Peripheral vascular disease (PVD) affects 8 million people in the United States, causes significant morbidity, and is associated with cardiovascular mortality. Given that many patients with PVD also suffer from impaired renal function, one must exercise caution in using CE-MRA because of concerns about the risks of nephrogenic systemic fibrosis (NSF), a serious and potentially lethal disorder. Recently, non-enhanced MRA techniques have been proposed to eliminate the risk of NSF. The overall goal of this proposal is to implement a methodology for non-contrast peripheral MRA that is insensitive to the timing of peak systolic flow;moreover, the technology should be fast, insensitive to patient motion, and accurate. For this purpose, we have implemented a novel approach consisting of a fat suppressed, single shot 2D saturation-recovery trueFISP (SR-TFI) pulse sequence. Although this approach for non-contrast MRA has not been previously reported, our initial clinical trials demonstrate excellent results even in the presence of severe PVD. The method does not require prior knowledge of flow patterns and eliminates the need for cine MRI to determine the timing of peak flow velocity, a requirement for FBI. Moreover, the method is less sensitive to patient motion than FBI and has proven robust for imaging of the pelvic arteries. For the small subset of patients in whom it is not possible to synchronize the data acquisition to the cardiac cycle (e.g. due to atrial fibrillation or other cardiac arrhythmias), we propose the use of ungated Ghost MRA. Ghost MRA uses the ghost artifacts generated by pulsatile flow to create an MRA with no signal contribution from background tissues.
Our specific aims are:
Specific Aim 1 : To optimize multi-station flow-insensitive SR-TFI of the peripheral arteries with a total acquisition time <10 minutes using spatial resolution on the order of 1-2 mm3.
Specific Aim 2 : To implement multi-station flow-dependent (Ghost) MRA of the peripheral arteries with an image acquisition time <5 minutes per station using spatial resolution on the order of 1 mm.
Specific Aim 3 : Evaluate non-contrast MRA in comparison with CE-MRA and/or x-ray DSA in patients
We have developed a set of novel technologies that will largely eliminate the need to administer contrast agents during magnetic resonance angiography in order to diagnose peripheral vascular disease. This study will result in better image quality, greater diagnostic accuracy, lower procedure cost, and enhanced patient safety.
|Edelman, Robert R; Flanagan, Oisin; Grodzki, David et al. (2015) Projection MR imaging of peripheral arterial calcifications. Magn Reson Med 73:1939-45|
|Edelman, Robert R; Giri, Shivraman; Murphy, Ian G et al. (2014) Ungated radial quiescent-inflow single-shot (UnQISS) magnetic resonance angiography using optimized azimuthal equidistant projections. Magn Reson Med 72:1522-9|
|Koktzoglou, Ioannis; Mistretta, Charles A; Giri, Shivraman et al. (2014) Simultaneous static and cine nonenhanced MR angiography using radial sampling and highly constrained back projection reconstruction. Magn Reson Med 72:1079-86|
|Amin, Parag; Collins, Jeremy D; Koktzoglou, Ioannis et al. (2014) Evaluating peripheral arterial disease with unenhanced quiescent-interval single-shot MR angiography at 3 T. AJR Am J Roentgenol 202:886-93|
|Ward, Emily V; Galizia, Mauricio S; Usman, Asad et al. (2013) Comparison of quiescent inflow single-shot and native space for nonenhanced peripheral MR angiography. J Magn Reson Imaging 38:1531-8|
|Edelman, R R; Giri, S; Dunkle, E et al. (2013) Quiescent-inflow single-shot magnetic resonance angiography using a highly undersampled radial k-space trajectory. Magn Reson Med 70:1662-8|
|Offerman, Erik J; Koktzoglou, Ioannis; Glielmi, Christopher et al. (2013) Prospective self-gated nonenhanced magnetic resonance angiography of the peripheral arteries. Magn Reson Med 69:158-62|
|Tan, Huan; Koktzoglou, Ioannis; Glielmi, Christopher et al. (2012) Optimization of single shot 3D breath-hold non-enhanced MR angiography of the renal arteries. J Cardiovasc Magn Reson 14:30|
|Offerman, Erik J; Hodnett, Philip A; Edelman, Robert R et al. (2011) Nonenhanced methods for lower-extremity MRA: a phantom study examining the effects of stenosis and pathologic flow waveforms at 1.5T. J Magn Reson Imaging 33:401-8|
|Hodnett, Philip A; Koktzoglou, Ioannis; Davarpanah, Amir H et al. (2011) Evaluation of peripheral arterial disease with nonenhanced quiescent-interval single-shot MR angiography. Radiology 260:282-93|
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