Evaluation of a reduced MR imaging sequencing protocol in adult patients with stroke

PURPOSE: To compare a reduced (three-sequence) magnetic resonance (MR) imag ing protocol with a full (eight- to 10-sequence) MR imaging protocol in adu lts suspected of having stroke. MATERIALS AND METHODS: Six neuroradiologists interpreted a consecutive samp le of 265 MR images in patients suspected of having stroke. Each read reduc ed-protocol images in a discrete series of 40 patients (one read images in only 15) and corresponding full-protocol images 1 month later (reduced/full protocol). Five of the readers each read images in 10 additional cases, fi ve each as full/full and reduced/reduced protocol controls. kappa values be tween full and reduced protocols, reader assessment of protocol adequacy, c onfidence level, and need for additional sequences or examinations were eva luated. RESULTS: In the reduced/full protocol, the kappa value for detecting ischem ia was 0.797; and that for detecting any clinically important abnormality, 0.635. Statistically similar kappa values were found with the full/full con trol design (kappa = 0.802 and 0.715, respectively). The full protocol was judged more adequate than the reduced protocol (2.0 of 5.0 points vs 1.6, P <.001) and generated greater diagnostic confidence (8.6 of 10.0 points vs 8.9, P =.01), less need for additional sequences (2.7 of 6.0 points vs 1.5, P <.001), and more requests for additional examinations (28.4% vs 36.3%). CONCLUSION: Disagreement between interpretations of reduced- and full-proto col images might be attributable to baseline-level intraobserver inconsiste ncy, as demonstrated in control designs. A greater number of sequences did not lead to greater consistency.