Diagnostic Accuracy of Triphasic Bone Scan and SPECT/CT in Foot and Ankle Osteoarthritis

Diagnostic Accuracy of Triphasic Bone Scan and SPECT/CT for the Evaluation of Foot and Ankle Osteoarthritis Using MRI as Reference Standard

This cross-sectional study aims to assess the diagnostic accuracy of triphasic bone scintigraphy and SPECT/CT in evaluating foot and ankle osteoarthritis, using magnetic resonance imaging (MRI) as the reference standard, and to determine the affected joints.

Osteoarthritis of the foot and ankle is a significant cause of chronic pain and functional impairment. Conventional radiography has limited sensitivity for early changes, while magnetic resonance imaging (MRI) is considered the reference standard for evaluating cartilage, bone marrow edema, and soft tissue structures.

Nuclear medicine techniques provide functional information about bone metabolism. Triphasic bone scan using technetium-99m methylene diphosphonate (99mTc-MDP) assesses perfusion, blood pool, and delayed skeletal uptake. However, planar imaging has limited spatial resolution and anatomical localization in the complex anatomy of the foot and ankle.

Hybrid SPECT/CT combines the functional data of SPECT with the precise anatomical localization of CT, improving diagnostic confidence and specificity. This study will evaluate the diagnostic accuracy of triphasic bone scan and SPECT/CT compared with MRI in patients with suspected foot and ankle osteoarthritis.

Inclusion Criteria:

Age ≥ 18 years

• Patients presenting with chronic foot and/or ankle pain suspected to be due to osteoarthritis
• Clinical and/or radiographic suspicion of foot or ankle osteoarthritis

Exclusion Criteria:

• Age < 18 years
• Previous surgery or joint replacement of the affected foot or ankle
• Bone tumors or metastatic bone disease
• Active osteomyelitis or septic arthritis
• Inflammatory arthropathies (e.g., rheumatoid arthritis, psoriatic arthritis, gout)