Eight CT lessons that we learned the hard way: an analysis of current patterns of radiological error and discrepancy...

To review cases discussed at a radiology departmental errors and discrepancies meeting, classify these to determine common patterns of error, and, focussing on CT, present a small number of specific errors that occur commonly.

All cases discussed at our departmental discrepancies and complications meeting over a 30 month period were reviewed. Those where a genuine error was agreed to have arisen were classified by error type: poor image interpretation (false positive, false negative, misclassification); technical error (poor technique or procedural complication); and communications error. The imaging method from which the error arose was also recorded. Specific recurring errors were identified and collated.

Two hundred and fifty-six errors were identified in 222 patients. Two hundred and twenty-five errors (88%) were due to poor image interpretation (14 false positive, 155 false negative, 56 misclassification). Seven errors (3%) were technical and 24 errors (9%) were due to poor communication. One hundred and fifty-nine (62%) of the 256 errors arose in relation to CT, 31 (12%) to ultrasound, 29 (11%) to magnetic resonance imaging (MRI), 24 (9%) to radiography, and 13 (5%) to fluoroscopy examinations, three (1.2%) of which involved vascular intervention. Several repeating errors arising during CT reporting were identified.

Error is commonly identified in relation to radiological examinations. Most errors involve image interpretation, but a significant proportion result from departmental miscommunication. The majority of errors are false-negative interpretations and occur during interpretation of CT examinations. Recurring false-negative CT errors include failure to appreciate unexpected bowel or pancreatic malignancy, incidental pulmonary emboli, abnormality of vascular structures, bone lesions, omental disease, incidental abnormality present on targeted examinations or lesions on the periphery of the field of view.