Fang Zhu MD, PhD, Presenter: Nothing to Disclose

Cheng Tao MD, Abstract Co-Author: Nothing to Disclose

James E. Bost PhD, Abstract Co-Author: Nothing to Disclose

Kathryn Mazzaferro MA, Abstract Co-Author: Nothing to Disclose

Catherine M. Meyers MD, Abstract Co-Author: Nothing to Disclose

Kyongtae Tyler Bae MD, PhD, Abstract Co-Author: Patent agreement, Tyco Healthcare (Mallinckrodt Inc), St Louis, MO Patent agreement, Bayer AG (MedRad, Inc), Pittsburgh, PA Medical Advisory Board, Bracco Group, Milan, Italy Research Consultant, Otsuka Pharmaceutical Co, Ltd, Rockville, MD

Arlene Chapman MD, Abstract Co-Author: Nothing to Disclose

Jared Grantham MD, Abstract Co-Author: Nothing to Disclose

Vicente E. Torres MD, Abstract Co-Author: Nothing to Disclose

Lisa M. Guay-Woodford MD, Abstract Co-Author: Nothing to Disclose

Deborah Ann Baumgarten MD, MPH, Abstract Co-Author: Nothing to Disclose

Philip James Kenney MD, Abstract Co-Author: Nothing to Disclose

Bernard F. King MD, Abstract Co-Author: Nothing to Disclose

Louis Herman Wetzel MD, Abstract Co-Author: Nothing to Disclose

William Gerald Bennett MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To compare and assess differences in kidney volume measurements that were obtained from pre- and post-gadolinium T1, and T2 images of patients with polycystic kidney disease (PKD) and to evaluate intra- and inter-reader variability of the measurements.

The Consortium for Radiologic Imaging Studies of PKD (CRISP) was formed to conduct imaging studies for assessing the progression of PKD. Twenty subjects were randomly selected with equal frequency from three kidney-size groups (1500 mL). Pre- and post-gadolinium 3D gradient-echo T1 (pre-T1, post-T1) without fat saturation and fast spin-echo T2 with fat saturation images were obtained using breath-hold, coronal MR imaging. Stereology method was applied to segment and measure kidney volumes. The measurement process was repeated at one-week intervals by two radiologists (reader1, reader2). Reliability was assessed with correlation coefficients. Intra- and inter-reader bias and measure differences were assessed with paired T-tests. The size effect was evaluated with one-way ANOVA.

Kidney volumes measured with pre-T1 was significantly (P1500 mL). The intra- and inter-reader reliability was extremely high (r=0.99) in all measurements. Overall bias and variability (mean±SD, mL) of the volume measurements were (intra-, inter-reader): (14.6±22.7, -9.6±30.0) with pre-T1; (9.5±22.1, -30.4±34) with post-T1; and (5.7±20.3, 60.7±47.4) with T2 images, all indicating no systematic intra-reader bias but small inter-reader bias for post-T1 and T2.

Kidney volumes measured with pre-gadolinium T1 were consistently smaller than those with post-gadolinium T1, and the percent differences tended to be smaller with increasing kidney size.

When kidney volume is used as a surrogate biomarker for the progression of disease in PKD, we should be aware that the volume measurement is affected by the type of MR images used.

Zhu, F, Tao, C, Bost, J, Mazzaferro, K, Meyers, C, Bae, K, Chapman, A, Grantham, J, Torres, V, Guay-Woodford, L, Baumgarten, D, Kenney, P, King, B, Wetzel, L, Bennett, W, et al, , et al, , Kidney Volume Measurements from MR Images: Comparison between Pre- and Post-Gadolinium T1 and T2 Images and Intra- and Inter-reader Variability.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5005660.html