Evaluating the Accuracy and Reliability of Splenic Artery Aneurysm Assessment on Computed Tomography Imaging

Splenic artery aneurysms (SAA) are the third most common abdominal arterial aneurysm. Several radiological features have been associated with their growth rate and rupture risk. We aim to evaluate the accuracy and reliability in assessing these features on computed tomography (CT) scans. Radiological reports were searched for scans positive for SAA between 2012 and 2021 inclusive. These scans were assessed with our novel radiological proforma by 2 radiologists to determine those criteria which were reliably reported. A non-expert was then compared against this baseline to assess the reliability of SAA assessment by non-radiologists. Pearson and Spearman rank correlation co-efficients and Cohen Kappa statistics was used to assess agreement. A cohort of 170 scans were assessed. A high degree of agreement (correlation co-efficient R=0.89-0.91) was achieved by radiologists for SAA diameter measurement. A high level of agreement was also achieved for calcification (Kappa = 0.827) and previous intervention (1.0), moderate agreement for presence of SAA (0.563), calcification percentage (0.563), morphology (0.446) and presence of thrombus (0.516). Rupture and pseudoaneurysm morphology demonstrated poor agreement (Kappa <0.01) but were rare events limiting interpretation. A non-expert could achieve comparable diameter measurements (p<0.05) but had consistently lower kappa agreements for all aneurysm characteristics compared to radiologists. Aneurysm diameter, calcification and previous intervention were the only features reported with high agreement between radiologists. Other SAA characteristics only achieved moderate or poor agreement and so should be used with caution in research and clinical settings.