CAJ | 학술논문

目的：应用1．5T磁共振采用不同 b值对骨折椎体行扩散加权成像（DWI）检查，通过数据分析优选最佳 b值。方法根据外伤时间，按T＜7天、14天≤T＜30天将患者分为二组，每组20例，共40例。所有入组病例均行DWI检查，采用单次激发自旋回波平面成像序列，b值分别取200、300、400、500、600、700、800、900、1000s/mm2，测量骨折椎体表观扩散系数（ADC）值并对比不同b值下椎体扩散加权成像（DWI）图像质量，应用ROC曲线分析不同b值下ADC值对不同时间段椎体压缩骨折的诊断价值。结果40例受检者骨折椎体DWI图像，随着b值由200s/mm2升高至1000s/mm2，图像信噪比逐渐降低，b值为300s/mm2时图像对比噪声比最高；b值为200、300、400、500、600、700、800、900、1000s/mm2时不同时间段压缩骨折ADC值的差异均有统计学意义（ P ＜0．01）；b值为300s/mm2时诊断新近压缩骨折（T＜7天）价值最大，其诊断敏感度、特异度分别为86．76％、81．87％。结论 b值为300s/mm2时，椎体DWI图像质量佳，所获得的ADC值诊断效能相对较高。
목적：응용1．5T자공진채용불동 b치대골절추체행확산가권성상（DWI）검사，통과수거분석우선최가 b치。방법근거외상시간，안T＜7천、14천≤T＜30천장환자분위이조，매조20례，공40례。소유입조병례균행DWI검사，채용단차격발자선회파평면성상서렬，b치분별취200、300、400、500、600、700、800、900、1000s/mm2，측량골절추체표관확산계수（ADC）치병대비불동b치하추체확산가권성상（DWI）도상질량，응용ROC곡선분석불동b치하ADC치대불동시간단추체압축골절적진단개치。결과40례수검자골절추체DWI도상，수착b치유200s/mm2승고지1000s/mm2，도상신조비축점강저，b치위300s/mm2시도상대비조성비최고；b치위200、300、400、500、600、700、800、900、1000s/mm2시불동시간단압축골절ADC치적차이균유통계학의의（ P ＜0．01）；b치위300s/mm2시진단신근압축골절（T＜7천）개치최대，기진단민감도、특이도분별위86．76％、81．87％。결론 b치위300s/mm2시，추체DWI도상질량가，소획득적ADC치진단효능상대교고。
Objective To determine reasonable b values in diffusion weighed imaging of vertebra with 1 .5 T MR .Meth-ods According to injury time ,40 patients were divided into two groups ,one group was less than seven days after the in-jury ,another group was 14 to 30 days after the injury ,with 20 cases in each group .All the patients received DWI of ver-tebra using a single shot EPI SE pulse sequence with different b values (200 ,300 ,400 ,500 ,600 ,700 ,800 ,900 ,1 000 s/mm2 ) .ADC values of vertebra were measured .The image quality of each group of DWI were analyzed and compared . The diagnostic value of ADC values at different b values was analysed to discriminate the time periods of vertebral com-pression fractures .Results As b values increasing from 200 s/mm2 to 1 000 s/mm2 ,SNR of vertebra decreased gradual-ly ,the CNR in b value 300 s/mm2 was maximum ,then decreased gradually .ROC curve was used to discriminate different time periods of vertebral compression fractures in different b value .b value of 300 s/mm2 had maximum value when the di-agnostic sensitivity specificity values were 86 .76% ,81 .87% .Conclusion The optimal b value is 300 s/mm2 .