title: The non-invasive detection of intracranial aneurysms: are neuroradiologists any better than other observers?
abstract: Can non-neuroradiologists detect intracranial aneurysms as well as neuroradiologists, using CT and MR angiography? Sixty patients undergoing intra-arterial digital subtraction angiography (IADSA) to detect aneurysms also underwent computed tomographic angiography (CTA) and time-of-flight magnetic resonance angiography (MRA). Consensus review of IADSA by two neuroradiologists was the reference standard. Two neuroradiologists, a neurosurgeon, a neuroradiographer and a general radiologist blinded to IADSA, plain CT and clinical data, independently reviewed hard-copy base and reconstructed maximum intensity projection images of the CTA and MRA studies. Thirty patients had a total of 63 aneurysms, 71.4% were </=5 mm in size. Compared with IADSA, mean accuracy per patient for neuroradiologists was CTA 0.87 (95% CI 0.75-0.94), and MRA 0.82 (0.70-0.90); for the other observers it was CTA 0.81 (0.75-0.86), and MRA 0.78 (0.71-0.84). Sensitivity per aneurysm for neuroradiologists was CTA 0.63 (0.50-0.75), and MRA 0.43 (0.6-0.74); for the other observers it was CTA 0.52 (0.44-0.59), and MRA 0.38 (0.31-0.45). Differences between readers and modalities were not statistically significant. Agreement with IADSA was "good" for neuroradiologists: kappa 0.73 for CTA, and 0.63 for MRA. For the other observers, agreement with IADSA was "moderate": kappa 0.59 for CTA, and 0.56 for MRA. Neuroradiologists performed consistently better than the other observers, although differences did not reach statistical significance.
authors.affiliation: University Department of Neurosurgery, Institute of Neurological Sciences, Southern General Hospital, Glasgow G52 4TF, UK. pmw@skull.dcn.ed.ac.uk
authors.forename: Philip M
authors.initials: PM
authors.lastname: White
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Lindsay
authors.forename: Stuart
authors.initials: S
authors.lastname: Sloss
authors.forename: Dilip K B
authors.initials: DK
authors.lastname: Patel
authors.forename: Evelyn M
authors.initials: EM
authors.lastname: Teasdale
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009485:Neuroradiography; D009493:Neurosurgery; D015588:Observer Variation; D010348:Patient Care Team; D011446:Prospective Studies; D012015:Reference Standards; D015203:Reproducibility of Results; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis; D036542:Tomography, Spiral Computed