Interexpert agreement between neuroradiologists in the diagnosis of middle cerebral artery stroke by computed tomography

Background. To evaluate the diagnostic accuracy of radiologists with a wide range of experience and training in emergency neuroradiology and other specialty hospitals, as well as the level of inter-experts’ agreement regarding CT signs of ischemic stroke.

Material and methods. Our study included a retrospective cohort of 100 patients who underwent NCCT, CT angiography (mCTA) and CT perfusion in St. Petersburg clinical hospital. Fifty patients had confirmed middle cerebral artery ischemic stroke. The study also randomly included fifty patients in whom this diagnosis was excluded, including on the basis of dynamic follow-up as part of further clinical evaluation and follow-up CT scan of the brain. All 100 CT were reviewed by 21 radiologists who independently assessed each study for CT evidence of ischemic stroke. Statistical analysis included the Kappa-Fleiss coefficient ( ) calculation of agreement for each sign of ischemic stroke, specificity, sensitivity, and accuracy of detection of these changes.

Results. The staff radiologist’s mean experience in emergency neuroradiology affects both diagnostic performance and consistency for detection of most CT features of ischemic stroke. At the same time, experience does not affect the diagnostic efficiency of radiologists with no experience in stroke assessment. The most highly specific and reproducible sign of ischemic stroke was the hyperdense middle cerebral artery sign, and the most ambiguous diagnostic sign was the gyral effacement. At the same time, all radiologists, regardless of length of service record and experience in emergency neuroradiology, are prone to over-diagnosis.

Conclusion. Further search for tools and solutions is needed to level out interexpert variability regarding assessment of ischemic CT signs, since this problem has high clinical importance.

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