PURPOSE: To compare a magnetization-prepared gradient-echo (GRE) sequence with a conventional GRE sequence for visualizing contrast agent-filled catheters. MATERIALS AND METHODS: Passive visualization of endovascular catheters using MRI was compared between two imaging sequences: 1) inversion recovery (IR)-fast low angle shot (FLASH), and 2) conventional FLASH. Two-dimensional projection images of the catheters filled with 4% diluted contrast agent in a phantom and the aorta of swine were obtained with each sequence with a temporal resolution of two frames per second. We compared background suppression and catheter visibility using the catheter-to-background signal ratio and the ratings of two radiologists. RESULTS: In the phantom, IR-FLASH allowed for a 200% increase in catheter-to-background ratio (p < 0.01) and improved depiction of catheters over conventional FLASH. In swine, the IR-FLASH images showed a statistically significant improvement of 80% (p < 0.001) over conventional FLASH in all comparisons of the catheter-to-background signal ratio, and an improvement of 160% (p < 0.05) in comparison with the radiologists' observations. CONCLUSION: This study shows that IR-FLASH is a better technique for passive tracking of contrast agent-filled catheters than conventional FLASH. Copyright 2002 Wiley-Liss, Inc.
PURPOSE: To compare a magnetization-prepared gradient-echo (GRE) sequence with a conventional GRE sequence for visualizing contrast agent-filled catheters. MATERIALS AND METHODS: Passive visualization of endovascular catheters using MRI was compared between two imaging sequences: 1) inversion recovery (IR)-fast low angle shot (FLASH), and 2) conventional FLASH. Two-dimensional projection images of the catheters filled with 4% diluted contrast agent in a phantom and the aorta of swine were obtained with each sequence with a temporal resolution of two frames per second. We compared background suppression and catheter visibility using the catheter-to-background signal ratio and the ratings of two radiologists. RESULTS: In the phantom, IR-FLASH allowed for a 200% increase in catheter-to-background ratio (p < 0.01) and improved depiction of catheters over conventional FLASH. In swine, the IR-FLASH images showed a statistically significant improvement of 80% (p < 0.001) over conventional FLASH in all comparisons of the catheter-to-background signal ratio, and an improvement of 160% (p < 0.05) in comparison with the radiologists' observations. CONCLUSION: This study shows that IR-FLASH is a better technique for passive tracking of contrast agent-filled catheters than conventional FLASH. Copyright 2002 Wiley-Liss, Inc.
Authors: A Shaibani; S Khawar; W Shin; T A Cashen; B Schirf; M Rohany; S Kakodkar; T J Carroll Journal: AJNR Am J Neuroradiol Date: 2006-09 Impact factor: 3.825