I write in reference to the article “Hepatic volume measurements in dogs with extrahepatic congenital portosystemic shunts (CPSS) before and after surgical attenuation” by Kummeling et al (2010;24:114–119). I feel that the conclusion “CT is the preferred imaging method for volumetric estimation because of speed” is inaccurate. The authors compared a single slice helical CT scanner with a 0.2 T open MRI; this is not an even comparison. The higher the magnet strength, the faster the image acquisition. We routinely use our 1.5 T MRI to evaluate for CPSS and liver volume. We also have a helical slice CT scanner. We have looked at both modalities in several cases and felt strongly that the MRI was more accurate and equally rapid. While I cannot say the study is not valuable, a comparison with a high field unit or some comments about the comparison should have been included in the summary.