Multiparametric Functional Magnetic Resonance Imaging for Evaluating Renal Allograft Injury

Abstract

Kidney transplantation is the treatment of choice for patients with end-stage renal disease, as it extends survival and increases quality of life in these patients. However, chronic allograft injury continues to be a major problem, and leads to eventual graft loss. Early detection of allograft injury is essential for guiding appropriate intervention to delay or prevent irreversible damage. Several advanced MRI techniques can offer some important information regarding functional changes such as perfusion, diffusion, structural complexity, as well as oxygenation and fibrosis. This review highlights the potential of multiparametric MRI for noninvasive and comprehensive assessment of renal allograft injury.

Physiological system analysis of the kidney by high‐temporal‐resolution monitoring of an oxygenation step response

“…The system parameters were quantified by fitting the above model functions to the T * 2 data acquired at different time, using nonlinear Levenberg-Marquardt least-squares optimization. 42 Fitting quality was indicated by the coefficient of determination R 2 . Figure 1 presents the results of the phantom measurements that were performed to evaluate the accuracy of the hightemporal-resolution T * 2 mapping.…”

“…To address this shortcoming, an increasing number of studies employ multi-parametric renal MRI. [42][43][44][45][46][47][48] This study enhances the amount of information by adding the time domain using high-temporal-resolution dynamic T * 2 mapping of the kidney's response to a test stimulus, including but not limited to changes in the inspiratory oxygenation fraction. 49,50 We hypothesize that high-temporal-resolution T * 2 monitoring of a step-like oxygenation stimulus facilitates physiological system analysis of the kidney.…”

Assessment of Chronic Allograft Injury in Renal Transplantation Using Diffusional Kurtosis Imaging

“…Among these parameters, MK is the signi cant one obtained from DKI, which renal allografts believed to be a natural complexity. The more complex the structure and the higher the MK value, the higher the degree of diffusion restriction on the non-Gaussian distribution of water molecules [8]. So, we supposed that the microstructural change in CAI might be demonstrated by the DKI technique more precisely than eGFR, and the DKI technique might be a non-invasive method for evaluating CAI This study is planned to evaluate the correlation between eGFR and DKI parameters and the potential feasibility of the DKI technique in non-invasive assessment for CAI.…”

More Studies are Needed Evaluating the Diagnostic Accuracy of Magnetic Resonance Elastography for Allograft Renal Transplant Rejection

“…Dear Editor, We read with interest the recently published genitourinary review by Yu et al (1) entitled "Multiparametric Functional Magnetic Resonance Imaging for Evaluating Renal Allograft Injury." The authors conducted a comprehensive evaluation of the literature on functional magnetic resonance imaging of renal allografts.…”

“…We read with interest the recently published genitourinary review by Yu et al ( 1 ) entitled “Multiparametric Functional Magnetic Resonance Imaging for Evaluating Renal Allograft Injury.” The authors conducted a comprehensive evaluation of the literature on functional magnetic resonance imaging of renal allografts. As the authors note, while rare, complications such as hemorrhage, graft loss, and bowel-perforation related peritonitis can occur with invasive transplant biopsies ( 2 3 ).…”