【摘要】 目的探讨腰椎溶骨型转移瘤的扩散特性、扩散加权成像(DWI)检查技术及其应用价值。方法20例腰椎溶骨型转移瘤患者(病变组)及20例对照者(对照组),分别行矢状面SET1WI,快速SE(FSE)T2WI,脂肪抑制FSET2WI(fatsaturationFSET2WI,FS FSET2WI)及单次激发自旋回波回波平面DWI,比较病变组在各序列的对比噪声比(CNR)。同时评价病变组与对照组的信号衰减率(signalattenuationratio,SAR)和表观扩散系数(apparaentdiffusioncoefficient,ADC)。结果(1)常规MRI表现:20例腰椎溶骨型转移瘤患者,共23个椎体受累。在SET1WI上,病变均呈低信号,在FS FSET2WI和DWI上呈高信号。在FSET2WI上,病变分别呈混杂信号(5例)、等信号(12例)或稍高信号(6例);(2)CNR值:病变组CNR值在FSET2WI上(5.70±3.82)小于SET1WI(25.62±11.73)、FS FSET2WI(23.37±7.48)及DWI(b=600s/mm2)(24.69±9.87)(U值分别为5.393、6.359、5.547,P值均<0.05);(3)SAR值:在DWI上,病变组病变椎体、邻近正常椎体与对照组正常椎体的SAR值分别为:b=165s/mm2时,(33.21±7.76)%、(20.41±5.25)%、(22.09±5.21)%;b=360s/mm2时,(48.28±7.11)%、(27.18±5.04)%、(29.08±5.35)%;b=600s/mm2时,(59.64±7.37)%、(33.82±5.75)%、(34.02±4.50)%。成像条件相同时,病变椎体的SAR值明显高于正常椎体(q值分别为9.844、17.065、20.464、8.246、14.978、19.586,P值均<0.05)。随b值的增高,相同兴趣区(ROI)的SAR值逐渐增高(q值分别为7.344、5.952、4.392、17.084、12.013、10.596、9.739、6.601、6.204,P值均<0.05);(4)ADC值:在DWI上,病变组病变椎体、邻近正常椎体与对照组正常椎体的ADC值分别为:b=165s/mm2时,(2.49±0.70)×10-3mm2/s、(1.36±0.41)×10-3mm2/s、(1.51±0.41)×10-3mm2/s;b=360s/mm2时,(1.87±0.36)×10-3mm2/s、(0.88±0.19)×10-3mm2/s、(0.96±0.21)×10-3mm2/s;b=600s/mm2时,(1.54±0.30)×10-3mm2/s、(0.68±0.16)×10-3mm2/s、(0.70±0.12)×10-3mm2/s。成像条件相同时,病变椎体的ADC值明显高于正常椎体(q值分别为6.683、12.304、12.039、10.422、8.034、8.745,P值均<0.05)。b值越大,相同ROI的ADC值越小(q值分别为8.218、5.686、6.389、10.997、8.512、9.091、8.218、7.037、7.192,P值均<0.05)。结论DWI是以量化的方式,从分子水平对组织病变进行定性,比MR常规序列成像对组织进行定性诊断更加客观。更多还原

【Abstract】 Objective To study diffusion characteristic, diffusion-weighted imaging （DWI） technique and its value in lumbar osteolytic metastases. Methods Twenty patients with lumbar osteolytic metastases and 20 controls were performed with sagittal SE T₁WI, FSE T₂WI, fat saturation FSE T₂WI（FS-FSE T₂WI）and single-shot spin-echo echoplanar DWI, respectively. Contrast noise ratios （CNRs） of the metastases on various series were compared. On DWI, signal attenuation ratios （SARs） and apparent diffusion coefficients （ADCs） of lumbar osteolytic metastases and normal vertebrae were analyzed. Results （1） Routine MRI appearance: There were 23 lesions in the 20 patients. The signal intensity of all lesions showed hypointense on SE T₁WI, hyperintense on FS-FSE T₂WI and DWI, and mixed signal intensity （5 cases）, isointense （12 cases） or slight hyperintense （6 cases） on FSE T₂WI. （2） CNR: The CNRs of patient group on FSE T₂WI（5.70±3.82）were lower than those on SE T₁WI（25.62±11.73）, FS-FSE T₂WI（23.37±7.48）and DWI （b=600 s/mm2）（24.69±9.87）（U values were 5.393, 6.359, and 5.547, respectively,P<0.05）. （3） SAR: On DWI, the SARs of lesions, normal vertebrae adjacent to lesions in patient group and normal vertebrae in control group were: b=165 s/mm2——（33.21±7.76）%, （20.41±5.25）%, and （22.09±5.21）%; b=360 s/mm2——（48.28±7.11）%, （27.18±5.04）%, and （29.08±5.35）%; b=600 s/mm2——（59.64±7.37）%, （33.82±5.75）%, and （34.02±4.50）%. The SARs of lesions were evidently higher than those of normal vertebrae at the same imaging parameters （q values were 9.844, 17.065, 20.464, 8.246, 14.978, 19.586, respectively, P<0.05）. In same ROIs: the higher b values, the higher SARs （q values were 7.344, 5.952, 4.392, 17.084, 12.013, 10.596, 9.739, 6.601, 6.204, respectively, P<0.05）. （4）ADC: On DWI, the ADCs of lesions, normal vertebrae adjacent to lesions in patient group and normal vertebrae in control group were: b= 165 s/mm2——（2.49±0.67）×10 -3mm2/s, （1.36±0.41）×10 -3mm2/s, and （1.51±0.41）×10 -3mm2/s; b=360 s/mm2——（1.87±0.36）×10 -3mm2/s, （0.88±0.19）×10 -3mm2/s, and （0.96±0.21）×10 -3mm2/s; b=600 s/mm2——（1.54±0.30）×10 -3mm2/s, （0.68±0.16）×10 -3mm2/s, and （0.70±0.12）×10 -3mm2/s. The ADCs of lesions were evidently higher than those of normal vertebrae at the same imaging parameters （q values were 6.683、12.304,12.039,10.422,8.034,8.745,respectively,P<0.05）. In the same ROIs: the higher b values, the smaller ADCs （q values were 8.218,5.686,6.389,10.997,8.512,9.091,8.218,7.037,7.192,respectively,P<0.05）. Conclusion DWIcan identify the lesion from molecular level by means of quantification. The diagnosis based on DWI is more objective than routine MRI.更多还原