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

Abstract

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.

Detection of cerebral cortical vein thrombosis with high-resolution susceptibility weighted imaging — A comparison with MR venography and standard MR sequences

“…In a recent study, enhanced MRV showed only 57% accuracy for the diagnosis of COVT [19]. Also, CEMRV failed to show cortical vein clots in all 7 cases in another study [13]. Further, Meckel S et al demonstrated 66% sensitivity for T2* GRE in comparison to 53% sensitivity for 2D TOF MRV and contrast enhanced MRV in combination with 3D VIBE (Volumetric Interpolated Brain Examination) to identify cortical vein clots [16].…”

“…Among the imaging techniques, susceptibility contrast of MRI has demonstrated the highest sensitivity to detect COVT. However, in a majority of the studies, a small cohort of cases was used for the evaluation of COVT and the susceptibility contrast was assessed mainly with T2* (GRE) with a lack of blinding to other MR sequences and clinical information [3][4][5][6][7][8][9][10][11][12][13]. Although high resolution susceptibility weighted imaging (SWI) sequence has been used in clinical practice for approximately 2 decades, to the best of our knowledge, its advantages and limitations for the detection of COVT have not been evaluated independently of other MR sequences including MR venography.…”

Primary intraventricular hemorrhage caused by Galen vein thrombosis in an elderly patient: A case report

“…T2*WI is reportedly useful for diagnosing CVT in the acute phase 6 . Its sensitivity for detecting clots in patients with CVT in the acute phase is higher than that of any other MRI sequence, including susceptibility‐weighted imaging 6,7 …”

“…6 Its sensitivity for detecting clots in patients with CVT in the acute phase is higher than that of any other MRI sequence, including susceptibility-weighted imaging. 6,7 CVT is more and less likely to occur in patients aged <50 years, 8 and in children, respectively. 9 This corresponds to the reported cases; however, in the present case, the patient was in his 70s.…”