Retrolabyrinthine Bone Thickness as a Radiologic Marker for the Hypoplastic Endotype in Menière Disease.

BACKGROUND AND PURPOSE: Menière disease (MD) manifests in 2 major endotypes: one with a hypoplastic, underdeveloped endolymphatic sac (MD-hp) and the other with a normally developed sac that degenerates over time (MD-dg). Determining the specific endotype in patients is important for predicting disease progression, tailoring patient counseling, and optimizing treatment strategies. Endotype diagnosis involves measuring an angular trajectory of the vestibular aqueduct (ATVA), with an ATVA ≥140° indicative of MD-hp and an ATVA ≤120° of MD-dg. However, assessing the ATVA can be challenging. This study aimed to explore the link between ATVA and the thickness of the retrolabyrinthine bone as an alternative diagnostic measure that could provide differentiation between MD endotypes using CT and MR imaging. MATERIALS AND METHODS: Retrospective review of CT temporal bone imaging from 32 adult patients with definite MD (60 ears) and 33 age-matched controls without MD or other inner ear symptoms (61 ears) was performed. The ATVA and retrolabyrinthine bone thickness were measured using uniform methodology on standardized axial CT images. Comparative analyses were performed to determine the correlation between ATVA and retrolabyrinthine bone thickness. Additionally, from a separate cohort of 11 patients (22 ears), CT and MR examinations of the temporal bone were retrospectively reviewed for retrolabyrinthine bone thickness measurements, to verify the correlation across the 2 modalities. RESULTS: The average retrolabyrinthine bone thickness was statistically significantly different between MD endotypes, being a mean of 0.8 (SD, 0.3) mm in patients with MD-hp (ATVA ≥140°) and 2.0 (SD, 0.9) mm in patients with MD-dg (ATVA ≤120°), with a consistent pattern of thin retrolabyrinthine bone in MD-hp and variable thickness in MD-dg. Receiver operating characteristic curve analysis within the MD cohort revealed that a retrolabyrinthine bone thickness ≥1.2 mm effectively rules out MD-hp. Excellent interrater reliability was noted for the retrolabyrinthine measurement, and there was near-perfect correlation between CT and MR measurements. CONCLUSIONS: Retrolabyrinthine bone thickness proved to be a useful and straightforward alternative marker for distinguishing MD endotypes, being particularly useful for excluding MD-hp. Including information on retrolabyrinthine bone thickness should be considered a routine part of reporting in the context of MD imaging.

The controversial entity of brain herniations into arachnoid granulations: A report of three cases with literature review.

Brain herniation into arachnoid granulation (BHAG) is a quite recently described controversial entity in terms of both etiology and clinical significance. It comprises a herniation of brain tissue into a presumed preexisting arachnoid granulation in dural venous sinuses, calvarium, meningeal or diploic veins. Most often described as an incidental finding in patients examined for unrelated pathologies, some BHAGs can possibly be related to headache, epilepsy or conditions with increased intracranial pressure such as idiopathic intracranial hypertension (IIH) or pseudotumor cerebri (PTC). The number of reported cases is low and there are only three more recently published observational studies on this subject with results lacking statistical significance due to relatively few BHAGs analyzed. Therefore, BHAGs still need an increased focus from both the radiologists and clinicians and more published studies and cases are necessary to help in understanding their factual meaning, clinical and treatment implications. In this article we describe three new cases of BHAGs to the literature, with patients presenting with different symptoms.

Listeria Monocytogenes Brain Abscesses in a Patient with Disseminated Non-Small Cellular Lung Cancer: MRI Findings.

Brain abscesses caused by Listeria monocytogenes (LM) are very rare and carry a high mortality risk. We present a patient with disseminated non-small cellular lung cancer (NSCLC) and multiple unusual LM brain abscesses. These abscesses have multiple elongated peripherally enhancing lesions in a characteristic formation that is "worm or tramtrack-like" following the white matter fiber tracts.

Preoperative Embolization of a Solitary Fibrous Tumor Originating from External Auditory Meatus: A Case Report with Literature Review.

Solitary fibrous tumors (SFTs) are mesenchymal, fibroblastic tumors with mostly favorable, but still unpredictable prognosis. Their rarity and occurrence at a variety of locations coupled with variable histological appearance make the diagnosis a challenge. This can be resolved by histological and immunohistochemical analysis on the histologic material eventually coupled with demonstration of NAB2-STAT6 gene fusion by next generation sequencing (NGS) analysis. Tumor removal with clear surgical margins is sufficient for complete cure in most cases. Percutaneous transcatheter embolization in well-vascularized lesions may minimize the risk of bleeding during subsequent removal. In this article we present a rare case of SFT arising from the external auditory canal and treated with preoperative endovascular arterial embolization. A literature review with focus on diagnostics and treatment of this entity in the head and neck region is following.

CT and MR neuroimaging findings in patients with Lyme neuroborreliosis: A national prospective cohort study.

BACKGROUND: We aimed to describe the use and findings of cranial computerized tomography (CT-head), spine and brain magnetic resonance imaging (MRI-spine/MRI-brain) in Lyme neuroborreliose (LNB). METHODS: Patients with LNB were identified using a nationwide, population-based prospective cohort of all adults treated for neuroinfections at departments of infectious diseases in Denmark from 2015 to 2019. Multivariate logistic regression analyses assessed associations between clinical characteristics and MRI-findings consistent with LNB. RESULTS: We included 368 patients (272 definite LNB and 96 probable LNB), 280 scans were performed in 198 patients. Neuroimaging was associated with older age (59 vs. 57, p = 0.03), suspicion of other diseases (77% vs. 37%, p < 0.0001), no history of tick bites (58% vs. 43%, p = 0.01), physical/cognitive deficits prior to admission (15% vs 5%, p = 0.006), peripheral palsy (10% vs. 2%, p = 0.0008), encephalitis (8% vs. 1%, p = 0.0007) and cognitive impairment (8% vs. 2%, p = 0.03) compared with those without neuroimaging. Normal or incidental findings were common (93/98 CT-head and 154/182 MRI). 1/98 CT-head, 19/131 MRI-brain and 6/51 MRI-spine had findings consistent with LNB. Symptoms ≥45 days was associated with MRI-findings consistent with LNB (adjusted odds ratio (aOR) 4.2, 95%confidence interval 1.2-14.4, p = 0.02). CONCLUSION: In this Danish cohort including 368 LNB-patients, use of neuroimaging was common and often performed in older comorbid patients without previous tick-bite intended to investigate alternative diagnoses. The results were in general without pathology and neuroimaging cannot exclude LNB or replace lumbar puncture. MRI is of value when investigating alternative neurological diseases and may support suspicion of LNB in cases with meningeal/leptomeningeal/neural enhancement.

Imaging of Nontraumatic Temporal Bone Emergencies.

This section aims to cover the non-traumatic pathologies affecting the temporal bone including external auditory canal, middle ear and inner ear which usually need emergent clinical attention. Many of the conditions in this section are secondary to infections in different clinical settings with resultant complications which may leave temporary or permanent sequelae if not suspected, timely diagnosed or treated.

R-CHOP(-like) treatment of diffuse large B-cell lymphoma significantly reduces CT-assessed vertebral bone density: a single center study of 111 patients.

Treatment of diffuse large B-cell lymphoma (DLBCL) with R-CHOP(-like) regimens include large cumulative doses of prednisolone. In this retrospective study, we evaluated changes in vertebral bone density (VD) in DLBCL patients by measuring CT-ascertained Hounsfield units (HU) at the L3 level. In total, 111 patients diagnosed from 2007 to 2012 and response assessed following first line treatment were included. Post-treatment VD was significantly reduced to 86% of pretreatment VD on average (p < .001). Neither female sex nor high age (>70 years) were significantly associated with greater post-treatment VD reduction. Two years after completing R-CHOP treatment, VD remained significantly lower than baseline VD (p < .001). Vertebral compression fractures visualized by CT were found in 16/111 patients (14%) during follow-up. In conclusion, bone mineral density is significantly reduced following R-CHOP(-like) treatment and vertebral compression fractures are common. Glucocorticoid-induced osteoporosis may therefore have impact on survivorship for the large fraction of DLBCL patients with durable remissions.