[CT angiography in arterial occlusive disease: comparison of 3 rendering techniques].
OBJECTIVE
To evaluate different rendering techniques of CT data for the assessment of long vessel segments in peripheral vascular occlusive disease.


METHODS
40 CT angiograms (aortoiliac: n = 20, leg arteries: n = 20) were viewed using three different rendering techniques: 1, maximum intensity projection (MIP); 2, volume rendering (VR); 3, shaded surface display (SSD). CT angiograms were obtained in 6 or 8 projections. Axial cross-section images were analysed using an interactive cine mode. Intraarterial DSA was the standard in all cases.


RESULTS
The sensitivities for the diagnosis of occlusive disease were 100% (cross-section images), 94% (MIP), 91% (VR) and 93% (SSD). The specificities were 100%, 99%, 99% and 99%, respectively. For the accurate grading of high-grade (> 75%) stenoses, the sensitivities were 85% (cross-section images), 62% (MIP), 44% (VR) and 35% (SSD). Specificity was 99% for all techniques.


CONCLUSIONS
CTA is accurate in occlusive disease. Interactive viewing of cross-section images is the most accurate technique. MIP is superior to VR in the imaging of high-grade stenoses because contrast-to-noise ratio is high and thresholding is not necessary.
Rieker
O
O
Klinik für Radiologie, Johannes Gutenberg-Universität Mainz.
Mildenberger
P
P
Neufang
A
A
von Zitzewitz
H
H
Schweden
F
F
Thelen
M
M
D015901:Angiography, Digital Subtraction; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D006801:Humans; D007866:Leg / Q000098:blood supply*; D007925:Leriche Syndrome / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*