Objective To investigate the diagnostic value of ⁹⁹Tc^m-MDP SPECT whole-body bone scan and local SPECT/CT tomography fusion imaging for insufficiency fracture (IF).

Methods Ninety patients (including 32 males and 58 females, aged 67.56±7.68, 22 cases with suspected IF, 68 cases with confirmed local IF) who were either diagnosed with IF in their partial skeleton or suspected to suffer from IF were enrolled in this study. The diagnostic value of ⁹⁹Tc^m-MDP SPECT whole-body bone scan and local SPECT/CT tomography fusion imaging for IF were retrospectively analyzed. The correct diagnosis were confirmed by clinical assessment and over 6 months of imaging follow-up.

Results A total of 234 lesions were detected in 90 patients by ⁹⁹Tc^m-MDP SPECT whole-body bone scan, which showed high radioactivity in all lesions. The common sites of the lesions were the pelvis (78 lesions), lumbar vertebrae (49 lesions), thoracic vertebrae (46 lesions), ribs (45 lesions), femur (8 lesions), tibia (4 lesions), calcaneus (3 lesions), and sternus (1 lesion). The sensitivity of ⁹⁹Tc^m-MDP whole-body bone scan and local SPECT/CT tomography fusion imaging for IF was 100% (234/234). A greater number of lesions were determined in approximately 68.89% (62/90) of the patients by combined imaging than the lesions which were confirmed as IF before combined imaging. A total of 293 fractures were identified in the scope of CT examination; of these, 234 were diagnosed as acute fractures and 59 were diagnosed as chronic fractures by SPECT/CT. The diagnostic sensitivity of SPECT/CT toward acute IF was 100% (234/234).

Conclusion ⁹⁹Tc^m-MDP SPECT whole body-bone scan and local SPECT/CT fusion imaging has high clinical value in the systemic display and diagnosis of IF in patients with osteoporosis.