Possibility of intravenous micro-bubbles as MRI contrast media for myocardial perfusion

• Project/Area Number: 11670887
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Osaka UNIVERSITY
• Principal Investigator: HAMADA Seiki Osaka University Graduate school for medicine, Lecturer, 医学系研究科, 講師 (80198803)
• Co-Investigator(Kenkyū-buntansha): HONDA Osamu Osaka University Graduate school for medicine, Assistant Professor, 医学系研究科, 助手 (80324755) ; JOHKOH Takeshi Osaka University Graduate school for medicine, Associate Professor, 医学系研究科, 助教授 (20263270) ; NAITO Hiroaki Osaka University Graduate school for medicine, Professor, 医学系研究科, 教授 (60217627) ; 富山 憲幸 大阪大学, 医学系研究科, 助手 (50294070)
• Project Period (FY): 1999 – 2001
• Project Status: Completed (Fiscal Year 2001)
• Budget Amount: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: echocardiographic contrast agent / cardiac magnetic resonance imaging / myocardial perfusion imaging / MRI / 超音波用微小気泡造影剤 / T^<2*>短縮効果 / T1短縮効果 / 心筋潅流 / 心筋灌流 / 微小気泡 / T2短縮効果 / susceptibility effect

Research Abstract

We investigated the possibility of intravenous micro-bubbles as MRI contrast media for myocardial perfusion. As now available micro-bubbles we used Levovist, which consisted of 99.9 % galactose and 0.1 % palmitic acid. Our preliminary experiment suggested that micro bubbles in the galactose solvent disturbs local magnetic field by means of paramagnetic characteristics due to susceptibility effect, therefore T2^* value is shortened. Simultaneously T1 shortening effect of oxygen molecules also is made sure as the change of signal intensity. In the evaluation of myocardial perfusion we should detect the first passage of contrast media and so the effect of T2^* value is inevitable. It is suitable to evaluate myocardial perfusion by means of T2^* shortening effect. These suggested the evaluation of myocardial perfusion with Levovist is necessary to use air micro bubbles, rather than oxygen micro bubbles. We tried myocardial perfusion imaging of normal volunteer with Levovist. MRI sequence is EPI of Gradient echo type. In the comparison of control, we detected the decrease of the signal intensity in the interventricular septum by bolus injection of Levovist. The possibility of micro bubbles as myocardial perfusion MRI tracer is suggested under the condition of sufficient concentration of micro bubbles.