PURPOSE: To improve gadolinium-enhanced magnetic resonance (MR) angiogram quality by automatically synchronizing acquisition of central k-space image data with the arterial phase of contrast material bolus infusion. MATERIALS AND METHODS: A spin-echo pulse sequence with orthogonal 90 degrees and 180 degrees pulses was used to monitor signal in a single 4 x 4 x 12-cm voxel that encompassed a segment of aorta. An increase in signal that corresponded to the arrival of gadolinium was used to trigger three-dimensional, spoiled gradient-echo abdominal MR angiography in 50 adult patients. RESULTS: Arterial signal intensity increased 28-fold with automatic compared to 19-fold with manual triggering (P < .05) at an approximate dose of 0.3 mmol/kg. Automatic triggering with a lower dose (approximately 0.2 mmol/kg) resulted in 20-fold arterial enhancement, which is comparable with enhancement after manual triggering at the high dose. In addition, venous enhancement was less (1.5-fold) with automatic than with manual (3.5-fold) triggering at the same dose (P < .05). CONCLUSION: Automatic triggering results in improved arterial-tovenous contrast. It increases arterial enhancement or enables MR angiograms to be obtained with less contrast material. The authors now routinely use this technique for aortorenal imaging with a gadolinium-based contrast material dose of 20 mmol (40 mL) in patients who weigh more than 50 kg and 10 mmol (20 mL) in patients who weigh less than 50 kg.
PURPOSE: To improve gadolinium-enhanced magnetic resonance (MR) angiogram quality by automatically synchronizing acquisition of central k-space image data with the arterial phase of contrast material bolus infusion. MATERIALS AND METHODS: A spin-echo pulse sequence with orthogonal 90 degrees and 180 degrees pulses was used to monitor signal in a single 4 x 4 x 12-cm voxel that encompassed a segment of aorta. An increase in signal that corresponded to the arrival of gadolinium was used to trigger three-dimensional, spoiled gradient-echo abdominal MR angiography in 50 adult patients. RESULTS: Arterial signal intensity increased 28-fold with automatic compared to 19-fold with manual triggering (P < .05) at an approximate dose of 0.3 mmol/kg. Automatic triggering with a lower dose (approximately 0.2 mmol/kg) resulted in 20-fold arterial enhancement, which is comparable with enhancement after manual triggering at the high dose. In addition, venous enhancement was less (1.5-fold) with automatic than with manual (3.5-fold) triggering at the same dose (P < .05). CONCLUSION: Automatic triggering results in improved arterial-tovenous contrast. It increases arterial enhancement or enables MR angiograms to be obtained with less contrast material. The authors now routinely use this technique for aortorenal imaging with a gadolinium-based contrast material dose of 20 mmol (40 mL) in patients who weigh more than 50 kg and 10 mmol (20 mL) in patients who weigh less than 50 kg.
Authors: R Schmitt; G Coblenz; O Cherevatyy; H Brunner; S Fröhner; E Wedell; G Karg; G Christopoulos Journal: Eur Radiol Date: 2005-07-22 Impact factor: 5.315
Authors: Alex Frydrychowicz; Scott K Nagle; Sharon L D'Souza; Karl K Vigen; Scott B Reeder Journal: J Magn Reson Imaging Date: 2011-07-12 Impact factor: 4.813