Linked Life Data

18701230

Source:http://linkedlifedata.com/resource/pubmed/id/18701230

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-2-9
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0730-725X
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
233-9
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Different magnetic resonance imaging features in two types of nontraumatic rabbit osteonecrosis models.
pubmed:affiliation
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. masaki_tko@umin.ac.jp
pubmed:publicationType
Journal Article