The Study Of Relationship Between Energy Metabolic Changes On Phosphorus-31 MR Spectroscopy And The Severity Degree Following Acute Hepatic Injury In Rabbit Models

Objective To investigate the value of phosphorus-31 MR spectroscopy(³¹p MRS) with analyzing hepatic energy metabolic changes compared with the liver damage score (LDS) following acute hepatic radiation injury in rabbit models.Methods A total of 30 rabbits with acute hepatic radiation injury of different radiation dose(ranging from 5Gy to 20Gy) were examined with hepatic and renal function and 31P MRS and compared to 10 healthy rabbits.All rabbits were divided into three groups,including mild hepatic injury group,moderate hepatic injury group and severe hepatic injury group,according to LDS:mild-with LDS≤3U,moderate with LDS 3-6 U and severe with LDS＞6 U.MR examination was performed on a 1.5 T imager using a 1H/31P surface coil by the 2D chemical shift imaging technique.The relative quantification of phosphomonoesters(PME),phosphodiesters(PDE),inorganic phosphate(Pi) and adenosine triphosphate(ATP) were measured.Resultsâ‘ Relative quantification of phosphorus metabolites:The ATP levels of control,mild hepatic injury,moderate hepatic injury and severe hepatic injury group were 1.83±0.33,1.55±0.24,1.27±0.07 and 0.98±0.18 respectively.There were significant changes among four groups.ATP levels progressively decreased with the increase of severity of hepatic injury(γ=-0.723,p＜0.001).The relative quantification of PME and Pi decreased in severe hepatic injury group,and there were significant changes compared to control respectively.The relative quantification of PDE levels were no significant changes among them.â‘¡The ratio of relative quantification of phosphorus metabolites:There were only significant changes of PDE/ATP ratio in moderate and severe hepatic injury group compared to control and mild hepatic injury respectively.No significant changes were found in ratio of relative quantification of other phosphorus metabolites.Conclusion ³¹p MRS is a useful method to evaluate acute hepatic injury.There is an evident correlation between the relative quantification of hepatic ATP levels and LDS, the relative quantification of hepatic ATP levels can reflect the severity of acute hepatic radiation injury correctly in rabbits.