Optimal Imaging Parameters and the Advantage of Renal Artery Image Using Time-spatial Labeling Inversion Pulse at 3 Tesla Magnetic Resonance Imaging: Comparison of Image Quality for 1.5 Tesla Magnetic Resonance Imaging.

With the recent spread of three tesla (3 T) magnetic resonance imaging (MRI), time-spatial labeling inversion pulse (Time-SLIP) technique at high magnetic field can be used. The purpose of this study was to determine appropriate renal artery imaging parameters and to compare with the 1.5 T MRI image quality of a renal artery using the Time-SLIP technique. The imaging sequence was 3D true steady-state free precession (True SSFP), and using respiratory gated by the voice instructions of breath interval 2, 4, 6 seconds. We measured the fat signals when changing the values of short TI inversion recovery (STIR TI), the renal artery and renal parenchyma signals when changing the values of black blood time interval (BBTI), and contrast-to-noise ratio (CNR) between renal artery and background in 11 healthy volunteers. Visual evaluation using a 4-stage score at renal artery in clinical cases was performed. 3 T MRI is compared with a 1.5 T MRI, and the null point of STIR TI value is 60 ms extension, null point of BBTI value in the renal parenchyma was an extension of 250 ms in any of the breath interval. In flow effect, there is no difference in the 1.5 T MRI and 3 T MRI, peaked at BBTI value 1500 ms. CNR and visual evaluation were better than 3 T MRI. 3 T MRI showed a better image quality by the background signal suppression effect of the extension of the T1 value.