title: Geometric distortion evaluation using a multi-orientated water-phantom at 0.2 T MRI.
abstract: Magnetic Resonance Imaging (MRI) has been one of the most revolutionary medical imaging modalities in the past three decades. It has been recognized as a potential technique in the clinical diagnosis of diseases as well as tumor differentiation. Although MRI has now become the preferred choice in many clinical examinations, there are some drawbacks, which still limit its applications. One of the crucial issues of MRI is the geometric distortion caused by magnetic field inhomogeneity and susceptibility effects. The farther the lesion from the center of a magnetic field (off-center field), the more severe the distortion becomes, especially in low-field MRI. Hence, it might hinder the diagnosis and characterization of lesions in the presence of field inhomogeneity. In this study, an innovative multi-orientated water-phantom was used to evaluate the geometric distortion. The correlations between the level of image distortion and the relative off-center positions, as well as the variation of signal intensities, were both investigated. The image distortion ratios of axial, coronal and sagittal images were calculated.
authors.affiliation: Department of Medical Imaging and Radiological Sciences, College of Health Sciences, Kaohsiung Medical University, 100, Shih-Chuan First Rd., Kaohsiung City, 80708, Taiwan, R.O.C.
authors.forename: Jochi
authors.initials: J
authors.lastname: Jao
authors.affiliation: Department of Radiology, Antai Medical Care Cooperation Antai Tian-Sheng Memorial Hospital, No.210, Sec. 1, Zhongzheng Rd., Donggang Township, Pingtung County 928, Taiwan, R.O.C.
authors.forename: Mingye
authors.initials: M
authors.lastname: Cheng
authors.affiliation: Department of Radiology, Antai Medical Care Cooperation Antai Tian-Sheng Memorial Hospital, No.210, Sec. 1, Zhongzheng Rd., Donggang Township, Pingtung County 928, Taiwan, R.O.C.
authors.forename: Hsintien
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Radiology, Antai Medical Care Cooperation Antai Tian-Sheng Memorial Hospital, No.210, Sec. 1, Zhongzheng Rd., Donggang Township, Pingtung County 928, Taiwan, R.O.C.
authors.forename: Julius
authors.initials: J
authors.lastname: Ting
authors.affiliation: Department of Biomedical Engineering, I-Shou University, No.8, Yida Rd., Jiaosu Village Yanchao District, Kaohsiung City, 82445, Taiwan, R.O.C.
authors.forename: Pochou
authors.initials: P
authors.lastname: Chen
mesh_terms: D016477:Artifacts; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water
chemical_list: D014867:Water
keywords: Geometric distortion; field inhomogeneity; multi-orientated water-phantom; off-center field