Electronic Posters: Cardiovascular

MRA: Preclinical Technical Developments

Hall B Monday 14:00-16:00 Computer 42

14:00 3773. Magnetic Resonance Venography with a Blood Pool Contrast Medium

Teik Choon See¹, Andrew Winterbottom¹, Edmund Soh², Ilse Joubert¹, Martin Graves¹, David Lomas<sup>1

1</sup>Radiology, University of Cambridge and Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; ²Singapore General Hospital, Singapore

Our prospective clinical trial authorised study aims to assess MR venography of the neck and thoracic central veinous system using Vasovist® (gadofosveset trisodium, Schering), a blood pool contrast agent, for first pass (FP) and steady state (SS) imaging. Images are assessed independently for image quality, artefacts, stenosis, and thrombosis. Sixteen participants recruited to date and 144 venous segments assessed. The result shows very favourable SS imaging quality compared to FP (although not quite statistically significant) with potential for improving diagnostic accuracy. Mild artefacts are seen in 50% of both techniques. No significant differences noted in detection of stenosis or thrombosis.

14:30 3774. Group-Encoded Ungated Inversion Nulling for Non-Contrast Enhancement in the Steady State (GUINNESS): A Balanced SSFP-Dixon Technique for Breath-Held Non-Contrast MRA

Manojkumar Saranathan¹, Ersin Bayram², James F. Glockner<sup>3

1</sup>Applied Science Lab, GE Healthcare, Rochester, MN, United States; ²GE Healthcare, Waukesha, WI, United States; ³Radiology, Mayo Clinic, Rochester, MN, United States

While contrast-enhanced MR Angiography (CEMRA) is widely used for evaluation of vascular pathology, recent nephrogenic systemic fibrosis (NSF) concerns following administration of Gadolinium based contrast agents have spurred interest in non-contrast MRA methods. Balanced steady state free precession (b-SSFP) imaging has shown great promise due to its high SNR and short scan times. We propose a balanced SSFP-Dixon technique with a novel group-encoded k-space segmentation scheme for breath-held non-contrast MRA.

15:00 3775. Optimization of Gradient Moment Nulling for Hybrid of Opposite-Contrast MRA Sequence

Tokunori Kimura¹, Masato Ikedo<sup>2

1</sup>MRI Systems Development Department, Toshiba Medical Systems , Otawara, Tochigi, Japan; ²MRI Systems Development Department, Toshiba Medical Systems, Otawara, Tochigi, Japan

We have proposed a new MR angiography technique named Hybrid of Opposite-Contrast MRA (HOP-MRA) with 3D dual-echo gradient-echo sequence combining Time-of-Flight (TOF) with a Flow-Sensitive Black-Blood (FSBB) employing flow dephasing gradients. In this study, for the purpose of decreasing flow-void appeared in major arteries, two types of gradient moment nulling (GMN) for the TOF part were compared between 1st order full 3-axis GMN and partial 2-axis GMN. We demonstrated that flow-void artifacts were decreased by using the 2-axis GMN in the TOF part and vessel misregistration due to phase-encode displacement in the TOF part was minor. The HOP technique is suitable for decreasing both flow-void and PED artifacts in MRA compared to TOF alone.

15:30 3776. Dynamically Changing Field-Of-View in the Comprehensive Neurovascular Exam

Petrice M. Mostardi¹, Clifton R. Haider¹, Norbert G. Campeau¹, John Huston¹, Stephen J. Riederer<sup>1

1</sup>Radiology, Mayo Clinic, Rochester, MN, United States

We define a comprehensive neurovascular exam (CNVE) as the high quality imaging of the aortic arch through the intracranial veins. The goal of this work is to image these territories by dynamically changing (scaling/shifting) the FOV during a contrast-enhanced acquisition. Volunteer studies were performed with an imaging protocol consisting of: (i) a large FOV, low dose (2 ml) time-resolved acquisition to provide overall diagnostic information and serve as a timing bolus and (ii) a high spatial resolution contrast-enhanced exam implementing dynamic change of the FOV to image the carotid arteries and the intracranial venous system.