Color-coded digital subtraction angiography in the management of a rare case of middle cerebral artery pure arterial malformation. A technical and case report

Abstract

The advent of flow dynamics and the recent availability of perfusion analysis software have provided new diagnostic tools and management possibilities for cerebrovascular patients. To this end, we provide an example of the use of color-coded angiography and its application in a rare case of a patient with a pure middle cerebral artery (MCA) malformation. A 42-year-old male chronic smoker was evaluated in the emergency room due to sudden onset of severe headache, nausea, vomiting and left-sided weakness. Head computed tomography revealed a right basal ganglia hemorrhage. Cerebral digital subtraction angiography (DSA) showed a right middle cerebral artery malformation consisting of convoluted and ectatic collateral vessels supplying the distal middle cerebral artery territory-M1 proximally occluded. An associated medial lenticulostriate artery aneurysm was found. Brain single-photon emission computed tomography with and without acetazolamide failed to show problems in vascular reserve that would indicate the need for flow augmentation. Twelve months after discharge, the patient recovered from the left-sided weakness and did not present any similar events. A follow-up DSA and perfusion study using color-coded perfusion analysis showed perforator aneurysm resolution and adequate, albeit delayed perfusion in the involved vascular territory. We propose a combined congenital and acquired mechanism involving M1 occlusion with secondary dysplastic changes in collateral supply to the distal MCA territory. Angiographic and cerebral perfusion work-up was used to exclude the need for flow augmentation. Nevertheless, the natural course of this lesion remains unclear and long-term follow-up is warranted.

Keywords: arterial malformation; color-coded angiography; intracerebral hemorrhage.

Figure 1

A) Cerebral CT angiogram showing right middle cerebral artery malformation consisting of ectatic and aneurysmal arterial collaterals. B) Gadolinium-enhanced T1WI MRI showing an area of acute basal ganglia hemorrhage associated with the arterial malformation.

Figure 2

A) Cerebral DSA of the right internal carotid, AP view, showing the MCA malformation consisting of convoluted ectatic and aneurysmal arterial collaterals coming from the ipsilateral supraclinoid carotid and anterior cerebral arteries. Note the associated occlusion of M1 segment of the MCA. B) DSA, lateral view. C) 3D reconstruction of the rotational angiographic views, demonstrating the spatial configuration of the arterial malformation. Note the small lenticulostriate artery aneurysm (arrow), likely associated with the basal ganglia hemorrhage.

Figure 3

A,B) Color-coded perfusion images, AP view, of the right ICA, showing delayed perfusion (TTP) in the distal middle cerebral artery territory. C) DSA perfusion images, AP view, of the left ICA for comparison. Note increased TTP values at the mid-M2 segment in A, corresponding to the blue color range, 3.41s-4.27s. Note the difference in parametric color-coding upon increasing series range in B, yet with a similar TTP value range. D,E) Color-coded perfusion images, AP view, of the left and right ICA using the peak opacification: TTP ratio; and peak opacification (POp) (F,G). Note the similarity in perfusion profile color progression between left and right distal middle cerebral artery territories when evaluating POp.

Figure 3

A,B) Color-coded perfusion images, AP view, of the right ICA, showing delayed perfusion (TTP) in the distal middle cerebral artery territory. C) DSA perfusion images, AP view, of the left ICA for comparison. Note increased TTP values at the mid-M2 segment in A, corresponding to the blue color range, 3.41s-4.27s. Note the difference in parametric color-coding upon increasing series range in B, yet with a similar TTP value range. D,E) Color-coded perfusion images, AP view, of the left and right ICA using the peak opacification: TTP ratio; and peak opacification (POp) (F,G). Note the similarity in perfusion profile color progression between left and right distal middle cerebral artery territories when evaluating POp.