LEARN NUCLEAR MEDICINE
Musculoskeletal · Case 03
Read the history, inspect the study, then reveal the teaching.
IMAGE PLACEHOLDER · Diagnostic study
Original study · Companion image placeholders
Clinical history
A 67-year-old diabetic presents to the ED with fever and focal pain in the left leg. He had a double knee replacement 4 months ago. Images from gallium-67 citrate scan are provided below.
Read the images before opening the teaching panel below.
Cellulitis
Imaging Findings
Linear focal uptake is seen within the left thigh, the activity appears be within the femur. SPECT/CT could be performed for further localization.
Essential Facts
Localized infection to the skin is referred to as cellulitis. Osteomyelitis is inflammation of the bone marrow secondary to infection. Patients often present with fever, focal pain, and swelling of the region. Common routes for spread of osteomyelitis are haematogenous, contiguous and direct inoculation.
Smokers, IV drug users, and people with chronic health conditions are more at risk of developing osteomyelitis. For example, diabetic foot ulcers can result in osteomyelitis in the feet. Trauma and open injuries are also risk factors.
Staphylococcus aureus is the causative organism in up to 80% of cases of osteomyelitis. Early detection is important for prompt antibiotic therapy, to prevent necrosis of the bone.
Scan Information
Gallium is taken up by tumors, inflammation, and infections, making it useful to identify a source of FUO or suspected osteomyelitis. In the past gallium scans were also used to follow treatment response of tumors such as lymphoma or to evaluate for sarcoid.
References
Nuclear Medicine Case Review Series, by Harvey A. Ziessman, Elsevier, 2011, p. 11-13.
https://drive.google.com/drive/folders/1Ie3LOc5F3RJvYvqD6nVyLqB49kn8J6Cz
https://drive.google.com/drive/folders/1pEEBm7ePE6APW–94IDH-ggpLzFWiRTz