Tavares N J, Auffermann W, Brown J J, Gilbert T J, Sommerhoff C, Higgins C B
Department of Radiology, University of California, San Francisco Medical School 94143.
AJR Am J Roentgenol. 1989 Jul;153(1):173-8. doi: 10.2214/ajr.153.1.173.
Spin-echo phase images have been shown to be sensitive to blood flow and have been used to differentiate slow flow from thrombus, with an apparent advantage in comparison with spin-echo intensity images alone. In order to quantify the diagnostic efficacy of phase images, a study was performed comparing the sensitivity and specificity of MR imaging in identifying intravascular thrombus using spin-echo magnitude images alone and combined with phase images. In 45 subjects, 66 vessels with questionable intraluminal signal were reviewed in a blinded manner by four radiologists using seven levels of certitude for the diagnosis of thrombus. Vessels in the thorax, abdomen, and pelvis were included in the evaluation and were selected on the basis of the presence of intraluminal signal, which raised the possibility of intravascular disease. Corroborative studies were available in all cases. Receiver-operator-characteristic curves were constructed for the accuracy of the decision of intraluminal thrombus vs flow signal when using magnitude images alone and when using magnitude plus phase images. Magnitude images identified thrombus with a sensitivity of 35% at a specificity of 90%. On the other hand, combining magnitude image and phase images yielded sensitivities of 85% and 83% at specificities of 90% and 95%, respectively. We conclude that addition of phase images substantially increases the level of confidence in detecting intravascular thrombosis.
自旋回波相位图像已被证明对血流敏感，并已用于区分缓慢血流和血栓，与单独的自旋回波强度图像相比具有明显优势。为了量化相位图像的诊断效能，进行了一项研究，比较了仅使用自旋回波幅度图像以及结合相位图像时磁共振成像识别血管内血栓的敏感性和特异性。在45名受试者中，4名放射科医生以盲法对66条管腔内信号可疑的血管进行了评估，使用七个确定程度级别来诊断血栓。胸部、腹部和骨盆的血管被纳入评估，并根据管腔内信号的存在情况进行选择，管腔内信号增加了血管内疾病的可能性。所有病例均有确证性研究。绘制了受试者工作特征曲线，以评估仅使用幅度图像以及使用幅度加相位图像时判断管腔内血栓与血流信号的准确性。幅度图像识别血栓的敏感性为35%，特异性为90%。另一方面，结合幅度图像和相位图像时，在特异性分别为90%和95%的情况下，敏感性分别为85%和83%。我们得出结论，添加相位图像可显著提高检测血管内血栓形成的置信度。
