. Taken together our study suggests that TSPO PET imaging can reveal CNS inflammation in natalizumab-associated PML. TSPO PET may facilitate longitudinal monitoring of disease activity and help to distinguish recurrent multiple sclerosis activity from PML progression.

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety.

OBJECTIVE: To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS). METHODS: A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined. RESULTS: PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis. CONCLUSION: ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer.

Radiation dose and image quality in intraoperative CT (iCT) angiography of the brain with stereotactic head frames.

OBJECTIVES: Intraoperative CT (iCT) angiography of the brain with stereotactic frames is an integral part of navigated neurosurgery. Validated data regarding radiation dose and image quality in these special examinations are not available. We therefore investigated two iCT protocols in this IRB-approved study. METHODS: Retrospective analysis of patients, who received a cerebral stereotactic iCT angiography on a 128 slice CT scanner between February 2016 and December 2017. In group A, automated tube current modulation (ATCM; reference value 410 mAs) and automated tube voltage selection (reference value 120 kV) were enabled, and only examinations with a selected voltage of 120 kV were included. In group B, fixed parameters were applied (300 mAs, 120 kV). Radiation dose was measured by assessing the volumetric CT dose index (CTDIvol), dose length product (DLP) and effective dose (ED). Signal-to-noise ratio (SNR) and image noise were assessed for objective image quality, visibility of arteries and grey-white differentiation for subjective image quality. RESULTS: Two hundred patients (n = 100 in each group) were included. In group A, median selected tube current was 643 mAs (group B, 300 mAs; p < 0.001). Median values of CTDIvol, DLP and ED were 91.54 mGy, 1561 mGy cm and 2.97 mSv in group A, and 43.15 mGy, 769 mGy cm and 1.46 mSv in group B (p < 0.001). Image quality did not significantly differ between groups (p > 0.05). CONCLUSIONS: ATCM yielded disproportionally high radiation dose due to substantial tube current increase at the frame level, while image quality did not improve. Thus, ATCM should preferentially be disabled. KEY POINTS: • Automated tube current modulation (ATCM) yields disproportionally high radiation dose in intraoperative CT angiography of the brain with stereotactic head frames. • ATCM does not improve overall image quality in these special examinations. • ATCM is not yet optimised for CT angiography of the brain with major extracorporeal foreign materials within the scan range.

Ruptured basilar artery perforator aneurysms--treatment regimen and long-term follow-up in eight cases.

INTRODUCTION: Basilar artery (BA) perforator aneurysms may lead to severe subarachnoid hemorrhage (SAH). The acute management is uncertain. The anatomic approach is challenging both for coiling and clipping, and flow diverter stenting may be dangerous due to the required antiplatelet therapy. We report on our experiences in eight patients. METHODS: We retrospectively analyzed eight patients with ruptured BA perforator aneurysm, including clinical characteristics, imaging data, treatment regimen, clinical course, and long-term outcome. RESULTS: Patients presented with major SAH and World Federation of Neurosurgical Societies (WFNS) scores of I in three, II in two, and V in three cases. In four patients, the aneurysm was detected in the initial angiography, in four only in follow-up angiography. Five patients were treated conservatively and three patients had endovascular therapy. In the conservative group, the aneurysm spontaneously thrombosed in three cases. One patient suffered from a re-SAH and stayed permanently dependent due to an associated perforator stroke (modified Rankin Scale (mRS) 5). The remaining four patients recovered well (mRS 0 and 1 in two cases, each) including three patients also exhibiting perforator strokes. Regarding the endovascular group, one parent vessel was an angioma feeder and embolized with Onyx. The second aneurysm spontaneously thrombosed periinterventionally. The third patient underwent coiling. Two parent vessels were occluded postinterventionally, resulting in perforator strokes. Final mRS scores were 0, 2, and 2, respectively. CONCLUSION: Conservative management of ruptured BA aneurysms might be a first-line treatment option with common spontaneous aneurysm occlusion, low rate of re-SAH, and promising clinical outcome.

Susceptibility-weighted angiography visualizes hypoxia in cerebral veins.

OBJECTIVES: The objective of this study was to evaluate the influence of short- and long-term hypoxia on the depiction of cerebral veins in the susceptibility-weighted angiography (SWAN) sequence. MATERIALS AND METHODS: In the context of a study on brain adaptation mechanisms to hypoxia, 16 healthy men (aged 20-28 years) were studied through magnetic resonance imaging (MRI) under room air conditions, short-term-hypoxia (7 minutes before and during the MRI scan), and long-term hypoxia (8.5 hours before and during the MRI scan). Oxygen saturation was continuously measured using a finger-mounted pulse oximeter. Two independent blinded readers compared the 3 scans of each participant and graded the SWAN source images and minimum intensity projections according to the size, number, and signal intensity of the cerebral veins. Signal intensities of deep cerebral veins were measured, and signal intensity proportions of deep cerebral veins to different parenchymal brain regions were calculated. RESULTS: Nine subjects could be included in the study. In all of them, both readers correctly distinguished the 2 hypoxia scans from the baseline scan, grading the SWAN images acquired under hypoxic conditions as visualizing cerebral veins more prominently. Signal intensities of the deep cerebral veins and signal intensity proportions were significantly lower in the hypoxia scans. No significant differences between short-term and long-term hypoxia were found on visual inspections and signal intensity measurements. This correlated with the results of the pulse oximetry: mean O2 saturation values were 97.9% ± 1.2% (baseline), 84.1% ± 3.8% (short-term hypoxia), and 82.8% ± 4.4% (long-term hypoxia), respectively. CONCLUSIONS: Hypoxia leads to visible and measurable changes in cerebral veins as depicted through SWAN. Possible clinical implications of this finding include stroke and tumor imaging and need further investigation.

Mechanical thrombectomy in basilar artery thrombosis: technical advances and safety in a 10-year experience.

PURPOSE: Multiple endovascular devices have been used for mechanical thrombectomy (MT) in basilar artery occlusion (BAO) for >10 years. Based on a single-center experience during the course of one decade, we present data on safety and efficacy of previous MT devices compared with modern stent retriever and suction thrombectomy. MATERIALS AND METHODS: Eighty-one patients (29 women, 52 men, mean age 61.5 years, range 17-90) with angiographically confirmed BAO that had been treated by MT between 2001 and 2011 were retrospectively evaluated. Patients in group 1 (n = 60) had been treated between 2001 and 2008 with different devices available at that time. Patients in group 2 (n = 21) had been treated by modern stent retriever or local suction devices between 2008 and 2011. Recanalization rate, needle to recanalization time, procedure-related complications, and distal embolization of thrombotic material were recorded and compared. RESULTS: Recanalization rates of 95% were high in both groups. Procedure-related dissection (n = 5) and subarachnoid hemorrhage (n = 9) occurred in group 1 but not in group 2 (p < 0.016). Needle-to-recanalization time was less than half in group 2 compared with group 1 (54.6 vs. 132.3 min, p < 0.01). Frequency of distal embolization was comparable in both groups (47%). CONCLUSION: High recanalization rates have been achieved since the introduction of MT in BAO. However, modern stent retriever and suction devices allow for safer and more rapid recanalization compared with previous MT devices.

Preceding intravenous thrombolysis facilitates endovascular mechanical recanalization in large intracranial artery occlusion.

BACKGROUND AND AIMS: Acute occlusions of the large intracranial arteries are relatively resistant to intravenous thrombolysis. Therefore, multimodal approaches combining intravenous thrombolysis with endovascular mechanical recanalization are increasingly being applied. In this setting, intravenous thrombolysis may facilitate subsequent mechanical thrombectomy. To test this hypothesis, we analyzed the influence of intravenous thrombolysis on net intervention time in subsequent endovascular mechanical recanalization. METHODS: In this retrospective single-center analysis, we compared net intervention time with and without preceding intravenous thrombolysis in patients treated by endovascular mechanical recanalization between 01/2003 and 06/2010. The net intervention time was defined as the interval between the onset of endovascular thrombus manipulation and successful vessel recanalization. RESULTS: We identified 65 eligible patients, 35 of whom were treated by intravenous thrombolysis before mechanical therapy. Recanalization was achieved in 26 patients with (74%) and 23 patients without preceding intravenous thrombolysis (77%). In the case of successful recanalization, the net intervention time was significantly shorter in patients with preceding intravenous thrombolysis (24·8 ± 22·8 vs. 44·2 ± 40·5 min; P<0·05). This difference remained significant after restricting the analysis to the patients treated by the Penumbra Stroke System(©) (n=32). After three-months, patients with preceding intravenous thrombolysis were more likely to be functionally independent (modified Rankin Scale≤2) than those without (P<0·05). CONCLUSIONS: Our findings suggest that preceding intravenous thrombolysis may reduce the intervention time in patients treated by endovascular mechanical recanalization. However, due to the retrospective design of our study, these findings have to be interpreted with caution and need confirmation in a larger patient population.