An experimental approach for dynamic rat liver observation in vivo and ex vivo by 31P localized MR spectroscopy for follow‐up of liver status at different steps of orthotopic transplantation–a feasibility study

Abstract

An experimental approach was evaluated to perform a follow-up of rat liver transplantation by 31P spectroscopy. The approach is based on the use of an implanted surface coil attached to the liver and inductively coupled to the receiver/transmitter line by an external coupling loop. Spatial localization to the liver was performed by selective excitation and dephasing of spins in a slice between the implanted and the coupling coil, the slice being positioned on a proton image acquired prior to spectroscopy. Characteristics of the protocol were established on a phantom and in vivo on non-transplanted rat livers indicating good localization and high signal-to-noise ratio. Preliminary results obtained on transplanted livers revealed a relation between evolution of the 31P spectrum and animal survival. As shown in separate experiments, the same technique also enabled easy acquisition of the 31P profile of livers stored at 4 degrees C in University of Wisconsin solution. Therefore, the experimental approach described here opens up the possibility of measuring changes of the 31P profile on the same liver during the whole transplantation procedure, i.e., in the donor, during preservation and after transplantation, and comparing evolution of spectra with transplantation outcome.