MR弥散加权成像骨髓对比率与核素骨显像在脊柱转移瘤诊断中的价值

Comparison of MR diffusion weighted imaging bone marrow ratio and radionuclide bone imaging in the diagnosis of spine metastasis

中文关键词:  脊柱转移瘤  弥散加权成像  核素显像

英文关键词:Spinal metastases  Diffusion-weighted imaging  ECT

中文摘要:

  【摘要】 目的：对比MR弥散加权成像（DWI）骨髓对比率与核素骨显像在脊柱转移瘤诊断中的价值。方法：脊柱转移瘤患者40例，21例经骨穿刺检查、13例手术病理证实，其余6例经MRI、CT（或X线）、核素骨显像综合分析和随访证实为转移瘤。均进行b=500s/mm2的DWI扫描，在DWI图上描出感兴趣区（ROI），ROI应尽量包括最典型病灶并避开坏死部分，于病灶ROI上测量异常骨髓信号强度值为SIA，并与相邻椎体ROI上测量的正常骨髓信号强度值SIN比较，骨髓对比率的计算公式为（SIA-SIN）/SIN，测量得出脊柱转移瘤DWI上最典型病灶的骨髓对比率。观察DWI信号变化，测量表观弥散系数（ADC），计算骨髓对比率；并同时进行核素骨显像检查对比。结果：40例脊柱转移瘤患者中，DWI阳性共39例，其中颈椎5例，胸椎14例，腰椎20例；并在病变椎体上发现高信号病灶162个；核素骨显像检查共31例阳性，并在脊柱发现病灶131个。经统计学处理结果：转移瘤的阳性检出率磁共振DWI（97.5%）高于核素骨显像检查（77.5%）（采用两独立样本t检验，P<0.05）。病灶腰椎体的ADC值[（1.37±0.51）×10-3mm2/s]明显高于邻近正常腰椎体[（0.534±0.23）×10-3mm2/s]，DWI病灶与邻近正常腰椎体信号强度的骨髓对比率（1.65±1.38）差异大。椎体转移瘤病灶的高信号（162个）和骨髓对比率变化检出比核素骨显像（131个）阳性率高，两者具有显著性差异（P<0.05）。结论：与核素骨显像比较，DWI的高信号或骨髓对比率在脊柱转移瘤的诊断中有一定的优势。

英文摘要:

  【Abstract】 Objectives: To compare MR diffusion weighted imaging(DWI) in bone marrow and radionuclide bone imaging in the diagnosis of spine metastasis. Methods: Among the 40 cases with spine metastasis, 21 cases were confirmed by bone biopsy, 13 cases by postoperative pathology, and the other 6 cases by MRI, CT(or X-ray), radionuclide bone imaging and follow-up. DWI(b=500s/mm2, and 1.5T MR scanner) were performed in all 40 patients. The regions of interests(ROIs) were measured on the DWI maps, ROI included the most typical lesions avoiding the necrosis zone. Abnormal marrow signal intensity value was measured as SIA, normal bone marrow signal intensity value in adjacent normal vertebral body was measured as SIN. The bone marrow ratio was defined as(SIA-SIN)/SIN for measuring the typical spinal metastatic bone marrow ratio on DWI. The DWI signal change apparent diffusion coefficient(ADC) and the bone marrow contrast ratio was meassured, which was compared with the radionuclide bone imaging at the same time. Results: Among the 40 cases of spine metastasise, 39 cases had positive DWI, which included 15 cervical, 14 thoracic, and 20 lumbar vertebrae. 162 high signal intensity lesions in the vertebral body were found. Among the 31 cases with positive radionuclide bone imaging, 131 lesions were found in the spine. DWI was more sensitive(97.5%) than radionuclide bone imaging(77.5%) in determing spine metastasis by two independent samples t test, P<0.05. The ADC value of lumbar vertebral body lesions was significantly higher[(1.37±0.51)×10-3mm2/s] than that of the adjacent normal vertebral body[(0.534±0.23)×10-3mm2/s]. The high signal lesions of vertebral metastasis(162) and bone marrow ratio change had higher positive rate than radionuclide bone imaging(131), both with significant differences(P<0.05). Conclusions: Compared with radionuclide bone imaging, DWI signal or bone marrow ratio shows higher potent in determining spine metastasis.