Mittl R L, Broderick M, Carpenter J P, Goldberg H I, Listerud J, Mishkin M M, Berkowitz H D, Atlas S W
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104.
Stroke. 1994 Jan;25(1):4-10. doi: 10.1161/01.str.25.1.4.
We compared two-dimensional time-of-flight magnetic resonance angiography (MRA) and duplex ultrasonography with arteriography for the detection of 70% to 99% stenoses at the carotid artery bifurcation (ie, surgical disease according to findings of the North American Carotid Endarterectomy Trial).
Three blinded readers independently measured stenoses on MRA in 73 vessels from 38 patients. Duplex ultrasonography was available in 66 vessels from 35 of these patients, and blinded reading was performed by one reader. Comparison was made to arteriography.
Magnetic resonance angiography demonstrated a sensitivity of 92.4%, specificity of 74.5%, and negative predictive value of 95.8% for 70% to 99% stenoses. Interobserver agreement was high (kappa = 0.91). Absence of signal at stenoses with evidence of distal flow usually, but not always, corresponded to surgical disease. Duplex ultrasonography demonstrated a sensitivity of 81.0%, specificity of 82.2%, and negative predictive value of 90.2% for surgical disease. There was no significant difference between MRA and duplex ultrasonography for the sensitivity or specificity in detecting 70% to 99% stenoses (P > .1, exact form of the McNemar test). MRA had no false positives or false negatives for complete occlusions of the carotid artery, whereas duplex ultrasonography missed one occlusion and falsely called two patent vessels occluded. In seven cases, both MRA and duplex ultrasonography overestimated stenoses to miscategorize them as surgical disease.
Although the sensitivity and specificity of MRA and duplex ultrasonography are not significantly different for distinguishing surgical and nonsurgical degrees of stenosis at the carotid bifurcation, MRA has some advantages that may make it the screening test of choice. Concordant MRA and duplex ultrasonography for surgical disease does not necessarily obviate the need for catheter arteriography.
我们将二维时间飞跃磁共振血管造影（MRA）和双功超声与动脉造影术进行比较，以检测颈动脉分叉处70%至99%的狭窄（即根据北美颈动脉内膜切除术试验结果确定的需手术治疗的疾病）。
三位不知情的阅片者独立测量了38例患者73条血管的MRA狭窄情况。其中35例患者的66条血管进行了双功超声检查，由一位阅片者进行不知情阅片。与动脉造影术进行比较。
磁共振血管造影显示，对于70%至99%的狭窄，其敏感性为92.4%，特异性为74.5%，阴性预测值为95.8%。观察者间一致性较高（kappa = 0.91）。狭窄处无信号且有远端血流证据时，通常（但不总是）对应需手术治疗的疾病。双功超声显示，对于需手术治疗的疾病，其敏感性为81.0%，特异性为82.2%，阴性预测值为90.2%。在检测70%至99%的狭窄时，MRA和双功超声在敏感性或特异性方面无显著差异（P >.1，McNemar检验的确切形式）。对于颈动脉完全闭塞，MRA无假阳性或假阴性，而双功超声漏诊了1例闭塞，并将2条通畅血管误诊为闭塞。在7例病例中，MRA和双功超声均高估了狭窄程度，将其错误分类为需手术治疗的疾病。
尽管在区分颈动脉分叉处手术和非手术狭窄程度方面，MRA和双功超声的敏感性和特异性无显著差异，但MRA具有一些优势，可能使其成为首选的筛查检查。MRA和双功超声对于需手术治疗疾病的结果一致并不一定意味着无需进行导管动脉造影。
