The MRV of the head is useful for confirming the presence of thrombus and ideally consists of both noncontrast TOF and contrast-enhanced MRV. Although contrast-enhanced venography is the most accurate means of assessment for CVT [104], contrast-enhanced and TOF MRV imaging techniques are complementary in that a contrast- enhanced MRV may provide a better assessment of a hypoplastic dural venous sinus with slow flow and TOF MRV mitigates against T1 isointense thrombus, which may mimic normal opacification of the sinus on contrast-enhanced MRV. Additionally, T1 hyperintense thrombus can mimic normal flow and enhancement patterns, which necessitates evaluation with noncontrast MRI. Volumetric MRI sequences are essential for contrast-enhanced MRV. Delayed postcontrast imaging can further increase the sensitivity for detection of T1 isointense thrombus. MRV Head Without IV Contrast MRV of the head along with MRI of the head is an essential component of the workup of CVT in most cases. Although contrast-enhanced venography is the most accurate means of assessment for CVT [104], TOF and phase- contrast MRV are noncontrast alternatives for the diagnosis of CVT. If the findings on noncontrast MRV are unclear, then further imaging with contrast-enhanced CTV or MRV should be considered. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid Doppler in the setting of CVT. However, US assessment of the adjacent venous structures could yield useful information about the extent of the thrombus if extending into the neck. US Duplex Doppler Transcranial There is no relevant literature to support the use of transcranial Doppler in the setting of CVT. Variant 8: Adult. Known venous sinus thrombosis. Surveillance imaging. CVT is an uncommon cause for stroke, accounting for approximately 1% to 2% of all strokes [99].
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. The MRV of the head is useful for confirming the presence of thrombus and ideally consists of both noncontrast TOF and contrast-enhanced MRV. Although contrast-enhanced venography is the most accurate means of assessment for CVT [104], contrast-enhanced and TOF MRV imaging techniques are complementary in that a contrast- enhanced MRV may provide a better assessment of a hypoplastic dural venous sinus with slow flow and TOF MRV mitigates against T1 isointense thrombus, which may mimic normal opacification of the sinus on contrast-enhanced MRV. Additionally, T1 hyperintense thrombus can mimic normal flow and enhancement patterns, which necessitates evaluation with noncontrast MRI. Volumetric MRI sequences are essential for contrast-enhanced MRV. Delayed postcontrast imaging can further increase the sensitivity for detection of T1 isointense thrombus. MRV Head Without IV Contrast MRV of the head along with MRI of the head is an essential component of the workup of CVT in most cases. Although contrast-enhanced venography is the most accurate means of assessment for CVT [104], TOF and phase- contrast MRV are noncontrast alternatives for the diagnosis of CVT. If the findings on noncontrast MRV are unclear, then further imaging with contrast-enhanced CTV or MRV should be considered. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid Doppler in the setting of CVT. However, US assessment of the adjacent venous structures could yield useful information about the extent of the thrombus if extending into the neck. US Duplex Doppler Transcranial There is no relevant literature to support the use of transcranial Doppler in the setting of CVT. Variant 8: Adult. Known venous sinus thrombosis. Surveillance imaging. CVT is an uncommon cause for stroke, accounting for approximately 1% to 2% of all strokes [99].