Quantitative assessment of synovial vascularity using contrast-enhanced power Doppler ultrasonography: correlation with histologic findings and mr imaging findings in arthritic rabbit knee model

Ultrasonography and X-ray micro-computed tomography characterization of the effects caused by carrageenin in the muscle of gilthead seabream (Sparus aurata)

The current work aimed to carry out an in vivo study of the λ-carrageenin-induced inflammation in the skin of gilthead seabream (Sparus aurata). The fish were injected intramuscularly with phosphate-buffered saline (PBS, as control) or λ-carrageenin (1% in PBS), and the injection zone was evaluated by real-time ultrasonography (Vevo Lab, VisualSonics) at 1.5, 3, 6, 12, and 24 h post-injection (p.i.). Results demonstrated that the skin thickness was increased in fish injected with λ-carrageenin and sampled at 1.5, 3, and 6 h p.i. However, the skin thickness of the injected area decreased to the normal values in those fish sampled at 12 and 24 h p.i. In addition, fish injected with λ-carrageenin and analysed at 1.5, 3, and 6 h p.i. showed, in the underlying muscle at the injection place, several hyperechoic small foci surrounded by an anechoic area which were not observed in control fish. Furthermore, the fish were analysed by X-ray micro-computed tomography (micro-CT). The analysis of the micro-CT acquisitions revealed also a dark area in the place of the injection with λ-carrageenin at 1.5, 3, and 6 h. These areas were smaller in fish analysed at longer times (12 h p.i.) and were almost disappeared in fish sampled at 24 h p.i. These areas had an average density of -850 to -115 HU, which did not correspond with any tissue density of the rest of the body. Furthermore, similar dark areas at the injection zones were never observed in control fish. Present results support the use of both non-invasive techniques to study the inflammatory process in fish of commercial interest such as gilthead seabream.

Longitudinal Changes in Knee Joint Synovial Vascularity in a Rabbit Model of Rheumatoid Arthritis: Quantification Using Power Doppler Ultrasound and Contrast-Enhanced Ultrasound

We studied a rabbit model of rheumatoid arthritis (RA) to examine the time course of changes in synovial neovascularization based on quantitative power Doppler ultrasound and contrast-enhanced ultrasound (CEUS). Twenty-five male New Zealand rabbits were in the ovalbumin-induced arthritis (OIA) group, and 5 were in the control group. Both rear knee joints of all rabbits were examined using conventional US and CEUS over 16 weeks. The knee synoviums of OIA rabbits were sampled by US-guided biopsy, and expression of CD31 and vascular endothelial growth factor (VEGF) was determined by immunohistochemistry. The correlation of joint damage based on multimodal US with microvessel density (CD31 positivity) and VEGF expression at different times was analyzed. OIA rabbits had increased synovial expression of CD31 and VEGF from weeks 6 to 12 (p < 0.01). During the early stage of CEUS enhancement, "dot enhancement" was more common at weeks 6 and 8, and "stripe enhancement" was more common at weeks 12 and 16 (p < 0.05). There were significant positive correlations of synovial CD31 and VEGF expression with power Doppler image grade, CEUS grade and peak intensity (p < 0.05 for all). Thus, OIA rabbits mimicked early-stage RA at 6 to 8 weeks, middle-stage RA at 8 to 12 weeks and late-stage RA at 12 to 16 weeks. Power Doppler image grade, CEUS grade and peak intensity, especially when combined with CD31 expression data, accurately characterized the extent of synovial vascularization in a rabbit model of RA. Increased vascularity based on CEUS may have value for the early diagnosis of RA.

Animal model of acute gout reproduces the inflammatory and ultrasonographic joint changes of human gout

INTRODUCTION

Gout is an inflammatory condition induced by the deposition of monosodium urate (MSU) crystals in the joints and soft tissues that can produce acute or chronic arthritis. Several animal models of crystal-induced inflammation have been proposed that involve direct injection of MSU-crystals into different anatomical structures; however, only a few of these models reflect a true diarthrodial joint microenvironment in which an acute gouty attack takes place. The aim of this study was to assess the inflammatory and structural joint changes in a rabbit model of acute gout attack by ultrasound (US), synovial fluid (SF) and histopathological analyses.

METHODS

Under US guidance, 42 rabbit knees were randomly injected with a suspension of 50 mg/ml of either MSU or allopurinol synthetic crystals. The control group received intra-articular vehicle of phosphate-buffered saline (PBS). US evaluation, SF and histopathological analyses were performed at days 1, 3, and 7.

RESULTS

A total of 21 rabbit knees were assigned to the control group, 12 to the MSU-crystals group, and 9 to the allopurinol crystals group. By US, the MSU crystals group displayed the double contour sign and bright stippled aggregates in 67% and 75% of joints, respectively. Neither control knees nor allopurinol crystals group displayed these US signs. Power Doppler (PD) signal was moderate to intense in the MSU-crystals group and greater than both the allopurinol crystal and control groups at day 1 (P<0.001) and 3 (P<0.05), with its practical disappearance by day 7. SF leukocyte count was 40,312±6,369 cells/mm3 in the MSU-crystals group, higher than in controls (P=0.004) and allopurinol crystal group (P=0.006). At day 7, SF leukocyte count decreased in both MSU and allopurinol crystal groups reaching the non-inflammatory range. Histologically, at day 3 intense synovial polymorphonuclear cells infiltration and MSU aggregates were identified.

CONCLUSION

The rabbit model of MSU crystal-induced acute arthritis efficiently reproduces the inflammatory, US, SF and histopathological changes of the human acute gouty attack.

Evaluation of finger joint synovial vascularity in patients with rheumatoid arthritis using contrast-enhanced ultrasound with water immersion and a stabilized probe

PURPOSE.: To assess synovial microvascularity in finger joints with rheumatoid arthritis (RA) by contrast-enhanced ultrasound (CEUS), distinguishing between cases of active disease and those in remission; to standardize the technique for software analysis. METHODS.: Fifty-two finger joints of RA patients (26 with active disease and 26 in remission) were immersed in water and examined by CEUS using a fixed probe. Signal intensity curves were calculated with the software. RESULTS.: Contrast enhancement was detectable in all 26 patients with active RA (100%), but not in 25 of 26 patients in remission (96%); one of the latter patients (4%) showed minimal enhancement. The method's sensitivity and specificity in distinguishing active disease from remission were 100% and 96%. The grades of synovial enhancement correlated with clinical disease activity and software flow parameters. The peak contrast levels correlated with clinical activity, a peak of 9% representing the cutoff between remission and active disease. CONCLUSIONS.: CEUS with a fixed probe on finger joints immersed in water detected synovial vascularization in RA, producing results suitable for standardized software analysis and avoiding artifacts.

Correlation between computerised findings and Newman's scaling on vascularity using power Doppler ultrasonography imaging and its predictive value in patients with plantar fasciitis

OBJECTIVES

The purpose of this study was to correlate findings on small vessel vascularity between computerised findings and Newman's scaling using power Doppler ultrasonography (PDU) imaging and its predictive value in patients with plantar fasciitis.

METHODS

PDU was performed on 44 patients (age range 30-66 years; mean age 48 years) with plantar fasciitis and 46 healthy subjects (age range 18-61 years; mean age 36 years). The vascularity was quantified using ultrasound images by a customised software program and graded by Newman's grading scale. Vascular index (VI) was calculated from the software program as the ratio of the number of colour pixels to the total number of pixels within a standardised selected area of proximal plantar fascia. The 46 healthy subjects were examined on 2 occasions 7-10 days apart, and 18 of them were assessed by 2 examiners. Statistical analyses were performed using intraclass correlation coefficient and linear regression analysis.

RESULTS

Good correlation was found between the averaged VI ratios and Newman's qualitative scale (ρ=0.70; p<0.001). Intratester and intertester reliability were 0.89 and 0.61, respectively. Furthermore, higher VI was correlated with less reduction in pain after physiotherapeutic intervention.

CONCLUSIONS

The computerised VI not only has a high level of concordance with the Newman grading scale but is also reliable in reflecting the vascularity of proximal plantar fascia, and can predict pain reduction after intervention. This index can be used to characterise the changes in vascularity of patients with plantar fasciitis, and it may also be helpful for evaluating treatment and monitoring the progress after intervention in future studies.

Evaluation of diffusion-weighted magnetic resonance imaging and contrast-enhanced harmonic ultrasonography in detection and location of prostate transition-zone cancer

This retrospective study was designed to evaluate the value of contrast-enhanced harmonic ultrasonography (CEHU), diffusion-weighted magnetic resonance imaging (DW-MRI) and CEHU plus DW-MRI for the diagnosis of prostate transition-zone (TZ) cancer. In total, 31 TZ cancers in 28 patients and 25 peripheral zone (PZ) cancers in 21 patients without a TZ cancer were evaluated. All patients underwent DW-MRI and CEHU followed by radical prostatectomy. Predictors for the diagnosis of prostate cancer were evaluated in three protocols (CEHU, DW-MRI, CEHU plus DW-MRI). Statistical analysis of the differences between these protocols and receiver operating characteristic (ROC) curve analysis were carried out. CEHU plus DW-MRI had a significantly higher sensitivity, accuracy and negative-predictive value (90.3%, 73.2% and 81.3%, respectively) for TZ cancer than either method alone. The area under the ROC curve values were 0.659, 0.679 and 0.712 for CEHU, DW-MRI, and CEHU plus DW-MRI, respectively. In conclusion, CEHU plus DW-MRI might be a useful protocol for the detection and location of TZ cancer.

In vivo visualization of vascular patterns of rotator cuff tears using contrast-enhanced ultrasound

BACKGROUND

Hypoxia and decreased blood supply have been proposed as risks for tendon rupture. Visualization of the vascularity of intact and torn rotator cuffs would be useful for improving treatments for rotator cuff tear.

PURPOSE

To assess vascularity inside a tendon or an adjacent rotator cuff insertion point in patients differing in age and extent of damage to the tendon.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Ten volunteers (all men) and 15 patients (10 men, 5 women) consented to participate in the study. Contrast agent for enhanced ultrasound was injected intravenously. Enhanced ultrasound images of the torn cuff and the contralateral shoulder were recorded for 1 minute. Four small regions of interest, the articular and bursal sides of the tendon and the medial and lateral sides of the bursa, were studied in all shoulders.

RESULTS

There was a significant decrease in blood flow in the intratendinous region in elderly subjects compared with young subjects, but age had no effect on blood flow in bursal tissue. Blood flow in ruptured rotator cuffs did not differ from that in intact rotator cuffs. The intraclass correlation coefficient for intraobserver reproducibility was 0.82 (95% confidence interval: 0.77-0.86).

CONCLUSIONS

The findings of this investigation were the hypovascular pattern in intratendinous tissue compared with the subacromial bursa, the age-related decrease in intratendinous vascularity, and the hypovascular pattern in the tendon, regardless of rupture of the tendon. Clarification of vascular patterns inside or around the torn ends of a rotator cuff will assist in the development of successful treatments for torn rotator cuffs.

Value of power Doppler and gray-scale US in the diagnosis of carpal tunnel syndrome: contribution of cross-sectional area just before the tunnel inlet as compared with the cross-sectional area at the tunnel

Objective

To determine the value of gray-scale and power Doppler ultrasonography in the evaluation of carpal tunnel syndrome (CTS).

Materials and Methods

Median nerves at the carpal tunnel were evaluated by using gray-scale and power Doppler ultrasonography and by using accepted and new criteria in 42 patients with CTS (62 wrists) confirmed by electromyogram and 33 control subjects. We evaluated the cross-sectional area of the nerve just proximal to the tunnel inlet (CSAa), and at mid level (CSAb). We then calculated the percentage area increase of CSAb, and area difference (CSAb-CSAa). We measured two dimensions of the nerve at the distal level to calculate the flattening ratio. The power Doppler ultrasonography was used to assess the number of vessels, which proceeded to give a score according to the vessel number, and lastly evaluated the statistical significance by comparing the means of patients with control subjects by the Student t test for independent samples. Sensitivities and specificities were determined for sonographic characteristics mentioned above. We obtained the receiver operating characteristic (ROC) curve to assess the optimal cut-off values for the diagnosis of CTS.

Results

A statistically significant difference was found between patients and the control group for mean CSAb, area difference, percentage area increase, and flattening ratio (p < 0.001, p < 0.001, p < 0.001, p < 0.05, respectively). From the ROC curve we obtained optimal cut-off values of 11 mm² for CSAb, 3.65 for area difference, 50% for the percentage of area increase, and 2.6 for the flattening ratio. The mean number of vessels obtained by power Doppler ultrasonography from the median nerve was 1.2. We could not detect vessels from healthy volunteers. Mean CSAbs related to vascularity intensity scores were as follows: score 0: 12.3 ± 2.8 mm², score 1: 12.3 ± 3.1 mm², score 2: 14.95 ± 3.5 mm², score 3: 19.3 ± 3.8 mm². The mean PI value in vessels of the median nerve was 4.1 ± 1.

Conclusion

Gray-scale and power Doppler ultrasonography are useful in the evaluation of CTS.

Contrast-enhanced harmonic ultrasonography for the assessment of prostate cancer aggressiveness: a preliminary study

OBJECTIVE

To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer.

MATERIALS AND METHODS

Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied.

RESULTS

Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of high-grade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001).

CONCLUSION

Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.