T2* 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 T(2) (*) 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.