T2* effects in the dual-sequence method for high-dose first-pass myocardial perfusion

PURPOSE: To examine whether T2* effects reduce the accuracy of arterial input function (AIF) measurement by the dual-sequence method. MATERIALS AND METHODS: The dual-sequence method obtains a low-resolution AIF image and high-resolution myocardial images in each cycle, with suitable T1 weightings. It was modified to assess T2* effects in the low-resolution AIF image (4.8x4.8x10 mm voxels, TE=0.58 msec) by minimizing T1 weighting in that sequence, while the myocardial sequence remained T1-weighted. In 10 patients who underwent perfusion MRI scans (0.5 M Magnevist, 0.1 mmol/kg, 15-ml flush, 7 mL/second right antecubital) the blood signal in the left ventricle (LV) was measured at the bolus peak and compared with the first cycle's fresh magnetization signal. RESULTS: The bolus peak measured 98%+/-4% (mean+/-SD, N=20) of the value before contrast agent arrival. CONCLUSION: T2* causes insignificant error in the dual-sequence method at the stated parameters.