Differentiation of solid-type serous cystic neoplasm from neuroendocrine tumour in the pancreas: Value of abdominal MRI with diffusion-weighted imaging in comparison with MDCT

AIM: To evaluate the value of abdominal MRI with diffusion-weighted (DW) imaging for differentiation of solid-type serous cystic neoplasm (SCN) from neuroendocrine tumour (NET) in the pancreas compared with that of CT. MATERIALS AND METHODS: Ten solid-type SCNs and 15 NETs were included in the study. Qualitative and quantitative analyses were performed, and two observers independently reviewed CT and MRI images for diagnosis of solid-type SCNs. Fisher's exact test and Mann-Whitney U-test, diagnostic performance [receiver operating characteristic (ROC) curve analysis] were evaluated. RESULTS: SCNs showed more frequently hypo-attenuation on unenhanced CT images and marked hyperintensity on T2-weighted images compared with NETs (p < 0.01). The density of the tumour on unenhanced CT images and the apparent diffusion coefficient (ADC) value of the tumour were significantly different between SCNs (mean 18.5 HU; mean 2.45 × 10^-3 mm²/s) and NETs (mean 39.2 HU; mean 1.51 × 10^-3mm²/s; p < 0.001). In the differentiation of SCNs from NETs, diagnostic performance of MRI with DW images was significantly higher than that of CT imaging (p < 0.01). CONCLUSION: Abdominal DW-MRI shows a higher diagnostic accuracy than abdominal CT imaging in the differentiation of solid-type SCNs from NETs.