Electronic Posters: Cardiovascular

Tuesday 13:30-15:30 Computer 39

13:30 3732. Hemorrhage Delineation and Blood Suppression Evaluation in Slab-Selection Phase-Sensitive Inversion-Recovery (SPI) Sequence with MRI

Dongxiang Xu¹, Jinnan Wang², Williams Kerwin¹, Chun Yuan<sup>1

1</sup>Radiology, University of Washington, Seattle, WA, United States; ²Philips Research North America, [e-mail], Seattle, WA, United States

Intraplaque hemorrhage (IPH) into the carotid atherosclerotic plaque has shown significant association with clinical symptoms and is believed to be a major factor causing plaque instability and progression according to previous histopathological and prospective studies. With the development of magnetic resonance imaging (MRI) in clinical diagnostics, several techniques have been developed to enable and improve the IPH evaluation. However, automated hemorrhage detection has been challenging due to either low IPH contrast or poor lumen contrast. Purpose: In this study, by incorporating the improved IPH and lumen contrasts in Slab-selection Phase-sensitive Inversion-recovery (SPI) MRI sequence, we develop a novel and robust image segmentation approach to automatically locate and delineate IPH in MR data. Quantitative IPH and lumen analysis results by this automatic segmentation technique were compared to a human reader, which demonstrated highly consistent performance.

14:00 3733. Direct and Indirect Surface Coil Correction for Cardiac Perfusion MRI

Hui Xue¹, Sven Zuehlsdorff², Jens Guehring<sup>1

1</sup>Corporate Research, Siemens Corporation, Princeton, NJ, United States; ²CMR Research and Development, Siemens Healthcare, Chicago, IL, United States

Although the first-pass myocardial perfusion MRI has proven its effectiveness in the early diagnosis of suspected ischemic heart diseases, this technique is still not routinely used. Certain technical difficulties prevent perfusion MRI from being added into the clinical workflow. Among of them includes the B1-field inhomogeneity caused by non-uniform characteristics of the receiver coils which still lacks intensive studies, when compared to perfusion imaging sequences or motion compensation. We therefore propose algorithms to perform the surface coil inhomogeneity correction (SCC) using proton density (PD) weighted images and B-Spline Free-Form Deformation (FFD).

14:30 3734. Saturation Correction of Dynamic Contrast Enhanced MRI Uptake Curves for Quantitative Myocardial Blood Flow Measurements Using an Assumed T₁ for Blood

John David Biglands¹, Abdulghani Larghat¹, Sven Plein¹, David L. Buckley¹, Michael Jerosch-Herold², Derek Magee³, Roger Boyle³, Aleksandra Radjenovic<sup>1

1</sup>School of Medicine, University of Leeds, Leeds, UK, United Kingdom; ²Radiology, Brigham and Womens Hospital, Boston, MA, United States; ³School of Computing, University of Leeds, Leeds, United Kingdom

Dynamic contrast enhanced magnetic resonance imaging of the myocardium using sufficiently high doses to be clinically useful generates uptake curves that require correction for signal saturation effects before they can be used for myocardial blood flow (MBF) estimation. Such corrections require knowledge of the native T1 of the blood and myocardium. This abstract shows that using an assumed blood T1 enables saturation correction of typical clinical datasets without the need for time consuming T1 measurements. MBF estimates from nine patients were consistent with literature values and were shown to be robust to variations in the assumed T1 of blood.

15:00 3735. Novel MRI T2 Mapping for Improved Myocardial Tissue Characterisation

Taigang He¹, Sanjay Prasad¹, Guang-Zhong Yang¹, Dudley Pennell¹, David Firmin<sup>1

1</sup>Royal Brompton Hospital and Imperial College London, London, United Kingdom

Synopsis: The aim of this study was to develop a novel T2 mapping method for improved myocardial tissue characterisation. The developed T2 sequence resulted in improved resolution with shorter echo time and echo spacing. The novel technique was consequently evaluated on nine human subjects. Preliminary results demonstrated that all images acquired were of good quality. Pixel wise T2 curve is well fitted and T2 mapping in the whole myocardium appeared homogeneous. This study suggests that T2 mapping may potentially be used for assessing regional disease variations across the myocardium.