title: Lower-limb MRI in the staging and re-staging of osteonecrosis in paediatric patients affected by acute lymphoblastic leukaemia after therapy.
abstract: OBJECTIVE
  To assess the diagnostic value of MRI examination in detecting and monitoring osteonecrotic lesions (ON) in childhood acute lymphoblastic leukaemia (ALL) after chemotherapy (CHT) and/or bone marrow transplantation (BMT).
  
  
  METHODS
  Seventy-three patients (37 males, mean age 12.4 years old) with ALL after treatment underwent a lower-limb MR examination between November 2006 and March 2012. In 47 there was clinical suspicion of ON, 26 were asymptomatic. Studies were performed with a 1 T and a 1.5 T scanner, acquiring short tau inversion recovery (STIR) and T1-weighted sequences in coronal plane from the hips to the ankles. The average acquisition time was 18 min. Considering baseline and follow-up examinations, the overall number of MRI studies was 195.
  
  
  RESULTS
  Fifty-four of 73 patients showed ON at MRI study, with an overall number of 323 ON (89 involving articular surface, 24 with joint deformity, JD). Twenty-five of 47 symptomatic patients showed subchondral ON lesions, 11 developed JD. Three of 26 asymptomatic patients showed subchondral bone ON at baseline examination but no JD at follow-up. Twenty-two of 28 BMT, 32/45 CHT patients developed ON.
  
  
  CONCLUSIONS
  Our MRI protocol proved to be feasible in evaluating ON in paediatric patients. Studies should be addressed only to symptomatic patients.
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy. davide.atena@tiscalinet.it.|Department of Diagnostic Radiology, H. San Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy. davide.atena@tiscalinet.it.
authors.forename: D
authors.initials: D
authors.lastname: Ippolito
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Diagnostic Radiology, H. San Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Masetto
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Diagnostic Radiology, H. San Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: C Talei
authors.initials: CT
authors.lastname: Franzesi
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Diagnostic Radiology, H. San Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: P A
authors.initials: PA
authors.lastname: Bonaffini
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Paediatric Haematology, H S. Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Sala
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Paediatric Haematology, H S. Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Biondi
authors.affiliation: School of Medicine, University of Milano-Bicocca Milan, Via Pergolesi 33, 20900, Monza (MB), Italy.|Department of Diagnostic Radiology, H. San Gerardo, Via Pergolesi 33, 20900, Monza (MB), Italy.
authors.forename: S
authors.initials: S
authors.lastname: Sironi
mesh_terms: D016026:Bone Marrow Transplantation; D002648:Child; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010020:Osteonecrosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications* / Q000628:therapy
keywords: Acute lymphoblastic leukaemia; MRI; Osteonecrosis