Comparison of Two High-End Ultrasound Systems for Contrast-Enhanced Ultrasound Quantification of Mural Microvascularity in Crohn's Disease

PURPOSE

To verify the reproducibility of contrast-enhanced ultrasound (CEUS) quantification results of two different high-end ultrasound systems and to evaluate the clinical utility of the method in patients with Crohn's disease (CD).

MATERIALS AND METHODS

18 patients with histologically confirmed CD (36.8 % women, 63.2 % men; mean age 43.7 ± 14.1 years) and wall segments thicker than 5 mm were recruited. CEUS quantification and conventional ultrasound investigation were performed under standardized settings using Toshiba Aplio500 and Siemens Acuson S3000 high-end ultrasound systems. CEUS was performed at a low mechanical index of 0.1 after bolus application of 4.8 ml of SonoVue(®) contrast medium. The recorded DICOM clips were quantified using VueBox(®) (version 4.3) calculating 11 quantitative parameters. Subsequently, CEUS quantification and conventional ultrasound results were analyzed.

RESULTS

Correlation of quantitative parameters between the Aplio500 and AcusonS3000 systems for peak enhancement (PE), rise time (RT), wash-in-rate (WiR) and quality of fit (QOF) yielded significance levels of p < 0.05 and p < 0.0001 for wash-in-wash-out area under the curve (WiWoAUC). Spearman rank test showed moderate levels of correlation for PE, RT, WiR and QOF (r = 0.5, 0.49, 0.49 and 0.5 respectively), and high correlation for WiWoAUC (r = 0.89) between the two ultrasound systems.

CONCLUSION

Due to multiple uncontrollable affecting factors, the method of CEUS quantification by VueBox in the intestine cannot be recommended for device-independent multicenter studies. Therefore we suggest to use identical ultrasound systems and probes as well as to establish adequate reference ROIS, like a AIF-ROI.

In-vivo monitoring of acute DSS-Colitis using Colonoscopy, high resolution Ultrasound and bench-top Magnetic Resonance Imaging in Mice

OBJECTIVE

The aim of this study was to establish and evaluate (colour Doppler-) high-resolution-ultrasound (hrUS) and bench-top magnetic resonance imaging (btMRI) as new methods to monitor experimental colitis.

MATERIALS AND METHODS

hrUS, btMRI and endoscopy were performed in mice without colitis (n = 15), in mice with acute colitis (n = 14) and in mice with acute colitis and simultaneous treatment with infliximab (n = 19).

RESULTS

Determination of colon wall thickness using hrUS (32 MHz) and measurement of the cross-sectional colonic areas by btMRI allowed discrimination between the treatment groups (mean a vs. b vs. c - btMRI: 922 vs. 2051 vs. 1472 pixel, hrUS: 0.26 vs. 0.45 vs. 0.31 mm). btMRI, endoscopy, hrUS and colour Doppler-hrUS correlated to histological scoring (p < 0.05), while endoscopy and btMRI correlated to post-mortem colon length (p < 0.05).

CONCLUSIONS

The innovative in vivo techniques btMRI and hrUS are safe and technically feasible. They differentiate between distinct grades of colitis in an experimental setting, and correlate with established post-mortem parameters. In addition to endoscopic procedures, these techniques provide information regarding colon wall thickness and perfusion. Depending on the availability of these techniques, their application increases the value of in vivo monitoring in experimental acute colitis in small rodents.

KEY POINTS

• Improved in vivo monitoring might balance interindividual differences in murine colitis. • In monitoring murine colitis, btMRI and hrUS are safe and technically feasible. • Very short examination times underline the usefulness especially of hrUS. • Results of btMRI and hrUS correlate with endoscopic and post-mortem findings.

Variable beta-catenin expression in colorectal cancers indicates tumor progression driven by the tumor environment

Invasion and dissemination of well-differentiated carcinomas are often associated with loss of epithelial differentiation and gain of mesenchyme-like capabilities of the tumor cells at the invasive front. However, when comparing central areas of primary colorectal carcinomas and corresponding metastases, we again found the same differentiated epithelial growth patterns. These characteristic phenotypic changes were associated with distinct expression patterns of beta-catenin, the main oncogenic protein in colorectal carcinomas, and E-cadherin. Nuclear beta-catenin was found in dedifferentiated mesenchyme-like tumor cells at the invasive front, but strikingly, as in central areas of the primary tumors, was localized to the membrane and cytoplasm in polarized epithelial tumor cells in the metastases. This expression pattern was accompanied by changes in E-cadherin expression and proliferative activity. On the basis of these data, we postulate that an important driving force for progression of well-differentiated colorectal carcinomas is the specific environment, initiating two transient phenotypic transition processes by modulating intracellular beta-catenin distribution in tumor cells.