探讨磁共振成像(MRI)在足跗骨隐匿性骨折临床诊断的应用价值。

对经数字X线摄影检查未发现骨折的足跗骨外伤，采取CT及MRI检查诊断为隐匿性骨折的80例患者，分析其影像学结果，比较其隐匿性骨折检出例数及总检出率。

80例患者CT检查中39例显示有骨小梁/骨皮质中断，74例常规MRI检查显示外伤性隐匿性骨折直接征象，即损伤处骨皮质连续性中断，中断处呈条状或线状，T1WI呈低信号，T2WI呈高信号。80例患者均存在骨挫伤征象：骨损伤处松质骨内见不规则网状、片状或地图样T1WI低信号、T2WI高信号征象。CT检查检出率为48.75%，MRI T1WI检查检出率88.75%，MRI T2WI检查检出率100.0%，MRI总检出率显著高于CT(χ²＝36.9，55.1；P<0.05)。

MRI可有效诊断足跗骨隐匿性骨折和骨挫伤，若患者足跗骨外伤后经X线或CT检查未发现骨折，但外伤位置持续肿胀、疼痛、不能受力，应辅以MRI检查。

To explore the clinical diagnosis value of magnetic resonance imaging(MRI) in occult fracture of tarsal bones.

In 80 cases of tarsal bone trauma patients without fracture by digital radiography examination, computed tomography (CT) and MRI examinations were performed to diagnose occult fracture.The results of images were analyzed.The detection case numbers and the total detection rate of occult fracture were compared.

CT examination in 80 patients showed that the bone trabeculae and bone cortex disrupted in 39 cases.Conventional MRI clearly demonstrated that the occult traumatic direct sign of fracture in 74 patients, injury of cortical bone at the discontinuity, interrupt at a strip-shaped or linear, low signal intensity in T1WI and high signal intensity in T2WI.All the patients had bone contusion, showing irregular mesh, patchy or map like lesions low signal in T1WI and high signal in T2WI.The detection rate of CT examination was 48.75%, MR T1WI was 88.75%, and MR T2WI was 100.00%.The occult fracture detection rate of MRI was significantly higher than that of CT (χ²=36.9, 55.1; P<0.05).

MRI can diagnose the foot tarsal occult fracture and bone bruise effectively.If patients with tarsal bone trauma are found no fracture by radiograph or CT examination, and the injury is persistent swelling, paining, and can not by force, MRI examination should be used to diagnose whether the occult fracture or not.