MR imaging of adventitial vasa vasorum in carotid atherosclerosis

Magn Reson Med. 2008 Mar;59(3):507-14. doi: 10.1002/mrm.21532.

Abstract

Vasa vasorum in the adventitia of atherosclerotic arteries may play a role in plaque progression. In this investigation, a method for characterizing vasa vasorum in the carotid artery is proposed, in which the perfusion properties of the adventitia are probed via dynamic contrast-enhanced (DCE) MRI. A parametric "vasa vasorum image" is automatically generated that depicts the plasma volume (vp) and transfer constant (K trans). The average K trans within the adventitia is proposed as a quantitative measurement related to the extent of the vasa vasorum. In 25 subjects with lesions meeting the requirements for carotid endarterectomy (CEA) significantly higher adventitial K trans of 0.155 +/- 0.045 min(-1) was observed, compared to 0.122 +/- 0.029 min(-1) in the remaining 20 subjects with moderate disease (P < 0.01). In the 25 subjects with endarterectomy specimens, histological evaluation showed that adventitial K trans was significantly correlated with the amount of neovasculature (R = 0.41; P = 0.04) and macrophages (R = 0.49; P = 0.01) in the excised plaque. In the remaining 20 subjects without histology, elevated adventitial K trans was significantly correlated with the log of C-reactive protein (CRP) levels (R = 0.57; P = 0.01) and was elevated in active smokers compared to nonsmokers (0.141 +/- 0.036 vs. 0.111 +/- 0.017 min(-1); P = 0.02). Because these factors are all associated with higher risk of atherosclerotic complications, these results suggest that adventitial K(trans) may be a marker of risk as well.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Atherosclerosis / pathology*
  • Carotid Arteries / pathology*
  • Carotid Stenosis / pathology*
  • Contrast Media
  • Female
  • Gadolinium DTPA
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Male
  • Reproducibility of Results
  • Vasa Vasorum / pathology*

Substances

  • Contrast Media
  • gadodiamide
  • Gadolinium DTPA