Utility of breath-hold fast-recovery fast spin-echo T2 versus respiratory-triggered fast spin-echo T2 in clinical hepatic imaging

OBJECTIVE. The objective of our study was to compare a breath-hold fat-suppressed fast-recovery fast spin-echo (FSE) T2-weighted sequence with a respiratory-triggered fat-suppressed FSE T2-weighted sequence to assess the effect on image quality and lesion detection and characterization in clinical hepatic imaging. MATERIALS AND METHODS. Both the breath-hold fat-suppressed fast-recovery FSE and respiratory-triggered fat-suppressed FSE T2-weighted sequences were acquired in 46 patients. Two radiologists, blinded to clinical data, independently evaluated randomized images from both sequences. Qualitatively, images were graded on a 5-point scale for five different characteristics. The number and location of lesions were recorded. The confidence of detection and the confidence of characterization (solid vs nonsolid) were graded on a 5-point scale. A consensus review using radiology, clinical, and pathology data served as the standard. Receiver operating characteristic (ROC) curve analysis (area under the ROC curve [A(z)]) was used to compare each reviewer's interpretation against the consensus interpretation. Quantitative analysis was performed by calculating the liver signal-to-noise ratio (SNR), liver-to-spleen contrast-to-noise ratio (CNR), and lesion-to-liver CNR. Both one- and two-tailed Student's t tests were used to check for significance. RESULTS. Qualitatively, both reviewers graded the breath-hold fat-suppressed fast-recovery FSE T2-weighted sequence better than the respiratory-triggered fat-suppressed FSE T2-weighted sequence on all five characteristics (p < 0.005). Of 78 lesions detected, 29 were characterized as solid; 47, nonsolid; and two, indeterminate. On ROC analysis, there were no significant differences between the breath-hold fat-suppressed fast-recovery FSE and respiratory-triggered fat-suppressed FSE T2-weighted sequences in lesion detection (A(z) reviewer 1. 0.77 and 0.83, respectively, [p = 0.12]; A(z) reviewer 2, 0.84 and 0.80, respectively [P = 0.12]) or in lesion characterization (A(z) reviewer 1, 0.86 and 0.92, respectively [P = 0.33]; A(z) reviewer 2, 0.90 and 0.91, respectively [p = 0.79]). Quantitatively, liver SNRs, spleen CNR, and lesion CNRs (solid and nonsolid lesions) were significantly better on the breath-hold fat-suppressed fast-recovery FSE T2-weighted images than on the respiratory-triggered fat-suppressed FSE T2-weighted images (p < 0.005). CONCLUSION. Breath-hold fat-suppressed fast-recovery FSE T2-weighted images were of better quality than respiratory-triggered fat-suppressed FSE T2-weighted images, and lesion detection and characterization were comparable.