Case Notes
History
42 year old male with right sided numbness and neck pain; history of seizures and hypertension.Exam
MRA of the Head
Our 3D MRA of the head is performed in axial plane post –contrast (IV Gadolinium). Rapidly obtained images are post processed to obtained MRA visualization of the intracranial cerebral arteries. The data set is obtained quickly and only once. Thus, there is no delayed imaging, as in CTA, to image the pial vessels nor venocapillary pool. Hence, this form of MRA is essentially a snapshot of the arterial phase only. Its’ value is that it is not affected by bone nor metal (surgical clips or wires). MRA of the head can be performed without contrast using time of flight technique, but this lacks the clarity of the post contrast 3D MRA.
Purpose
1. To define sites of afferent supratentorial arterial thrombosis or flow-limiting high-grade stenosis or lesser but tandem stenosis or stenosis plus incomplete circle of Willis with isolated arterial circuit;
2. To define sites of afferent infratentorial arterial thrombosis or flow-limiting high-grade stenosis;
3. To determine features of vessel wall and intimal status;
4. To assess presence of tandem stenosis or stenosis plus incompetent circle of Willis;
5. In case of ICA stenosis/occlusion is there effective EC-IC collateral;
6. Is there a watershed stroke zone affecting the usual anastomotic arterial boundary zones;
7. in case of afferent arterial block, plus an incomplete circle of Willis, is there a potential end-of the-line type of watershed stroke;
8. To assess status of retrograde pial collateral and asses for any pial collateral gap between proximal thrombus & retrograde pial collateral;
9. To assess for delayed venous egress (need to prove on post contrast CT head whether it is just delayed or is actually persistently reduced or absent).
Our 3D MRA of the head is performed in axial plane post –contrast (IV Gadolinium). Rapidly obtained images are post processed to obtained MRA visualization of the intracranial cerebral arteries. The data set is obtained quickly and only once. Thus, there is no delayed imaging, as in CTA, to image the pial vessels nor venocapillary pool. Hence, this form of MRA is essentially a snapshot of the arterial phase only. Its’ value is that it is not affected by bone nor metal (surgical clips or wires). MRA of the head can be performed without contrast using time of flight technique, but this lacks the clarity of the post contrast 3D MRA.
Purpose
1. To define sites of afferent supratentorial arterial thrombosis or flow-limiting high-grade stenosis or lesser but tandem stenosis or stenosis plus incomplete circle of Willis with isolated arterial circuit;
2. To define sites of afferent infratentorial arterial thrombosis or flow-limiting high-grade stenosis;
3. To determine features of vessel wall and intimal status;
4. To assess presence of tandem stenosis or stenosis plus incompetent circle of Willis;
5. In case of ICA stenosis/occlusion is there effective EC-IC collateral;
6. Is there a watershed stroke zone affecting the usual anastomotic arterial boundary zones;
7. in case of afferent arterial block, plus an incomplete circle of Willis, is there a potential end-of the-line type of watershed stroke;
8. To assess status of retrograde pial collateral and asses for any pial collateral gap between proximal thrombus & retrograde pial collateral;
9. To assess for delayed venous egress (need to prove on post contrast CT head whether it is just delayed or is actually persistently reduced or absent).
Prior Study
Non-Contrast Head CT1. Acute thrombus in the high cervical and vertical intrapetrous segments of the left cervical ICA without evidence of acute cerebral stroke. The history of acute upper neck pain makes dissection a very likely possibility.
2. Head is negative for hyperacute stroke changes.
MRA of the Neck
1. Acute dissection of the high cervical and vertical intrapetrous ICA on the left with intraluminal thrombus producing high-grade luminal stenosis (or occlusion) leaving at best minimal residual antegrade blood flow. Patent EC-IC collateral likely provide most of the collateral.
2. Given a history of seizures, this spontaneous left ICA dissection may have been the result of a recent grand mal type of seizure. No underlying vasculopathy is evident.
3. The right carotid, both vertebral arteries, and the left common carotid including the bifurcation were normal in appearance