title: Evaluation of Imaging Quality and ADC for the Tetrahedral Gradients of Diffusion Weighted Imaging.
abstract: The diffusion weighted images (DWIs) are used widely in clinical practice. Recently, the gradient overplus imaging was developed in addition to orthogonal technique for the duration method of motion-probing gradient pulses. The gradient overplus technique can reduce the load of a gradient strength, and enables setting of the shortest TE compared with the orthogonal gradients, and moreover it has the information on diffusion tensor. The apparent diffusion coefficient (ADC) values, signal-to-noise ratio (SNR), and geometric distortion were compared for the two duration methods of DWI using four different phantoms of coefficient of viscosity. In the gradient overplus, the time of smallest TE became smaller than the orthogonal gradients according to the increase of the b value. As a result, SNR increased by shortening of TE, and thus the geometric distortion was improved. Moreover, the ADC value did not show any difference in the two duration methods of DWI. The gradient overplus technique is a more useful technique in a clinical study than the orthogonal gradients because the quality of image is improved, and the ADC value is the same as the orthogonal gradients.
authors.affiliation: Department of Radiology, Tokyo Metropolitan Tama Medical Center.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Ogura
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Koyama
authors.forename: Kouki
authors.initials: K
authors.lastname: Osakabe
authors.forename: Isamu
authors.initials: I
authors.lastname: Hatano
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio