While most diffusion-weighted imaging (DWI) is acquired using single-shot diffusion-weighted spin-echo echo-planar imaging, steady-state DWI is an alternative method with the potential to achieve higher-resolution images with less distortion. Steady-state DWI is, however, best suited to a segmented three-dimensional acquisition and thus requires three-dimensional navigation to fully correct for...

Diffusion-weighted magnetic resonance (MR) imaging (DWI) is increasingly applied to evaluate tumors in the abdomen and pelvis. However, DWI is susceptible to a variety of artifacts that arise from motion, use of strong gradient pulses, and echo-planar imaging technique. We discuss practical issues to help radiologists optimize the use of DWI to evaluate tumors in the body, including breath-hold...

Diffusion-weighted imaging (DWI) obtained with interleaved echo-planar imaging (EPI) pulse sequence has great potential of characterizing brain tissue properties at high spatial-resolution. However, interleaved EPI based DWI data may be corrupted by various types of aliasing artifacts. First, inconsistencies in k-space data obtained with opposite readout gradient polarities result in Nyquist ar...

introduction: despite widespread use of 67gallium for lymphoma evaluation, timing of imaging after injection is a matter of controversy and to the extent of our knowledge no direct comparison has been made between early and delayed gallium images. we aimed to compare 24 and 48 hours post injection planar gallium imaging for evaluation of lymphoma recurrence. methods: 255 patients suspicious of...

Y. Bito, T. Shirai, S. Hirata, Y. Taniguchi, K. Hirata, Y. Otake, Y. Soutome, H. Ochi, T. Ebisu, Y. Kawai, M. Umeda, T. Higuchi, and C. Tanaka Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan, Neurosurgery, Nantan General Hospital, Kyoto, Japan, Medical Informatics, Meiji University of Integrative Medicine, Kyoto, Japan, Neurosurgery, Meiji University of Integrative Medic...

Goal This lecture aims to give an overview of ultrafast image techniques such as echo-planar imaging (EPI) and spiral imaging. While these techniques offer significant speed improvement, they are often accompanied by practical issues that degrade the quality of the images, thereby compromising their benefits. Therefore, it is important to take proper control of the tradeoff between imaging spee...

Single-shot line scan imaging (LSI) was adapted to diffusion-weighted (DW) MRI by replacing the initial 90 degrees radiofrequency pulse of the underlying high-speed stimulated echo sequence by a DW spin-echo preparation period. Implementation on a 2. 0 T whole-body MRI system yielded DW images of the human brain with b factors of 750 s mm(-2) and total imaging times of about 500 ms either for a...

OBJECTIVES We evaluated use of the periodically rotated overlapping parallel lines with enhanced reconstruction diffusion-weighted imaging sequence, compared with conventional echo planar magnetic resonance imaging, in the detection of middle-ear cholesteatoma. MATERIAL AND METHODS Sixteen patients awaiting second-stage combined approach tympanoplasty and three patients awaiting first-stage c...