Journal of computer assisted tomography
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J Comput Assist Tomogr · Jul 2005
Case ReportsAge dependence of diffusion-weighted magnetic resonance imaging findings in maple syrup urine disease encephalopathy.
A patient with maple syrup urine disease (MSUD) who developed encephalopathy twice and underwent magnetic resonance examinations, including diffusion-weighted (DW) imaging, is presented. Areas of abnormal intensity on DW images dramatically differed between the initial and second attacks, apparently attributable to the difference in myelination. Our observation demonstrates the age dependence of DW imaging findings in MSUD encephalopathy attributable to progression of myelination and would help in the proper diagnosis of MSUD encephalopathy at any age.
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J Comput Assist Tomogr · Jul 2005
Case ReportsComputed tomographic angiography for determination of brain death.
A 69-year-old woman developed deep coma and brain stem areflexia after subarachnoid hemorrhage. Due to unstable vital signs, she was not a candidate for an apnea test. Computed tomographic angiography revealed absence of intracranial circulation, and brain death was diagnosed.
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J Comput Assist Tomogr · Jul 2005
Comparative Study Clinical TrialEfficacy of contrast medium use for neuroimaging at 3.0 T: utility of IR-FSE compared to other T1-weighted pulse sequences.
As inversion-recovery (IR) technique improves T1 contrast at high field strength, signal enhancement by T1-shortening contrast media may be affected. To clarify the different enhancement properties at 3.0 T, the authors compared T1-weighted sequences. Twelve contrast-enhancing lesions were investigated by spin-echo (SE), inversion recovery fast spin-echo (IR-FSE), two-dimensional gradient-echo (2D GE), and magnetization-prepared three-dimensional gradient-echo (3D GE) sequences and evaluated by comparing signal-intensity enhancements within the lesions. ⋯ CNR of gray matter versus white matter was significantly higher for IR SE and GE imaging than for genuine SE and 2D GE acquisitions (Wilcoxon test), while 2D GE imaging alone had an excellent SNR. As IR-FSE images provide an excellent CNR for gray and white matter in the brain and contrast enhancement performs almost similarly well compared with SE imaging, this technique appears to be well suited for T1-weighted neuroimaging without and with contrast enhancement at 3.0 T. However, the inherent blurring of the IR-FSE can lead to poor performance for very small lesions.