CMR2009: 10.06: Can magnetic forces be used to induce anisotropic migration of iron oxide labeled stem cells in normal tendon?

✍ Scribed by E. R. Wisner; M. Spriet; S. M. Puchalski; M. A. Vidal; L. D. Galuppo; N. J. Walker; R. F. Larson; D. L. Borjesson

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 76 KB
• Volume: 4
• Category: Article
• ISSN: 1555-4309
• DOI: 10.1002/cmmi.352

✦ Synopsis

Materials and Methods: 24 ApoE À/À mice were divided in four groups (N¼6) and put onto a high-cholesterol diet at 2 weeks of age. One group per MR time point was investigated at 10, 16, 24 and 34 weeks of age. Each MR point was performed on a 4.7 T scanner and consisted of baseline and 48 h post-USPIO administration imaging sessions. A USPIO contrast agent with the r 1 /r 2 ratio of 6.2 measured in water at 1.42 T, 378C was used. Vessel wall area measurements were performed on high resolution spin echo images. Multiecho gradient echo images were used to calculate T 2 Ã maps of the vessel wall using a pixel-by-pixel mono-exponential fit. A one-way ANOVA was performed to characterize the temporal variation of vessel wall area, susceptibility artifact area, baseline and post-USPIO T 2 Ã values. Results: A significant increase was found for the aortic wall area from 142AE17 at 10 weeks to 213AE27 pixels at 34 weeks of age (p<0.05). All post-USPIO images showed signal loss regions. A significant increase in the size of the susceptibility artifact was also observed until the third point from 48.75AE22.02 to 252.33AE100.89, followed by a decrease to 213AE104 at the last point. The increase was significant between the first point and the last two points (p<0.05). The T 2 Ã values calculated on the post-USPIO images were shorter compared with baseline. The decrease was 34.05AE16.52% at 10 weeks, 57.32AE11% at 16 weeks, 57.05AE16.04% at 24 weeks and 48AE13.26% at 34 weeks. The mean T 2 Ã values of the vessel wall showed a significant decrease at the second and third point compared with the first point (Fig. 1). A correlation test showed a good and statistically significant correlation for vessel wall surface (r¼0.695) measured on MR images and histology slides, and a good correlation was obtained between the signal loss area and the macrophages covered area (r¼0.65). Conclusions: This study demonstrated the feasibility of USPIOenhanced MRI in assessing the inflammatory status related to the temporal progression of the atherosclerosis plaque in ApoE À/À transgenic mice.