title: Abdominal apparent diffusion coefficient measurements: effect of diffusion-weighted image quality and usefulness of anisotropic images.
abstract: This study aimed to assess the effect of diffusion-weighted image (DWI) quality on abdominal apparent diffusion coefficient (ADC) measurements and the usefulness of anisotropic images. Twenty-six patients (10 men and 16 women; mean, 58.1 years) who underwent DW imaging and were diagnosed not to have any abdominal diseases were analyzed. Single-shot spin-echo echo-planar DW imaging was performed, and one isotropic and three orthogonal anisotropic images were created. ADCs were calculated for liver (four segments), spleen, pancreas (head, body, tail) and renal parenchyma. Image quality for each organ part was scored visually. We estimated the correlation between ADC and image quality and evaluated the feasibility of using anisotropic images. ADCs and image quality were affected by motion probing gradient directions in the liver and pancreas. A significant inverse correlation was found between ADC and image quality. The r values for isotropic images were -.46, -.48, -.70 and -.28 for the liver, spleen, pancreas and renal parenchyma, respectively. Anisotropic images had the best quality and lowest ADC in at least one organ part in 17 patients. DWIs with the best quality among isotropic and anisotropic images should be used in the liver and pancreas.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan. yoshikawa0816@aol.com
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kawamitsu
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Seo
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Zamora
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Aoyama
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000005:Abdomen / Q000473:pathology*; D000328:Adult; D000368:Aged; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric