SAR reduced black-blood cine TPM for increased temporal resolution at 3T

Object The objectivewas to improve the temporal resolution in black-blood CINE tissue phasemapping sequences at high field MR systems. The temporal resolution is limited due to SAR constraints causing idle times into the sequence. The aim was to avoid these idle times and therefore providing an increased number of heart phases. Materials and methods Thirteen volunteers were enrolled in this study. Each volunteer underwent different myocardial short-axis scans comprising scans with application of both presaturation pulses, with alternating application of presaturation pulses and with an attenuation of the excitation angle. The last two approaches enable a SAR reduction or increased temporal resolution. The contrast to noise ratio
(CNR) between myocardium and blood and the influence on the measured tissue motion were investigated. Results High CNR between myocardium and blood could be obtained with the application of alternating presaturationpulses. Reduction of the flip angle of the presaturation-pulses provided reduced CNR relative to both the original and the alternated presaturation-pulses approach. More details of the myocardial motion were observed with increased temporal resolution.