摘要
目的探讨磁共振扩散加权成像对放射性肝损伤的诊断价值及其反映照射后不同时期肝脏病理学改变的能力。方法将雄性新西兰大白兔60只，随机分为6组：C0组，即对照组，不行照射，C1、C2、C3、C4、C5组，均行虚拟肿瘤靶区照射，处方剂量50Gy／10F，隔Et1次，并分别于照射后ld、3d、2周、1个月、2个月行DWI和病理学研究。上述6组兔均在弥散敏感系数b值分别取50、300、600、800、1000s／mm2的情况下，测定肝脏感兴趣区的表观扩散系数（ADC）值。根据资料不同分别采用配对样本t检验、方差分析、Spearman相关分析或受试者工作特征曲线等进行统计学分析。结果光镜下观察发现C3、C4、C5组照射区出现特征性的小叶中央静脉血管闭塞性损伤。当b为300、600、800、1000s／mm^2时，C2、C3、C4、C5组受照射区较未照射区ADC值降低（尸〈0．05）I当b=600s／mm^2时，ADC值与病理分期相关性最佳，Spearman相关分析显示呈负相关（，=-0．459，P〈0．01）；在预测正常组（C0）与照射区组（≥C1），b=600S／mmm^2时，ADC值为1．9550×10^-3mm^2／s为阈值时诊断效能最大；在预测HE染色正常组（≤C1）与HE染色异常组（≥C2）和C0～C2组与C3～C5组，b=1000s／mm^2时，选ADC阈值分别为1．5250×10^-3mm^2／s和1．5150×10^-3mmm^2／s时诊断效能最大。结论选择适当b值，DWI能够于照射后3d即发现放射性肝损伤；并能够通过ADC值的测量较为准确地判断其部分时期的病理演进过程，有着早期预测放射性肝损伤病理异常的潜力。
Objective To evaluate the clinical value of magnetic resonance （MR） diffusion-weighted imaging （DWI） for diagnosing radiation-induced liver injury （RILl） and detecting changes in hepatic pathology at different post-irradiation times. Methods Male New Zealand white rabbits received no irradiation （CO, control group; n = 10） or irradiation of 50 Gy/10F once every other day by virtual three dimensional conformal radiotherapy （3D-CRT） for one day （C1; a = 10）, three days （C2; n = 10）, two weeks （C3; n = 10）, one month （C4; n = 10） or two months （C5; n = 10）. One member of all groups were sacrificed for DWI examination and pathologic study on post-irradiation day 1, day 3, week 2, month 1 and month 2. The apparent diffusion coefficient （ADC） values were measured using a range of b values （50, 300, 600, 800 and 1000 s/mm2）. Results Hematoxylin-eosin （H-E） staining showed that livers of rabbits in the C3, C4 and C5 groups had the characteristic features of veno-occlusive disease. DWI examination showed that the irradiated livers of rabbits in C2, C3, C4 and C5 groups had significantly lower ADC values than the livers of the non-irradiated rabbits at b values of 300, 600, 800 and1000 s/n＇lnl2 （P 〈~ 0.05）. When the b value was 600 s/nln＇l2, the best negative correlation between ADC values and pathological stage was seen for the irradiated livers （Spearman＇s rank, r= -0.459, P 〈 0.01）. The threshold ADC value to distinguish the normal group （CO） from an irradiated group （ ≥ C1） was 1.955 x 10-3 mm2/s at 600 s/mm2 b value. When the b value was 1000 s/ram2, the threshold ADC value to predict an irradiated group with normal H-E staining （C1） from an irradiated group with abnormal H-E staining （ 〉i C2） was 1.5250 x 10.3 mm2/s; the ADC threshold value was 1.5150 x 10.3 mm2/s to predict groups C0-2 and groups C3-5. Conclusion DWI has high sensitivity for detecting RILI at three days after irradiation with proper b values. Use of the ADC value is feasible for estimating the evolutionary process of pathological features of RILI damage. DWI may represent an important clinical tool for detection of early pathological changes in RILl.
出处
《中华肝脏病杂志》
CAS
CSCD
北大核心
2014年第2期128-135,共8页
Chinese Journal of Hepatology
关键词
肝损伤
放射性
磁共振成像
扩散加权成像
Liver injury, radiation-induced
Magnetic resonance imaging
Diffusion-weighted imaging
