13例骨梗死的MRI表现及其分期初探

MRI manifestation and staging of bone infarction

目的:探讨骨梗死的MRI表现及其分期。方法:13例骨梗死患者行MRI及X线平片检查,均经手术病理和随访证实;并对其临床症状、X线平片和MRI表现进行量化分级,分析其X线平片与MRI表现及其相关的病理学改变。结果:①病变主要累及股骨下端和胫骨上端,双侧发病占61.5%(8/13),亦可累及胫骨下端和距骨。②平片改变与临床症状有较大差异,而MRI分级与临床表现与病理改变吻合性较好。③根据骨梗死的X线平片和MRI表现及其病理演变过程,亦将骨梗死分为五期:0期,MRI表现正常或轻度骨髓水肿,或呈多发灶状脂肪聚集;Ⅰ期,MRI显示骨梗死灶边缘出现花边状纤维肉芽组织增生带,中心信号正常;Ⅱ期,MRI见骨梗死灶边缘出现硬化带,呈典型"地图样"改变,病灶中心信号不均匀;Ⅲ期,MRI见骨梗死累及关节面;Ⅳ期,MRI显示骨梗死区的正常骨髓成分消失,明显骨质增生。结论:平片对本病诊断价值有限;MRI是本病最好的检查手段,能完全明确本病的诊断和侵及范围,同时能反映不同时期的病理学变化。MRI分期将为骨梗死的早期诊断与正确治疗提供理论依据。

Objective：To investigate the MRI manifestation and staging of the bone infarction. Methods： Thirteen cases of bone infarction were examined by MRI and X-ray plain film and all confirmed by operation, pathology and following. The clinical symptom, X-ray and MRI manifestation were further quantitated and the relationship between X-ray and MRI manifestation and their pathology. Results： ①The bone infarction were occurred on the low part of femur and the upper part of tibia in both sides （61.5%）; ②X-ray changes did not matched with the clinical symptom, but MRI manifestation matched the clinical symptom and pathology well. ③According to X-ray and MRI features and their pathology, bone infarction were divided into five stages： Stage 0 was marked by normal or slight marrow edema, or local fat gathered. Stage Ⅰ was marked by normal signal intensity in the central area and proliferation of fibrous granulation tissue at the peripheral region of the focus. Stage Ⅱ was marked by peripheral sclerosis and typical map-like changes of the focus. Stage Ⅲ was marked by the articular facets involved. Stage Ⅳ was marked by normal marrow signal disappeared completely and obvious sclerosis of the focus. Conclusion： The diagnosyic value of X-ray plain film is limited. MRI is the best way to examine and identify bone infarction. It can define diagnosis and reflect changes in different stages pathologically. MRI staging would provide theoretical basis for the early diagnosis and accurate therapy of bone infarction.