F-18 PET IMAGING - FREQUENCY, DISTRIBUTION AND APPEARANCE OF BENIGN LESIONS

Purpose: We evaluated the frequency, distribution and appearance of be nign lesions in F-18-PET scans. Methods: Between March 1996 and May 19 97, 18F-PET scans were performed in 59 patients in addition to convent ional planar bone scintigraphy. Eleven patients were subjected to addi tional SPECT imaging. The main indication was searching for bone metas tases (58 pat.). The diagnosis was confirmed radiologically. Results: With F-18-PET in 39 patients (66,1%) 152 benign lesions, mostly locate d in the spine were detected. Tc-99m bone scans revealed 45 lesions in 10 patients. Osteoarthritis of the intervertebral articulations (69%) or of the acromioclavicular joint (15%) were the most common reasons for degenerative lesions detected with F-18-PET. Osteophytes appeared as hot lesions located at two adjacent vertebral endplates. Osteoarthr itis of the intervertebral articulations showed an enhanced tracer upt ake at these localizations, whereas endplate fractures of the vertebra l bodies appeared very typical; solitary fractures of the ribs could n ot be differentiated from metastases. Rare benign lesions were not stu died. Conclusion: Most of the degenerative lesions (84%) detected with F-18-PET had a very typical appearance and could be detected with the improved spatial resolution and advantages of a tomographic technique . F-18-PET had an increased accuracy in detecting degenerative bone le sions.