MRI Investigation of the Association of Left Atrial and Left Atrial Appendage Hemodynamics with Silent Brain Infarction.

BACKGROUND: Left atrial (LA) myopathy is thought to be associated with silent brain infarctions (SBI) through changes in blood flow hemodynamics leading to thrombogenesis. 4D-flow MRI enables in-vivo hemodynamic quantification in the left atrium (LA) and LA appendage (LAA). PURPOSE: To determine whether LA and LAA hemodynamic and volumetric parameters are associated with SBI. STUDY TYPE: Prospective observational study. POPULATION: A single-site cohort of 125 Participants of the multiethnic study of atherosclerosis (MESA), mean age: 72.3 ± 7.2 years, 56 men. FIELD STRENGTH/SEQUENCE: 1.5T. Cardiac MRI: Cine balanced steady state free precession (bSSFP) and 4D-flow sequences. Brain MRI: T1- and T2-weighted SE and FLAIR. ASSESSMENT: Presence of SBI was determined from brain MRI by neuroradiologists according to routine diagnostic criteria in all participants without a history of stroke based on the MESA database. Minimum and maximum LA volumes and ejection fraction were calculated from bSSFP data. Blood stasis (% of voxels <10 cm/sec) and peak velocity (cm/sec) in the LA and LAA were assessed by a radiologist using an established 4D-flow workflow. STATISTICAL TESTS: Student's t test, Mann-Whitney U test, one-way ANOVA, chi-square test. Multivariable stepwise logistic regression with automatic forward and backward selection. Significance level P < 0.05. RESULTS: 26 (20.8%) had at least one SBI. After Bonferroni correction, participants with SBI were significantly older and had significantly lower peak velocities in the LAA. In multivariable analyses, age (per 10-years) (odds ratio (OR) = 1.99 (95% confidence interval (CI): 1.30-3.04)) and LAA peak velocity (per cm/sec) (OR = 0.87 (95% CI: 0.81-0.93)) were significantly associated with SBI. CONCLUSION: Older age and lower LAA peak velocity were associated with SBI in multivariable analyses whereas volumetric-based measures from cardiac MRI or cardiovascular risk factors were not. Cardiac 4D-flow MRI showed potential to serve as a novel imaging marker for SBI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Prevalence of Retinal Venous Malformations in Patients With Cerebral Cavernous or Arteriovenous Malformations.

BACKGROUND: Cerebral vascular malformations (CVMs) may result in hemorrhage, seizure, neurologic dysfunction, and death. CVMs include capillary telangiectasias, venous malformations, cavernous malformations, and arteriovenous malformations. Cavernous and arteriovenous malformations carry the highest risk of complications. Retinal venous malformations (RVMs) have been proposed as an associated finding. Our objective was to determine the prevalence of RVMs in patients with high-risk CVMs. METHODS: We retrospectively reviewed patients diagnosed with cerebral cavernous or arteriovenous malformations (high-risk CVMs) who were evaluated by the ophthalmology service at Northwestern University between 2017 and 2020. Patients were stratified into 3 cohorts based on level of certainty: dilated funduscopic examination (DFE), DFE with any form of ocular imaging, and DFE with complete imaging of the macula. We recorded ophthalmic examination abnormalities, ocular imaging findings, and major CVM complications. RESULTS: We evaluated 156 patients with high-risk CVMs who had undergone DFE. Ocular imaging of any type was performed in 56 patients, of whom 46 had complete imaging of the macula. Zero RVMs were identified in any cohort (95% confidence interval: 0%-1.9% for the entire cohort, 0%-5.4% for any ocular imaging cohort, and 0%-6.5% for the complete macular imaging cohort). Cerebral hemorrhage or seizure occurred in 15%-33% of patients. Associated visual field defects or cranial nerve palsies were found in 14%-20% of patients. CONCLUSIONS: Zero RVMs were identified in patients with high-risk CVMs. However, neuro-ophthalmic findings were common. Therefore, we recommend neuroimaging for patients with RVMs and neuro-ophthalmic signs or symptoms. In asymptomatic patients with RVMs, a potential algorithm for neuroimaging is proposed.

Multimodal Presurgical Evaluation of Medically Refractory Focal Epilepsy in Adults: An Update for Radiologists.

Surgery is a potentially curative treatment option for patients with medically refractory focal epilepsy. Advanced neuroimaging modalities often improve surgical outcomes by contributing key information during the highly individualized surgical planning process and intraoperative localization. Hence, neuroradiologists play an integral role in the multidisciplinary management team. In this review, we initially present the conceptual background and practical framework of the presurgical evaluation process, including a description of the surgical treatment approaches used for medically refractory focal epilepsy in adults. This background is followed by an overview of the advanced modalities commonly used during the presurgical workup at level IV epilepsy centers, including diffusion imaging techniques, blood oxygenation level-dependent functional MRI (fMRI), PET, SPECT, and subtraction ictal SPECT, and by introductions to 7-T MRI and electrophysiologic techniques including electroencephalography and magnetoencephalography. We also provide illustrative case examples of multimodal neuroimaging including PET/MRI, PET/MRI-diffusion-tensor imaging (DTI), subtraction ictal SPECT, and image-guided stereotactic planning with fMRI-DTI.

Calcified lymph nodes in the setting of head and neck squamous cell carcinoma: A predictor of HPV positivity?

PURPOSE: Human papillomavirus (HPV) is an important cause of head and neck squamous cell carcinoma (HNSCC) and accounts for a large majority of new cases. The purpose of this study is to determine whether there is an association between nodal calcification and HPV positivity in the setting of metastatic HNSCC. METHODS: Consecutive patients with HNSCC who underwent CT were retrospectively identified. Patients were then divided into two groups: those with HPV-positive HNSCC and those with HPV-negative HNSCC. Demographic, clinical, and CT data were compared between the two groups to determine factors associated with HPV-positive HNSCC. RESULTS: A total of 179 patients with HNSCC were included in the final analyses, 104 (58%) of whom had HPV-positive tumors. Univariate analyses demonstrated that those with HPV-positive HNSCC were more likely to have calcified lymph nodes (p = 0.044). Analyses also confirmed previously known associations with male gender (p = 0.001), primary oropharyngeal tumors (p < 0.001), and cystic lymph nodes (<0.001). The HPV-positive HNSCC group was also less likely to have necrotic lymph nodes (p < 0.001). CONCLUSION: In addition to known clinical and imaging factors associated with HPV-positive metastatic HNSCC, such as male gender, oropharyngeal primary location, and cystic lymph nodes, the presence of calcifications within cervical lymph nodes, although infrequent, provides an additional useful feature to predict HPV positivity in HNSCC. Additionally, if calcified lymph nodes are present, then a primary oropharyngeal tumor site should be considered.

Nevus of Ota with midface tumors and a vanishing orbital mass.

Nevus of Ota, also known as oculodermal melanocytosis, is a benign melanocytic lesion that develops along the distribution of the V1 and V2 branches of the trigeminal nerve. Prior reports have described the typical imaging and clinical features of nevus of Ota. We present a rare case of a 31 year-old female with midface tumors and presumed hemorrhage into an orbital lesion in the setting of nevus of Ota resulting in acute loss of vision.

Posterior reversible encephalopathy syndrome and venous thrombosis.

Posterior reversible encephalopathy syndrome (PRES) and venous thrombosis are frequently encountered first in the emergency setting and share some common characteristics. The clinical presentation in both entities is vague, and the brain parenchymal findings of PRES syndrome may resemble those of venous thrombosis in some ways. Both entities often occur in a bilateral posterior distribution and may be associated with reversible parenchymal findings if the inciting factor is treated. These diagnoses should be at the forefront of the differential diagnosis when confronted with otherwise unexplained brain edema, among other findings described in this article.

Adrenal lesions with heterogeneous suppression on chemical shift imaging: clinical implications.

PURPOSE: To investigate the frequency and significance of adrenal lesions that demonstrate heterogeneous suppression on chemical shift magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective search of adrenal lesions identified on MR from November 1997-July 2001 was performed. The adrenal lesions were classified as having suppression typical for an adenoma, nonsuppression, or atypical heterogeneous suppression. Lesions with heterogeneous suppression were further reviewed. Follow-up for the heterogeneous lesions consisted of imaging studies or pathology from surgical excision. RESULTS: Adrenal lesions were identified in 242 patients. Heterogeneously suppressing lesions were seen in 34 (14%) patients. Several different patterns of heterogeneous suppression were identified. Imaging or pathologic follow-up was available for 18 of the heterogeneously suppressing lesions (one patient had both). Fifteen patients with follow-up imaging showed stability of the lesion over a significant interval, suggesting a benign lesion. Pathology was available for four patients revealing two patients with adenomas and two patients with nodular hyperplasia. Thus, all 18 patients with heterogeneous suppression had a benign lesion. CONCLUSION: Adrenal lesions that have a heterogeneous pattern of suppression on out-of-phase chemical shift MR images are a common finding. Our small series suggest that these lesions are probably benign.