Functional MR imaging in transplanted kidney dysfunction

Kidney transplantation has emerged as the treatment of choice in patients with end-stage renal disease. During clinical practice, the primary goal of medical follow-up is to enable surveillance of clinical parameters which can be indicators of allograft dysfunction. Clinical manifestation is typically an increase in serum creatinine level and the differential diagnosis must be approached systematically. The etiologies can vary within time after transplantation, usually guiding clinicians and surgeons through the investigation of all causes, also considering prerenal, postrenal, and intrinsic factors during each time period. In this scenario modern imaging techniques, either invasive or noninvasive, concede an early and accurate diagnosis that radically changes the approach to these disorders. In the last decade, new advances in magnetic resonance imaging (MRI) technology have enabled calculation of various renal parameters in a noninvasive manner through the implementation of sequences that are essential in the functional evaluation of the allograft. These sequences are diffusion-weighted imaging (DWI), diffusion-tensor imaging (DTI), blood-oxygen level-dependent MR, MR nephro/urography, and MR angiography. Given the functional information provided by these sequences, MRI is considered a powerful and promising tool in the assessment of allograft dysfunction.