Table 2. Absolute distance of four validation points (centroid of the liver structure and three anatomical landmarks) between exhale CT and exhale MR images for all patients.

	Distance (± standard deviation) (mm)
Axis	Liver	Noticeable point	PV conjunction	SMA bifurcation
x (L-R)	1.7 (±2.1)	2.3 (±2.2)	1.8 (±1.9)	2.5 (±3.3)
y (C-C)	3.3 (±4.1)	3.6 (±6.1)	3.2 (±3.8)	2.1 (±2.8)
z (A-P)	2.3 (±2.6)	2.2 (±2.2)	2.8 (±3.1)	2.8 (±3.4)
VSUM	5.1 (±4.6)	5.6 (±6.2)	5.4 (±4.5)	5.1 (±4.8)

A-P, anterior–posterior; C-C, craniocaudal; L-R, left–right; PV, portal vein; SMA, superior mesenteric artery; V_SUM, vector value between the points on CT and MR images.