A final set of postcontrast images was obtained with the standard T1-weighted SE sequence. Pre- and serial postcontrast (Cd-DTPA, 0.1 mmol./kg) RASE sequences were then performed during suspended respiration. Eighteen patients with CT evidence of renal masses were first evaluated with standard T1-and T2-weighted SE sequences. RASE imaging combines a short TR (275 msec)/short TE (10 msec), single excitation pulse sequence with half-Fourier data sampling. This paper compares the diagnostic accuracy of Gd-DTPA-enhanced rapid-acquisition spin-echo (RASE) imaging with standard spin-echo techniques for detecting renal cysts and solid renal neoplasms. Early results are extremely encouragingĭiagnostic accuracy of dynamic contrast-enhanced MR imaging of renal masses with rapid-acquisition spin-echo techniqueĮilenberg, S.S. The method has been validated with phantoms and is undergoing initial clinical evaluation. The magnitude weighting provides additional vessel contrast, suppresses background noise, maintains the flow direction information, and still allows quantitative data to be retrieved. Images with pixel values equal to MΔΘ where M is the magnitude of the flow compensated image and ΔΘ is the phase difference at the pixel, are produced.
Complex image data from the first acquisition are used as a phase reference for the second, yielding immunity from phase accumulation due to causes other than motion. One is flow compensated while the second has a specified flow encoding (both peak velocity and direction) that causes signals to contain additional phase in proportion to velocity in the specified direction. The method, called VIGRE (velocity imaging with gradient recalled echoes), consists of two interleaved, narrow flip angle, gradient-recalled acquisitions. Image-comparison grip-lines arrow-top-right zip arrow-right video minus arrow-back text shop twitter file home quick-order arrow-left youtube search arrow-down check all filter site_references image Slice 1 zoom 🎬 icons / _ icon size / _ download-queueĬhevron-down arrow-right picture pdf podcast exe plus hotline close xxx-1 burger clipboard linked-in ppt Artboard 🎬 icons / _ icon size / _ download-queue_addĬreated by potrace 1.International Nuclear Information System (INIS)Ī rapid, phase-contrast, MR imaging method of imaging flow has been implemented.
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