Efficacy of color Doppler ultrasound and contrast-enhanced ultrasound in identifying vascular invasion in pancreatic ductal adenocarcinoma

Objectives: To compare color Doppler ultrasound and contrast-enhanced ultrasound (CEUS) in evaluating vascular invasion in pancreatic ductal adenocarcinoma (PDAC).

Materials and methods: This retrospective study included 210 patients with PDAC who were evaluated by color Doppler ultrasound, CEUS, and contrast-enhanced computed tomography (CECT) at our institution between January 2017 and December 2020. Pathologic results were used as the gold standard in patients who underwent surgical and intraoperative exploration. For nonsurgical patients, CECT results were used as the reference standard. The vessels evaluated included those in the peripancreatic arterial system and venous system. The diagnostic performances of color Doppler ultrasound and CEUS for vascular invasion were compared.

Results: In 51 patients who underwent surgery and intraoperative exploration, color Doppler ultrasound and CEUS differed only in assessing venous system invasion in patients with PDAC of the pancreatic body and tail, with the former being superior to the latter. In 159 nonsurgical patients, there was no difference between CEUS and color Doppler ultrasound in assessing superior mesenteric arteriovenous invasion. CEUS was superior to color Doppler ultrasound in evaluating the celiac artery and its branches, with an accuracy of up to 97.8% for some vessels. Color Doppler ultrasound was ideal for evaluating the splenic and portal veins.

Conclusion: CEUS is more suitable for the evaluation of peripancreatic arteries than color Doppler. CEUS combined with color Doppler ultrasound can be used as a potential supplement to CECT and is also expected to be used to evaluate vascular invasion of PDAC after chemotherapy.

Critical relevance statement: Contrast-enhanced US and color Doppler in the assessment of vascular invasion in pancreatic ductal adenocarcinoma have their respective advantages, through standardized ultrasound processes are expected to improve the efficiency of inspection.

Key points: Contrast-enhanced US has unique advantages in assessing pancreatic ductal adenocarcinoma invasion of the celiac artery. Doppler imaging is of high value in assessing venous system invasion. Standardization of ultrasound imaging procedures for pancreatic ductal adenocarcinoma is expected to improve efficiency.