European radiology
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A 69-year-old diabetic male with salmonella bacteremia developed hypovolemic shock and swelling of the neck. A CT examination revealed massive mediastinal hemorrhage extending into the neck soft tissues caused by false aneurysm rupture of the descending thoracic aorta. ⋯ Although surgical intervention was immediately performed, the patient died 3 weeks later from multiple-organ failure. In this report, CT and angiographic findings of mycotic aneurysm rupture are presented and a review is given.
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Comparative Study
MR imaging of uterine cervical carcinoma: comparison between fast spin-echo MRI and GRASE.
The aim of our study was to compare the image quality of T2-weighted gradient-echo-and-spin-echo (GRASE) MRI and fast spin-echo (FSE) MRI for imaging of cervical carcinoma. In 40 patients FSE8 (TR/TE = 3400/90 ms) MRI with echo train length (ETL) of 8, GRASE (3400/90) MRI with ETL of 18, turbo factor of 6 and 3 gradient reversals, and FSE18 (2500/120) MRI with ETL of 18 were performed. Tissue contrast, subjectively rated image quality, and accuracy of tumor delineation were compared. ⋯ The accuracy of FSE and GRASE MRI for the delineation of cervical carcinoma is similar. Based on measurement of image quality and CNRs, however, high turbo factor FSE provides better image quality in MRI of cervical carcinoma. Whether the superior characteristics may result in better staging has to be explored in larger clinical trials.
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Application of a three-dimensional half-fourier single-shot fast spin-echo sequence to MR cisternography is presented. This technique is capable of demonstrating normal cranial nerves. It is also useful in screening for acoustic neuroma as well as in the diagnosis of neurovascular compression.
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The aim of this study was to review the physical basis of MRI using hyperpolarized noble gases as well as the present status of preclinical and clinical applications. Non-radioactive noble gases with a nuclear spin 1/2 (He-3, Xe-129) can be hyperpolarized by optical pumping. Polarization is transferred from circularly polarized laser light to the noble-gas atoms via alkali-metal vapors (spin exchange) or metastable atoms (metastability exchange). ⋯ Xe-129 is also under investigation for imaging of white matter disease and functional studies of cerebral perfusion. Magnetic resonance imaging using hyperpolarized gases is emerging as a technical challenge and opportunity for the MR community. Preliminary experience suggests potential for functional imaging of pulmonary ventilation and cerebral perfusion.
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The aim of our study was to compare gradient-spin-echo (GRASE) to fast-spin-echo (FSE) sequences for fast T2-weighted MR imaging of the brain. Thirty-one patients with high-signal-intensity lesions on T2-weighted images were examined on a 1.5-T MR system. The FSE and GRASE sequences with identical sequence parameters were obtained and compared side by side. ⋯ Fatty tissue was less bright on GRASE. With current standard hardware equipment, the FSE technique seems preferable to GRASE for fast T2-weighted routine MR imaging of the brain. For the assessment of hemosiderin or ferritin depositions, GRASE might be considered.