Optimization of 3D phase contrast venography for the assessment of the cranio-cervical venous system at 1.5 T.

PURPOSE: The aim of this work was to optimize a three-dimensional (3D) phase-contrast venography (PCV) product MR pulse sequence in order to obtain clinically reliable images with less artifacts for an improved depiction of the cranio-cervical venous vessels. METHODS: Starting from the product sequence, the 3D PCV protocol was optimized in eight steps with respect to the velocity encoding (Venc) direction and value, slice thickness, reduction of susceptibility artifacts and arterial contamination, gradient mode and radio-frequency (RF)-spoiling, B0-Shimming, asymmetric echo technique and RF-pulse type, and flip angle. The product and optimized protocol was used to perform 3D PCV in 12 healthy male volunteers with a median age of 50 years using a state-of-the-art 1.5-T MR system. For evaluation, the cranio-cervical venous system was divided into 15 segments. These segments were evaluated by three radiologists with experience in neuroradiology. An ordinal scoring system was used to access the overall diagnostic quality, arterial contamination, and the quality of visualization. RESULTS: Image quality in the optimized 3D PCV was graded as "excellent" by all readers in 65.3% of the cases (p < 0.0001). The visualization of venous segments was strongly improved: it was considered diagnostic in 81.8% of all cases using the optimized sequence and in 47.6% for the product 3D PCV (p < 0.0001), respectively. The optimized protocol improved the imaging of all venous segments (p < 0.0001). CONCLUSION: The optimized 3D PCV pulse sequence showed superior results compared to the product 3D PCV for the visualization and evaluation of the venous system in all healthy volunteers.

MRI signs of intracranial hypertension in morbidly obese and normal-weight individuals.

PURPOSE: Idiopathic intracranial hypertension (IIH) is associated with intracranial abnormalities, although not obligatory, which can be detected with cranial MRI. Obesity is an important risk factor for IIH and a pathogenetic link is suspected but the extent to which these MRI signs are already related to obesity has not yet been examined. We investigated whether IIH-MRI signs are present more often in obese individuals with a BMI > 30 kg/m² than in individuals of normal weight. MATERIALS AND METHODS: Brain MRI of 32 obese and 53 normal-weight participants from the Food-Chain-Plus cohort were analyzed for three main signs of IIH: (I) stenosis of the transverse sinus, (II) increased width of the optic nerve sheath, and (III) reduction of pituitary height. In addition, a scoring system for the MRI signs was applied. Furthermore, tortuosity of the optic nerve and flattening of the posterior globe were considered as additional MRI signs. RESULTS: Obese participants had a significantly higher MRI score (p < 0.001) than those in the normal-weight cohort, with significant differences in quantitative measurements of cerebral venous sinus stenosis (p < 0.001), widening of the optic nerve sheath (p < 0.05), and flattening of the pituitary gland (p < 0.05) also always being observed more frequently and in a more pronounced manner in the obese group. Furthermore, our findings correlated significantly with BMI and proportionately with hip and waist circumference. CONCLUSION: Obese individuals show a significantly higher prevalence of cerebral MRI signs related to IIH. This supports the hypothesis that obesity is a risk factor for possible intracranial hypertension and reinforces the suspicion that obesity is involved in the pathomechanism of IIH. KEY POINTS: · Obesity is associated with changes such as those seen in IIH.. · BMI, weight, and body measurements correlate with the expression of MRI signs of IIH.. · To prevent IIH symptoms in obesity, the pathomechanism must be further clarified..

Neck apposition is a key factor for aneurysm occlusion after Woven EndoBridge device embolization.

BACKGROUND: Sealing of the aneurysm neck with a Woven EndoBridge (WEB) device is recommended for disrupting the blood flow inside the aneurysm. This study investigates the relationship between WEB neck apposition and aneurysm occlusion rates. METHODS: Aneurysms treated with a WEB from March 2017 to May 2022 at a single center were included. WEB neck apposition (poor/good) and WEB protrusion (yes/no) were evaluated on post-detachment high resolution cone beam CT images. Angiographic occlusion was assessed with the Bicêtre Occlusion Scale score (BOSS). Univariate and multivariable analysis tested the association between neck apposition and occlusion rates. RESULTS: The study included 159 aneurysms in 141 patients (mean age 55.8±11.2 years; 64.2% women). Good neck apposition and protrusion were noted in 123 (77.4%) and 30 (18.9%) cases, respectively. Inter-rater agreements were good for neck apposition (κ=0.75) and protrusion (κ=0.78). Complete and adequate occlusion was achieved in 104 (65%) and 130 (82%) cases, respectively (median follow-up 18 months). Good neck apposition was a strong independent predictor for both adequate (adjusted OR (aOR)=5.9, 95% CI 2.4 to 14.9; P<0.001) and complete occlusion (aOR=7.1, 95% CI 3.0 to 18.1; P<0.001). Protrusion was more frequent in the adequate occlusion group versus the aneurysm recurrence group without reaching statistical significance (P=0.06), but was associated with more thromboembolic complications (9/30 (30%) vs 12/129 (9%); P<0.01). WEB shape modification was significantly greater in poor apposition cases (P=0.03). CONCLUSIONS: Achieving good neck apposition of the WEB strongly predicts aneurysm occlusion during follow-up. WEB protrusion should be minimized due to the increase in thromboembolic risk with limited impact on aneurysm occlusion.

Magnetic resonance imaging of human variegated squirrel bornavirus 1 (VSBV-1) encephalitis reveals diagnostic pattern indistinguishable from Borna disease virus 1 (BoDV-1) encephalitis but typical for bornaviruses.

Human bornavirus encephalitis is an emerging disease caused by the variegated squirrel bornavirus 1 (VSBV-1) and the Borna disease virus 1 (BoDV-1). While characteristic brain magnetic resonance imaging (MRI) changes have been described for BoDV-1 encephalitis, only scarce diagnostic data in VSBV-1 encephalitis exist. We systematically analysed brain MRI scans from all known VSBV-1 encephalitis patients. Initial and follow-up scans demonstrated characteristic T2 hyperintense lesions in the limbic system and the basal ganglia, followed by the brainstem. No involvement of the cerebellar cortex was seen. Deep white matter affection occurred in a later stage of the disease. Strict symmetry of pathologic changes was seen in 62%. T2 hyperintense areas were often associated with low T1 signal intensity and with mass effect. Sinusitis in three patients on the first MRI and an early involvement of the limbic system suggest an olfactory route of VSBV-1 entry. The viral spread could occur per continuitatem to adjacent anatomical brain regions or along specific neural tracts to more distant brain regions. The number and extent of lesions did not correlate with the length of patients' survivals. The overall pattern closely resembles that described for BoDV-1 encephalitis. The exact bornavirus species can thus not be deduced from imaging results alone, and molecular testing and serology should be performed to confirm the causative bornavirus. As VSBV-1 is likely of tropical origin, and MRI investigations are increasingly available globally, imaging techniques might be helpful to facilitate an early presumptive diagnosis of VSBV-1 encephalitis when molecular and/or serological testing is not available.

MRI-findings in idiopathic intracranial hypertension (Pseudotumor cerebri). / MRT-Befunde bei der idiopathischen intrakraniellen Hypertension (Pseudotumor cerebri).

BACKGROUND: Pseudotumor cerebri, also known as idiopathic intracranial hypertension, is a disorder of increased intracranial pressure of unknown etiology. Main symptom is headache which has a characteristic similar to other headache diseases, therefore the idiopathic intracranial hypertension often remains undetected. The incidence is 1/100 000 with the number of unreported cases being much higher. This article highlights the essential role of MRI in the differential diagnosis. METHODS: A literature search was carried out on idiopathic intracranial hypertension and Pseudotumor cerebri in English and German. Original and Review articles as well as case reports were taken into account. Since the main focus of the article is MRI diagnostics, some images were selected to illustrate the characteristic MRI morphological features. RESULTS AND CONCLUSION: The diagnosis of idiopathic intracranial hypertension is based on an exclusion procedure. Most common syndromes are headache, transient visual obscurations, pulsatile tinnitus and nausea. In the presence of an underlying cause for the increased intracranial pressure one speaks of a secondary intracranial hypertension. The diagnostics include a detailed medical history, neurological and ophthalmic examination, lumbar puncture, and neuroradiological imaging procedures. MRI, in particular, has become increasingly important in recent years, since signs for changes in cerebrospinal fluid pressure are now detectable and well-defined. The therapeutic approaches are symptom-oriented and aim to lower the pressure. With a precise diagnosis and timely start of therapy, idiopathic intracranial hypertension has a good prognosis, especially with regard to the preservation of eyesight. KEY POINTS: · The idiopathic intracranial hypertension is an important differential diagnosis for unspecific headache and impaired vision. · Overweight women in childbearing age are particularly affected. · The most important component in diagnostics is MRI. CITATION FORMAT: · Juhász J, Hensler J, Jansen O. MRT-Befunde bei der idiopathischen intrakraniellen Hypertension (Pseudotumor cerebri). Fortschr Röntgenstr 2021; 193: 1269 - 1276.

A comparison of arterial spin labeling and dynamic susceptibility perfusion imaging for resection control in glioblastoma surgery.

Resection control using magnetic resonance imaging during neurosurgical interventions increases confidence regarding the extent of tumor removal already during the procedure. In addition to morphological imaging, functional information such as perfusion might become an important marker of the presence and extent of residual tumor mass. The aim of this study was to implement arterial spin labeling (ASL) perfusion imaging as a noninvasive alternative to dynamic susceptibility contrast (DSC) perfusion imaging in patients suffering from intra-axial tumors for resection control already during surgery. The study included 15 patients suffering from glioblastoma multiforme in whom perfusion imaging using DSC and ASL was performed before, during, and after surgery. The data obtained from intraoperative scanning were analyzed by two readers blinded to any clinical information, and the presence of residual tumor mass was evaluated using a ranking scale. Similarity of results was analyzed using the intraclass correlation coefficient and Pearson's correlation coefficient. The results show that intraoperative ASL is as reliable as DSC when performing intraoperative perfusion imaging. According to the results of this study, intraoperative imaging using ASL represents an attractive alternative to contrast agent-based perfusion imaging.