We describe a method for rapid calculation of maximum intensity projection (MIP) images. The method is applied to 10 example cases with more extensive testing in 1 case. Measurements of calculation time for all 10 cases show good performance (less than 1.2 seconds) for calculating a MIP image that is a very faithful representation of the original (less than 2% of pixels differ from original image). We also demonstrate that the computation time is related linearly to the number of pixels used, allowing arbitrarily rapid computation rates. This technique may be helpful as a navigation aid in evaluation magnetic resonance (MR) angiography data.