The CT scout view: does it need to be routinely reviewed as part of the CT interpretation?

The objective of our study was to determine whether the CT scout view should be routinely reviewed by comparing diagnostic information on the scout view with that provided by the correlative CT study.

Two radiologists blinded to history and CT findings reviewed retrospectively 2032 scout views. All cases with major findings (defined as any abnormality that would prompt additional diagnostic tests or require management) were correlated with the CT study, other imaging study, or medical record when necessary by a third radiologist to determine the validity of the scout view finding and whether the finding was identifiable on the current CT study.

Major findings were identified in 257 (13%, reader 1) and 436 (23%, reader 2) of cases. Most major findings were confirmed (69-78%) or refuted (13-16%) by the CT study. However, 15 (6%, reader 1) and 48 (11%, reader 2) of the major findings were not included in the CT FOV, of which five (2%, reader 1) and 21 (5%, reader 2) constituted a missed pathologic finding. The most common one was cardiomegaly detected on a nonchest CT scout view. Additional pathologic findings included fracture, metastasis, avascular necrosis or subluxation of the humeral head, dilated bowel, and thoracic aortic dilatation. The most common false-positive finding was cardiomegaly.

In a small percentage of cases, review of the CT scout view will disclose significant pathologic findings not included in the CT FOV. The results of this study support the routine inspection of the scout view, especially for the detection of pathologic findings in anatomic regions not imaged by CT.