[Basic examination of CEMRA with 4D time-resolved angiography using keyhole (4D-TRAK) in 3T pelvic region]

Time-resolved MRA has recently been reported, and high-resolution MRA that does not miss timing is possible. In this examination, CEMRA that used 4D time-resolved angiography using keyhole (4D-TRAK) at 3T for the pelvic region was studied. 4D-TRAK is a method of using keyhole imaging together with sensitivity encoding (SENSE) and contrast-enhanced timing robust angio (CENTRA). The method changed flip angle (FA) and examined relative signal intensity, TR, TE, dynamic keyhole scan duration (DKSD) of the dilution contrast media, and keyhole% (KP). Image quality was examined with a blood vessel phantom. The presence of the partial echo method (PE) was examined in all cases. Relative signal intensity rose when FA increased. It has decreased in the PE method. TR did not show a difference by the PE method in FA15 degrees or more. DKSD was extended by the PE method. In the blood vessel Phantom, the PE method made the ringing artifacts remarkable. The artifacts that originated in keyhole imaging were observed. Shortening TR is difficult because of peculiar SAR to 3T. The PE method is not effective and becomes useless. It is necessary to note a point different from the parameter setting by 1.5T.