Topics in magnetic resonance imaging : TMRI
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Top Magn Reson Imaging · Dec 2006
ReviewMagnetic resonance imaging of abdominal pain during pregnancy.
The objective of this review is to demonstrate magnetic resonance imaging as an important adjunct to ultrasound and computed tomography in the evaluation of the pregnant patient with abdominal pain. With the advent of ultrafast T2-weighted pulse sequences, fetal and bowel motion cause minimal artifact on the images. ⋯ T1-weighted gradient echo images with and without fat saturation are useful for identifying blood and fat, especially in the case of adnexal masses. Gadolinium-diethylenetriamine pentaacetic acid is rarely used to diagnose inflammatory or obstructive disease and is reserved for those patients with suspected malignancies.
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Top Magn Reson Imaging · Aug 2006
ReviewMagnetic resonance and diffusion tensor imaging in pediatric white matter diseases.
The central nervous system undergoes profound and predictable developmental changes during the first few years of life that provide the structural and functional elements necessary for normal neurological development. The establishment and maturation of white matter pathways is a critical component of the developing nervous system. ⋯ Furthermore, it has helped characterize the relation between white matter integrity and cognitive abilities. In the future, DTI is expected to play an increasingly large role in defining developmental abnormalities at an early age and in assessing therapies for pediatric disorders such as leukodystrophies.
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Top Magn Reson Imaging · Jun 2006
ReviewMagnetic resonance-guided high-intensity ultrasound ablation of the prostate.
This paper describes our work in developing techniques and devices for magnetic resonance (MR)-guided high-intensity ultrasound ablation of the prostate and includes review of relevant literature. ⋯ The catheter-based ultrasound devices can produce spatially selective regions of thermal destruction in prostate. The MR thermal imaging and thermal dose maps, obtained in multiple slices through the target volume, are useful for controlling therapy delivery (rotation, power levels, duration). Contrast-enhanced T1-weighted MRI and diffusion-weighted imaging are useful tools for assessing treatment.
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Top Magn Reson Imaging · Jun 2006
ReviewImage-based control of the magnetic resonance imaging-guided focused ultrasound thermotherapy.
Magnetic resonance imaging (MRI)-guided focused ultrasound surgery (FUS) is a full noninvasive approach for localized thermal ablation of deep tissues, coupling the following: (1) a versatile, nonionizing physical agent for therapy and (2) a state-of-the art diagnosis and on-line monitoring tool. A commercially available, Food and Drug Administration-approved device using the MRI-guided FUS exists since 2004 for the ablation of benign tumors (uterine fibroids); however, the ultimate goal of the technological, methodological, and medical research in this field is to provide a clinical-routine tool for fighting localized cancer. ⋯ This paper reviews some significant developments reported in the literature related to the image-based control of the FUS therapy for kidney, breast, prostate, and brain, including the own experience of the authors on the active feedback control of the temperature during FUS ablation. In addition, preliminary results of an original study of MRI-guided FUS ablation of VX2 carcinoma in kidney, under active temperature control, are described here.
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Top Magn Reson Imaging · Jun 2005
ReviewNeuroimaging in drug and substance abuse part I: cocaine, cannabis, and ecstasy.
Multiple neurological complications of cocaine abuse have been described including both ischemic and hemorrhagic cerebrovascular events, atrophy in the case of chronic abuse, and an increase in incidence of congenital malformations in the setting of maternal use. The abuse of cannabis may cause a number of neurovascular changes that, in turn, may result in ischemic events, however, a direct connection between these has not been fully established. The use of MDMA (ecstasy), a popular recreational drug, has been related to ischemic and hemorrhagic cerebrovascular events, as well as atrophy. Neuroimaging studies are vital in the assessment of the extent of neurologic damage in these patients.