혈관 조영 사진을 이용한 두개내 뇌동맥 협착의 표준화된 측정법 개발

Abstract

Background: To measure the degree of stenosis, a diameter of maximum stenotic point and that of the presumably normal portion of the diseased artery (Dnormal) should be determined. However, largely due to a lack of consensus on the definition of the Dnormal, a standard method of measuring intracranial artery stenosis has been lacking. This study was aimed to determine Dnormal for the development of a reliable method to measure the intracranial arterial stenosis.

Methods: Using jeweller’s eyepiece, arterial diameters from 20 cases with a normal cerebral angiogram, were measured by two neurologists at the proximal portions of C2, C4, C6, and C7 segments of the bilateral internal carotid arteries (ICA). The proximal, middle, and distal portions were measured in the M1 segment of the bilateral middle cerebral arteries (MCA), the basilar artery (BA), and the intracranial segments of the bilateral vertebral arteries (VA). After determination of interobserver and intra-observer agreements, to establish the representative site of the Dnormal, measured diameters from the portions within the arterial segment and that of a corresponding portion of the contralateral artery were compared.

Results: In the MCA, BA, and VA, agreements of measurements were all acceptable and high in the order of the middle, distal, proximal, and the contralateral corresponding portions. However, in the ICA, correlation rates of each segment were moderate, and the proximal portion of the BA demonstrated low interobserver agreement.

Conclusions: From these findings, the middle portion of the diseased artery may be used for the representative point to determine the Dnormal. When the middle portion is diseased, the distal, proximal, and the contralateral corresponding artery, in the order, can be chosen. This method could be validated in part by demonstrating a very high interobserver agreement when the degree of stenosis was measured in 20 angiograms with a MCA stenosis.