Liver diffusion-weighted MR imaging: reproducibility comparison of ADC measurements obtained with multiple breath-hold, free-breathing, respiratory-triggered, and navigator-triggered techniques.
OBJECTIVE
To prospectively compare the reproducibility of normal liver apparent diffusion coefficient (ADC) measurements by using different respiratory motion compensation techniques with multiple breath-hold (MBH), free-breathing (FB), respiratory-triggered (RT), and navigator-triggered (NT) diffusion-weighted (DW) imaging and to compare the ADCs at different liver anatomic locations.


METHODS
The study protocol was approved by the institutional review board, and written informed consent was obtained from each participant. Thirty-nine volunteers underwent liver DW imaging twice. Imaging was performed with a 1.5-T MR imager with MBH, FB, RT, and NT techniques (b = 0, 100, and 500 sec/mm(2)). Three representative sections--superior, central, and inferior--were selected on left and right liver lobes, respectively. On each selected section, three regions of interest were drawn, and ADCs were measured. Analysis of variance was used to assess ADCs among the four techniques and various anatomic locations. Reproducibility of ADCs was assessed with the Bland-Altman method.


RESULTS
ADCs obtained with MBH (range: right lobe, [1.641-1.662] × 10(-3)mm(2)/sec; left lobe, [2.034-2.054] ×10(-3)mm(2)/sec) were higher than those obtained with FB (right, [1.349-1.391] ×10(-3)mm(2)/sec; left, [1.630-1.700] ×10(-3)mm(2)/sec), RT (right, [1.439-1.455] ×10(-3)mm(2)/sec; left, [1.720-1.755] ×10(-3)mm(2)/sec), or NT (right, [1.387-1.400] ×10(-3)mm(2)/sec; left, [1.661-1.736] ×10(-3)mm(2)/sec) techniques (P < .001); however, no significant difference was observed between ADCs obtained with FB, RT, and NT techniques (P = .130 to P >.99). ADCs showed a trend to decrease moving from left to right. Reproducibility in the left liver lobe was inferior to that in the right, and the central middle segment in the right lobe had the most reproducible ADC. Statistical differences in ADCs were observed in the left-right direction in the right lobe (P < .001), but they were not observed in the superior-inferior direction (P = .144-.450). However, in the left liver lobe, statistical differences existed in both directions (P = .001 to P = .016 in the left-right direction, P < .001 in the superior-inferior direction).


CONCLUSIONS
Both anatomic location and DW imaging technique influence liver ADC measurements and their reproducibility. FB DW imaging is recommended for liver DW imaging because of its good reproducibility and shorter acquisition time compared with that of MBH, RT, and NT techniques.
From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Road, Guangzhou 510080, China (X.C., D.P., Y.H., L.Y., G.W., Y.L., C.L., Z.L.); Graduate College, Southern Medical University, Guangzhou, China (X.C., D.P.); and Department of Radiology, Dana-Farber Cancer Institute, Boston, Mass (L.Q.).
Xin
X
Chen
Lei
L
Qin
Dan
D
Pan
Yanqi
Y
Huang
Lifen
L
Yan
Guangyi
G
Wang
Yubao
Y
Liu
Changhong
C
Liang
Zaiyi
Z
Liu
D000328:Adult; D000465:Algorithms; D062485:Breath Holding; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008099:Liver / Q000033:anatomy & histology*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results