Evaluation of kidney function by multy-modal magnetic resonance imaging and spectroscopy in renal transplantation

Kidney transplantation is the preferred procedure in end-stage renal disease, since it offers the best prognosis and a superior quality of life. Intense monitoring using a non-invasive reliable and repeatable technique for the detection of graft dysfunction is fundamental to improve the rate of successful outcome of renal transplantation.
Diffusion-weighted (DW) - and blood oxygenation level-dependent (BOLD) - magnetic resonance imaging (MRI) and MR spectroscopy (MRS) are promising functional MR-methods for the diagnostic work-up of the kidney and to noninvasively monitor functional derangements in renal allografts, providing complementary information.

Before these functional MR-methods can be applied in clinical practice, they have first to be optimized methodologically to provide reliable and robust results, second, their sensitivity to detect changes in renal function has to be demonstrated, and, third, since renal function deteriorates after kidney transplantation for multiple reasons, clinically relevant confounding factors presumably affecting the results have to be defined. These three aspects are addressed in the grant.

We expect that the project with its main focus on improving the methodology will provide robust and sensitive functional MR-tools that can be applied in clinical practice. Although the primary target of application of this proposal will be on kidney transplantation, we anticipate that the same methods are useful for abdominal functional imaging in general. Thus it is reasonable to predict that these areas will also benefit from technical developments proposed in this grant.
With the proposed approach we shall be able first, to elucidate with some restriction the effect of uninephrectomy on the performance of the remaining kidney and second, to define the functional impact as assessed by MRI and MRS of calcineurin withdrawal. In the latter study the functional MR data can be linked with histological results. They provide information about the degree of fibrosis, narrowing of blood vessel lumen, tubular atrophy or glomerular damage, whereas BOLD imaging is very sensitive to any changes in oxygenation that may occur due to changed blood flow or changes in reabsorption and concentration-dilution function, diffusion MRI document changes in tissue make-up mainly linked with fibrosis, edema or fluid transport, and 1H-MRS yields an estimate of tissue lactate and osmolytes.

Dr. Peter Vermathen, Dr. Ute Eisenberger, Dr. Roland Kreis, Dr. Harriet Thöny

Swiss National Foundation, Project no. 111959