Hemodynamic analysis of an intracranial aneurysm model with tagged MR imaging and investigation of rupture site of the aneurysm

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12470186
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Hamamatsu University School of Medicine
• Principal Investigator: ISODA Haruo Hamamatsu University School of Medicine Radiology, Assistant Professor, 医学部・附属病院, 講師 (40223060)
• Co-Investigator(Kenkyū-buntansha): INAGAWA Shoichi Hamamatsu University School of Medicine Radiology, Clinical Instructor, 医学部・附属病院, 助手 (60303567)
• Project Period (FY): 2000 – 2001
• Keywords: Intracranial aneurysm / hemodynamics / magnetic resonance imaging / tagged MR imaging / particle image velocimetry

Research Abstract

Flow dynamics in intracranial aneurysms and their adjacent parent vessels play very important roles in the development of intracranial aneurysms and in their rupture. The purpose of this study was to investigate the possibility of visualization of hemodynamics in an intracranial aneurysm replica by using tagged MR imaging and particle image velocimetry (PIV) software.
Our phantom system included a pulsatile flow pump and a replica of an anterior communicating artery aneurysm. We used a mixture of glycerol and distilled water (ratio, 2 : 3) as flowing fluid. The peak systolic velocity of the internal carotid artery was adjusted to 50ml/sec. Imaging was performed using a 1.5 T superconducting MR system with a commercially available head coil. Tagged MR imaging was carried out using ECG gated fast spoiled gradient echo sequence combined with spatial modulation of magnetization technique with the following parameters : TR/TE/NEX, 9.1/2.1/8 ; slice thickness, 5 mm ; tag space, 3 mm. Imaging planes included the anterior communicating artery and the center of the aneurysm. Tag stripes were placed at 3mm interval in a grid pattern in the aneurysm model. We estimated hemodynamics by observing the motion of the tag lines in the aneurysm model. We also analyzed tagged MR image data with PIV software.
Rotation of tag stripes in the aneurysm replica was observed. We could estimate the hemodynamics in the aneurysm. Analysis of tagged MR image data with PIV revealed the velocity and direction of flowing fluid at each location in the aneurysm model every nine milliseconds.
analysis would be a promising and noninvasive technique for revealing hemodynamics in intracranial aneurysms.