The value of respiratory triggered T2-weighted turbo spin-echo imaging of the liver using a phased array coil

The purpose of this study was to evaluate the value of the respiratory trig gered turbo spin-echo (TSE) technique for T2-weighted MRI of liver lesions. Fifty-nine patients (32 men, 27 women; mean age, 63.3 years) with focal he patic lesions were prospectively studied with MRI at 1.5 T with use of a bo dy phased array coil. In the first 15 patients, breath-hold TSE, respirator y triggered TSE, and conventional nonrespiratory triggered TSE T2-weighted imaging were compared. Because nonrespiratory triggered TSE imaging was sig nificantly inferior (P < .01) to breath-hold or respiratory triggered image s, breath-hold and respiratory triggered TSE T2-weighted images were compar ed in the remaining 44 patients. Images were analyzed quantitatively by mea suring the liver signal-to-noise ratio and the lesion-liver and spleen-live r contrast-to-noise ratios and qualitatively by evaluating the lesion consp icuity, liver parenchymal homogeneity, and sharpness of intrahepatic vessel s. The imaging time was 26 seconds for breath-hold TSE imaging, 49 to 219 s econds (mean, 149 seconds) for the respiratory triggered TSE imaging, and 7 9 to 379 seconds (mean, 239 seconds) for the nonrespiratory triggered TSE i maging. Quantitatively, the signal-to-noise ratio of the liver for breath-h old imaging was comparable to that for respiratory triggered imaging, The l esion-liver and liver-spleen contrast-to-noise ratios for the respiratory t riggered images were greater by 37% and 39%, respectively, than for the bre ath-hold T2-weighted TSE images. Qualitatively, the respiratory triggered i mages showed lower frequency of image artifact, better lesion conspicuity, and greatly superior depiction of intrahepatic structures compared with the breath-hold T2-weighted TSE images. The respiratory triggered T2-weighted TSE technique provides better quality liver images than the breath-hold TSE technique or nonrespiratory triggered technique within a reasonable acquis ition time.