Detection and assessment of XXXX : value of CT angiography with shaded-surface display.

@entity1 @entity439 @entity438
OBJECTIVE: The purpose of this study was to evaluate the efficacy of circle of Willis CT angiography with shaded-surface display in the detection and assessment of suspected @entity438 . MATERIALS AND METHODS: Twenty-three @entity1 who had clinical or radiologic suspicion of @entity438 were studied prospectively with CT angiography and conventional angiography. The images were obtained and interpreted in a double-blind fashion by different radiologists. Conventional angiography, which was the reference standard in this study, diagnosed 17 @entity439 in 15 @entity1 . The usefulness of the two types of images for surgical planning was evaluated by two neurosurgeons. RESULTS: No @entity439 were detected with either technique in eight @entity1 . Both techniques showed 15 @entity439 in 14 @entity1 . The maximum dimensions were less than 3.0 mm in three cases, 3.0-5.0 mm in four cases, and greater than 5.0 mm in eight cases. With conventional angiography used as the reference standard, CT angiography has one false-positive and two false-negative findings, resulting in a sensitivity of 88% (15/17) and a specificity of 89% (8/9). For 12 of 15 @entity439 , CT angiography was rated equal or superior to conventional angiography in depicting all aspects (shape, orientation, neck, and parent vessel) of the @entity439 . CONCLUSION: We were able to detect @entity439 of the circle of Willis as small as 2 mm in size. Using conventional angiography as the reference standard, CT angiography has a sensitivity of 88% and a specificity of 89% for the detection of @entity439 in the circle of Willis. In almost all cases, CT angiography was equal or superior to conventional angiography in characterizing the @entity439 for surgical planning.
