CT and MR imaging of the liver - Clinical importance of nutritional status

Purpose: In an experimental study in rats a correlation between nutritional status and hepatic attenuation in CT and signal intensities in MR imaging was shown. Is physiological nutritional status of importance in clinical CT and MR imaging? Material and Methods: In a cross-over study including 12 healthy volunteers (6 women and 6 men, mean age 34 years), CT and MR imaging of the liver wer e performed with nutritional status at three different levels, i.e., normal , fasting and after glycogen-rich meals. CT and MR were performed on clinic al imaging systems and hepatic attenuation and signal intensity, respective ly, were assessed. In MR, T1-weighted, proton density-weighted and T2-weigh ted pulse-sequences were used. Results: In CT there were significantly (p<0.01) higher liver attenuations in normal nutritional status and after glycogen rich-meals compared to the fasting condition. The difference between fasting and glycogen-rich meals w ere 10.5 HU for men, 7.4 for women and mean 8.8 HU for all 12 volunteers. I n MR imaging the differences were small and non-significant. The results of this study are in accordance with an earlier experimental study in rats. Conclusion: In CT it may be of importance not to have patients in a fasting condition as it lowers the attenuation in normal liver tissue. The finding s are important for planning of clinical studies where hepatic attenuation will be assessed and may be of some importance in clinical CT. In MR imagin g the results indicate that the nutritional status is of less importance.