Introduction:. Charcot arthropathy is a complex condition affecting diabetic patients with neuropathy. Diagnosis of acute Charcot arthropathy particularly in absence of any perceptible trauma is very challenging as clinically it can mimic osteomyelitis and cellulitis. Delay in recognition of Charcot arthropathy can result in gross instability of foot and ankle. Early diagnosis can provide an opportunity to halt the progression of disease. We report the role of SPECT /CT in the early diagnosis and elucidation of the natural progression of the disease. Methods:. Our multidisciplinary team analysed the scans of neuropathic patients presented with acute red, hot, swollen foot with normal radiological findings (Eichenholtz stage 0), attending the diabetic foot clinic from 2009–2013. The patients were selected from our database, clinic and nuclear medicine records. Initial workup included the assessment of peripheral neuropathy, temperature difference, between the feet, serum inflammatory markers and weight bearing dorsoplantar, lateral and oblique x-rays. All patients had three dimensional triple Phase Bone Scan using 800Mbq . 99m. Tc HDP followed by CT scan. Those patients with obvious radiological findings and signs of infection were excluded. Results:. We evaluated 193 scans in 189 patients. One hundred and forty nine patients showed increase in focal radionuclide uptake at ligament insertion or subchondral bone with a positive predictive value of 77 percent. Forty four out of 193 were negative for Charcot changes and they were not treated as Charcot. These patients did not develop any Charcot changes in the mean follow up of 8 months, indicating a clinically false positive rate of 23%. Conclusion:. SPECT/CT scan is a highly sensitive and specific tool for early diagnosis and accurate localisation of Charcot neuroarthropathy as clinical examination results in high false positive rate. SPECT/CT also helps to understand the natural progression of this disease

Aim

Single-photon emission computed tomography is a new imaging modality combining high detail CT with highly sensitive triple phase nuclear bone scanning to help clinicians in diagnosis and management of various conditions. Little has been published about its particular usefulness in foot and ankle pathology. We conducted a prospective study to evaluate the role of SPECT for the same.

The precise localisation of osteoarthritic changes is crucial for selective surgical treatment. Single photon-emission CT-CT (SPECT-CT) combines both morphological and biological information. We hypothesised that SPECT-CT increased the intra- and interobserver reliability to localise increased uptake compared with traditional evaluation of CT and bone scanning together. We evaluated 20 consecutive patients with pain of uncertain origin in the foot and ankle by radiography and SPECT-CT, available as fused SPECT-CT, and by separate bone scanning and CT. Five observers assessed the presence or absence of arthritis. The images were blinded and randomly ordered. They were evaluated twice at an interval of six weeks. Kappa and multirater kappa values were calculated.

The mean intraobserver reliability for SPECT-CT was excellent (κ = 0.86; 95% CI 0.81 to 0.88) and significantly higher than that for CT and bone scanning together. SPECT-CT had significantly higher interobserver agreement, especially when evaluating the naviculocuneiform and tarsometatarsal joints.

SPECT-CT is useful in localising active arthritis especially in areas where the number and configuration of joints are complex.