title: Motion artifact in T2-weighted fast spin-echo images of the liver: effect on image contrast and reduction of artifact using respiratory triggering in normal volunteers.
abstract: The purpose of our study was to evaluate the effect of respiratory motion on the image contrast of T2-weighted fast spin-echo (FSE) images of the liver as well as the reduction of motion artifact using respiratory triggering of the data acquisition. We imaged the livers of 10 healthy volunteers using a fast spin-echo T2-weighted sequence. Images were obtained both without and with patient triggering. Triggered images were acquired in a segmented fashion during multiple sequential breath-holds using an echo train of 8 or 16, both with and without flow compensation (gradient moment nulling). Ratios of signal difference to noise (SD/N) of the liver and gallbladder as well as the liver and spleen were compared for all sequences. All of the triggered images showed statistically significant improvement of SD/N for the liver and gallbladder as well as for the liver and spleen when compared with the nontriggered images. Triggered images obtained with an echo train length of 8 and, with flow compensation, showed the highest SD/N ratios. In one volunteer whose liver contained multiple small cysts, the triggered images showed improved visualization of individual cysts and identified a larger number of cysts. Respiratory motion causes a significant loss of contrast on T2-weighted fast spin-echo images of the liver. This can be reduced by using a segmented data acquisition triggered by the respiratory cycle obtained during sequential breath-holds.
authors.affiliation: Department of Diagnostic Imaging, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Choe
authors.forename: R C
authors.initials: RC
authors.lastname: Smith
authors.forename: K
authors.initials: K
authors.lastname: Wilkens
authors.forename: R T
authors.initials: RT
authors.lastname: Constable
mesh_terms: D000328:Adult; D016477:Artifacts; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000033:anatomy & histology*; D008297:Male; D009068:Movement; D012016:Reference Values; D012119:Respiration / Q000502:physiology*; D012680:Sensitivity and Specificity