Detection of Total Parenteral Nutrition‐Induced Fatty Liver Infiltration in the Rat by in Vitro Proton Nuclear Magnetic Resonance

In an effort to determine if NMR techniques might be used to detect TPN-induced hepatic steatosis, the NMR spin-lattice (T1) and spin-spin (T2) relaxation times were measured on liver tissue from rats who received one of five dietary regimens: (1) 100% of nonprotein calories as lipid (Fat); (2) a mixture of 50% lipid and 50% glucose nonprotein calories (50/50); (3) 100% of nonprotein calories as glucose (CHO); (4) intravenous saline and standard laboratory rat chow (Saline); and (5) rat chow alone (Oral). The parenteral diets were isonitrogenous and isocaloric. Serum liver function tests were also measured. Animals in the Fat and 50/50 groups had the greatest amounts of liver fat and significantly longer T1 and T2 times (p less than 0.01) than any other group. Furthermore, the correlation of T2 time with liver fat content (r = 0.82) was far superior (p less than 0.001) to that of serum SGPT (r = 0.48) which was the only liver function test which correlated significantly with liver fat content. In a multiple linear regression analysis, T1 and T2 predicted liver fat content with an r value of 0.84 (p less than 0.001). These data suggest that in vivo NMR imaging techniques might be used to detect TPN-induced fatty infiltration of the liver noninvasively.