Narrowed petrous carotid canal detection for the early diagnosis of moyamoya disease.

Abstract

PURPOSE: Patients with moyamoya disease (MMD) exhibit narrowed internal carotid arteries (ICAs) because the distal ends of the bilateral ICAs have become progressively stenosed, starting mainly in childhood. Accordingly, the petrous carotid canals in MMD patients are suspected to be more hypoplastic than those in control subjects. In this study, the diagnostic value of conventional computed tomography for MMD patients was retrospectively evaluated by comparing the caliber of the bilateral carotid canals in MMD patients with that in control subjects. MATERIALS AND METHODS: Thirty-five patients with MMD (15 males, 20 females; age range/average age: 6-71 / 26.1 years old) and age- and sex-matched control subjects underwent conventional head computed tomography. The maximal petrous carotid canal diameters of the two groups were measured and compared. RESULTS: The maximal petrous carotid canal diameter was significantly smaller in the moyamoya patients (mean +/- standard deviation [mm] = 4.70 +/- 0.61) than in the control subjects (5.62 +/- 0.61, p < 0.01). CONCLUSION: Conventional head computed tomography revealed narrowed petrous carotid canals in the MMD patients. This basic information could be utilized to screen patients who will require further examination, especially among those with underlying MMD.