Incidental findings in multislice CT of the body

Abstract

In radiology, an incidental finding (“incidentaloma”) is an incidentally discovered mass or lesion, detected by CT or other modality performed for an unrelated reason. With high-resolution cross-sectional imaging, such findings are very frequent, and an everyday challenge for radiologists. In this chapter on incidental CT findings, the use and misuse of the term is discussed, as well as the frequency, characteristics, workup, and importance of common incidental findings in the abdomen, pelvis, and chest, with reference to guidelines for management. Emphasis is, e.g., on controversies over management of adrenal incidentalomas, as management has changed with increasing knowledge about their clinical importance. Incidental renal tumors and complex cysts are discussed in depth, as over half of renal cancers are detected incidentally, potentially providing better prognosis. On the other hand, early detection may lead to overdiagnosis of indolent tumors with little clinical risk, also discussed in this chapter. Common incidental findings in the liver, pancreas, and reproductive organs are also discussed. In the chest, focus is on detection, management, and clinical importance of incidental pulmonary nodules, thyroid lesions, and vascular (including coronary) calcifications, with reference to updated international guidelines. There is also focus on technical CT factors that may limit detection of incidental findings, on reasons for not reporting incidental findings, and on patients’ opinions of incidental findings. In conclusion, this chapter may deepen the understanding of incidental findings, and aid in the delicate task for the radiologist to balance benefits and risks when reporting such findings and recommending certain actions.