  Purpose: To explore the usability and normal T1rho value of liver parenchyma
with a novel single breathhold black blood single shot fast spin echo
acquisition based liver imaging sequence. Materials and Methods: In total 19
health subjects (10 males, 9 females; mean age: 37.4 yrs; range: 23-54 yrs)
participated in the study. 11 subjects had liver scanned twice in the same
session to access scan-rescan repeatability. 12 subjects had liver scanned
twice in two sessions with 7-10 days' interval to access scan-rescan
reproducibility. MR was performed with a 3.0 T scanner with dual transmitter.
The MR sequence allows simultaneous acquisition of 4 spin lock times (TSLs:
0ms, 10 ms, 30 ms, 50ms) in 10 second. Inherent black blood effect of fast spin
echo and double inversion recovery were utilized to achieve blood signal
suppression. Results: The technique demonstrated good image quality and minimal
artifacts. For liver parenchyma, Bland-Altman plot showed the scan-rescan
repeatability mean difference was 0.025 ms (95% limits of agreement: -1.163 to
1.213 ms), and intraclass correlation coefficient (ICC) was 0.977. The
scan-rescan reproducibility mean difference was -0.075 ms (95% limits of
agreement: -3.280 to 3.310 ms), and ICC was 0.820 which is better than the ICC
of 0.764 of a previous bright blood multi-breath hold gradient echo acquisition
technique. The liver T1rho value was 39.9 +/- 2.4 ms (range: 36.1 - 44.2 ms),
which is lower than the value of 42.8=/-2.1 ms acquired with the previous
bright blood technique. Conclusion: This study validated the application of a
single breathhold black blood single shot fast spin echo acquisition based for
human liver T1rho imaging. The lower liver parenchyma T1rho value and higher
scan rescan reproducibility may improve of the sensitivity of this technique.
