Search

Arteriography involves injecting a radiopaque dye to visualize arteries on X-ray; ultrasound is a noninvasive procedure that uses sonar to visualize internal structures. Both arteriography and ultrasound can accurately determine the amount of vascular narrowing or stenosis caused by atheroma (plaque of cholesterol, fat and cellular debris formed within the inner lining within an artery) of the carotid artery, which supplies blood to the brain. An ulcerated plaque is considered to be a high-risk indicator for a subsequent neurologic event or stroke, and the formation of an ulcerated plaque may be associated with hemorrhage within the plaque itself. There has been disagreement regarding the ability of B-mode carotid imaging by ultrasonography to detect ulcerated plaques in the carotid artery. In this prospective study of 126 patients, the results of previous arteriography and ultrasound were compared by examining the plaque specimens obtained during carotid endarterectomy (excision of the core or inner lining of the carotid artery). Of the 126 plaques removed, 60 percent (76) were ulcerated. The sensitivity of the two diagnostic procedures was 47 percent (correctly identified) for ultrasound, and 53 percent for arteriography; the degree of stenosis affected the diagnostic sensitivities. Plaques which narrowed the lumen, or opening, of the artery by 50 percent or less were detected in 77 percent of the cases by both arteriography and ultrasound. When the degree of stenosis was more than 50 percent, the sensitivities were 41 percent for ultrasound and 48 percent for arteriography. These results demonstrate that there is no significant difference in the diagnostic sensitivities of arteriography and B-mode carotid imaging. There is potential diagnostic error in cases of high-grade stenosis when B-mode carotid imaging is used. This should not affect patient care because patients with severe atheroma would most likely be advised to undergo carotid endarterectomy in any case. (Consumer Summary produced by Reliance Medical Information, Inc.)

The noninvasive diagnosis of deep vein thrombosis (DVT) has relied on detection of alterations in blood flow in the affected area. Phleborheography is one of the most sensitive tests; however, it cannot identify all thrombi (clots blocking blood flow). A new technique called venous duplex imaging (VDI) has been studied and is being rapidly accepted as a method to identify thrombi. The role of this test as an alternative to other methods is reviewed. Patient selection is important for assessing the capability of hemodynamic tests for DVT. One hundred and three patients with possible DVT were evaluated. Overall sensitivity and the sensitivity of detecting above-the-knee thrombi were significantly different between the two noninvasive tests used. VDI was significantly more sensitive in detecting both above-the-knee and below-the-knee thrombi than phlebography. VDI detected smaller clots that were missed by ascending phlebography. This non-invasive technique can thus replace hemodynamic tests for detection of DVT and may become the new diagnostic standard for deep venous thrombosis. (Consumer Summary produced by Reliance Medical Information, Inc.)