儿童骨骼尤文肉瘤的影像学诊断和鉴别诊断

目的 探讨儿童骨骼尤文肉瘤在X线平片、CT和MRI上的影像学征象，以提高对其诊断和鉴别诊断能力。资料与方法 回顾性分析经临床病理证实的儿童骨骼尤文肉瘤11例，其中X线平片检查7例，单行MRI扫描2例，单行CT扫描4例，同时行MRI及CT扫描者4例。结果 11例尤文肉瘤中发生于骨盆4例，股骨3例，胫骨、肋骨、趾骨和脊柱各1例，其中胫骨和髂骨各1例术后出现颅骨转移。X线平片上6例表现为虫蚀状或溶骨性破坏，2例病灶略呈膨胀性改变，骨皮质破坏伴单层、多层或放射状骨膜反应，邻近软组织层次欠清；发生于肋骨的1例以硬化为主，CT像上髓腔密度增高，骨质鼠咬状或斑片状破坏伴骨皮质裂隙状或不规则破坏；2例骨皮质呈膨胀、变薄、中断，周围见不完整的层状骨膜反应及较大软组织肿块；MRI上表现为大片长T1长T2信号的骨质破坏和巨大的软组织肿块；1例肿块呈跨关节生长。结论 X线平片、CT和MPI在骨尤文肉瘤的评估方面有重要作用。X线平片可有助于肿瘤的定性和定位；MRI平扫T1WI像及短反转时间反转恢复技术(STIR)能清晰显示肿瘤的范围，在显示肿瘤对骨骺及邻近软组织的侵犯方面尤为敏感；CT在显示骨及骨皮质破坏等方面优于MRI。

Imaging Diagnosis and Differentiation of Ewing''''s Sarcoma in Children

Objective To investigate the imaging features of Ewing's sarcoma in children, to improve its diagnosis and differentiation.Materials and Methods Imaging findings of 11 children with pathologically-proved Ewing's sarcoma were retrospectively analyzed. The imaging materials included plain radiograph (n=7), only MRI (n=2), only CT (n=4) and both MRI and CT (n=4).Results Of 11 cases, the lesion was located at the pelvis in 4, at the femur in 3, and at the tibia, rib, tarsal and vertebra in one for each. Metastasis of the skull was found in 2 cases. On plain film, the lesion was presented as moth-eaten or osteolytic destruction (n=6), with slight expansion (n=2). The cortex was destructed and single- or multiple-layered periosteal reaction was seen. On CT scan, increased bone marrow density, moth-eaten or patch bony destruction with irregular cortex destruction were demostrated. In two cases, the cortex was expanded, thinned and interrupted with incompleted layered periosteal reaction and huge soft-tissue mass. On MRI, the lesion was displayed as large bony destruction area, characterized by long T 1 and long T 2, with huge soft-tissue mass. The tumor grew across the articular space in one case.Conclusion Plain radiograph, CT and MRI are all of great value in assessing Ewing's sarcoma. Plain radiography is helpful for qualitative and localizing diagnosis, while plain MRI, including T 1WI and STIR, can clearly demonstrate the tumor's extent and is especially sensitive in displaying the involvement of the epiphysis and the neighboring soft-tissue. CT is superior to MRI in detecting bony destruction.