Radiology-pathology correlation: Giant tumefactive perivascular spaces.

Dilated perivascular spaces (PVSs) are common and easily recognized on imaging. However, rarer giant tumefactive PVSs (GTPVSs) can have unusual multilocular cystic configurations, and are often confused for other pathologic entities, including neoplasms, cystic infarctions, and neuroepithelial cysts. Because GTPVSs are scarcely encountered and even more infrequently operated upon, many radiologists are unaware of the imaging and pathologic features of these lesions. Here, a case of a resected GTPVS is presented, highlighting both its radiologic and histologic characteristics, and discussing how such lesions can be differentiated from their closest mimickers on imaging.

Signal intensity of perirolandic cortex identifies the central sulcus on double inversion recovery MRI.

BACKGROUND: Identification of the central sulcus can require inspection of subtle differences or require certain pulse sequences. This study identifies the central sulcus by signal intensity on double inversion recovery (DIR) images in multiple anatomic locations and imaging planes. METHODS: Forty-nine patients (98 hemispheres) were retrospectively reviewed by three neuroradiologists and one radiology resident. The central sulcus was compared to the surrounding sulci for differences in signal intensity at axial hand knob, axial operculum, and lateral convexity sagittal images (294 locations) on DIR images. The use of the "disappearing central sulcus sign" where the window level is increased at constant width and black/white inversion were also assessed. RESULTS: In 49 patients (22 females, 27 males; median age 36 years), the central sulcus cortex signal intensity was lower than adjacent sulci with a frequency of 90/98 (91.8%) at the axial hand knob level, 68/98 (69.4%) at the axial operculum level, and 76/98 (77.5%) at the sagittal level. With black and white inversion, the frequencies were of 96/98 (98%), 92/98 (94%), and 87/98 (89%). The central sulcus was the first to disappear at all three levels with high degrees of inter-reader agreement (86-99%). Traditional anatomic landmarks were absent or conflicting in seven hemispheres (5 patients). The central sulcus was identified by DIR signal intensity in all seven hemispheres. CONCLUSIONS: The central sulcus can be identified by differences in signal intensity of the perirolandic cortex on DIR. Use of black/white inversion and the disappearing central sulcus sign may further facilitate identification.

Agreement between neuroimages and reports for natural language processing-based detection of silent brain infarcts and white matter disease.

BACKGROUND: There are numerous barriers to identifying patients with silent brain infarcts (SBIs) and white matter disease (WMD) in routine clinical care. A natural language processing (NLP) algorithm may identify patients from neuroimaging reports, but it is unclear if these reports contain reliable information on these findings. METHODS: Four radiology residents reviewed 1000 neuroimaging reports (RI) of patients age > 50 years without clinical histories of stroke, TIA, or dementia for the presence, acuity, and location of SBIs, and the presence and severity of WMD. Four neuroradiologists directly reviewed a subsample of 182 images (DR). An NLP algorithm was developed to identify findings in reports. We assessed interrater reliability for DR and RI, and agreement between these two and with NLP. RESULTS: For DR, interrater reliability was moderate for the presence of SBIs (k = 0.58, 95 % CI 0.46-0.69) and WMD (k = 0.49, 95 % CI 0.35-0.63), and moderate to substantial for characteristics of SBI and WMD. Agreement between DR and RI was substantial for the presence of SBIs and WMD, and fair to substantial for characteristics of SBIs and WMD. Agreement between NLP and DR was substantial for the presence of SBIs (k = 0.64, 95 % CI 0.53-0.76) and moderate (k = 0.52, 95 % CI 0.39-0.65) for the presence of WMD. CONCLUSIONS: Neuroimaging reports in routine care capture the presence of SBIs and WMD. An NLP can identify these findings (comparable to direct imaging review) and can likely be used for cohort identification.

Clinical 7-T MRI for neuroradiology: strengths, weaknesses, and ongoing challenges.

Since the relatively recent regulatory approval for clinical use in both Europe and North America, 7-Tesla (T) MRI has been adopted for clinical practice at our institution. Based on this experience, this article reviews the unique features of 7-T MRI neuroimaging and addresses the challenges of establishing a 7-T MRI clinical practice. The underlying fundamental physics principals of high-field strength MRI are briefly reviewed. Scanner installation, safety considerations, and artifact mitigation techniques are discussed. Seven-tesla MRI case examples of neurologic diseases including epilepsy, vascular abnormalities, and tumor imaging are presented to illustrate specific applications of 7-T MRI. The advantages of 7-T MRI in conjunction with advanced neuroimaging techniques such as functional MRI are presented. Seven-tesla MRI produces more detailed information and, in some cases, results in specific diagnoses where previous 3-T studies were insufficient. Still, persistent technical issues for 7-T scanning present ongoing challenges for radiologists.

Thalamic venous infarction from trauma mimicking a glioma.

Traumatic brain injuries (TBI) are commonly associated with motor vehicle accidents. Neuroimaging plays a crucial role in the initial management of TBIs. We present a case of a TBI related to a motor vehicle accident in an 18-year-old woman. Initial brain imaging revealed significant traumatic injuries and an enhancing mass, without restricted diffusion, in the thalamus favored to be a thalamic glioma. Subsequent imaging revealed resolution of enhancement of the thalamic lesion and reduction in size. On review of the original imaging, it was determined that the thalamic lesion was related to a tear and partial thrombosis of a large thalamic vein resulting in infarction and hemorrhage.

Diffuse large B cell lymphoma involving Meckel's cave masquerading as biopsy-negative giant cell arteritis: a case report.

BACKGROUND: Given the absence of consensus diagnostic criteria for giant cell arteritis, clinicians may encounter difficulty with identification of new-onset headache in patients older than age 50 years presenting with visual changes and elevated inflammatory markers, particularly if temporal artery biopsies are performed and negative. CASE PRESENTATION: We present a case of a 57-year-old white man with headache, diplopia, and jaw paresthesia initially diagnosed and managed as steroid-refractory biopsy-negative giant cell arteritis. Further investigation disclosed evidence of soft tissue infiltration into Meckel's (trigeminal) cave bilaterally. Positron emission tomography suggested the presence of a lymphoproliferative disorder. Histology confirmed the diagnosis of diffuse large B cell lymphoma. CONCLUSIONS: Metastatic involvement in Meckel's cave in diffuse large B cell lymphoma is extremely rare and presents a diagnostic challenge. Patients with suspicion of giant cell arteritis should undergo advanced imaging, particularly those with negative biopsy, atypical features, or lack of response to standard therapy, in order to assess for the presence of large-vessel vasculitis or other mimicking pathologies.

CT angiogram findings in carotid-cavernous fistulas: stratification of imaging features to help radiologists avoid misdiagnosis.

BACKGROUND: Carotid-cavernous fistulas (CCFs) are commonly misdiagnosed on computed tomography angiography (CTA). PURPOSE: This study sought to identify the most sensitive and specific imaging features of CCFs on CTA. MATERIAL AND METHODS: A retrospective review identified 18 consecutive patients suspected of having a CCF on CTA and subsequently underwent digital subtraction angiography (DSA). Two blinded reviewers assessed multiple findings on CTA: cavernous sinus asymmetry/enlargement; arterial-phase contrast in the cavernous sinus; proptosis; pre- or post-septal orbital edema; and dilated regional vasculature. Each was graded as positive, possible, and negative; "possible" was counted as positive. A third blinded reviewer served as a tiebreaker. RESULTS: Of 18 patients, nine were true-positive and nine were false-positive. Superior ophthalmic vein early enhancement and dilatation had 100.0% sensitivity (95% confidence interval [CI] 40.0-100.0) and 77.8% specificity (95% CI 44.4-100.0); arterial-phase contrast in the cavernous sinus had 88.9% sensitivity (95% CI 44.4-100.0) and 66.7% specificity (95% CI 18.5-90.1); peri-orbital edema had 88.9% sensitivity (95% CI 35.5-100.0) and 77.8% specificity (95% CI 22.2-100.0). The most specific markers of CCF were superior petrosal sinus and inferior ophthalmic vein dilatation/enhancement (100.0%, 95% CI 88.8-100.0 and 88.9%, 95% CI 44.4-100.0, respectively); the specificity of asymmetric cavernous enlargement was 44.4% (95% CI 11.1-77.7). CONCLUSIONS: Among patients in whom a CCF is suspected on CTA, superior ophthalmic vein dilatation/enhancement and arterial-phase contrast within the cavernous sinus are the most sensitive findings. Asymmetric cavernous sinus enlargement has poor specificity and may result in false-positive diagnoses of CCFs. False positive cases were less likely to have an optimally timed contrast bolus.

Association between carotid artery tortuosity and carotid dissection: a case-control study.

BACKGROUND: Carotid artery dissections have long been associated with compromise of the structural integrity of the arterial wall from heritable connective-tissue disorders, hypertension, and trauma. However, an association between spontaneous internal carotid artery dissection and tortuous or redundant carotid anatomy has not been fully explored. METHODS: Patients with CTA confirmed spontaneous cervical internal carotid artery dissections were compared to a group of age and sex matched controls who also received CTA of the neck. Patients with trauma or aortic dissections were excluded. Five radiologists reviewed the CTA images to evaluate internal carotid artery tortuosity (reported as loops, kinks or coils), retrojugular and retropharyngeal courses of the internal carotid artery, presence of fibromuscular dysplasia and presence of atherosclerotic disease. Baseline data collected included demographic characteristics (sex, age, smoking history) and cardiovascular comorbidities. RESULTS: A total of 83 cervical internal carotid artery dissection and their age and sex matched controls were included in this study. 46% of patients were female in each group and mean age was 49.2±10.6 years. The presence of any carotid tortuosity was 53% (N.=44) and 34% (N.=28) in the per-patient analysis of dissection and control groups, respectively (P=0.02). Loops were reported in 22% (N.=18) of dissection patients and 8% (N.=7) of controls (P=0.03). Retrojugular course of the internal carotid artery were seen in 23% (N.=38) of dissection patients and 9% (N.=15) of controls (P=0.0009) in the per-vessel analysis. CONCLUSIONS: Our study suggests that there is an association between the presence of tortuous carotid artery anatomy and spontaneous carotid artery dissection. This finding emphasizes the importance of the presence of tortuous arteries on CTA imaging to increase the index of suspicion for a potential dissection.

The clinical relevance of cerebral microbleeds in patients with cerebral ischemia and atrial fibrillation.

The clinical significance of cerebral microbleeds (CMB) in patients hospitalized with atrial fibrillation (AF) and cerebral ischemia is unclear. We aimed to determine the prevalence of CMB in this population and determine the future risk of intracerebral hemorrhage (ICH) and cerebral infarction (CI). The medical records and brain imaging of patients hospitalized with cerebral ischemia due to AF between 2008 and 2011 were reviewed. Followup was obtained through medical record review, mailed survey, and acquisition of death certificates. Prevalence was calculated from those patients with a hemosiderin-sensitive MRI sequence. Recurrent CI and ICH were calculated using Kaplan-Meier curves censored at 3 years. Among 426 patients hospitalized with cerebral ischemia due to AF, 134 had an MRI with hemosiderin-sensitive sequences. The prevalence of CMB was 27.6%. At 3 years, 90.6% of CMB-negative patients were overall stroke free (ICH and CI) compared to 78.6% CMB-positive patients (p = 0.0591). Only one patient in the CMB-positive group had an ICH distant to the CMB. There was a nonsignificant trend toward higher recurrent CI, recurrent overall stroke rate, and mortality in patients with 5 or more CMB compared to 0-4 CMB. The rate of prospective CI in patients with prior cerebral ischemia due to AF is higher than the rate of ICH in patients with CMB. Further study is warranted to assess larger numbers of patients to determine appropriate antithrombotic use in this high-risk population.

Emergent, After Hours Magnetic Resonance Imaging of the Spine.

BACKGROUND AND PURPOSE: Requests for after-hours emergent spine MR imaging seem to be increasing. We sought to review the trend in after hours spine MRI utilization at our institution and to determine how these results impacted therapeutic intervention. METHODS: Following Institutional Review Board approval, reports from 179 after hours spinal MRI's performed over the past 13 years were obtained and the relevant electronic medical records were reviewed. RESULTS: Emergent after hours spine MRI utilization increased from 7 per year to 23 over 13 years. Fifty-eight percent (104/179) had significant findings. Twenty-nine percent (52/179) of all patients imaged underwent surgery to treat pathologies identified on MR. Surgery was performed in only 2% (4/179) of these patients within 3 hours and 6% (10/179) within 6 hours of MRI completion. Five percent (8/179) had findings that were treated with radiation therapy and in 78% of these it was performed within 6-12 hours. Of those in whom steroids or antibiotics were initiated, 41% and 50% were treated within 3 hours of MR scanning, respectively. DISCUSSION: Clinical use of emergent after hours spine MRI is steadily increasing at our institution. While MR imaging often discerned significant pathologies, performing these emergent studies rarely resulted in immediate surgical or radiotherapeutic intervention.

Cerebral and cerebellar white matter abnormalities with magnetic resonance imaging in a child with Feingold syndrome.

Feingold syndrome is a rare autosomal dominant condition that is characterized by variable expressivity of microcephaly, limb malformations, esophageal atresia, and a host of other malformations. This syndrome results from mutations in the MYCN proto-oncogene. Few examples of cross-sectional imaging of the brain in these patients are found in the literature. We present a patient who was found to have areas of cerebral and cerebellar white matter hyperintensity with T2 weighted magnetic resonance (MR) imaging. To the best of our knowledge, this finding has not been previously described. While the significance and pathologic basis of this finding are unknown, its recognition is important since it has potential to be confused with imaging findings in other conditions. Moreover, it is likely to be observed in the future due to increased use of MR imaging.

Posterior reversible encephalopathy syndrome during pregnancy: seizures in a previously healthy parturient.

Posterior reversible encephalopathy syndrome refers to a neuroradiologic disorder in which seizure activity (multiple seizures are more common than single events) is commonly the initial presenting symptom. We describe a case of posterior reversible encephalopathy syndrome in a previously healthy parturient who presented to the labor and delivery suite with generalized tonic-clonic seizures. Prompt recognition and treatment of this potentially catastrophic disease may avert injury to the patient and neonate.