Electronic Posters: Cardiovascular

Tuesday 13:30-15:30 Computer 41

13:30 3761. Unenhanced ECG-Gated Fast Spin-Echo MR Digital Subtraction Angiography (MRDSA) Using SPACE with Constant Flip Angle Mode of Femoral Arteries

Satoru Morita¹, Shinya Kojima¹, Masami Hirata¹, Masaru Suzuki¹, Kazufumi Suzuki¹, Ai Masukawa¹, Eiko Ueno<sup>1

1</sup>Department of Radiology, Tokyo Women's Medical University Medical Center East, Arakawa-ku, Tokyo, Japan

Unenhanced electrocardiographically-gated fast spin-echo-based magnetic resonance digital subtraction angiography (MRDSA) can obtain hemodynamic information of pulse wave transmission. We prospectively compared the image quality of MRDSA using sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) with constant flip angle mode and conventional half-Fourier single-shot turbo spin-echo (HASTE) sequence of femoral arteries in 10 healthy volunteers at 1.5T MRI. All quantitative and qualitative analyses of the SPACE were significantly better than those of the HASTE. We show that unenhanced electrocardiographically-gated fast spin-echo MRDSA using SPACE with constant flip angle mode provides good visual hemodynamic information of arteries.

14:00 3762. Nonenhanced Time-Resolved MR Angiography for the Arteriovenous Malformation/Fistula of the Pelvis and the Lower Extremity.

Masaaki Akahane¹, Jiro Sato¹, Shuhei Komatsu¹, Yasushi Watanabe², Yoshiro Satake², Kuni Ohtomo<sup>1

1</sup>Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan; ²Clinical Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan

Nonenhanced MRA by spin-labeling technique with subtraction between labeled and non-labeled images was applied to the time-resolved study for better background suppression in any inversion time. Seven patients having arteriovenous malformations or fistulas of the pelvis or lower extremity underwent nonenhanced time-resolved MRA using respiratory-gated balanced steady state free precession (SSFP) sequence with 1.5-T scanner (Toshiba EXCELART Vantage, Japan). Inversion times (TI) were assigned as 300, 800, 1300 and 1800 ms. Nonenhanced time-resolved MRA was useful for the evaluation of hemodynamics of the arteriovenous malformation or fistula and the distinction of feeding arteries.

14:30 3763. Adapted Random 3D Sampling Patterns for CE-MRA

Florian Knoll¹, Christian Clason², Manuela Aschauer³, Franz Ebner³, Rudolf Stollberger<sup>1

1</sup>Institute of Medical Engineering, Graz University of Technology, Graz, Austria; ²Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria; ³Department of Radiology, Medical University Graz, Graz, Austria

Variable density 3D random sampling trajectories have great potential for subsampled CE-MR angiography techniques which deliver data sets with high contrast to noise ratio. The goal of this work was to present a parameter-free method to construct variable density sampling patterns which are tailored to angiography. Sampling patterns are generated with the use of a probability density function that is constructed by using measured k-space data as a reference, which automatically ensures an appropriate distribution of sample points.

15:00 3764. Imaging of Pulmonary Artery and Vein Using ASL Based Non-Contrast MRA Technique

Tomoyuki Okuaki^1,2, Takeshi Ishimoto³, Momoe Kawakami³, Masaru Ishihara⁴, Tetsuro Ogino¹, Ivan Zimine¹, Marc Van Cauteren⁵, Toshiaki Miyati<sup>6

1</sup>Clinical Science, Philips Electronics Japan, Minato-ku, Tokyo, Japan; ²Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan; ³Hyogo Brain and Heart Center, Japan; ⁴Kakogawa Medical Center, Japan; ⁵Philips Healthcare, Netherlands; ⁶Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan

For lung imaging, depiction of pulmonary artery (PA) and vein (PV) can be done using ASL based technique. However, visualization of PV using conventional ASL approach is challenging because tagged blood in the pulmonary artery requires several seconds to reach the vein. In this work we evaluated the possibility of simultaneous visualization of PA and PV using ASL based technique at multiple inversion times (TI). For PA, high scores were observed at TI=800ms and 1100ms respectively; For PV, highest score was observed at TI=300ms. Expected clinical application is imaging of patients with pulmonary infarction.