Unilateral Nonvisualization of a Transverse Dural Sinus on Phase-Contrast MRV: Frequency and Differentiation from Sinus Thrombosis on Noncontrast MRI

Identification and quantitative evaluation of symptomatic cerebral venous thrombosis using 3D variable flip angle turbo spin echo

PURPOSE

To explore the feasibility of MR 3D T1w Sampling Perfection with Application optimized Contrasts by using different flip angle Evolutions (SPACE) sequence imaging in symptomatic CVT diagnose, extracting the imaging features with quantitative analysis.

METHODS

Fifty-nine patients with suspected CVT with neurological symptoms were retrospectively included in this study. Of them, 35 patients were enrolled in the comparation of diagnostic accuracy between the contrast-enhanced magnetic resonance venograms (CE-MRV) and 3D T1w SPACE imaging. Forty-five patients with 101 involved segments were identified for the quantitative analysis. All MR images were acquired on a 3.0 T MR scanner. The reference standard used in this study was a comprehensive combination of the imaging techniques and clinical information. CVT patients were grouped as acute (≤48 h), subacute (>48 h and ≤30d), and chronic (>30d) clinical phase. CVT segments were grouped based on pre-contrast T1WI, as type A: hypo intense signal; B: heterogeneously hyper intense signal; C: iso intense signal. The feasibility of 3D T1w SPACE imaging for diagnosing CVT was explored. Diagnostic accuracy of T1w SPACE imaging was analyzed and compared with the CE-MRV. The signal intensity of pre-contrast images (SpreCE), signal intensity of post-contrast images (SpostCE), and contrast enhancement (CE) rate, CE rate relative to that of pituitary gland (PG), white matter (WM), gray matter (GM), and normal vein vessel wall (nVVW) were compared based on both patients and segments. The CE rate grade of CVT segments of different imaging types was compared.

RESULTS

The MR 3D T1w SPACE imaging achieved a higher sensitivity and specificity (100%/94.1% and 100%/100% based on patients/segments separately) than that of the CE-MRV (73.9%/56.9% and 83.3%/98.9% based on patients/segments separately). No statistical correlation was found between the imaging types of CVT segments and onset time of clinical symptoms (χ2 = 6.649, P = 0.171). Quantitative analysis showed that the CE rate relative to PG and that to WM were higher in the chronic CVT patients than that in the other two groups (H = 10.330 and P = 0.006, H = 9.898 and P = 0.007, separately). CE rate relative to GM in the chronic group was higher than that in the subacute group (H = 7.143 and P = 0.028). All of the quantitative parameters were statistically different across CVT segments of three imaging types (all P≤0.001).

CONCLUSION

MR 3D T1w SPACE imaging has the advantage to accurately diagnose CVT of different clinical stages, and identify the involved thrombus segments.

Analysis of perceptual errors in skull-base pathology

PURPOSE

Medical errors result in significant mortality and morbidity. The purpose of this study is to analyze skull-base errors at a single tertiary institution, identify common anatomic sites of errors, and offer strategies to reduce errors in this region.

METHODS

A Neuroradiology Quality Assurance Database of radiologic errors was searched for attending physician computer tomography and magnetic resonance imaging errors in skull-base pathology from 2014 to 2020. Data were limited to CT and MRI reports. Errors were separated into four subcategories (tumor, trauma, vascular, and congenital) and further divided by relevant anatomic site.

RESULTS

A total of 90 skull-based errors were identified. Most errors were perceptual (87%), with common study types including MRI Brain (39%) and CT Head (24%). Most common errors were tumors (55%), followed by trauma (24%), vascular (10%), and congenital (7%). Six anatomic sites were identified and encompassed over half of errors (58%): sella, occipital bone, cerebellopontine angle/internal auditory canal (CPA/IAC), foramen magnum and clivus, cavernous sinus, and dural venous sinus.

SUMMARY

Most of the skull-base errors were perceptual. Placing a strong emphasis on both the pathology and closely examining its critical anatomic site (sella, occipital bone, CPA/IAC, foramen magnum and clivus, cavernous sinus, and dural venous sinus) could potentially reduce up to 60% of errors in these regions.

Clinical Reasoning: Woman With Acute Bilateral Ophthalmoplegia

This is a case of a 75-year-old woman who presented with severe headache, left eye ptosis, and binocular diplopia and was found to have multiple cranial neuropathies on examination. This case reviews the localization and workup of multiple cranial neuropathies and emphasizes the importance of not prematurely narrowing the differential diagnosis.

Imaging Approach to Venous Sinus Thrombosis

Cerebral venous thrombosis (CVT) is a rare cerebrovascular disease caused by an occlusion of the cerebral venous sinuses or cortical veins. It has a favorable prognosis if diagnosed and treated early. CVT can be difficult to diagnose on clinical grounds, and imaging plays a key role. We discuss clinical features and provide an overview of current neuroimaging methods and findings in CTV.

Comparison of susceptibility-weighted angiography (SWAN) and T2 gradient-echo sequences for the detection of acute cerebral venous thrombosis

OBJECTIVES

To assess the diagnostic accuracy and lesion conspicuity of susceptibility-weighted angiography (SWAN) and T2* for the clot detection in acute cerebral venous thrombosis (CVT) by comparison with contrast-enhanced MR venography.

METHODS

Venous thrombi detection and conspicuity were assessed by two readers for 18 venous segments on both T2*, SWAN source images, 2D SWAN reformats matching with T2*, and 3D SWAN images (SWAN-MinIP). Images obtained with the three reading techniques were systematically scored and compared to CE MRV findings, in a blinded fashion, per patient and per segment, and compared to each other.

RESULTS

In 30 patients, 137 thrombosed venous segments were evaluated. The sensitivity of T2*, SWAN source images, 2D SWAN, and SWAN MinIP were, respectively, of 89.3%/82.1%, 82.1%, and 82.1% for dural sinus thrombosis and of 100%/100%/100%/96.6% for cortical venous thrombosis. There were significant differences in thrombus detection between T2* and SWAN: T2* versus SWAN source images and 2D SWAN (p = 0.04) and versus SWAN MinIP (p = 0.03). There were no significant differences between the three modalities of SWAN images. T2* was more sensitive than all SWAN images for both sigmoid sinus thrombosis and intracranial internal jugular vein thrombosis (p = 0.04). Inter-observer agreement was slightly superior with T2* (p < 0.05).

CONCLUSION

In this small cohort, SWAN sequence at 3T did not yield additional value for thrombus detection in acute CVT compared to T2*. This study highlights SWAN's greatest weakness both for diagnostic accuracy and lesion conspicuity compared to T2* for acute venous clot detection near the skull base.

Non-contrast magnetic resonance venography with Inhance 3D Velocity: diagnostic performance for intracranial venous thrombosis

PURPOSE

The aim of this study was to evaluate the diagnostic performance of Inhance 3D Velocity (I3DV) in intracranial venous thrombosis and investigate the possible impact of venous sinus hypoplasia/aplasia on false thrombosis diagnosis made with I3DV.

METHODS

This study included 540 patients. Contrast-enhanced magnetic resonance venography combined with conventional sequences was considered the gold standard test (GST), while I3DV was considered as diagnostic test. We accessed the diagnostic success of I3DV for intracranial venous thrombosis detection, thrombosed vessel identification, and total/partial thrombus distinction. The possible relationship between false-positive thrombus diagnosed by I3DV and venous sinus hypoplasia or aplasia diagnosed by GST was investigated.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of I3DV in the detection of intracranial venous thrombosis were 95.7%, 92.1%, 64.1%, 99.3%, and 92.6%, respectively. A significant association was observed between I3DV and GST in terms of thrombosis detection and total/partial thrombus distinction (p < 0.001). A significant relationship was observed between false-positive thrombosis diagnosis in I3DV and hypoplasia in the left transverse sinus (p < 0.001).

CONCLUSION

Intracranial venous thrombosis may be diagnosed faster and more accurately than traditional phase contrast magnetic resonance angiography in I3DV. This technique can be used in situations where contrast medium application is contraindicated. As in other non-contrast magnetic resonance venography techniques, left transverse sinus hypoplasia can be diagnosed as a thrombosed vessel in I3DV.

Imaging Mimics of Brain Tumors

Nonneoplastic entities may closely resemble the imaging findings of primary or metastatic intracranial neoplasia, posing diagnostic challenges for the referring provider and radiologist. Prospective identification of brain tumor mimics is an opportunity for the radiologist to add value to patient care by decreasing time to diagnosis and avoiding unnecessary surgical procedures and medical therapies, but requires familiarity with mimic entities and a high degree of suspicion on the part of the interpreting radiologist. This article provides a framework for the radiologist to identify "brain tumor mimics," highlighting imaging and laboratory pearls and pitfalls, and illustrating unique and frequently encountered lesions.