Evaluating the Velocity and Extent of Cortical Venous Filling in Patients With Severe Middle Cerebral Artery Stenosis or Occlusion

Abstract

Objective: To investigate the velocity and extent of cortical venous filling (CVF) and its association with clinical manifestations in patients with severe stenosis or occlusion of the middle cerebral artery (MCA) using dynamic computed tomography angiography (CTA). Methods: Fifty-eight patients (36 symptomatic and 22 asymptomatic) with severe unilateral stenosis (≥70%) or occlusion of the MCA M1 segment who underwent dynamic CTA were included. Collateral status, antegrade flow, and CVF of each patient were observed using dynamic CTA. Three types of cortical veins were selected to observe the extent of CVF, and the absence of CVF (CVF-) was recorded. Based on the appearance of CVF in the superior sagittal sinus, instances of CVF, including early (CVF₁), peak (CVF₂), and late (CVF₃) venous phases, were recorded. The differences in CVF times between the affected and contralateral hemispheres were represented as rCVFs, and CVF velocity was defined compared to the median time of each rCVF. Results: All CVF times in the affected hemisphere were longer than those in the contralateral hemisphere (p < 0.05). Patients with symptomatic MCA stenosis had more ipsilateral CVF- (p = 0.02) and more delayed CVF at rCVF₂ and rCVF₂₁ (rCVF₂-rCVF₁) (p = 0.03 and 0.001, respectively) compared to those with asymptomatic MCA stenosis. For symptomatic patients, fast CVF at rCVF₂₁ was associated with poor collateral status (odds ratio [OR] 6.42, 95% confidence interval [CI] 1.37-30.05, p = 0.02), and ipsilateral CVF- in two cortical veins was associated with poor 3-month outcomes (adjusted OR 0.025, 95% CI 0.002-0.33, p = 0.005). Conclusions: Complete and fast CVF is essential for patients with symptomatic MCA stenosis or occlusion. The clinical value of additional CVF assessment should be explored in future studies to identify patients with severe MCA stenosis or occlusion at a higher risk of stroke occurrence and poor recovery.

Keywords: cortical venous filling; dynamic computed tomography angiography; middle cerebral artery; occlusion; severe stenosis.

Figure 1

Case 1. A 66-year-old man with a history of hypertension and lipid disorder presented with dizziness for 3 days. (A) The arterial and venous time attenuation curves (TACs; red and blue, respectively). The selected arterial phase on TAC (A-TAC) was 16.2 s, and the time-to-peak on the venous TAC (V-TAC) was 24.8 s. (B) The arrow points to the left MCA M1 severe stenosis at A-TAC on three-dimensional (3D) computed tomographic angiography (CTA). (C–H) The 3D computed tomography venography (CTV) shows cortical venous filling (CVF) draining into the superior sagittal sinus at early (CVF₁), peak (CVF₂), and late venous phases (CVF₃) in the affected (double white arrow) and contralateral (white arrow) hemispheres. Cortical veins begin to be visible in the contralateral (C, CVF₁, 19.0 s) and affected hemispheres (D, CVF₁, 20.9 s). The maximum contrast opacification of all cortical veins in the contralateral (E, CVF₂, 24.8 s) and affected hemispheres (F, CVF₂, 24.8 s) appear at the same time, and contrast medium in all cortical veins disappears in the contralateral (G, CVF₃, 32.7 s) and affected hemispheres (H, CVF₃, 37.7 s). CVF₂₁ and CVF₃₁ of the contralateral hemisphere are 5.8 s and 13.7 s, respectively, while the CVF₂₁ and CVF₃₁ of the affected hemisphere are 3.9 s and 16.8 s, respectively. The mean difference between the affected and contralateral hemispheres is 1.9 s for rCVF₁, 0 s for rCVF₂, 5 s for rCVF₃,−1.9 s for rCVF₂₁, and 3.1 s for rCVF₃₁. The presence (color arrow) and absence (circle) of SMCV (green), VOL (red), and VOT (blue) across all whole venous phases (marked as SMCV+/VOL+/VOT+ and SMCV-/VOL-/VOT-, respectively) are displayed in the 3D CTV and (I–K) axial planes of the V-TAC. SMCV-, VOL-, and VOT- are not found in the bilateral hemispheres. (L,M) Antegrade flow assessment at TAC in the coronal and axial planes. Contrast filling of the MCA M1 segment and its distal branches in the affected hemisphere is more than two-thirds of the contralateral hemisphere. the contralateral hemisphere, and antegrade flow is preserved. (N,O) Collateral status assessment at A-TAC and V-TAC in the axial plane. Complete contrast enhancement of collateral flow at V-TAC in the affected hemisphere with good collateral status.

Figure 2

Case 2. A 54-year-old woman with a history of hypertension and diabetes presented with left-sided and left facial droop hemiparesis. The NIHSS score was 5 on admission. 3 months mRS score was 1 (good outcome). (A) The selected arterial and venous phases are 12.6 s and 19.2 s, respectively. (B) The arrow points to the right M1 severe stenosis. (C–H) The CVF₁, CVF₂, CVF₃, CVF₂₁, and CVF₃₁ of the contralateral hemisphere (white arrow) are 12.6 s, 19.2 s, 25.2 s, 6.6 s, and 12.6 s, respectively, while the CVF₁, CVF₂, CVF₃, CVF₂₁, and CVF₃₁ of the affected hemisphere (double white arrow) are 14.6 s, 21.2 s, 29.1 s, 6.6 s, and 14.5 s, respectively. The mean difference between the affected and contralateral hemisphere is 0 s for rCVF₂₁. (C–K) The presence (color arrow) and the absence (circle) of SMCV (green), VOL (red), and VOT (blue). SMCV- is found in the affected hemisphere, and VOL- is found in the contralateral hemisphere. (L–O) Compromised antegrade flow and poor collateral status.

Figure 3

Case 3. A 50-year-old man with a history of hypertension, diabetes, and smoking presented with dysarthria and right-sided hemiparesis. NIHSS score was 6 on admission and 3-month mRS score was 3 (poor outcome). (A) The selected arterial phase and the venous phase are 14.5 s and 21.0 s, respectively. (B) The arrow points to the left M1 occlusion. (C–H) The CVF₁, CVF₂, CVF₃, CVF₂₁, and CVF₃₁ of the contralateral hemisphere (white arrow) are 14.5 s, 23.0 s, 28.9 s, 8.5 s, and 14.4 s, respectively, while CVF₁, CVF₂, CVF₃, CVF₂₁, and CVF₃₁ of the affected hemisphere (double white arrow) are 16.4 s, 25.0 s, 32.9 s, 8.6 s, and 16.5 s, respectively. The mean difference between the affected and contralateral hemisphere is 0.1 s for rCVF₂₁. (C–K) SMCV-, VOL-, and VOT- are not found in the contralateral hemisphere (color arrow), while VOL- (red circle) and VOT- (blue circle) are shown in the affected hemisphere. (L–O) Compromised antegrade flow and poor collateral status.