Simple cystic lesions of the pancreas: image quality and diagnostic accuracy of photon-counting detector computed tomography

Abstract Purpose To evaluate image quality and diagnostic accuracy of photon-counting detector (PCD) CT for the detection of pancreatic cystic lesions (PCLs) compared to energy-integrating detector (EID) CT with MRI serving as reference standard. Material and methods We included consecutive patients who underwent contrast-enhanced PCD-CT of the abdomen and for whom an additional abdominal EID-CT was available. Multiparametric MRI served as the reference standard. CT images were assessed for the presence of PCLs by three radiologists independently in a blinded reading. Image quality, lesion conspicuity, and diagnostic confidence were rated on a 5-point Likert scale (5 = excellent). The coefficient of variation (CV) and the density difference between PCLs and visually normal pancreatic parenchyma were calculated as quantitative imaging measures. Radiation dose was assessed using CTDIvol [mGy]. Results Among 106 included patients (age 62.7 ± 12.6 years; 45 [42.5%] male), 46 had MRI-confirmed cystic lesions (mean size 8.7 ± 7.4 mm; range 2–45 mm). Diagnostic accuracy for PCLs was significantly higher for PCD-CT vs. EID-CT (area under the curve: 0.81 vs. 0.74; p = 0.002; sensitivity: 76.8% vs. 59.4%). Image quality, lesion conspicuity, and diagnostic confidence were rated superior for PCD-CT vs. EID-CT (all p < 0.001). Quantitative analyses revealed a significantly lower CV (0.19 vs. 0.24; p = 0.002) and a higher density difference (94.1 HU vs. 76.6 HU p < 0.001) between PCLs and visually normal pancreatic parenchyma at lower radiation doses (7.13 vs. 8.68 mGy; p < 0.001) for PCD-CT vs. EID-CT. Conclusion PCD-CT provided significantly higher diagnostic accuracy and superior image quality for the detection of PCLs compared to conventional EID-CT at lower radiation dose.