Purpose: Purpose of the study was to compare the sensitivity and specificity of various display modalities in the detection of renal artery stenosis. In particular, the difference between hard-copy reading and interactive analysis at the workstation was assessed.
Materials and methods: Selected patients (n = 31) with expected suboptimal conditions for CT angiography due to long-standing hypertension and compromised renal function were included. Six radiologists evaluated independently a total of 77 renal arteries with 49 renal artery stenoses proven by angiography. Image analysis included: mode A: interactive display, analysis of multiplanar reformats and axial sections at the workstation, mode B: visualization of MIPs in the coronal and axial planes as hard copies only, mode C: visualization of MIPs and axial sections as hard copies only.
Results: The following sensitivities and specificities were found for internal readers and (readers from outside institutions): mode A: 94.8%, 87.9%, mode B: 97.7% (95.1%), 80.3% (75.4%); mode C: 97.0% (95.3%), 78.8% (76.6%). The differences were statistically not significant (p > 0.05).
Conclusions: Standardized hard copies of MIPs plus axial CT provide sufficient accuracy to detect renal artery stenosis compared to interactive imaging even in this highly selected group of patients.