Purpose: The purpose of this study was to classify solitary, scintigraphy-positive and radiography-negative rib lesions and to clarify the features of rib fractures by using thin-section reformatted helical computed tomography (CT).
Methods: Forty-seven patients whose whole-body bone scans showed a solitary hot spot in a rib as their first abnormal scintigraphic finding and whose plain radiograph showed negative or indeterminate results were examined by thin-section reformatted CT. Final diagnosis was based on follow-up over a 20-month period.
Results: The final diagnosis included 17 cases of fractures where CT findings were fracture line, focal sclerosis, and callus formation. Fourteen ribs demonstrated intramedullary, focal osteosclerosis, and 8 ribs did not demonstrate any abnormalities. Four metastatic lesions appeared as intramedullary mixture of osteolysis and osteosclerosis, or bone destruction. Four intramedullary lesions with cystic appearance remained unchanged.
Conclusions: Thin-section reformatted helical CT delineated minute, radiographically occult fractures of the rib. Excluding fractures, helical CT can avoid further unnecessary examinations.