title: Navigator-echo-based MR provides high-resolution images and precise volumetry of swine livers without breath holding or injection of contrast media.
abstract: The accurate calculation of hepatic volume by computed tomography (CT) or magnetic resonance (MR) is complicated by the need for breath holding and the injection of contrast media. These are often contraindicated in patients with liver failure, and we examined the ability of unenhanced 3-dimensional (3-D) navigator-echo-based MR (NE-MR) to accurately image livers and measure volumes without breath holding compared to unenhanced (plain) or gadolinium-diethylene triamine pentaacetic acid enhanced MR (Gd-MR) in miniature swine (n = 8). Without breath holding, diaphragm movement monitoring with NE-MR reduced motion artifacts in hepatic images compared with the other modalities. Without the injection of contrast media, the signal-to-noise ratios of the images obtained using NE-MR were significantly higher than those from plain MR; Gd-MR was superior to NE-MR, however (79.5 +/- 7.5 vs. 63.2 +/- 6.0 or 97.8 +/- 8.1, respectively; P < 0.01 for each). Overall, NE-MR produced improved high-resolution liver images. Consequently, liver volumes calculated based on NE-MR images were more highly correlated with actual liver weights compared to plain or Gd-MR in the whole livers (n = 8; r = 0.937 vs. 0.835 or 0.904, respectively). Also, NE-MR demonstrated significantly strong correlation between actual weights and volumetry-calculated volumes in regenerative livers 7 days after massive hepatectomy (n = 10, r = 0.989, P < 0.01). In conclusion, our results indicate that without breath holding or the injection of contrast media, 3-D NE-MR can provide both high-resolution liver images and precise hepatic volumes in patients with liver failure due to liver surgery (massive hepatectomy and living donor liver transplantation) or fulminant hepatic failure.
authors.affiliation: Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan. ildeok@kuhp.kyoto-u.ac.jp
authors.forename: Il-Deok
authors.initials: ID
authors.lastname: Kim
authors.forename: Takashi
authors.initials: T
authors.lastname: Azuma
authors.forename: Akio
authors.initials: A
authors.lastname: Ido
authors.forename: Akihiro
authors.initials: A
authors.lastname: Moriuchi
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Numata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Teramukai
authors.forename: Jun
authors.initials: J
authors.lastname: Okamoto
authors.forename: Sadami
authors.initials: S
authors.lastname: Tsutsumi
authors.forename: Koichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Hirohito
authors.initials: H
authors.lastname: Tsubouchi
mesh_terms: D000818:Animals; D016477:Artifacts; D003287:Contrast Media; D004195:Disease Models, Animal; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006498:Hepatectomy; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008099:Liver / Q000473:pathology*; D011336:Probability; D011897:Random Allocation; D012119:Respiration; D012680:Sensitivity and Specificity; D013552:Swine; D013556:Swine, Miniature
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA