Analysis of subtraction methods in three-dimensional contrast-enhanced peripheral MR angiography

PURPOSE: To compare the effectiveness of three image subtraction algorithms designed to improve arterial conspicuity in first-pass contrast-enhanced magnetic resonance (MR) angiography. MATERIALS AND METHODS: Three subtraction methods were analyzed through computer simulations, phantom studies, and clinical studies. These algorithms were: complex subtraction, magnitude subtraction, and maximum intensity projection subtraction. RESULTS: In high resolution three-dimensional imaging, maximum intensity projection subtraction generally yields the best background suppression. Complex subtraction is effective in reducing partial volume effects in low resolution imaging. Magnitude subtraction works better in high resolution, low contrast concentration protocols. CONCLUSION: Choosing the appropriate subtraction method according to the protocol is helpful in optimizing image quality.