Different strategies for MRI measurements of renal cortical volume

✍ Scribed by Kristian Karstoft; Anders B. Lødrup; Thomas H. Dissing; Thomas S. Sørensen; Jens R. Nyengaard; Michael Pedersen

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 351 KB
• Volume: 26
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.21121

✦ Synopsis

Abstract

Purpose

First, to measure renal cortical volume (Vc) using different MRI methods combined with a semiautomatic segmentation method. Second, to compare MRI measurements of Vc using the semiautomatic segmentation method with a manual segmentation method. Third, to evaluate the reproducibility of Vc measurements.

Materials and Methods

A total of 22 pigs, 13 with healthy kidneys and nine with diseased kidneys, underwent MRI with two non‐contrast‐agent methods (MRI~100×900~ and MRI~300×1100~) and one contrast‐agent method (MRI~Gd~). For each of these methods, Vc was estimated using semiautomatic (Vc~100×900~, Vc~300×1100~, and Vc~Gd~), as well as manual (Vc~MANUAL~) segmentation. Reference volumes were estimated by stereological means (Vc~STEREOLOGY~). MRI‐derived volumes were compared with reference volumes using a two‐tailed paired t‐test, and variances between methods were visualized with Bland Altman plots. Reproducibilities were analyzed using covariance analysis.

Results

Neither measurements of Vc~100×900~, Vc~300×1100~, nor Vc~Gd~ differed markedly from Vc~STEREOLOGY~ using semiautomatic segmentation. Vc was comparable when semiautomatic and manual segmentations were performed at the same scan. Reproducibility of MRI estimated Vc values offered intra‐ and interindividual differences <5%.

Conclusion

Vc can in both healthy and diseased kidneys be measured accurately with MRI using both semiautomatic and manual segmentation, and measurements can be obtained with a high reproducibility. Measurements of Vc~100×900~ may in the future become suitable in patients with chronic renal failure. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.