中文摘要：

目的探讨儿童局灶性纤维软骨发育不良（focal fibrocartilaginous dysplasia,FFCD）的影像特点,提高对本病的认识。方法回顾分析2010-2017年间我院收治的经病理证实的12例FFCD的临床及影像资料,其中男8例,女4例,年龄范围1.4-11.6岁,平均3.4岁。由2名有10年以上骨骼放射诊断经验的医师对其X线及MRI表现进行分析,总结FFCD的影像特点。结果 12例中,4例（33%）位于右侧前臂,其中3例为尺骨远段,1例位于桡骨远段;8例（67%）位于胫骨内侧（左、右侧各4例）,其中6例位于近端干骺端,2例位于远端干骺端;X线表现为患侧骨干弯曲,其中1例前臂病变伴桡骨头脱位,胫骨病变均见内翻畸形;病灶处骨皮质局部凹陷及条状透亮区,边界清晰,病变远端皮质增厚,并骨质硬化区,局部髓腔变窄,未见骨膜反应。MRI表现为尺桡骨或胫骨骨干弯曲,病灶处凹陷呈条带状低信号,部分伴等T1WI、高T2WI异常信号;在3D-VIBE序列可见纤维条索及/或软骨信号深入其内,邻近皮质呈带状低信号。其中3例（25%）病灶周围见轻度骨髓水肿,2例（17%）病变旁软组织轻度水肿。结论 FFCD的X线及MRI表现具有特征性,正确认识这些特点有助于疾病做出正确诊断,减少误诊。

英文摘要：

Objective To explore the imaging features of focal fibrocartilaginous dysplasia（ FFCD） in children. Methods X-ray and MRI exams of 12 patients with histologically proven focal fibrocartilaginous dysplasia were reviewed retrospectively. There were 8 males and 4 females, aged 1.4-11.6 years（ average： 3.4 years）. X-ray and MRI findings of these patients were evaluated by 2 senior musculoskeletal radiologists. Results In the total of 12 cases, FFCD occurred in 4 cases（ 33%） in the right distal forearm, including 3 ulnar and 1 radius, in the remaining 8 cases（ 67%） FFCD occurred in the tibia. Radiographs revealed that the tibia and forearm deformity was associated with a well-defined lucent defect at the medial aspect of the metaphysis, which bulged slightly and was surrounded by an area of sclerotic bone. The MRI findings were virtually identical in all cases. Areas corresponding to the cortical lucency and sclerosis on plain films were low signal intensity on T1 WI and T2 WI, while the areas of the bony defect were intermediate signal on T1 WI and intermediate to high signal on T2 WI. Additionally, MRI showed the intermediate to high signal band-like structure on 3D-VIBE of the bony defect. Periosteal reaction and extraosseous masses were not apparent in any cases. Surrounding bone marrow mild edema were found in 3 cases（ 25%） and adjacent soft tissue edema in 2 cases（ 17%）. Conclusions X-ray and MR imaging findings of focal fibrocartilaginous dysplasia are specific. Being familiar with these findings of focal fibrocartilaginous dysplasia would allow accurate diagnosis and avoid misdiagnosis as other diseases.