Solitary hot spots in the ribs on bone scan: value of thin-section reformatted computed tomography to exclude radiography-negative fractures.
OBJECTIVE
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.
Niitsu
Mamoru
M
Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305-8575, Japan. mniitsu@md.tsukuba.ac.jp
Takeda
Tohoru
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010014:Osteolysis; D010026:Osteosclerosis; D011877:Radionuclide Imaging; D012253:Rib Fractures / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*