Radiology, Vol 196, 395-400, Copyright © 1995 by Radiological Society of North America
Pulmonary nodules: effect of increased data sampling on detection with spiral CT and confidence in diagnosis
JA Buckley, WW Scott Jr, SS Siegelman, JE Kuhlman, BA Urban, DA Bluemke and EK Fishman
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
PURPOSE: To compare spiral computed tomography (CT) with interscan spacing
of 4-5 mm versus 8-10 mm for detection rate and level of confidence in
diagnosis of pulmonary nodules. MATERIALS AND METHODS: Four radiologists
(two junior and two senior faculty members) retrospectively reviewed 67
spiral CT studies with one to six nodules per study. Every second image was
masked, which resulted in 8-mm sections every 8 or 10 mm; then all images
reconstructed every 4 or 5 mm were reviewed. Lesions were classified as
definite, probable, or possible. RESULTS: Narrow interscan spacing yielded
more lesions overall (583 vs 566, P < .025) and more definite lesions
and fewer equivocal lesions (482 vs 431 and 101 vs 135, respectively; P
< .055). The greatest effects were in the reduction of possible lesions
(50 vs 88, P < .001) and in the reduction of false-positive diagnoses
made by less experienced radiologists. CONCLUSION: Increased reconstruction
frequency of spiral CT volume data sets improves detection of pulmonary
nodules and enhances confidence in the diagnosis.
