MRI诊断应力骨折24例

MRI findings in diagnosis of stress fracture

目的分析应力性骨折的解剖学和生物力学特征及MRI表现,提高对应力性骨折的MRI诊断。方法回顾性分析经临床随访或病理证实的24例不同部位应力骨折患者的MRI图像。结果24例中,髂骨、耻骨、坐骨及股骨头颈部和上段2例,股骨下段4例,胫骨11例,胫骨上段和股骨下段同时发病3例,跖骨2例,腓骨中上段2例。MRI均可见骨髓腔内斑片状长T1、长T2水肿信号,范围远较平片广泛;3例骨皮质周围见环形或半环形长T1、长T2骨膜水肿信号;4例可见骨折线,冠、矣状位表现为髓腔内斜形或横形线条状长T1、短T2信号影,骨皮质中断;10例可见骨皮质增厚,呈长T1、短T2信号;软组织肿胀呈弥漫性长T1、长T2信号。结论MRI能够更敏感地发现早期应力性骨折,为诊断和判断骨折愈合情况提供更多信息。

Objective To improve MRI diagnosis of stress fracture by analyzing its features of anatomy and biomechanics and MRI findings.Methods MRI findings in 24 cases with stress fractures confirmed by follow-up and pathology results were retrospectively analyzed.Results The stress fracture was observed in the pelvis and femoral head,neck,superior part in 2 cases,in the inferior part of the femur in 4 cases,tibia in 11 cases,in the proximal tibia and distal femur in 3 cases,metatarsal in 2 cases,in the middle-superior part of the fibula in 2 cases.On MRI,all 24 patients demonstrated diffusion long T1 and long T2 signal in the medullary cavity suggesting marrow edema,which showed more extensive than plain film.Periosteoedema was seen displaying ring-shaped or half ring-shaped long T1 and long T2 signal intensity around the cortex in 3 cases.Fracture line in 4 cases showed a linear band of long T1 and short T2 signal in the medullary cavity on sagittal and coronal,disruption of the bony cortex.Thickened cortex in 10 cases showed long T1 and short T2 signal intensity.Soft tissue swelling was also identified showing diffuse long T1 and long T2 signal intensity.Conclusion MRI could be a more sensitive method in the detection of the early stress fracture and provide more information for diagnosis and bony healing.