Combined contrast-enhanced power Doppler and real-time sonoelastography performed during EUS, used in the differential diagnosis of focal pancreatic masses (with videos)

Background

Contrast-enhanced power Doppler (CEPD) and real-time sonoelastography (RTSE) performed during EUS were previously described to be useful for the differential diagnosis between chronic pseudotumoral pancreatitis and pancreatic cancer.

Objective

To prospectively assess the accuracy of the combination of CEPD and RTSE to differentiate pancreatic focal masses.

Design

Cross-sectional feasibility study.

Setting

A tertiary-care academic referral center.

Patients

The study group included 54 patients with chronic pancreatitis (n = 21) and pancreatic adenocarcinoma (n = 33).

Interventions

Both imaging methods (CEPD and RTSE) were performed sequentially during the same EUS examination. Power Doppler mode examination was performed after intravenous injection of a second-generation contrast agent (2.4 mL of SonoVue), and the data were digitally recorded, comprising both the early arterial phase and venous/late phase. Three 10-second sonoelastographic videos were also digitally recorded that included the focal mass and the surrounding pancreatic parenchyma. Postprocessing analyses based on specially designed software were used to analyze the CEPD and RTSE videos. A power Doppler vascularity index was used to characterize CEPD videos, the values being averaged during a 10-second video in the venous phase. Hue histogram analysis was used to characterize RTSE videos, with the mean hue histogram values being also averaged during a 10-second video.

Main Outcome Measurements

To differentiate chronic pancreatitis and pancreatic cancer.

Results

The sensitivity, specificity, and accuracy of combined information provided by CEPD and RTSE to differentiate hypovascular hard masses suggestive of pancreatic carcinoma were 75.8%, 95.2%, and 83.3%, respectively, with a positive predictive value and negative predictive value of 96.2% and 71.4%, respectively.

Limitation

A single-center, average size of study population.

Conclusions

A combination of CEPD and RTSE performed during EUS seems to be a promising method that allows characterization and differentiation of focal pancreatic masses.

Abbreviations: CEPD, contrast-enhanced power Doppler, EUS-FNA, EUS-guided fine needle aspiration, NPV, negative predictive value, PDVI, power Doppler vascularity index, PPV, positive predictive value, ROI, region of interest, RTSE, real-time sonoelastography