Failure to detect a 1.5 centimeter lung nodule by chest computed tomography.

Although computed tomography (CT) of the chest is the most sensitive modality for the detection of pulmonary nodules, false negatives occur. A case is presented in which a 1.5 cm nodule in the lung confirmed by surgery and linear tomography was not detected by using a state-of-the-art CT scanner. The reason for this failure is movement of the nodule between scans due to variations in respiratory excursion. This effect can be somewhat reduced by scanning at end tidal volumes with thick overlapping or contiguous scans.