Live nephron imaging by MRI.
Authors Qian C, Yu X, Pothayee N, Dodd S, Bouraoud N, Star R, Bennett K, Koretsky A
Submitted By Submitted Externally on 1/6/2015
Status Published
Journal American journal of physiology. Renal physiology
Year 2014
Date Published 11/15/2014
Volume : Pages 307 : F1162 - F1168
PubMed Reference 25186296
Abstract The local sensitivity of MRI can be improved with small MR detectors placed
close to regions of interest. However, to maintain such sensitivity advantage,
local detectors normally need to communicate with the external amplifier through
cable connections, which prevent the use of local detectors as implantable
devices. Recently, an integrated wireless amplifier was developed that can
efficiently amplify and broadcast locally detected signals, so that the local
sensitivity was enhanced without the need for cable connections. This integrated
detector enabled the live imaging of individual glomeruli using negative
contrast introduced by cationized ferritin, and the live imaging of renal
tubules using positive contrast introduced by gadopentetate dimeglumine. Here,
we utilized the high blood flow to image individual glomeruli as hyperintense
regions without any contrast agent. These hyperintense regions were identified
for pixels with signal intensities higher than the local average. Addition of
Mn(2+) allowed the simultaneous detection of both glomeruli and renal tubules:
Mn(2+) was primarily reabsorbed by renal tubules, which would be distinguished
from glomeruli due to higher enhancement in T1-weighted MRI. Dynamic studies of
Mn(2+) absorption confirmed the differential absorption affinity of glomeruli
and renal tubules, potentially enabling the in vivo observation of nephron

Investigators with authorship
Kevin BennettWashington University in St Louis