T*2 measurement during first-pass contrast-enhanced cardiac perfusion imaging

First-pass contrast-enhanced (CE) myocardial perfusion imaging will experience T-2* effects at peak concentrations of contrast agent. A reduction in the signal intensity of left ventricular (LV) blood due to T-2* losses may effect estimates of the arterial input function (AIF) used for quantitative perfusion measurement. Imaging artifacts may also result from T-2* losses as well as off-resonance due to the bolus susceptibility. We hypothesized that T-2* losses would not be significant for measurement of the AIF in full-dose studies using a short echo time (TE = 0.6 ms). The purpose of this study was to directly measure T-2* in the LV cavity during first-pass perfusion. For single-dose Gd-DTPA (0.1 mmol/kg at 5 ml/s), the LV blood pool 72 had a mean value of 9 ms (N = 10) at peak enhancement. Distortion of the AIF due to T-2* signal intensity loss will be less than 10% using TE = 0.6 ms.