Yin Huang, Presenter: Nothing to Disclose

Nathan Artz, Abstract Co-Author: Nothing to Disclose

David Niles, Abstract Co-Author: Nothing to Disclose

Elizabeth A. Sadowski MD, Abstract Co-Author: Nothing to Disclose

Sean B. Fain PhD, Abstract Co-Author: Research grant, General Electric Company Research Consultant, Marvel Medtech, LLC

The purpose of this work is to measure cortical T1 values on a subject-specific basis in both native and transplanted kidneys.

A total of 22 subjects (22 native and 11 transplant kidneys) with a wide range of renal function (eGFR) were recruited. Two MR exams were performed at least 24 hours apart for an inter-day reproducibility study. An inversion recovery single shot fast spin echo (SSFSE) sequence on a 1.5 T MR scanner with different inversion times (TI) ranging from 100-3500 ms was used to measure T1 (TR/TE=4000/24.8 ms, and FOV=34 cm). The T1 map was calculated on a pixel-by-pixel basis in the whole kidney. The mean value of the T1 was calculated over the segmented cortical region and averaged over the two native kidneys when applicable. The reproducibility of kidney cortical T1 values were investigated by calculating the percent differences between days 1 and 2.

The mean, standard deviation (SD) and standard error of the mean (SEM) for the transplanted-kidney group are all higher than those of native kidney group. The mean T1 values of native and transplant kidneys were statistically significant (p=0.002). The inter-day variation of T1 values was greater for the transplant kidneys (SD=3.2 for native and SD=8.3 for transplant).

Cortical tissue in transplanted kidneys demonstrates larger T1 variation than native kidneys.

The arterial spin labeling allows the measurement of kidney perfusion without the risk of nephrogenic systemic fibrosis. Our work in T1 variation is applicable in ASL perfusion calculation.

Huang, Y, Artz, N, Niles, D, Sadowski, E, Fain, S, MR Analysis of T1 Relaxation Times in the Renal Cortex of Native and Transplanted Kidneys.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016955.html