Diffusion-weighted MR imaging of upper abdominal organs at different time points: Apparent diffusion coefficient normalization using a reference organ.
To compare the apparent diffusion coefficient (ADC) of upper abdominal organs acquired at different time points, and to investigate the usefulness of normalization.



We retrospectively evaluated 58 patients who underwent three rounds of magnetic resonance (MR) imaging including diffusion-weighted imaging of the upper abdomen. MR examinations were performed using three different 3.0 Tesla (T) and one 1.5T systems, with variable b value combinations and respiratory motion compensation techniques. The ADC values of the upper abdominal organs from three different time points were analyzed, using the ADC values of the paraspinal muscle (ADCpsm) and spleen (ADCspleen) for normalization. Intraclass correlation coefficients (ICC) and comparison of dependent ICCs were used for statistical analysis.



The ICCs of the original ADC and ADCpsmshowed fair to substantial agreement, while ADCspleenshowed substantial to almost perfect agreement. The ICC of ADCspleenof all anatomical regions showed less variability compared with that of the original ADC (P < 0.005).



Normalized ADC using the spleen as a reference organ significantly decreased variability in measurement of the upper abdominal organs in different MR systems at different time points and could be regarded as an imaging biomarker for future multicenter, longitudinal studies.



5 J. MAGN. RESON. IMAGING 2017;45:1494-1501.
Department of Radiology, Chonbuk National University Medical School and Hospital, Chonbuk, South Korea.|Research Institute of Clinical Medicine of Chonbuk National University, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk, South Korea.
Ji Soo
JS
Song
Department of Radiology, Chonbuk National University Medical School and Hospital, Chonbuk, South Korea.|Research Institute of Clinical Medicine of Chonbuk National University, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk, South Korea.
Hyo Sung
HS
Kwak
Department of Radiology, Chonbuk National University Medical School and Hospital, Chonbuk, South Korea.
Jung Hee
JH
Byon
Department of Radiology, Chonbuk National University Medical School and Hospital, Chonbuk, South Korea.|Research Institute of Clinical Medicine of Chonbuk National University, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk, South Korea.
Gong Yong
GY
Jin
D000005:Abdomen / Q000000981:diagnostic imaging*; D000368:Aged; D002908:Chronic Disease; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006521:Hepatitis, Chronic / Q000000981:diagnostic imaging; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009068:Movement; D012016:Reference Values; D012119:Respiration; D012189:Retrospective Studies
MRI; abdomen; apparent diffusion coefficient; diffusion-weighted imaging; normalization