Contrast-enhanced ultrasound as a non-invasive diagnostic modality for pancreatic ductal adenocarcinoma: The question of Ki67 for study validation

Core Tip

Core Tip: Correlations have been reported between contrast-enhanced ultrasound (CEUS) quantitative parameters and Ki67/tumor differentiation. However, the validation process is still a work in progress. Meticulous attention should be paid to subtypes of pancreatic ductal adenocarcinoma selected for testing, the suitability of Ki67 as the gold standard, the counting methodology and grade cut-offs. Overall, CEUS appears valuable in assessing pancreatic ductal adenocarcinoma. However, it should be regarded one more additional tool along with other imaging modalities such as computed tomography, magnetic resonance imaging and positron emission tomography scan. CEUS can also be augmented by endoscopic ultrasound-guided fine needle biopsy for tissue procurement. In certain situations, detective flow imaging endoscopic ultrasonography could be an alternative to CEUS.