Comparison of angio-CT versus multidetector CT in the detection and location for insulinomas

Abstract

To compare the diagnostic performance of angio-computed tomography (CT) with multidetector CT (MDCT) in the detection and location for insulinomas. From April 2015 to April 2018, 60 consecutive patients who underwent MDCT and angio-CT for clinically suspected insulinomas were identified retrospectively. The CT attenuation values of tumours, normal pancreatic parenchyma, and tumour-to-pancreas contrast were measured quantitatively in the arterial phase (AP) and portal venous phase (PVP) of both methods by two radiologists with interobserver agreement. The detection sensitivity and localisation accuracy were calculated based on surgical and pathological findings, which are the reference standard, and compared between both methods using the chi-square test. Receiver operating characteristic (ROC) analysis was performed to compare diagnostic performance. Fifty-four patients with insulinoma with a mean age of 53.8 years old (range 21-69 years) were reviewed. The detection sensitivity and location accuracy were 68.5%, 58.3% for MDCT and 94.4%, 90.7% for angio-CT, respectively; the detection sensitivity and location accuracy of angio-CT were significantly higher than those obtained with MDCT (p < 0.05). The mean tumour-to-pancreas attenuations were 105.1±25 HU in the AP of MDCT and 285±48.7 HU in the AP of angio-CT. There were significant differences in the tumour-to-pancreas contrast in the AP between MDCT and angio-CT (p < 0.05). The Az values were 0.93 and 0.84 for the AP of angio-CT and MDCT, 0.62 and 0.54 for the PVP. The AP of angio-CT was significantly more accurate for insulinoma detection (p < 0.05). Angio-CT produces higher tumour conspicuity and is superior in the detection and location of insulinomas compared to MDCT.