磁共振成像扫描对股骨头缺血性坏死的诊断价值

Value of MRI in Diagnosis of Avascular Necrosis of Femoral Head

目的探讨磁共振成像(MRI)扫描对股骨头缺血性坏死(AVN)的诊断价值。方法选择2012年5月—2014年5月收治的股骨头缺血性坏死26例,整理X线、CT、MRI检查的影像学资料,观察影像学表现,比较X线、CT、MRI对AVN的检查阳性率。结果 X线对AVN检出阳性率为73.68%,影像学表现为股骨头变形、关节轮廓不规则及其内部密度不均匀;CT对AVN检出阳性率为84.21%,影像学表现为骨小梁增粗变形、骨皮质不连续及星芒状结构消失;MRI扫描对AVN检出阳性率为97.36%,影像学表现为T1WI序列中出现明显"线样征"改变,粗隆间骨髓水肿,关节腔积液呈高信号改变。结论 MRI对AVN早期诊断敏感度和特异性优于X线与CT扫描,可为定性诊断及准确病变程度的评估提供依据。

Objective To investigate value of magnetic resonance imaging （MRI） in diagnosis of avascular nec- rosis of femoral head （AVN）. Methods A total of 26 patients with AVN admitted during May 2012 and May 2014 were recruited in this study. Imaging data of X-ray, CT and MRI of 26 patients were collected. Imaging manifestations were observed, and positive detection rates of X-ray, CT and MRI in diagnosis of AVN were compared. Results Positive detection rate of X-ray in diagnosis of AVN was 73.68% , and imaging manifestations were distorted femoral head, irregular joint profile and nonuniform internal density. Positive detection rate of CT in diagnosis of AVN was 84.21% , and imaging manifestations were thickening and distorted bone trabecula, incontinuous bone cortex and disappeared star structure. Positive detection rate of MRI in diagnosis of AVN was 97.56% , and imaging manifestations were obvious string sign changes in T1WI rank, intertrochanteric bone marrow edema and highly signal changes in arthroedema. Conclusion MRI in early diagnose of avascular necrosis of femoral head can achieve better sensibility and specificity than those by X- ray and CT scanning, and therefore it can provide basis for diagnosing qualitatively and evaluating degree of pathological change accurately.