MRI Diagnosis for Post-Traumatic Osteomyelitis of Extremities Using Conventional Metal-Artifact Reducing Protocols: Revisited

RATIONALE AND OBJECTIVES

To assess the diagnostic power of MR imaging features for post-traumatic osteomyelitis (PTOM) of the extremities with metal implants using a 3.0-T machine with conventional metal-artifact reducing (MAR) protocols.

MATERIALS AND METHODS

Between December 2012 and September 2016, 261 consecutive patients underwent MRI for clinical suspicion of PTOM in the appendicular skeleton at our hospital. A total of 72 enrolled patients with metal implants were divided into two groups, one with surgical, histologic, or microbiologic proven to be PTOM, and the other proven not to be PTOM. Their MR images were reviewed by two musculoskeletal radiologists who qualitatively analyzed various findings regarding PTOM, and concluded diagnosis of PTOM or without PTOM for each patient. All MR images were obtained using conventional MAR protocols.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and accuracy of MR diagnosis by two observers were 55%/38%, 81%/93%, 67%/40%, 73%/78%, and 71%/71%, respectively. Among the findings, T1 low signal intensity, medullary location, confluent pattern, typical features (concurrence of T1 low signal intensity, medullary, and confluent patterns), heterogeneous or no enhancement, and cortical destruction were statistically significant by univariate analysis (p<0.05). Among these features, only medullary involvement was significant by multivariate analysis (p = 0.007). Medullary involvement and no enhancement pattern were significant by step-wise discrimination analysis. Interobserver correlation was moderate with a weighted kappa value of 0.512 (confidence interval: 0.3-0.723).

CONCLUSION

The overall accuracy for diagnosis of PTOM of the extremities using 3.0-T MRI with conventional metal-artifact reduction parameters was 71%. The strongest diagnostic MR imaging feature was medullary involvement of T1 low signal intensity. PTOM of the extremities can be accurately diagnosed with a 3.0-T MR machine using conventional MAR protocols.

Chronic recurrent multifocal osteomyelitis: a case report

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare idiopathic inflammatory disease that affects mainly children and young adults. The clinical signs and symptoms are nonspecific, hindering and delaying diagnosis. Radiological and histopathological tests are essential for its definition. A case of CRMO is reported, demonstrating the importance of clinical, laboratory, and radiological data for diagnosis.

Garré's sclerosing osteomyelitis: case report

The aim of this study was to report on a rare case of Garré’s sclerosing osteomyelitis. The patient was a 54-year-old woman with a history of treatment for lupus using corticoids for 20 years, and for osteoporosis using alendronate for five years. She presented edema and developed a limitation of left knee movement one year earlier, with mild effusion and pain on metaphyseal palpation, but without fever. She was in a good general state, without local secretion. Images of her knee showed trabecular osteolysis of the distal metaphysis of the femur and a periosteal reaction in both proximal tibias and both distal femurs, compatible with chronic osteomyelitis of low virulence and slow progression. Magnetic resonance imaging showed T2 hypersignal in the femur and tibia. Curettage was performed on the left distal femur, with release of secretion, but this was negative on culturing. A biopsy showed chronic infection and inflammation, fibrosis, xanthogranulomatous reaction and foci of suppuration. Antibiotic therapy was administered for six months. The etiology was not clarified: bacterial infection was suspected, but culturing was generally negative. The chronic process was maintained by low-virulence infection or even after treatment. The differential diagnoses were fibrous dysplasia, syphilis, pustulosis palmoplantaris, rectocolitis, Crohn's disease, SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) and Paget's disease. The unifocal diseases were osteoid osteoma, Ewing's disease, osteosarcoma and eosinophilic granuloma.