| Different magnetic resonance imaging features in two types of nontraumatic rabbit osteonecrosis models. | |
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MedLine Citation:
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PMID: 18701230 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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A single injection of high-dose steroid (20 mg/kg) has been reported to induce necrotic lesions in the proximal metaphysis and diaphysis of the rabbit femur. In the rabbit osteonecrosis (ON) model induced by two-dose horse serum injections, contrast-enhanced magnetic resonance imaging (MRI) and T2*-weighted dynamic MRI have been reported to detect necrotic lesions at 3 days after the second serum injection sensitively. The purpose of the present study was to determine whether contrast-enhanced MRI and T2*-weighted dynamic MRI could detect early development of necrotic lesions in the rabbit proximal femora after a single high-dose steroid injection and compare MRI features of the two types of nontraumatic rabbit ON models. We performed nonenhanced MRI, contrast-enhanced MRI and T2*-weighted dynamic MRI of bilateral proximal femora 3 days (10 femora), 1 week (10 femora), 3 weeks (10 femora), 6 weeks (18 femora) and 9 weeks (18 femora) after a single 20 mg/kg steroid injection. Femoral signal intensity of each T2*-weighted dynamic MRI was measured from a 1-cm(2) region of interest in the proximal metaphysis and diaphysis. As a control, MRI was performed in untreated animals (six femora). Histologically, no necrotic lesions were observed in the proximal femora at 3 days and 1 week. Bone marrow necrosis was observed in four (40%) femora at 3 weeks, two (11.1%) femora at 6 weeks and six (33.3%) femora at 9 weeks. Bone marrow lesion completely replaced by granulation tissue was observed in one femur at 6 weeks and one femur at 9 weeks. Histologic evidence of repair tissue surrounding bone marrow necrosis was seen after 6 weeks. Average lesion area including repair tissue was 4.40 mm(2) (range, 0.32 to 20.2 mm(2)). At 9 weeks, contrast-enhanced MRI could detect four (66.7%) femora with bone marrow necrosis of more than 4 mm(2) in the lesion area, while T2*-weighted dynamic images showed a finding of complete ischemia in only one of these four femora. In conclusion, neither contrast-enhanced MRI nor T2*-weighted dynamic MRI could detect early development of necrotic lesions in the single-dose steroid ON model. These results indicated that development of necrotic lesions in the single-dose steroid ON model was not accompanied by as diffuse a femoral hemodynamic change as the two-dose horse serum ON model. |
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Authors:
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Masaki Takao; Nobuhiko Sugano; Takashi Nishii; Takashi Sakai; Nobuo Nakamura; Hideki Yoshikawa |
Publication Detail:
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Type: Journal Article Date: 2008-08-12 |
Journal Detail:
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Title: Magnetic resonance imaging Volume: 27 ISSN: 0730-725X ISO Abbreviation: Magn Reson Imaging Publication Date: 2009 Feb |
Date Detail:
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Created Date: 2009-02-09 Completed Date: 2009-04-16 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8214883 Medline TA: Magn Reson Imaging Country: United States |
Other Details:
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Languages: eng Pagination: 233-9 Citation Subset: IM |
Affiliation:
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Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. masaki_tko@umin.ac.jp |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Bone Marrow / pathology Contrast Media / administration & dosage Disease Models, Animal* Femur / pathology* Gadolinium DTPA / administration & dosage Horses / blood Image Processing, Computer-Assisted Magnetic Resonance Imaging / methods* Male Methylprednisolone Osteonecrosis / chemically induced, pathology* Rabbits Statistics, Nonparametric |
| Chemical | |
Reg. No./Substance:
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0/Contrast Media; 80529-93-7/Gadolinium DTPA; 83-43-2/Methylprednisolone |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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