DTI在快速直观评价子宫肌瘤组织特征中的应用研究

A Simple Approach to Show the Features of Uterine Fibroid in DTI: Preliminary Results

目的探索子宫肌瘤内部组织的扩散张量成像（DTI）直观特征表现。方法搜集2014年3月至2015年1月于本院经临床或病理证实子宫肌瘤患者行常规盆腔磁共振平扫、增强及DTI扫描。在常规MRI图像中,由两名十年以上磁共振诊断经验的放射科医师根据不同的T2信号强度将所有子宫肌瘤进行五类分组,并取得一致性意见,分为：低信号组（A组）、等信号组（B组）、不均匀高信号组（C组）、均匀轻度高信号组（D组）及均匀显著高信号（E组）。采用DTI后处理工作站AW 4.4 Funtool进行数据测量,分别测量各个肌瘤及子宫肌层的平均扩散系数（MD）、各向异性分数（FA）及相对各向异性（RA）值;同时医师根据后处理工作站的DTI纤维束图像显示的形态及分布将肌瘤纤维束分为四类,分析各组肌瘤的纤维束分类,并取得一致性意见。数据经统计学处理,来比较各组肌瘤的MD值、FA及RA值,尤其是纤维束分类表现。结果 112例患者,共156个子宫肌瘤的MD值各组之间差异有统计学意义（P〈0.05）;B组与C组肌瘤的FA值（P=0.918）及RA值（P=0.951）差异无统计学意义,余各组肌瘤间比较均存在显著差异;A组子宫肌瘤与余四组肌瘤比较P值远远小于0.05。各组子宫肌瘤分别与肌层进行比较,A、B、C、D四组肌瘤FA值及RA值均大于肌层,MD值均小于肌层,且差异有统计学意义;E组MD值小于肌层,但各参数值与肌层比较无显著差异。纤维束分类在各组间具有特征性：A组低信号肌瘤以长密型表现为主占69.1%（38/55）,B组等信号肌瘤以短密型为主占36.7%（11/30）,C组混杂高信号肌瘤以长稀型为主占38.5%（15/39）,D组均匀稍高信号及E组均匀显著高信号肌瘤以短稀型为主占47.6%（10/12）、72.7%（8/11）;各组表现有显著差异（P=0.000）。结论子宫肌瘤间DTI相关参数存在差异,且DTI纤维束图能够直观显示这种差异。

Objective Simplified approach to evaluate the leiomyoma features in diffusion tensor imaging（ DTI） with the images directly undergoing reformatting by using the imager workstation. Methods The patients with uterine fibroids were confirmed by pathology,surgery and clinical curative at the First Affiliated Hospital of Chongqing Medical University from March 2014 to January 2015,who were checked by routine MRI and DTI. All uterine fibroids were classified into five types on T2 WI： hypointense,isointensity,heterogeneous hyperintense,slightly homogenous hyperintense,markedly homogenous hyperintense,measuring separately with the value of MD、FA and RA; Classified fiber bundles which were reformatted by using the imager workstation as follows： long much and dense,short much and dense,long few and loose,short few and loose. All above images were analyzed by two experienced readers and achieved consensus. Statistical analysis was performed. Results All 112 patients with 156 were included. Among groups MD values had significant difference,while there was no statistically difference（ P = 0. 951） in FA and RA value,except which was between group B and C. Uterine fibroids of group A to D had significantly greater value of FA and RA than uterine muscle layer and less in MD value. As to group E,the value of MD was little less than it in muscle layer without statistical difference. Fiber type among groups had some characteristic： Low T2 signal uterine leiomyomas group A was given priority with long dense-fiber type 69. 1%（ 38/55）,group B with short dense type,36. 7%（ 11/30）,mixed high signal fibroids group C with long thin type 38. 5%（ 15/39）,higher signals group D and E with short thin type,47. 6%（ 10/12）,72. 7%（ 8/11）. Among every two groups all performed significant difference（ P 〈 0. 000）. Conclusion DTI can quantitatively analyze the tissue structure,which directly distinguished the differences among uterine fibroids. With DTI,it lays the foundation for radiography to classify uterine fibroids subtype and degeneration.