Effect of parallel radiofrequency transmission on arterial input function selection in dynamic contrast-enhanced 3 Tesla pelvic MRI.

BACKGROUND: To evaluate whether parallel radiofrequency transmission (mTX) can improve the symmetry of the left and right femoral arteries in dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of prostate and bladder cancer. METHODS: Eighteen prostate and 24 bladder cancer patients underwent 3.0 Tesla DCE-MRI scan with a single transmission channel coil. Subsequently, 21 prostate and 21 bladder cancer patients were scanned using the dual channel mTX upgrade. The precontrast signal ( S0) and the maximum enhancement ratio (MER) were measured in both the left and the right femoral arteries. Within the patient cohort, the ratio of S0 and MER in the left artery to that in the right artery ( S0_LR, MER_LR) was calculated with and without the use of mTX. Left to right asymmetry indices for S0 ( S0_LRasym) and MER ( MER_LRasym) were defined as the absolute values of the difference between S0_LR and 1, and the difference between MER_LR and 1, respectively. RESULTS: S0_LRasym, and MER_LRasym were 0.21 and 0.19 for prostate cancer patients with mTX, and 0.43 and 0.45 for the ones imaged without it (P < 0.001). Also, for the bladder cancer patients, S0_LRasym, and MER_LRasym were 0.11 and 0.9 with mTX, while imaging without it yielded 0.52 and 0.39 (P < 0.001). CONCLUSION: mTX can significantly improve left-to-right symmetry of femoral artery precontrast signal and contrast enhancement.