title: MR evaluation of bone cysts treated with intracavital steroid injection.
abstract: The objective of this study was to evaluate the role of MR examination in showing the effects of intralesional steroid injection on bone cysts. Nineteen patients with radiologically suspected (group A, n=15) or already treated (group B, n=4) bone cysts underwent MRI (0.5 T; protocol: T2* gradient recalled echo; short tau inversion recovery or inversion recovery fast spin echo; T1 SE before and after contrast administration, 0.2 mmol/kg). All patients underwent steroid therapy for bone cysts and were followed up for 6-18 months after treatment. Evaluation of bone cyst response to therapy was based mainly on the detection of reparative tissue outlining all cystic portions at first MRI control. In group A, as early as 1 month after the first injection, the presence of a thin reparative tissue lining the cystic wall was observed. Follow-up studies revealed the progressive thickening of this reparative tissue and new bone formation. Similar features were present in the cysts of group B. Residual cystic cavities were depicted in 7 cases, with no evidence of enhancing tissue, requiring further treatment. The formation of a reparative tissue is the first feature of bone cyst recovery after intracavital steroid injection and is appreciable only on MRI. Because of the optimal visualisation of this reparative tissue and of residual cystic cavities, MRI could be proposed as a non-invasive, alternative and effective tool for evaluating the efficacy of steroid injection therapy of bone cysts.
authors.affiliation: Department of Oncology, Transplants and Advanced Technologies in Medicine, Division of Diagnostic and Interventional Radiology, University of Pisa, Via Roma 67, 56126, Pisa, Italy. virna.zampa@hotmail.com
authors.forename: Virna
authors.initials: V
authors.lastname: Zampa
authors.forename: Irene
authors.initials: I
authors.lastname: Bargellini
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Michelassi
authors.forename: Donatella
authors.initials: D
authors.lastname: Trippi
authors.forename: Simona
authors.initials: S
authors.lastname: Ortori
authors.forename: Mirco
authors.initials: M
authors.lastname: Cosottini
authors.forename: Carlo
authors.initials: C
authors.lastname: Bartolozzi
mesh_terms: D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001845:Bone Cysts / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D006811:Humerus / Q000473:pathology; D015552:Injections, Intralesional; D007867:Leg Bones / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage / Q000627:therapeutic use*; D014945:Wound Healing
chemical_list: D000893:Anti-Inflammatory Agents; D008775:Methylprednisolone