The Dixon technique and the frequency-selective fat suppression technique in three-dimensional T ₁ weighted MRI of the liver:A comparison of contrast-to-noise ratios of hepatocellular carcinomas-to-liver

Objective: The use of three-dimensional T ₁ weighted gradient echo sequences such as the Dixon technique and the frequency-selective fat suppression (FS) technique is currently widely accepted method in MRI examinations of the liver. To assess the image qualities of the Dixon technique and the frequency-selective FS technique, the contrast-to-noise ratios (CNRs) of hepatocellular carcinoma (HCC)-to-liver and fat-to-liver were compared between the two techniques in the hepatobiliary phase (HBP) following administration of gadolinium-ethoxybenzyldiethylenetriamine penta-acetic acid. Methods: MR images of 59 patients with a total of 86 HCCs were retrospectively evaluated. Images were consecutively obtained with the Dixon and frequency-selective FS methods in the HBP and their CNRs of HCC-to-liver and fat-to-liver were compared. CNRs and contrast ratios were calculated by the mean value of the liver parenchyma, HCC, fat and standard deviation of the liver parenchyma. The Wilcoxon signed-ranks test was used for statistical analysis. Results: The median CNRs for the frequency-selective FS and Dixon techniques of HCC-to-liver were 4.3 and 5.4 (p < 0.01), mesenteric fat-to-liver were 9.9 and 12.8 (p < 0.01) and subcutaneous fat-to-liver were 9.9 and 13.2 (p < 0.01), respectively. Conclusion: The Dixon technique yielded higher CNRs of HCC-to-liver than that of the frequency-selective FS technique. Advances in knowledge: There are a limited number of reports on quantitative analysis of the image qualities of the Dixon technique and the frequency-selective FS technique, particularly within the same patient and examination.