Comparison of breath‐hold T1‐weighted MR sequences for imaging of the liver

Abstract

Three rapid T1-weighted gradient-echo techniques for imaging of the liver were compared: fast low-angle shot (FLASH) and section-selective (SSTF) and non-section-selective (NSTF) inversion-recovery TurboFLASH. Ten healthy volunteers were imaged at 1.5 T, with breath-hold images acquired in the transaxial and coronal planes and non-breath-hold images in the transaxial plane. Breath-hold images were evaluated quantitatively and qualitatively, and non-breath-hold images were evaluated qualitatively. FLASH images had significantly higher (P < .001) spleen-liver signal difference-to-noise ratios (SD/Ns) than NSTF and SSTF images. Liver signal-to-noise ratios (S/Ns) were significantly higher (P < .001) on FLASH images than on NSTF and SSTF images. With breath hold, FLASH images were rated as having the highest quality in the axial plane, followed by NSTF and SSTF images. In the coronal plane, NSTF images were rated as having the highest quality. For images acquired during patient respiration, NSTF images had the highest quality and showed the least degradation. The results suggest that FLASH images have the highest SD/N and S/N for liver imaging and have the highest quality in the axial plane. In patients who cannot suspend respiration. NSTF images may be least affected by breathing artifact and provide reasonable image quality.

Multisection T1‐weighted hybrid‐rare: A pulse sequence for MR imaging of the entire liver during suspended respiration

“…The imaging pro-770 Tara et al In the hvbrid-RARE implementation used in this work, the number of profiles per section must be a multiple of ETL (=6), consequently, the calculated value of 92 is reduced to only 90. tocol consisted of: (a) T1W-hybrid-RARE, (b) T1W-FLASH, and (c) T1W-CSE, the key scan parameters of which are listed in Table 2. The T1W-FLASH sequence was implemented without RF spoiling and with TR, TE, anti flip angle chosen to closely match the settings reported to produce optimum TI contrast and image quality (50). To achieve a minimum TE,,, of 10 ms, the TIWhybrid-RARE sequence was used with the low-high echoto-view mapping scheme in which the sub-echoes corresponding to the low order phase encoding profiles are positioned at the beginning of the CPMG train (Fig.…”

“…These include large flip angle sequences, the gradient-echo based fast-low-angleshot (FLASH) and the spin-echo based rapid acquisition spin-echo (RASE). The ADCS values of these are limited to approximately 30 k-lines/s at 10 mTesla/m (39,50) because of the long TE to TR inactive interval required for 'T, contrast. Approximately a threefold improvement in ADCS can be achieved with the low flip angle Turbo-FLASH (41,43) sequence in which the TE to TR interval can be minimized since the TI contrast is produced by a preinversion pulse.…”

Imaging for Diagnosis of Hepatocellular Carcinoma

“…The MRI protocol should include T2-weighted sequences and dynamic contrast-enweighted sequences HCCs are usually hyperintense. Tumor vascularity is best seen on contrast-enhanced dy-hanced MRI with breathhold gradient echo sequences after gadolinium chelate injection [18]. Analogous to binamic T1-weighted sequences in the arterial phase analogous to CT [9].…”

Comparison of T1‐weighted in‐ and out‐of‐phase single shot magnetization‐prepared gradient‐recalled‐echo with three‐dimensional gradient‐recalled‐echo at 3.0 tesla: Preliminary observations in abdominal studies

“…One solution that has been used for unenhanced T1-weighted imaging at higher field strengths is incorporating a magnetization preparation prepulse for gradient-echo imaging, commonly designated as magnetization-prepared (MP)-GRE (7,9). This single-shot technique allows the acquisition of each slice in less than 1 s, and so it is principally used in patients unable to suspend respiration (11)(12)(13)(14)(15).…”