Abstract
Introduction
Diagnosis of chronic osteomyelitis (COM) is based mainly on the correlation between history, clinical picture, lab analysis, bacteriological, pathological, and imaging studies. Bone biopsy for culture and sensitivity is the gold standard for the correct identification of the causative organism. The present prospective study aims to evaluate the accuracy of FDG PET-CT in the diagnosis of COM in comparison to the bacteriological, pathological findings.
Materials and Methods
18 patients (16 males/two females) underwent FDG-PET/CT scanning for clinically or radiologically suspected COM of the lower extremity. Fourteen patients had septic non-union, three patients with aseptic non-union, and one with chronic diffuse sclerosing OM of Garre. Seven patients had implants at site of examination at the time of the scan. Diagnosis of COM was confirmed by deep surgical cultures and pathological analysis (index debridement done by s single surgeon in one centre) following PET/CT scanning. FDG-PET uptake was measured by SUV max (the highest uptake of the radioisotope in the infection area). These findings were correlated to the microbiological and histopathological results.
Results
Infection was clinically evident at a mean of 15 weeks (range, 2 to 60 weeks) after the date of injury. Patients had a mean of 2.3 (range 0 – 7) operations, before index debridement.
The mean SUV max on the affected side was (9.55 ± 5.22), While mean SUV max on the contralateral healthy side was (1.82 ± 0.98). The pattern of FDG-uptake was diffuse in nine (50%), localised in seven (38.9%), and intramedullary in two (11.1%) patients respectively.
The sensitivity, specificity, accuracy, PPV and NPV of PET SUV max were 100%, 66.7%, 94.44%, 93.75% and 100% respectively in the diagnosis of COM at a cut-off value of (4.46). The present study included 15 true positive, two true negative and one false-positive PET/CT results.
Conclusions
18F-FDG PET/CT is a highly sensitive and specific method for the evaluation of chronic osteomyelitis in patients with or without trauma. PET/CT provides anatomical localisation and characterisation of the infected area and has a crucial role in preoperative planning.
