title: Basic study of susceptibility-weighted imaging at 1.5T.
abstract: With the aim of sequence optimization in susceptibility-weighted imaging (SWI), 2 image acquisition parameters (slice thickness and matrix size) and 2 image processing conditions (number of slices per minimum intensity projection (MIP) and Sliding Window) were investigated using a 1.5-T magnetic resonance imaging (MRI) system. The subjects were 12 healthy volunteers and the target region for scanning was the whole brain. Informed consent was obtained from all subjects. First, susceptibility-weighted images were acquired with various slice thicknesses from 1mm to 5mm and various matrix sizes from 256 x 256 to 512 x 512, and the images were assessed in terms of the contrast-to-noise ratio (CNR) and were also visually evaluated by three radiologists. Then, the number of slices per MIP and the usefulness of the Sliding Window were investigated. In the study of the optimal slice thickness and matrix size, the results of visual evaluation suggested that a slice thickness of 3mm and a matrix size of 448 x 448 are optimal, while the results of evaluation based on CNR were not significant. As regards the image processing conditions, the results suggested that the number of slices per MIP should be set to a minimum value of 2 and that the use of Sliding Window is effective. The present study provides useful reference data for optimizing SWI sequences.
authors.affiliation: Department of Medical Radiotechnology, Okayama University Graduate School of Health Sciences, Okayama 700-8558, Japan. m-toshiy@okayama-dic.or.jp
authors.forename: Toshi
authors.initials: T
authors.lastname: Matsushita
authors.forename: Daigo
authors.initials: D
authors.lastname: Anami
authors.forename: Tadashi
authors.initials: T
authors.lastname: Arioka
authors.forename: Seiji
authors.initials: S
authors.lastname: Inoue
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kariya
authors.forename: Masako
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ida
authors.forename: Nobuya
authors.initials: N
authors.lastname: Sasai
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Kaji
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
authors.forename: Ikuo
authors.initials: I
authors.lastname: Joja
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008954:Models, Biological