High-Resolution T2-Weighted Imaging for Surveillance in Postoperative Vestibular Schwannoma: Equivalence with Contrast-Enhanced T1WI for Measurement and Surveillance of Residual Tumor.

BACKGROUND AND PURPOSE: Patients with surgically resected vestibular schwannoma will undergo multiple postoperative surveillance examinations, typically including postcontrast sequences. The purpose of this study was to compare high-resolution T2WI with gadolinium T1WI in the postoperative assessment of vestibular schwannoma. MATERIALS AND METHODS: This was a retrospective study of patients with a history of resected vestibular schwannoma at a single institution. High-resolution T2WI and gadolinium T1WI were independently evaluated for residual disease. In addition, 3D and 2D measurements were performed in the group of patients with residual tumor. Statistical analysis was performed to evaluate the agreement between sequences on the binary assessment (presence/absence of tumor on initial postoperative examination) and to evaluate the equivalence of measurements for the 2 sequences on 3D and 2D quantitative assessment in individuals with residual disease. RESULTS: One hundred forty-eight patients with retrosigmoid-approach resection of vestibular schwannomas were included in the final analysis. There was moderate-to-substantial agreement between the 2 sequences for the evaluation of the presence versus absence of tumor (Cohen κ coefficient = 0.78; 95% CI, 0.68-0.88). The 2 sequences were significantly equivalent for 2D and 3D quantitative assessments (short-axis P value = .021; long-axis P value = .015; 3D P value = .039). CONCLUSIONS: In this retrospective study, we demonstrate moderate-to-substantial agreement in the categoric assessment for the presence versus absence of tumor and equivalence between the 2 sequences for both 2D and volumetric tumor measurements as performed in the subset of patients with measurable residual. On the basis of these results, high-resolution T2WI alone may be sufficient for early postoperative imaging surveillance in this patient population.

Intraosseous Venous Malformations of the Head and Neck.

Intraosseous venous malformations represent a subtype of venous vascular malformations that arise primarily in bone. In the head and neck, intraosseous venous malformations are most frequently found in the skull, skull base, and facial skeleton, with location at the geniculate ganglion of the facial nerve perhaps the most widely recognized. These non-neoplastic lesions are characterized by dilated venous channels with characteristic internal bony spicules on CT but may present with a more complex appearance on MR imaging and may share features with more aggressive lesions. Further confounding the imaging-based diagnosis of intraosseous venous malformation is the frequent misrepresentation of these lesions as hemangiomas in the radiology and clinical literature, as well as in daily practice. Because most intraosseous venous malformations can be left alone, their correct diagnosis may spare a patient unnecessary concern and intervention.

Brain Imaging of Patients with COVID-19: Findings at an Academic Institution during the Height of the Outbreak in New York City.

BACKGROUND AND PURPOSE: A large spectrum of neurologic disease has been reported in patients with coronavirus disease 2019 (COVID-19) infection. Our aim was to investigate the yield of neuroimaging in patients with COVID-19 undergoing CT or MR imaging of the brain and to describe associated imaging findings. MATERIALS AND METHODS: We performed a retrospective cohort study involving 2054 patients with laboratory-confirmed COVID-19 presenting to 2 hospitals in New York City between March 4 and May 9, 2020, of whom 278 (14%) underwent either CT or MR imaging of the brain. All images initially received a formal interpretation from a neuroradiologist within the institution and were subsequently reviewed by 2 neuroradiologists in consensus, with disputes resolved by a third neuroradiologist. RESULTS: The median age of these patients was 64 years (interquartile range, 50-75 years), and 43% were women. Among imaged patients, 58 (21%) demonstrated acute or subacute neuroimaging findings, the most common including cerebral infarctions (11%), parenchymal hematomas (3.6%), and posterior reversible encephalopathy syndrome (1.1%). Among the 51 patients with MR imaging examinations, 26 (51%) demonstrated acute or subacute findings; notable findings included 6 cases of cranial nerve abnormalities (including 4 patients with olfactory bulb abnormalities) and 3 patients with a microhemorrhage pattern compatible with critical illness-associated microbleeds. CONCLUSIONS: Our experience confirms the wide range of neurologic imaging findings in patients with COVID-19 and suggests the need for further studies to optimize management for these patients.

Olfactory Bulb Signal Abnormality in Patients with COVID-19 Who Present with Neurologic Symptoms.

BACKGROUND AND PURPOSE: Unique among the acute neurologic manifestations of Severe Acute Respiratory Syndrome coronavirus 2, the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic, is chemosensory dysfunction (anosmia or dysgeusia), which can be seen in patients who are otherwise oligosymptomatic or even asymptomatic. The purpose of this study was to determine if there is imaging evidence of olfactory apparatus pathology in patients with COVID-19 and neurologic symptoms. MATERIALS AND METHODS: A retrospective case-control study compared the olfactory bulb and olfactory tract signal intensity on thin-section T2WI and postcontrast 3D T2 FLAIR images in patients with COVID-19 and neurologic symptoms, and age-matched controls imaged for olfactory dysfunction. RESULTS: There was a significant difference in normalized olfactory bulb T2 FLAIR signal intensity between the patients with COVID-19 and the controls with anosmia (P = .003). Four of 12 patients with COVID-19 demonstrated intraneural T2 signal hyperintensity on postcontrast 3D T2 FLAIR compared with none of the 12 patients among the controls with anosmia (P = .028). CONCLUSIONS: Olfactory bulb 3D T2 FLAIR signal intensity was greater in the patients with COVID-19 and neurologic symptoms compared with an age-matched control group with olfactory dysfunction, and this was qualitatively apparent in 4 of 12 patients with COVID-19. Analysis of these preliminary finding suggests that olfactory apparatus vulnerability to COVID-19 might be supported on conventional neuroimaging and may serve as a noninvasive biomarker of infection.

MR Myelography for the Detection of CSF-Venous Fistulas.

CSF-venous fistula is an important treatable cause of spontaneous intracranial hypotension that is often difficult to detect using traditional imaging techniques. Herein, we describe the technical aspects and diagnostic performance of MR myelography when used for identifying CSF-venous fistulas. We report 3 cases in which the CSF-venous fistula was occult on CT myelography but readily detected using MR myelography.

COVID-19-Associated Miller Fisher Syndrome: MRI Findings.

Miller Fisher syndrome, also known as Miller Fisher variant of Guillain-Barré syndrome, is an acute peripheral neuropathy that can develop after exposure to various viral, bacterial, and fungal pathogens. It is characterized by a triad of ophthalmoplegia, ataxia, and areflexia. Miller Fisher syndrome has recently been described in the clinical setting of the novel coronavirus disease 2019 (COVID-19) without accompanying imaging. In this case, we report the first presumptive case of COVID-19-associated Miller Fisher syndrome with MR imaging findings.

Differentiation between Tuberculous and Pyogenic Spondylodiscitis: The Role of the Anterior Meningovertebral Ligament in Patients with Anterior Epidural Abscess.

BACKGROUND AND PURPOSE: Differentiation between tuberculous and pyogenic spondylodiscitis is a diagnostic challenge because imaging often does not reliably distinguish the 2 entities and percutaneous biopsies are often culture-negative. The purpose of this study was to determine whether violation of the anterior meningovertebral ligament in the setting of anterior epidural abscess discriminates between these entities. MATERIALS AND METHODS: This was a retrospective cohort study of all patients with acid-fast bacillus testing and anterior epidural abscess diagnosed on spinal MR imaging between May 2014 and September 2019, with a final diagnosis of tuberculous or pyogenic spondylodiscitis. Six cases of tuberculous spondylodiscitis (mean age, 45.5 years; 80% male) and 35 cases of pyogenic spondylodiscitis were evaluated (mean age, 56.6 years; 49% male). Demographic characteristics were recorded. Cases were assessed for anterior meningovertebral ligament destruction on MR imaging, as demonstrated by the shape of the epidural collection. Segmental location of the infection was also assessed. Independent 2-sample t tests and χ2 tests of independence were performed to evaluate the significance of the difference between the groups. RESULTS: Five of 6 (83.3%) cases of tuberculous epidural abscess had an intact anterior meningovertebral ligament, and 0/35 cases of pyogenic epidural abscess demonstrated an intact ligament (P < .001). The presence of an intact anterior meningovertebral ligament had 83.3% sensitivity and 100% specificity for tuberculous spondylodiscitis, a 100% positive predictive value, and a 97.2% negative predictive value. CONCLUSIONS: The presence of an intact anterior meningovertebral ligament has high sensitivity and specificity for tuberculous spondylodiscitis-associated epidural abscess, though these results should be validated in a larger sample.

Bidirectional Changes in Anisotropy Are Associated with Outcomes in Mild Traumatic Brain Injury.

BACKGROUND AND PURPOSE: Mild traumatic brain injury results in a heterogeneous constellation of deficits and symptoms that persist in a subset of patients. This prospective longitudinal study identifies early diffusion tensor imaging biomarkers of mild traumatic brain injury that significantly relate to outcomes at 1 year following injury. MATERIALS AND METHODS: DTI was performed on 39 subjects with mild traumatic brain injury within 16 days of injury and 40 controls; 26 subjects with mild traumatic brain injury returned for follow-up at 1 year. We identified subject-specific regions of abnormally high and low fractional anisotropy and calculated mean fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity across all white matter voxels brain-wide and each of several white matter regions. Assessment of cognitive performance and symptom burden was performed at 1 year. RESULTS: Significant associations of brain-wide DTI measures and outcomes included the following: mean radial diffusivity and mean diffusivity with memory; and mean fractional anisotropy, radial diffusivity, and mean diffusivity with health-related quality of life. Significant differences in outcomes were found between subjects with and without abnormally high fractional anisotropy for the following white matter regions and outcome measures: left frontal lobe and left temporal lobe with attention at 1 year, left and right cerebelli with somatic postconcussion symptoms at 1 year, and right thalamus with emotional postconcussion symptoms at 1 year. CONCLUSIONS: Individualized assessment of DTI abnormalities significantly relates to long-term outcomes in mild traumatic brain injury. Abnormally high fractional anisotropy is significantly associated with better outcomes and might represent an imaging correlate of postinjury compensatory processes.

Sexual behaviour among London GUM clinic attenders: implications for HIV education.

The aim of this study was to describe the sexual behaviour of a sample of genitourinary medicine (GUM) clinic attenders, 5 years after the launch of the UK government HIV media campaigns. A gender-specific and anonymous cross-sectional self-completion questionnaire was modified from the National Survey of Sexual Attitudes and Lifestyle and completed by 250 men and 250 women. The majority of the respondents were in their twenties, lived in London and were employed or students. Sixty-eight per cent of the men reported that one or more of their last 3 partners was not a regular partner. For those men whose last sexual encounter was with a new partner, 27% of heterosexuals and 33% of homosexuals reported using a condom. Fifty-one per cent of women reported one or more non-regular partners among their last 3 partners. For those women whose last sexual encounter was with a new partner, 43% of heterosexuals and 75% of bisexuals used a condom. Seventy-eight per cent of men and 75% of women had had a previous sexually transmitted disease (STD). These findings highlight the persistence of practices associated with the risk of contracting or transmitting HIV infection and which needs to be addressed in future educational campaigns. The GUM clinic population is an important population to monitor over time, either by longitudinal or serial cross-sectional studies. The results of this study provide a baseline against which to gauge the effects of future educational interventions.