Lev Michael H, Romero Javier M, Goodman Daniel N F, Bagga Ranjit, Kim H Young Kwon, Clerk Neil A, Ackerman Robert H, Gonzalez R Gilberto
Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
AJNR Am J Neuroradiol. 2003 Jun-Jul;24(6):1123-9.
Routine carotid sonography and MR angiography cannot reliably detect the markedly reduced flow velocities associated with very severe carotid stenosis. In this study, we sought to evaluate the accuracy of single row detector helical CT angiography in distinguishing hairline residual lumen from total occlusion of severely stenosed internal carotid arteries (ICAs).
From our departmental data base of single row detector CT angiography studies performed for evaluation of ICA occlusive disease, 21 cases were identified with evidence of either hairline residual lumen or total occlusion on correlative conventional catheter radiographic arteriograms; these included seven cases of proved hairline residual lumen and 14 cases of proved total occlusion. Two neuroradiologists, blinded to the radiographic arteriography results, graded the diseased ICA on each CT angiogram as definitely occluded, probably occluded, indeterminate, probably patent, or definitely patent. Receiver operating characteristic curves were generated for each neuroradiologist.
At an operating point on the receiver operating characteristic curve corresponding to 90% sensitivity, the first reader achieved 95% specificity and the second reader achieved 80% specificity for distinguishing hairline residual lumen from total occlusion. Absolute accuracy rates were 95% and 85%, respectively. No significant difference in accuracy was observed between the two readers (P =.28, two-tailed t test).
Single row detector CT angiography can distinguish total ICA occlusion from hairline residual lumen with a high degree of accuracy. In equivocal cases, conventional catheter arteriography may be desirable to confirm the diagnosis.
常规颈动脉超声检查和磁共振血管造影无法可靠地检测出与极重度颈动脉狭窄相关的显著降低的血流速度。在本研究中，我们试图评估单排探测器螺旋CT血管造影在区分严重狭窄的颈内动脉（ICA）的发丝样残余管腔与完全闭塞方面的准确性。
从我们科室用于评估ICA闭塞性疾病的单排探测器CT血管造影研究数据库中，识别出21例在相关的传统导管放射动脉造影片上有发丝样残余管腔或完全闭塞证据的病例；其中包括7例经证实的发丝样残余管腔病例和14例经证实的完全闭塞病例。两位神经放射科医生在不知动脉造影结果的情况下，将每张CT血管造影上的病变ICA分级为明确闭塞、可能闭塞、不确定、可能通畅或明确通畅。为每位神经放射科医生绘制了受试者操作特征曲线。
在受试者操作特征曲线上对应90%敏感度的操作点处，第一位阅片者区分发丝样残余管腔与完全闭塞的特异度为95%，第二位阅片者为80%。绝对准确率分别为95%和85%。两位阅片者之间的准确率无显著差异（P = 0.28，双侧t检验）。
单排探测器CT血管造影能够高度准确地区分ICA完全闭塞与发丝样残余管腔。在不明确的病例中，可能需要传统导管动脉造影来确诊。
