MRI imaging:
(1) Transverse section of the liver at the level of the bifurcation of the portal vein following administration of contrast material (gadolinium).
(2) In the method of Harbin et al the dividing line is drawn through the main portal vein parallel to the midsagittal plane.
(3) In the modified method of Awaya et al the dividing line is drawn through the right portal vein parallel to the midsagittal plane. This usually will be lateral to Harbin's line and results in a smaller right lobe and larger caudate lobe.
Measurements:
(1) right lobe measurement in cm = distance from lateral-most edge of the right lobe to the Awaya line
(2) caudate lobe measurement in cm = distance from the medial-most edge of the caudate lobe to the Awaya line
ratio of caudate lobe to right lobe =
= (measurement of the caudate lobe) / (measurement of the right lobe)
Interpretation:
• The higher the ratio the more likely the patient has cirrhosis.
• The optimum cutoff is >= 0.90.
• The ratio in Child B > Child C > Child A cirrhosis. (In severe cirrhosis there is marked contraction of the liver.)
Performance:
• The sensitivity at the optimum cutoff is 0.72 and specificity 0.77, which are not stellar but better than parameters shown by the ratio of Harbin et al. The accuracy in the study was 74%. The AUC was 0.80.
• A ratio >= 1.30 is 98% specific but only 13% sensitive.
