Author + information
- Received March 28, 2010
- Revision received August 4, 2010
- Accepted August 6, 2010
- Published online December 1, 2010.
- Sang Chol Lee, MD⁎,†,
- Chad L. Carr, MD⁎,
- Brian P. Davidson, MD⁎,
- Dilantha Ellegala, MD⁎,
- Aris Xie, MS⁎,
- Azzdine Ammi, PhD⁎,
- Todd Belcik, BS, RDCS⁎ and
- Jonathan R. Lindner, MD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Jonathan R. Lindner, Cardiovascular Division, UHN-62, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239
Objectives We sought to determine whether contrast-enhanced ultrasound (CEU) microangiography with maximum intensity projection (MIP) processing could temporally evaluate proliferation of the vasa vasorum (VV) in a model of mural hemorrhage.
Background Expansion of the VV and plaque neovascularization contributes to plaque growth and instability and may be triggered by a variety of stimuli, including vascular hemorrhage. However, quantitative in vivo methods for temporal assessment of VV remodeling are lacking.
Methods In 24 rabbits fed a high-fat diet, either autologous whole blood or saline was percutaneously injected into the media-adventitia of the femoral artery using ultrahigh-frequency ultrasound guidance. Functional VV density at the injection site and contralateral control artery was assessed 1, 2, and 6 weeks after injection with CEU imaging with MIP processing. In vitro studies with renathane microtubes were also performed to validate linear density measurement with CEU and MIP processing.
Results In vitro studies demonstrated that MIP processing of CEU data reflected the relative linear density of vessels in a manner that was relatively independent of contrast concentration or microtube flow rate. On CEU with MIP, there was a 3-fold increase in femoral artery VV microvascular density at 1 and 2 weeks after blood injection (p < 0.01 vs. contralateral control), whereas VV density increased minimally after saline injection. At 6 weeks, VV vascular density decreased in blood-treated vessels and was not different from saline-injected or contralateral control vessels.
Conclusions CEU with MIP processing can provide quantitative data on temporal changes in the functional density of the VV. This method may be useful for evaluating high-risk features of plaque neovascularization or response to therapies aimed at plaque neovessels.
Supported by grants R01-DK063508, R01-HL078610, and R01-HL074443 from the National Institutes of Health (NIH), Bethesda, Maryland (to Dr. Lindner) and a grant from Genentech Inc., South San Francisco, California. Dr. Carr is supported by a post-doctoral fellowship grant from the American Heart Association. Dr. Davidson is supported by an NIH training grant (T32-HL094294). Dr. Lindner is a past member of the Scientific Advisory Board for VisualSonics, Inc. All other authors report that they have no relationships to disclose.
- Received March 28, 2010.
- Revision received August 4, 2010.
- Accepted August 6, 2010.
- American College of Cardiology Foundation