Multisection T1-weighted hybrid-RARE: a pulse sequence for MR imaging of the entire liver during suspended respiration.
It is shown that the maximum average-data-collection-speed (ADCS) of multisection 2D hybrid-RARE sequences is independent of TR and TEeff, and a monotonically increasing function of echo-train-length (ETL). This result was used in the design of an optimized T1-weighted hybrid-RARE sequence that produces 20 images of the abdomen in 31 s divided into four breath-hold periods. The resulting ADCS is 58 lines in k-space per second. Twenty-four subjects (2 healthy volunteers and 22 patients) were imaged with a protocol that also included: (a) breath-hold T1-weighted FLASH which acquires data at 34 lines in k-space per second (49 s scan time), and (b) T1-weighted conventional spin-echo (9:44 minutes scan time) with respiratory compensation. The experiments show that this T1-weighted-hybrid-RARE sequence has: (1) a level of T1 weighting that is comparable with the conventional sequences, (2) very low vulnerability to susceptibility artifacts, (3) high data acquisition efficiency, and (4) higher SNR than T1-weighted-FLASH. In conclusion, the T1-weighted-hybrid-RARE sequence described herein is an efficacious and reproducible technique for rapid imaging of the upper abdomen during suspended respiration.
Jara
H
H
Boston City Hospital Center for MRI, Boston University School of Medicine, Massachusetts, USA.
Soto
J A
JA
Yu
B
B
Hentzen
P C
PC
van Yperen
G H
GH
Yucel
E K
EK
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008099:Liver; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012119:Respiration; D013154:Spleen