Evaluation of a reduced MR imaging sequencing protocol in adult patients with stroke.
OBJECTIVE
To compare a reduced (three-sequence) magnetic resonance (MR) imaging protocol with a full (eight- to 10-sequence) MR imaging protocol in adults suspected of having stroke.


METHODS
Six neuroradiologists interpreted a consecutive sample of 265 MR images in patients suspected of having stroke. Each read reduced-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, five each as full/full and reduced/reduced protocol controls. kappa values between full and reduced protocols, reader assessment of protocol adequacy, confidence level, and need for additional sequences or examinations were evaluated.


RESULTS
In the reduced/full protocol, the kappa value for detecting ischemia was 0.797; and that for detecting any clinically important abnormality, 0.635. Statistically similar kappa values were found with the full/full control 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%).


CONCLUSIONS
Disagreement between interpretations of reduced- and full-protocol images might be attributable to baseline-level intraobserver inconsistency, as demonstrated in control designs. A greater number of sequences did not lead to greater consistency.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, USA. annejohn@iupui.edu
A J
AJ
Johnson
D K
DK
Kido
W D
WD
Shannon
M M
MM
Bahn
M H
MH
Gado
B C
BC
Lee
C J
CJ
Moran
F J
FJ
Wippold
B
B
Littenberg
D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis*