New magnetic resonance imaging methods in nephrology Jeff L. Zhang, Glen Morrell, Henry Rusinek, Eric E. Sigmund, Hersh Chandarana, Lilach O. Lerman, Pottumarthi V. Prasad, David Niles, Nathan Artz, Sean Fain, Pierre-Hugues Vivier, Alfred K. Cheung, Vivian S. Lee  Kidney International  Volume 85, Issue 4, Pages 768-778 (April 2014) DOI: 10.1038/ki.2013.361 Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 1 Conventional anatomic magnetic resonance imaging (MRI) of kidney. The cyst, (a) with long T1, is dark on a T1-weighted image, and (b) with long T2, bright on a T2-weighted image. Kidney International 2014 85, 768-778DOI: (10.1038/ki.2013.361) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 2 Kidney T2* maps from blood oxygen level–dependent (BOLD) imaging. The scale on the right side is T2* value, with unit of milliseconds. Higher T2* corresponds to lower deoxyhemoglobin concentration. (a) Typical T2* map with conventional BOLD scan (20-s breath-hold, matrix size 256 × 256, field of view (FOV) 32 × 32cm2). (b) T2* map with free-breathing prospectively navigated sequence (10-m imaging time, matrix size 512 × 512, FOV 50 × 50cm2). The free-breathing images offer greater image quality. Kidney International 2014 85, 768-778DOI: (10.1038/ki.2013.361) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 3 Difference images obtained from renal arterial spin labeling (ASL) scans. (a) Acquired at 800ms after arterial blood labeling, when the labeled blood is mostly in the renal cortex; (b) acquired at 1000ms after the labeling, and some labeled blood reaches the renal medulla. The images were acquired by a modified TrueFISP FAIR ASL (true-fast imaging with steady-state precession flow-sensitive alternating inversion recovery arterial spin labeling) sequence (eight averages, acquisition time ∼24s, with breath-hold). Kidney International 2014 85, 768-778DOI: (10.1038/ki.2013.361) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 4 Kidney diffusion-weighted imaging using diffusion tensor imaging (DTI) methods. Following imaging processing, color-coded primary diffusion eigenvectors display radial pattern of medullary tubules. Kidney International 2014 85, 768-778DOI: (10.1038/ki.2013.361) Copyright © 2014 International Society of Nephrology Terms and Conditions

Figure 5 Primitive right megaureter on a bifid ureter in a 6-month-old boy. (a) T2-weighted image with fat saturation. (b) Coronal view of volume-rendered T2-weighted images. (c) Oblique view of volume-rendered T2-weighted images. (d) Maximum intensity projection of T1-weighted images at excretory phase. (e) Renography before contrast arrival. (f) Renography at arterial phase. (g) Renography at tubular phase. (h) Renography at excretory phase. Symmetric enhancement and excretion of contrast bilaterally suggests that the marked dilatation of the right collecting system and ureter is not a functional obstruction. Kidney International 2014 85, 768-778DOI: (10.1038/ki.2013.361) Copyright © 2014 International Society of Nephrology Terms and Conditions