- The IST-3 Collaborative Group
- Download as Adobe PDF
Rights statement: Available under Open Access
Final published version, 292 KB, PDF document
Original language | English |
---|
Pages (from-to) | 1-9 |
---|
Number of pages | 9 |
---|
Journal | Neuroradiology |
---|
Volume | 57 |
---|
Issue number | 1 |
---|
Early online date | 7 Oct 2014 |
---|
DOIs | |
---|
Publication status | Published - Jan 2015 |
---|
Introduction
CT angiography (CTA) is often used for assessing patients with acute ischaemic stroke. Only limited observer reliability data exist. We tested inter- and intra-observer reliability for the assessment of CTA in acute ischaemic stroke.
Methods
We selected 15 cases from the Third International Stroke Trial (IST-3, ISRCTN25765518) with various degrees of arterial obstruction in different intracranial locations on CTA. To assess inter-observer reliability, seven members of the IST-3 expert image reading panel (>5 years experience reading CTA) and seven radiology trainees (<2 years experience) rated all 15 scans independently and blind to clinical data for: presence (versus absence) of any intracranial arterial abnormality (stenosis or occlusion), severity of arterial abnormality using relevant scales (IST-3 angiography score, Thrombolysis in Cerebral Infarction (TICI) score, Clot Burden Score), collateral supply and visibility of a perfusion defect on CTA source images (CTA-SI). Intra-observer reliability was assessed using independently repeated expert panel scan ratings. We assessed observer agreement with Krippendorff’s-alpha (K-alpha).
Results
Among experienced observers, inter-observer agreement was substantial for the identification of any angiographic abnormality (K-alpha = 0.70) and with an angiography assessment scale (K-alpha = 0.60–0.66). There was less agreement for grades of collateral supply (K-alpha = 0.56) or for identification of a perfusion defect on CTA-SI (K-alpha = 0.32). Radiology trainees performed as well as expert readers when additional training was undertaken (neuroradiology specialist trainees). Intra-observer agreement among experts provided similar results (K-alpha = 0.33–0.72).
Conclusion
For most imaging characteristics assessed, CTA has moderate to substantial observer agreement in acute ischaemic stroke. Experienced readers and those with specialist training perform best.
- Cerebral angiography, Stroke, Inter-observer variability, Intra-observer variability, TISSUE-PLASMINOGEN-ACTIVATOR, NONCONTRAST CT, THROMBOLYSIS, PERFUSION, SCORE, AGREEMENT, UTILITY, EXTENT, KAPPA, SCALE
ID: 17017022