Objective: We investigated whether circle of Willis (COW) morphology on 3D time-of-flight (TOF) MR angiography differs between young normal subjects, older normal subjects, and patients with carotid atherosclerotic plaques. Methods: One hundred seventy-seven subjects were grouped according to age into a young group (20 – 40 years; n = 91) and an older group (> 60 years; n = 86). Subjects underwent brain MR examination as part of a health check-up. Fifty-three patients with carotid atherosclerotic plaque were also included for evaluation in this study. COW morphology on 3D TOF MR angiography was analyzed in terms of completeness or incompleteness of the anterior and posterior components of the circle and completeness of the circle. Results: An incomplete pattern of anterior circulation was significantly more common in carotid atherosclerotic plaque patients (20.7%) than normal older subjects (5.5%) (p < 0.01). A complete posterior circulation pattern was more frequent in normal young subjects (46.5%) than in normal older subjects (16.5%) or the patient group (18.9%) (p < 0.01). Of patients with carotid artery stenosis, 18.9% had a bilateral incomplete connection and were significantly more likely to have an incomplete pattern than normal young (2.3%) or normal older subjects (2.2%) (p < 0.001). Conclusion: Young, healthy subjects were significantly more likely to have a complete pattern of posterior circulation than older subjects. Patients with carotid atherosclerotic plaques were significantly more likely to have incomplete anterior circulation and an incomplete circle than young, normal subjects.
Circle of Willis

No abstract available.
Aneurysm* ; Angiography* ; Circle of Willis*

Blood Pressure ; Cerebrovascular Circulation ; Circle of Willis ; Humans

Moyamoya disease is a cerebrovascular disease of unknown etiology which leads to spontaneous occlusion of circle of Willis. Cerebral ischemic or hemorrhagic episodes occur as moyamoya disease progresses. To establish an efficient collateral circulation for the ischemic brain of this disease many surgical the therapeutic methods have been proposed. We analyzed the surgical results of encephaloduroarteriomyosynangiosis(EDAMS) and compared with that of direct bypass surgery, superfical temporal artery to middle ce rebral artery(STA-MCA) anastomosis to determine the efficacy of new indirect revascularization procedure, EDAMS, in the treatment of moyamoya disease. Twenty three patients with moyamoya disease who underwent revascularization procedure were included in this study. EDAMS was performed on 18 sides in 16 patients and STA-MCA anastomosis was done on 12 sides in 7 patients. Two patients underwent encephaloduroarteriosynangiosis(EDAS). The surgical results of EDAMS were excellent to good in 14 patients and fair in 2 patients. No statistical significance of the outcome was observed in comparision of EDAMS and STA-MCA anastomosis(p-value=0.471). Regardless of surgical procedures, outcome of child-onset moyamoya disease was found to be superior to those of adult-onset moyamoya disease(p-delete=0.024). In conclusion, EDAMS is considered to be one of the effective indirect revascularization methods to prevent the ischemic attack and establish the revascularization for moyamoya disease.
Brain ; Circle of Willis ; Collateral Circulation ; Humans ; Moyamoya Disease ; Temporal Arteries

Moyamoya disease is a progressive and occlusive disorder of the cerebral vasculature with particular involvements of the circle of Willis and the arteries that feed it. It occurs commonly in Japan and Korea, but less frequently in the Western countries. The etiology of moyamoya disease is still unclear, but frequent familial occurrence suggests that some genetic factors may be important in its etiology. Approximately 7-10% of moyamoya disease are familial. We experienced 2 siblings with moyamoya disease, and report the case with a review of previously published cases of moyamoya disease within a family.
Arteries ; Circle of Willis ; Humans ; Japan ; Korea ; Moyamoya Disease* ; Siblings*

PURPOSE: To determine differences in angiographic variations of the circle of Willis between atherosclerosis and normal groups. MATERIALS AND METHODS: In 289 patients we reviewed complete cerebral angiograms obtained using biplane digital subtraction angiography. Atherosclerosis was diagnosed in 189 patients, while 100 were normal. Patients were divided into four subgroups according to the relative size of each segment and the presence of cross-filling of opposite-sided vessels. When the circle was completely present, we determined whether or not it was balanced, and statistically compared variation patterns between the two groups. RESULTS: In the atherosclerosis group, the anterior half of the circle was complete in 74% of cases(139/189), and the posterior half in 38% (72/189). In the normal group, the anterior half was complete in 90% of cases, and the posterior half in 63%. An incomplete circle was more common in the atherosclerosis group than among normal subjects (26% vs 10%, p<.05; 62% vs 37%, p<.001). In the atherosclerosis group with incomplete circle, agenesis was found in the anterior communicating artery in 19% of cases (36/189), the A1 segment in 7% (14/189), the posterior communicating artery in 58% (109/189), and the P1 segment in 7% (14/189). In the normal group with incomplete circle, agenesis was seen in the anterior communicating artery in 9% of cases, in the A1 segment in 1%, in the posterior communicating artery in 36%, and in the P1 segment in 3%. Agenesis of the anterior communicating artery (19% vs 9%, p<.05), the A1 segment (7% vs 1%, p<.05), or the posterior communicating artery (58% vs 36%, p<.001) was more common in the atherosclerosis group than in the normal group. Unbalanced type with a size discrepancy between A1 segments was also more common in the atherosclerosis group (19% vs 8%, p<.05). There was no significant difference between the two groups regarding posterior communicating arteries equal to or larger than the P1 segment (42% vs 27%, p>.05) and agenesis of the P1 segment (7% vs 3%, p>.05). CONCLUSION: An incomplete and unbalanced circle of Willis was more common in the atherosclerosis group than in the normal group. Agenesis of the anterior communicating artery, the A1 segment, or the posterior communicating artery was common in the atherosclerosis group, as was size discrepancy between A1 segments.
Angiography, Digital Subtraction ; Arteries ; Atherosclerosis* ; Circle of Willis* ; Humans ; Intracranial Arteriosclerosis

The authors studied and analyzed microscopically the structure, length and diameter of each part of Willis circle in 264 cerebral hemispheres of 182 autopsied patients in the Taegu area from 1984 to 1990. The mean length of each A1 was 14.1mm and diameter at distal A1 was 2.25mm. The most common anatomical anomaly of the ACA part was A1 that of hypoplasia which appeared in 7.5% of the cases. The origin of the Heuner a. was accounted for the highest incidence of AcoA(82.5%). The length of AcoA. Noted 3.5mm with the incidence of duplication and triplication in 38.6%. The inner diameter of ICA noted 3.9mm at the communicating segment in ICA, and the average length of C4 was 12.5m. Except 5 hemispheres of undetectable origin at ICA, all the anterior choroidal a. originated from ICA, and the double stump of which noted 15.5%. Fetal type PcoA. Showed 6.6% of all and average length of the a. was 13.5mm. The inner diameter of MCA was 3.1mm and the mean length of M1 noted 15.5mm. The length of each P1 noted 6.95mm and the inner diameter of basilar a. at 1cm below the bifurcation was 3.3mm. The mean circumference of willis circle including both side of A1, P1, PcoA. AcoA. And choroidal and communicating segment of ICA was 88.6mm. Incidental finding of unruptured aneurysm noted 5.3% and junctional dilatation of PcoA. Showed 11.4% of all the cases.
Aneurysm ; Cerebrum ; Choroid ; Circle of Willis* ; Daegu ; Dilatation ; Humans ; Incidence ; Incidental Findings

Carotid occlusion is an inevitable therapeutic modality for the treatment of complex aneurysms such as giant, traumatic, and intracavernous aneurysms. Late complications of carotid occlusion include 'de novo' aneurysm formation at a distant site because of hemodynamic changes in the circle of Willis. We report a case of de novo aneurysm in a vessel that appeared to be normal on initial angiography. The patient developed an anterior communicating artery aneurysm and marked growth of a basilar bifurcation aneurysm 9 years after trapping of the left internal carotid artery for the treatment of a ruptured large saccular aneurysm involving ophthalmic and cavernous segments. We propose that patients who undergo therapeutic carotid occlusion should be periodically followed by magnetic resonance angiography or computed tomographic angiography to evaluate the possibility of de novo aneurysm formation; this advice is in line with previous reports.
Aneurysm ; Angiography ; Carotid Artery, Internal ; Caves ; Circle of Willis ; Glycosaminoglycans ; Hemodynamics ; Humans ; Intracranial Aneurysm ; Magnetic Resonance Angiography

PURPOSE: To evaluate the usefulness of axial 2-D PC MRA of the circle of Willis in the evaluation of acute cerebral infarction. MATERIALS AND METHODS: We evaluated 42 patients with acute cerebral infarction who had undergone T2 weighted and diffusion weighted MR imaging (T2WI, DWI) and 2-D PC MRA of the circle of Willis within 72 hours of the onset of symptoms. In conjunction with high-signal lesions on DWI, the findings of 2-D PC MRA were classified as normal, stenotic, or indicative of arterial occlusion; negative 2-D PC MRA was not considered useful. In addition, the signal intensity of T2WI and DWI was compared. RESULTS: (The findings of 2-D PC MRA showed that 15 cases (35.7%) were normal, 13(31%) were stenotic, and that in 14 (33.3 %), occlusion was present). Thus, 2-D PC MRA detected vascular abnormality in 27 cases (64.3 %). On T2WI, six cases (14.3 %) showed no signal change and 36 (85.7 %) showed high signal change. In six cases without signal change, MR images were obtained within 12 hours of ictus; in one of these patients MRA findings were normal, one had stenosis, and in four, occlusion was noted. CONCLUSION: 2-D PC MRA is a useful modality for the detection of vascular abnormality in patients with acute cerebral infarct.
Cerebral Infarction ; Circle of Willis* ; Constriction, Pathologic ; Diffusion ; Humans ; Infarction* ; Magnetic Resonance Imaging

PURPOSE: To assess the usefulness of CT angiography(CTA) compared with compared with conventional angiography(CA) in the evaluation of intracranial occlusive vascular disease. MATERIALS AND METHODS: We evaluated 26 patients with clinically suspected intracranial occlusive vascular disease studied with both CTA and CA. Incases where there was no vascular lesion on CA, we used CTA to retrospectively review the detection rate and size of individual vessels, and compared the findings with those obtained by CA. In cases of occlusive vascular lesion, we evaluated the degree of stenosis on CTA and compared this with the CA findings. We also measured the time taken to use both modalities. RESULTS: Sixteen patients had no vascular lesion and ten patients had occlusive vascularlesions. Compared with CA, CTA detected 97%(124/128) of normal intracranial arteies ; their diameter measured on CTA was slightly smaller than that on CA. On CTA, the degree of stenosis was correctly estimated in eight lesions, underestimated in one and overestimated in one. Examination time ranged between 15 and 20 minutes with CTA and between 40 and 60 minutes with CA. CONCLUSION: Compared with CA, CTA shows good correlation in the delineation of intracranial normal and occlusive vessels around the Circle of Willis. CTA may be an additional tool for the evaluation of the Circle of Willis in patients with suspected intracranial occlusive vascular disease. CTA may, additionally, be used as a follow-up method in patients with acute cerebral infarctions after thrombolytic therapy.
Angiography* ; Cerebral Infarction ; Circle of Willis* ; Constriction, Pathologic ; Humans ; Retrospective Studies ; Vascular Diseases*