Vertebral and Basilar Arteries: Transcranial Color-Coded Duplex Ultrasonography versus Conventional TCD in Detection of Narrowings

We prospectively compared the accuracies of conventional transcranial Doppler ultrasound (TCD) and transcranial color-coded duplex sonography (TCCS) in the diagnosis of narrowing of the basilar (BA) and vertebral arteries (VA). Fifty-six consecutive patients (mean age 55.8 years; 34 women) after subarachnoid hemorrhage (n=46), stroke or transient ischemic attack (n=5), and for other reasons (n=5) underwent on the same day TCD, TCCS and the intra-arterial digital subtraction angiography (DSA) – the reference standard. The accuracy of peak-systolic (VPS), mean (VM), and end-diastolic velocities (VED) in detection of any arterial narrowing was estimated using the receiver operator characteristic (ROC) curve methodology and the total area (Az) under the curve. Accuracy of TCCS in detection of VA narrowing based on VPS and VM measurements was significantly higher than accuracy of TCD (Az =0.65 for VPS and Az =0.62 for VM versus Az =0.51 and Az =0.50, respectively, p<0.05 for both). Accuracy of TCCS in detection of BA narrowing was also higher than accuracy of TCD based on VPS measurements (Az =0.69 versus Az =0.50, respectively), with a trend toward significant difference, p=0.085. The accuracy of TCCS is superior to accuracy of TCD in detection of narrowings of vertebral and basilar arteries, thus TCCS should be preferred in routine clinical practice.

Magnetic resonance arteriography of the pelvis and lower extremities

Reconstructive vascular surgery is the last resort for limb salvage in patients with vascular insufficiency. Planning the sites of arterial bypass grafts depends on an exact knowledge of the angiographic anatomy. Currently, conventional contrast angiography is the primary preoperative study for surgical planning. Recently, magnetic resonance (MR) arteriography has been shown to be an accurate technique for the evaluation of slow arterial flow in the lower extremities. The purpose of this review will be to show how MR arteriography can be used as both an adjunct to and in some cases instead of conventional angiography for the preoperative assessment of lower-extremity vascular reconstruction. The derivation of common artifacts, the many pitfalls of interpretation, and the evaluation of peripheral arterial occlusion and percentage stenosis will be discussed. MR arteriography of the lower extremities is an important advance for the noninvasive evaluation of disease of the peripheral vasculature.