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Background and ObjectivesSpontaneous intracranial hypotension (SIH) is characterized by loss of CSF volume. We hypothesize that in this situation of low volume, a larger CSF flow and spinal cord motion at the upper spine can be measured by noninvasive phase contrast MRI.MethodsA prospective, age-, sex-, and body mass index (BMI)-matched controlled cohort study on patients with SIH presenting with spinal longitudinal extradural fluid collection (SLEC) was conducted from October 2021 to February 2022. Cardiac-gated 2D phase contrast MRI sequences were acquired at segment C2/C3, and C5/C6 for CSF flow, and spinal cord motion analysis. Data processing was fully automated. CSF flow and spinal cord motion were analyzed by peak-to-peak amplitude and total displacement per segment and heartbeat, respectively. Clinical data included age, height, BMI, duration of symptoms, Bern score according to Dobrocky et al., and type of the spinal CSF leak according to Schievink et al. Groups were compared via the Mann-WhitneyUtest; multiple linear regression analysis was performed to address possible relations.ResultsTwenty patients with SIH and 40 healthy controls were analyzed; each group consisted of 70% women. Eleven patients with SIH presented with type 1 leak, 8 with type 2, and 1 was indeterminate. CSF flow per heartbeat was increased at C2/C3 (peak-to-peak amplitude 65.68 ± 18.3 vs 42.50 ± 9.8 mm/s, total displacement 14.32 ± 3.5 vs 9.75 ± 2.7 mm,p< 0.001, respectively). Craniocaudal spinal cord motion per heartbeat was larger at segment C2/C3 (peak-to-peak amplitude 7.30 ± 2.4 vs 5.82 ± 2.0 mm/s, total displacement 1.01 ± 0.4 vs 0.74 ± 0.4 mm,p= 0.006, respectively) and at segment C5/C6 (total displacement 1.41 ± 0.7 vs 0.97 ± 0.4 mm,p= 0.021).DiscussionSLEC-positive patients with SIH show higher CSF flow and higher spinal cord motion at the upper cervical spine. This increased craniocaudal motion of the spinal cord per heartbeat might produce increased mechanical strain on neural tissue and adherent structures, which may be a mechanism leading to cranial nerve dysfunction, neck pain, and stiffness in SIH. Noninvasive phase contrast MRI of CSF flow and spinal cord motion is a promising diagnostic tool in SIH.Trial Registration InformationGerman Clinical Trials Register, identification number: DRKS00017351.Classification of EvidenceThis study provides Class III evidence that noninvasive phase contrast MRI of the upper spine identifies differences in CSF flow and spinal cord motion in patients with SIH compared with healthy controls.

PurposeThe head circumference is typically used as a surrogate parameter for the development of the central nervous system and intracranial structures and is an important clinical parameter in neuropediatrics. As magnetic resonance images (MRI) can be freely zoomed, visual analysis of the head size often relies on impressions, such as the craniofacial ratio or a simplified gyral pattern. Aim of this study was to validate an MRI-based method to measure the head circumference.MethodsHead circumferences of 85 children (41 microcephalies, 22 macrocephalies and 22 normal controls; 47 male, mean age 3.22 ± 2.45 years, range 0.19–10.42 years) were retrospectively measured using sagittal 3D-T1w (MPRAGE) data sets. Three readers independently placed an ovoid region of interest in an axial plane starting from the supraorbital bulge and covering the largest supra-auricular head circumference. Clinical measurements of the head circumference taken within an acceptable period served for comparative purposes. Reliability was assessed by calculating the total error of measurement (TEM) and the intraclass correlation coefficient (ICC).ResultsA close correlation was found between MRI-based and clinical measurements. The interrater reliability was excellent (ICC 0.985, 95% confidence interval 0.952–0.993). Absolute TEM ranged from 0.47–0.75, resulting in relative TEM ranging from 1.0–1.6%. Thus, TEMs were classified as acceptable. The mean accuracy of MRI-based measurements was high at 0.94.ConclusionThe head circumference can be reliably determined with a simple measurement on 3D sequences using multiplanar reformations. This approach may help to diagnose microcephaly and macrocephaly, especially when the head circumference is not reported by the referring physician.

CSF-venous fistulas — initially described in 2014 — are a significant cause of spontaneous intracranial hypotension. Dynamic lateral decubitus digital subtraction and/or CT myelography typically show a hyperdense paraspinal vein. In case of a central drainage toward the internal vertebral venous plexus, it is the “hyperdense basivertebral vein” which should be searched for carefully.

Focal cortical dysplasia (FCD) are histopathologically categorized in ILAE type I to III. Mild malformations of cortical development (mMCD) including those with oligodendroglial hyperplasia (MOGHE) are to be integrated into this classification yet. Only FCD type II have distinctive MRI and molecular genetics alterations so far. Subtle FCD including FCD type II located in the depth of a sulcus are often overlooked requiring the use of dedicated sequences (MP2RAGE, FLAWS, EDGE) and/or voxel (VBM)- or surface-based (SBM) postprocessing. The added value of 7 Tesla MRI has to be proven yet.

Design Prospective diagnostic study. Objectives Primary imaging-based diagnosis of spinal cord tumor-suspected lesions is often challenging. The identification of the definite entity is crucial for dedicated treatment and therefore reduction of morbidity. The aim of this trial was to investigate specific quantitative signal patterns to differentiate unclear intramedullary tumor-suspected lesions based on diffusion tensor imaging (DTI). Setting Medical Center - University of Freiburg, Germany. Methods Forty patients with an unclear tumor-suspected lesion of the spinal cord prospectively underwent DTI. Primary diagnosis was determined by histological or clinical work-up or remained indeterminate with follow-up. DTI metrics (FA/ADC) were evaluated at the central lesion area, lesion margin, edema, and normal spinal cord and compared between different diagnostic groups (ependymomas, other spinal cord tumors, inflammations). Results Mean DTI metrics for all spinal cord tumors (n = 18) showed significantly reduced FA and increased ADC values compared to inflammatory lesions (n = 8) at the lesion margin (p p = 0.001) and reduced FA at the central lesion area (p n = 10) and other spinal cord tumors (n = 8), but remaining differences for both compared to the inflammation subgroup. We found significant higher ADC (p = 0.040) and a trend to decreased FA (p = 0.081) for ependymomas compared to inflammations at the edema. Conclusion Even if distinct differentiation of ependymomas from other spinal cord neoplasms was not possible based on quantitative DTI metrics, FA and ADC were feasible to separate inflammatory lesions. This may avoid unnecessary surgery in patients with unclear intramedullary tumor-suspected lesions.