Effects of breath-hold patterns, gadolinium concentrations and temporal resolutions on determination of mean left atrial circulation transit time by MR first pass perfusion

Methods Twenty three patients were prospectively recruited to undergo MRI in a 1.5 T scanner. First pass perfusion imaging was performed using a saturation recovery steady state free precession sequence with ECG gating during breath-hold with Gadopentetate dimeglumine (Gd) injected at 0.01 mmol/kg. Imaging was repeated with freebreathing followed by breath-hold imaging using Gd at 0.025 mmol/kg separated with washout periods of 10 to 15 minutes. LATT was determined from the time intensity curves of the first pass using a custom program to assess time-signal integral and normalized by RR duration. nLATT was compared using paired t-test between images acquired in 3 settings. Additional 7 volunteers were recruited to undergo first pass perfusion with dynamic image acquired every 113 ms (TR) without ECG gating. To evaluate the effect of temporal resolution, LATT was assessed using simulated TR sampling dynamic signal intensity at multitudes of TR, respectively.