Computed tomography of solitary pulmonary nodules: experience with scanning times longer than breath-holding

Thirty-one patients with solitary pulmonary nodules--18 benign and 13 malignant--proven by either tissue diagnosis or prolonged follow-up were evaluated by computed tomography (CT). A device (ACTA scanner 0100) with scanning times greater than breath-holding was used with full understanding of its related limitations. A retrospective study of the CT features of these nodules led us to establish several criteria for benign nodules. CT evidence of calcium is felt to be the most important feature of benignancy. In the absence of calcium, irregular nodule margins, perinodular fibrosis, satellite nodules, and pleural thickening opposite a peripherally situated nodule are helpful to suggest its benign nature.