Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jan 1994
Carotid and vertebral artery blood flow in left- and right-handed healthy subjects measured with MR velocity mapping.
The goal of the study was to establish normal carotid artery flow rates in left-handed and right-handed individuals as a standard against which patients with carotid artery disease could be compared. Antegrade and retrograde flow were measured in the ascending aorta, in the right and left common, internal, and external carotid arteries, and in the vertebral arteries of 12 healthy subjects. Five subjects were right-handed, five left-handed, and two ambidextrous. ⋯ There were no significant differences in left and right common carotid artery flow rates between left- and right-handed subjects. The standard deviation of a single measurement was 5%. The flow rates were similar to those obtained previously with other techniques and could be used as a normal standard.
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J Magn Reson Imaging · Nov 1991
Comparative StudyBowel disease: prospective comparison of CT and 1.5-T pre- and postcontrast MR imaging with T1-weighted fat-suppressed and breath-hold FLASH sequences.
The potential of new high-field-strength magnetic resonance (MR) imaging sequences to evaluate bowel disease was investigated and compared with computed tomographic (CT) studies. Thirty-two patients were studied, 14 with known or suspected gastrointestinal tumors and 18 with known or suspected bowel inflammatory conditions. T1-weighted fat-suppressed spin-echo and breath-hold FLASH (fast low-angle shot) images were obtained before and after intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine. ⋯ In the 18 cases of bowel inflammation, CT scans showed concentric wall thickening in 16, while MR images showed concentric wall thickening in 14 and increased contrast enhancement in 17. Contrast enhancement was better appreciated on fat-suppressed images than on FLASH images. The results suggest that MR imaging may play a role in the evaluation of bowel disease.
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The influence of magnetic resonance (MR) imaging on the integrity and function of an implantable, programmable drug infusion pump and the distortion of the image by this device were tested. Six identical pumps were tested in magnetic fields of 1.5 T. Pump memory was not affected by the procedure. ⋯ No structural damage to the electrical or mechanical pump components was detected. The pump caused a circular image artifact (a signal dropout) within 8-10 cm of the device. The authors conclude that MR imaging is accurate if the area of interest is at least 10 cm from the pump, and that with awareness of temporary infusion cessation, it is safe to perform MR imaging in patients with this implanted pump.