Contrast-enhanced coded phase-inversion harmonic sonography of knee synovitis correlates with histological vessel density: 2 automated digital quantifications.

OBJECTIVE: To use contrast-enhanced coded phase-inversion harmonic B-mode sonography to assess the acoustic enhancement of the synovial area of the knee; and to compare the data with the histological vessel density. METHODS: Eleven patients eligible for a knee arthroscopy were studied. Acoustic quantification was carried out by a digital image analysis program that detects the time-dependent increase [intensity (time) = k x time + C] of gray-level intensity in all the pixels of a specific region of interest (ROI) following intravenous injection of the microbubble contrast agent sulfur hexafluoride. Echo-guided synovial biopsies were carried out in the same ROI. Synovial vessel areas were quantified after Factor VIII immunostaining of synovial biopsies using an automated digital image analysis. RESULTS: Significant (p < 0.05) correlations were observed between histological vessel density and percentage of the synovial area with a k value > 0.01 (r = 0.93) and k(max) values (r = 0.79), as well as between the 2 latter parameters (r = 0.72). The histological vessel density and the 2 acoustic parameters were also significantly correlated with the logarithm of erythrocyte sedimentation rate (r = 0.77, r = 0.87, r = 0.67, respectively) and with log C-reactive protein serum concentration (r = 0.69, r = 0.83, r = 0.62, respectively). CONCLUSION: Contrast-enhanced coded phase-inversion harmonic B-mode sonography coupled with an appropriate data analysis method is a new tool to identify and quantify vessel density in knee synovitis.

Contrast ultrasound perfusion imaging of lower extremities in peripheral arterial disease: a novel diagnostic method.

AIMS: The purpose of this study was to establish contrast-enhanced ultrasound perfusion imaging (CUPI) of the lower extremities as a novel non-invasive diagnostic tool for patients with peripheral arterial disease (PAD). METHODS AND RESULTS: Ultrasound contrast agent (SonoVue) was injected into a peripheral vein of 16 control subjects and 16 PAD patients and its appearance in the calf muscle was detected by low-energy harmonic ultrasound. Analysis of the wash-in curves revealed that PAD patients had a significantly longer time to peak intensity (TTP), i.e. duration of maximum contrast perfusion [37 s (19-79 s) in control subjects vs. 56 s (32-104 s) in PAD patients at rest, age-adjusted P=0.002]. Exercise stress test of the calf muscle resulted in a decrease of the TTP, maintaining the significant difference in TTP between the groups [19 s (8-37 s) in control subjects vs. 32 s (18-48 s) in PAD patients after exercise, age-adjusted P=0.004]. Neither ankle-brachial index and TTP nor age and TTP showed a significant correlation. CONCLUSION: CUPI reflects the regional blood circulation of the calf muscle. In this pilot study, PAD patients show a significantly longer TTP than control subjects. The clinical relevance of CUPI is topic of ongoing studies.