学龄前儿童正常腹部实质脏器MRI扩散加权成像ADC值研究

目的i探讨使用GEsigna1．5TMR机扫描正常学龄前儿童腹部实质性脏器表观扩散系数（ADC值）均值范围。方法：60例健康学龄前儿童行腹部DWI检查，最大b值分别使用500s／mm^2,700s／mm^2、1000s／mm^2。在ADC图上测量肝脏、脾脏、肾脏、胰腺的ADC值并进行比较，三组比较用随机区组方差分析，每两组间ADC值比较用LSD法，P〈0．05差异具有统计学意义。结果：正常学龄前儿童肝脏、脾脏、肾脏、胰腺在b值分别为500s／mm^2、700s／mm^2、1000s／mm^2时的ADC值（×10^-3mm^2/s，x±s）分别为1．37±0．05、0．78±0．06、1．75±0．07、1．60±0．05；1．20±0．06、0．64±0．05、1．61±0．05、1．47±0．07；1．11±0．08、0．59±0．07、1．49±0．06、1．38±0．08。不同b值时同一脏器ADC值有统计学差异；同一b值时4种实质性脏器ADC值有统计学差异。结论：正常学龄前儿童腹部实质性脏器的ADC值差异有显著性，按照ADC值由大到小排序为：肾脏、胰腺、肝脏、脾脏。为今后应用DWI诊断腹部实质性脏器疾病提供一定的正常值参考数据。

Investigation of apparent diffusion coefficient of solid abdominal organs in preschool healthy children

Objective： To investigate the normal apparent diffusion coefficient （ADC） values of the abdominal organs of the preschool healthy children on a 1.5T MR. Methods： Sixty healthy preschool children were examined with DWI using b values including 500 s/mm^2, 700 s/mm^2 and 1 000 s/mm^2. The ADCs were calculated with ROIs positioned in the parenchyma of the liver, kidney, spleen and pancreas. The ADCs were compared statistically using analysis of variance （ANOVA）, P〈0.05, was considered as significant. Results： There was a statistically significant difference in ADC values among the same parenchyma organs at different b values. There was a statistically significant difference in ADC values among the four solid organs at same b values. Conclusions： The ADCs of parenchyma organs in the abdomen of preschool heahhy children were kidney〉pancreas〉 liver〉spleen. This study provide valuable refence for the diagnosis of parenchyma organ disease by using DWI.