Comparison between CT and CEUS in the diagnosis of pancreatic adenocarcinoma

Purpose: The aim of this study is to compare CEUS and MDCT features of pancreatic ductal adenocarcinoma in relation to tumor size.

Materials and methods: All patients with pathological diagnosis of pancreatic adenocarcinoma and studied by means of CEUS and MDCT were enrolled in this study. Two radiologists evaluated tumor size, site and imaging appearance. Patients in which at least one method yielded a positive result were divided into 4 groups on the basis of lesion size. For each dimensional category, sensitivity of the two imaging methods was calculated and compared using McNemar test.

Results: One hundred thirty-three patients were included in this study. In 9 of 133 patients neither MDCT nor US/CEUS could identify the lesion, while in 9 of 133 patients only MDCT and in 13 of 133 only US/CEUS could identify the lesion. In the remaining 102 patients, both MDCT and US/CEUS yielded a positive result. US/CEUS sensitivity was 86.47% while MDCT sensitivity was 83.58%, with no statistically significant difference (p = 0.523). For lesions smaller than 2 cm US/CEUS had a 100% sensitivity, while MDCT had a 73.33% sensitivity with no statistically significant difference (p = 0.125). For lesions between 2.1 and 3 cm US/CEUS had a sensitivity of 95.35%, while MDCT had a sensitivity of 83.72% with no statistically significant difference (p = 0.180). For lesions between 3.1 and 4 cm, US/CEUS had a sensitivity of 87.88%, while MDCT had a sensitivity of 93.94% with no statistically significant difference (p = 0.688). For lesions larger than 4 cm US/CEUS, had a sensitivity of 90.91%, while MDCT had a sensitivity of 100% with no statistically significant difference (p = 0.250).

Conclusion: US/CEUS sensitivity in diagnosing pancreatic ductal adenocarcinoma is adequate and does not statistically differ from that of MDCT. US/CEUS sensitivity seems to be higher for small and medium lesions, while MDCT sensitivity is higher for large lesions. By combining both the imaging methods a higher accuracy in diagnosing pancreatic ductal adenocarcinoma can be expected.