Quantitative Assessment of Synovial Vascularity Using Contrast-Enhanced Power Doppler Ultrasonography: Correlation with Histologic Findings and MR Imaging Findings in Arthritic Rabbit Knee Model.
- Author:
Sang Hoon LEE
1
;
Jin Suck SUH
;
Myung Jin SHIN
;
Seong Moon KIM
;
Namkug KIM
;
Sang Hyun SUH
Author Information
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords: Arthritis; Joints, US; Synovitis; Ultrasound (US), Power Doppler studies; Magnetic resonance (MR); Arthrtis, animal studies
- MeSH: Animals; Contrast Media; Gadolinium DTPA/diagnostic use; Image Processing, Computer-Assisted; Immunohistochemistry; Magnetic Resonance Imaging; Osteoarthritis, Knee/pathology/*ultrasonography; Polysaccharides/diagnostic use; Rabbits; Statistics, Nonparametric; Synovial Membrane/*blood supply/pathology/ultrasonography; *Ultrasonography, Doppler
- From:Korean Journal of Radiology 2008;9(1):45-53
- CountryRepublic of Korea
- Language:English
- Abstract: OBJECTIVE: To validate contrast-enhanced power Doppler ultrasonography (PD US) for the evaluation of synovial vascularity in an arthritic rabbit knee model in correlation with MR and histological findings. MATERIALS AND METHODS: Power Doppler ultrasonography was performed for carrageenin-induced arthritic left knee and control right knee of 13 rabbits, first without and then with sonic contrast agent enhancement (Levovist, Schering, Berlin Germany), followed by gadolinium-enhanced MR imaging. Synovial vascularity was quantitatively assessed by calculating the color pixel area in power Doppler sonography using a computer-aided image analysis program and by grading the enhancement on MR images: grade 1, enhancement of knee joint is less than one-third of the area; grade 2, one-third to two-thirds enhancement; and grade 3, more than two-thirds enhancement. Microvessel density (MVD) was measured on slides stained immunohistochemically for CD31 antigen for histological assessment. RESULTS: The mean area of color pixels in PD US changed from 4.37 to 16.42 mm2 in the arthritic knee after enhancement (p < 0.05), whereas it changed from 0.77 to 2.31 mm2 in the control knee (p < 0.05). Arthritic knees had greater power Doppler signal than control knees both before and after contrast administration (p < 0.05). The average MVD was 88 in arthritic knees and 46 in control knees. MVDs correlated with color pixel areas of contrast-enhanced power Doppler imaging in arthritic knees. In MR grading of arthritic knees, five were grade 2 and eight were grade 3. MVD and PD US revealed no significant difference between grade 2 and 3 arthritic knees (p > 0.05). CONCLUSION: Sonic contrast-enhanced PD US improves the visualization of synovial vascularity and allows quantitative measurement in experimentally induced rabbit arthritic knees.
