Purpose: The literature is confusing when it comes to defining/differentiating periosteal reaction from periostitis, Sub-Periosteal New Bone Formation (SPNBF), and calcifying sub-periosteal hemorrhage. Furthermore, sub-periosteal fluid, readily seen on MRI, can be pus from osteomyelitis as well as hemorrhage from trauma. However, MRI is often obtained to evaluate for osteomyelitis, thus potentially leading to a confirmation bias where sub-periosteal fluid is attributed to infection. This is particularly concerning in cases of Non Accidental Trauma (NAT), where the history may be vague. In addition, trauma can produce elevated inflammatory markers, further clouding the picture. The purpose of this study is to report our experience with MRI and x-ray in patients with sub-periosteal hemorrhage, all of whom were ultimately diagnosed with NAT.
Methods: A retrospective search of the authors’ suspected abuse database (1997-2020) was performed to identify patients who had sub-periosteal hemorrhage on x-ray and/or MRI. Imaging findings were correlated with clinical history, inflammatory markers, and follow-up course.
Results: From the database, 2206 patients with skeletal surveys were identified, aged 3 weeks to 12 months old. Of those, MRIs had been obtained as a workup for infection in 5 cases of unexplained extremity swelling. Although MRI showed sub-periosteal fluid in all 5 cases, trauma was not considered as the etiology.
Conclusion: It is essential to avoid anchoring the radiological interpretation to infectious etiology, and thus consider hemorrhage as a potential cause of sub-periosteal fluid on MRI in an infant or young child to avoid missing a diagnosis of Non Accidental Trauma.
Published Date: 2022-06-29; Received Date: 2022-06-01