AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Sep 1999
Contrast enhancement of intracranial lesions: conventional T1-weighted spin-echo versus fast spin-echo MR imaging techniques.
The T1-weighted fast spin-echo (T1-FSE) MR imaging sequence is not used routinely, since the speed advantage is not as dramatic as it is in T2-weighted imaging. We evaluated the T1-FSE sequence to determine whether this technique can replace the conventional T1-weighted spin-echo (T1-SE) sequence for routine contrast-enhanced imaging. ⋯ The T1-FSE sequence reduces imaging time and has the potential to replace the conventional T1-SE sequence for the evaluation of enhancing lesions in the brain when time is a consideration.
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AJNR Am J Neuroradiol · Sep 1999
Diffusion-weighted MR imaging in a rat model of syringomyelia after excitotoxic spinal cord injury.
Recent experimental data have shown that an increase of excitatory amino acids and the initiation of inflammatory responses within the injured spinal cord may play a role in post-traumatic syringomyelia. The purpose of this study was to determine whether diffusion-weighted MR imaging with apparent diffusion coefficient (ADC) maps could provide earlier evidence of spinal cord cavitation in a rat model of syringomyelia than available with conventional MR imaging. ⋯ In an animal model of syringomyelia, diffusion-weighted imaging with ADC maps detected cystic lesions within spinal cord gray matter before they were seen on conventional T1- and T2-weighted images.
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AJNR Am J Neuroradiol · Aug 1999
Case ReportsIntracystic hemorrhage of the middle fossa arachnoid cyst and subdural hematoma caused by ruptured middle cerebral artery aneurysm.
We report a case of a cerebral aneurysm arising from the bifurcation of the left middle cerebral artery that ruptured into a left middle cranial fossa arachnoid cyst, associated with acute subdural hematoma. We discuss the relationships of aneurysm, arachnoid cyst, and subdural hematoma.
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AJNR Am J Neuroradiol · Aug 1999
Relationship between MR imaging and histopathologic findings of the brain in extremely sick preterm infants.
MR imaging can now be used safely in extremely preterm infants. The aim of this study was to compare the MR imaging appearance of the immature brain with neuropathologic findings at postmortem examination. ⋯ MR imaging can be used to observe normal developing brain anatomy in extremely premature infants; it can detect areas of hemorrhage and infarction within the developing brain, but conventional MR imaging may not detect more subtle histologic abnormalities.
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AJNR Am J Neuroradiol · Aug 1999
Analysis of cystic intracranial lesions performed with fluid-attenuated inversion recovery MR imaging.
T1-, T2-, and proton density (PD)-weighted sequences are used to characterize the content of cystic intracranial lesions. Fluid-attenuated inversion recovery (FLAIR) MR sequences produce T2-weighted images with water signal saturation. Therefore, we attempted to verify whether FLAIR, as compared with conventional techniques, improves the distinction between intracranial cysts with a free water-like content versus those filled with a non-free water-like substance and, consequently, aids in the identification of these lesions as either neoplastic/inflammatory or maldevelopmental/porencephalic. ⋯ FLAIR imaging depicts far more accurately the content of cystic intracranial lesions and better reveals the distinction between maldevelopmental/porencephalic and neoplastic/inflammatory lesions than do conventional sequences. FLAIR has the added advantage of a higher signal intensity difference between cystic intracranial lesions and CSF.