Traditional Posters: Body Imaging

Mike Notohamiprodjo¹, Michael Pedersen², Klaus-Peter Lodemann³, Maximilian F. Reiser, Christian Glaser, Steven P. Sourbron

¹Institute for Clinical Radiology, University Hospitals Munich, Munich, Bavaria, Germany; ²Skejby Sygehus Aarhus, Aarhus, Denmark; ³BRACCO S.p.a.
In this study a method is proposed to detect albumin leakage across the glomerular membrane with DCE-MRI. Four healthy piglets were examined with a dual-agent protocol with the contrast agent Gd-DTPA and the albumin-bound Gd-BOPTA. The small variability in the GFR values indicates that the measurement approach may be sufficiently precise to detect subtle variations in Gd-BOPTA relaxivity due to increased albumine leakage. This technique may help detecting such diseases in an early stage, where tubular reabsorption of albumine masks the leakage in urine samples. Further studies in a model with albumine leakage is warranted.

2685. Counting Total Number of Kidney Glomeruli Using MRI

Scott Charles Beeman¹, Megan Henriksen¹, David Frakes¹, Kevin M. Bennett<sup>1

1</sup>Bioengineering, Arizona State University, Tempe, AZ, United States

We present a method for counting number of renal glomeruli using MRI. Rats were given intravenous injections of CF followed by resection of kidneys. Ex vivo Imaging revealed spots of hypointensity throughout the cortex of the kidney due to accumulation of CF in the glomerular basement membrane, consistent with individual glomeruli. Thresholding techniques applied to the image volumes yielded a glomerular count of 43,362 glomeruli. This is in agreement with and lies within 10% of a histological count of 39,514 glomeruli in the contralateral kidney, indicating an accurate glomerular count of the whole kidney.

2686. Segmentation of Kidney Cortex and Medulla on MR Images by Use of Multi-Feature K-Means Method

Yin Huang¹, Deborah Yagow², Nathan Artz¹, Elizabeth Sadowski³, Arjang Djamali⁴, Sean Fain<sup>1

1</sup>Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; ²Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; ³Radiology, University of Wisconsin-Madison, Madison, WI, United States; ⁴Nephrology, University of Wisconsin-Madison, Madison, WI, United States

The K-means segmentation method was implemented to automatically segment kidney cortex and medulla on MR images of 24 subjects based on two kidney feature values -- T1 and perfusion weighted information. Manual segmentation results on the same subjects were used as reference and three similarity measures were calculated to evaluate the effectiveness of K-means segmentation. The segmentation time was radically shortened by K-means compared with manual operation. However, there are about 30% of all subjects that K-means segmentation did not work well so that a semi-automated strategy can be suggested to incorporate manual segmentation when necessary.

2687. Changes in Kidney Volume in Experimental PKD Quantified by a Clinical 3T MR Scanner

Sheryl Foster¹, Mayuresh S. Korgaonkar², Gopi K. Rangan³, Kristina G. Schwensen³, Anthony Peduto<sup>1

1</sup>Radiology, Westmead Hospital, University of Sydney, Australia; ²Brain Dynamics Center, Westmead Millennium Institute, Westmead, NSW, Australia; ³Centre for Transplant and Renal Research, Westmead Millennium Institute, University of Sydney, Australia

The goal of this study was to assess the feasibility of using a 3T whole body clinical scanner along with a conventional available wrist coil in a longitudinal study of drug treatment in small rodents. We studied longitudinal kidney structural changes in rodents with Polycystic Kidney Disease (PKD); and also evaluated the effect of sirolimus treatment, an immunosuppressant drug currently used in clinical trials in humans with PKD, during early disease on the progression of kidney enlargement in this animal model.

2688. Comparison of DCE-MRI and DCE-CT in Patients with Renal Cell Carcinoma: Effects of Temporal Resolution and Total Measurement Time