Diagnostic value of maximum intensity projections versus source images for assessment of contrast-enhanced three-dimensional breath-hold magnetic resonance coronary angiography.

Rationale and Objectives: We compared maximum intensity projections (MIP) versus original source images (SI) in respect to detection of coronary artery stenoses by means of magnetic resonance (MR) coronary angiography.
Methods: MR coronary angiography was performed on 61 patients. MIP and SI were independently evaluated as to presence of significant stenoses in the proximal and midcoronary segments and compared with x-ray angiography.
Results: A total of 315 of 427 (74%) coronary artery segments could be evaluated in MIP and 328 of 427 (77%) in SI. In segments able to be evaluated, MIP images demonstrated 84% (54/64) sensitivity and 87% (219/251) specificity, whereas SI images showed 85% (58/68) sensitivity and 90% (235/260) specificity. Overall accuracy was 87% (273/310) for MIP and 89% (293/328) for SI. There was no statistically significant difference between both modalities.
Conclusions: The MIP reconstructions showed comparable accuracy to unprocessed SI. However, MIP postprocessing is compromised by a higher number of images that were unable to be evaluated due to overlap of coronary arteries with adjacent cardiac structures.