【作者】 徐鹏举；

【导师】 王建华； 严??林江；

【作者基本信息】 复旦大学 ， 影像医学与核医学， 2006， 博士

【摘要】 第一部分mSENSE技术在SE-EPI弥散加权成像中对HCC小病灶（≤3cm）的应用研究——不同b值的比较研究目的：评价在肝脏DWI中应用mSENSE技术是否有助于提高图像质量及对HCC小病灶的表观弥散系数测量有无影响，以进一步优化DWI的检查技术。材料和方法：分别用常规DWI和mSENSE-DWI对32例肝癌行单次屏气SE-EPI弥散加权成像（b值为300、500、800sec／mm²）。对两组成像序列不同b值下病灶的CNR、图像质量、病灶的ADC值进行观测和比较，并行统计学分析。结果：在同一b值条件下，mSENSE-DWI组的图像质量均优于常规DWI组（P＜0.01）；病灶的CNR也高于常规DWI组（P＜0.01）；在大b值条件下（500、800sec／mm²），两组所测得的病灶的ADC值无明显差别（P=0.383 0.388）。随着b值的升高，在常规DWI和mSENSE-DWI组中病灶的CNR、病灶的ADC值逐渐变小（P＜0.01），图像质量也随之下降（P＜0.01）。结论：在肝脏DWI中应用mSENSE技术可获得高质量的图像，同时对HCC小病灶的ADC值测量没有影响。第二部分弥散加权成像与MRI动态增强对HCC小病灶检测的比较研究目的：比较DWI与2D DCE MRI扫描对慢性肝病基础上的HCC小病灶的检出敏感性，评价DWI的临床应用价值。材料和方法：54例病人共74个HCC病灶（≤3cm）被纳入研究对象，所有病人均一次同时进行DWI和2D DCE MRI，DWI成像采用mSENSE—DWI（SE-EPI）序列，在三个b值条件（300、500、800sec／mm²）下进行。2D DCE MRI采用FLASH序列，行Gd-DTPA动态增强成像；两位阅片者独立随机顺序分析DWI和2D DCE MRI图像，对结果行ROC曲线分析，并统计病灶的检出敏感性和阳性预测值。结果：对所有≤3cm小病灶和≤1cmMHCC病灶，两位阅片者ROC曲线下平均面积DWI（0.95，0.86）均高于2D DCE MRI（0.86，0.64），并且差别有统计学意义（P＜0.01），对所有≤3cm小病灶和≤1cmMHCC病灶，DWI对病灶检出的敏感性均高于2D DCE MRI（P＜0.05）。对于MHCC病灶，DWI和2D DCE MRI敏感性分别为95.8-96％，62.5-68％；对MHCC病灶，DWI的阳性预测值要高于2D DCE MRI（P＜0.05）。结论：对于慢性肝病基础上的肝癌病例而言，DWI对HCC小病灶的检出敏感性要高于2D DCE MRI扫描，而且可以补充提供有价值的鉴别珍断信息。第三部分弥散加权成像在小肝癌与肝细胞增生性结节鉴别诊断中的价值目的：评价弥散加权成像对SHCC与肝细胞增生性结节的鉴别价值。材料和方法：利用mSENSE技术在b=500sec／mm²条件下行肝脏的DWI，观察经手术病理证实的28个SHCC和10个DN病灶、11个FNH病灶在DWI上的信号特点，测量其ADC值并行统计学分析。结果：28个SHCC病灶表现为高信号，平均ADC值1.30±0.21 X10^-3mm²／sec，10个DN病灶表现为等低信号，平均ADC值为1.51±0.22 X10^-3mm²／sec，11个FNH病灶为高信号，平均ADC值1.85±0.33X10^-3mm²／sec，SHCC病灶与周围的肝组织ADC值之间的差异有统计学意义（P=0.001），FNH病灶与周围肝组织ADC值之间的差异有统计学意义（P=0.006），DN病灶与周围肝组织ADC值之间的差异无统计学意义（P=0.575），SHCC病灶与DN病灶、FNH病灶ADC值之间的差异有统计学意义（P=0.021、0.000）。根据病灶的信号特征改变结合ADC值的测定对SHCC和肝细胞增生结节鉴别的准确性达89.8％，动态增强鉴别的准确性为69.4％，联合应用动态增强和DWI，鉴别的准确性为97.9％。结论：综合应用DWI上的病灶信号特征改变和ADC值的量化分析，DWI可以为SHCC和肝细胞增生性结节的鉴别诊断提供重要的补充信息。第四部分弥散加权成像与肝细胞肝癌分化程度及PCNA表达相关性的初步探讨目的：探讨DWI上HCC的ADC值与HCC病理分级和相关病理指标PCNA有无相关性。材料和方法：自2005年4月至2005年12月，共搜集病理确诊的HCC27例共29个病灶。利用mSENSE技术行DWI（b=500sec／mm²），分析所有病灶在DWI上的信号特点，并测量ADC值；对29个病灶的手术标本进行病理取材并作常规HE染色切片及相应部位的免疫组化切片。采用统计学方法分析和判断病灶的ADC值与病理分化程度及PCNA免疫组化阳性指数之间有无相关性。结果：29个HCC病灶在DWI上均表现为高信号，ADC值范围从0.86-1.69X10^-3mm²／sec，Edmondson分级结果，高分化14个，低分化15个，分化程度不同的HCC之间的ADC值差异没有统计学意义（P=0.913），HCC的ADC值与组织的胞核胞浆面积比没有相关性（r=0.149），与PCNA免疫组化阳性指数之间也无明显相关性（r=0.364）。结论：在b值500 sec／mm²的DWI中，ADC值的变化不能在体反映和评估HCC的分化程度和侵袭性。更多还原

【Abstract】 Objective: To prospectively evaluate whether DWI with mSENSE （mSENSE-DWI）can help to improve image quality and affect the calculation of lesion’s ADC,compared with DWI with conventional phase encoding（conventional DWI）in patientswith small HCC lesions.Materials and methods: 32 patients with 47 small HCC lesions underwentsingle-shot spin-echo echo-planar DWI with conventional phase encoding andmSENSE. Three b values of 300, 500 and 800 sec/mm² were used. mSENSE-DWIand conventional DWI were compared for image quality, and CNR with different bvalue. Lesion’s ADC with conventional phase encoding and mSENSE at MR imagingwere also observed and compared; Friedman test and matched-pairs Wilcoxon signedrank test was used to test statistical significance.Results: Higher image quality scores were achieved at mSENSE-DWI group （P<0.01） and CNR of the lesions was also higher than that of conventional DWI （P<0.01） with the same b value. There was no significant difference in the measurementof lesion’s ADC between mSENSE-DWI group and conventional DWI group withhigh b value（500 and 800 sec/mm², P=0.383,0.388 respectively）. With the increase ofb value, the image quality 、 CNR and ADC decreased at mSENSE-DWI group as wellas that of conventional DWI group（P<0.01）.Conclusion: Higher quality images can be achieved in liver DWI with mSENSEwithout compromising small HCC lesion’s ADC calculation.Objective: To compare the sensitivity of DWI and 2D DCE MRI for the detection ofsmall HCC lesion （≤ 3 cm）in the patients with chronic liver disease, and evaluate theclinical value for DWI.Materials and methods: 54 patients with 74 small HCC lesions（≤3cm） underwentDWI and 2D DCE MRI at the same time. The DWI was performed using mSENSEtechnology with different b value（300 500 800sec/mm²）. The dynamic MRIexamination was performed using 2D FLASH sequence. Two observersindependently interpreted the images in random order, separately. The diagnosticperformance of each technique was evaluated using the ROC curves. The sensitivityand positive predictive value were also calculated.Results: The mean area under the ROC curve （Az） of DWI （0.95, 0.86） wasstatistically higher than that of 2D DCE MRI （0.86, 0.64） for all small HCC lesionsand MHCC lesions （P<0.01）. The sensitivities of DWI for two observers weresignificantly higher than those of 2D DCE MRI for all small lesions and for MHCC（P<0.05）; For MHCC, the sensitivity of DWI and 2D DCE MRI was 95.8-96%,62.5-68% respectively, The positive predictive value for MHCC lesions in DWI wasstatistically higher than in 2D DCE MRI（P<0.05）.Conclusion: For the detection of small HCC lesions in the patients with chronic liverdisease, DWI is more sensitive than 2D DCE MRI. It can provide valuableinformation in the differential diagnosis.Part IIIThe value of diffusion-weighted imaging in differentiating SHCC from Hepatichyperplastic nodulesObjective: To evaluate the value of DWI of liver in differentiating SHCC from hepatic hyperplastic nodules（including DN and FNH）.Materials and methods: the DWI of liver were performed with mSENSE technology under b value 500 sec/mm², the signal feature of 28 SHCC lesions 10 DN lesions and11 FNH lesions confirmed with surgery and pathology were observed retrospectively and ADC value of all lesions were calculated and analyzed statistically. Results: All of 28 SHCC lesions showed as hyperintense on DWI, isointensity or hypointensity was showed in 10 DN lesions, hyperintensity was showed in 11 FNH lesions, the mean ADC value of SHCC、 DN and FNH was 1.30±0.21 X10^-3mm²/sec, 1.51±0.22 X10^-3mm²/sec, 1.85±0.33X10^-3mm²/sec respectively. There was statistically significant difference in ADC value between SHCC lesions and DN lesions （P=0.021）, between SHCC lesions and FNH lesions（P=0.000）, between SHCC lesions and surrounding hepatic tissues（P=0.001）, between FNH lesions and surrounding hepatic tissues（P=0.006）; there was no statistically significant difference in ADC value between DN lesions and surrounding hepatic tissues（P=0.575）. Combination of ADC value and signal features, The accuracy of DWI for differentiating SHCC from hepatic hyperplasia nodules was 89.8%. The accuracy of dynamic contrast-enhanced was 69.4%. The combination of dynamic contrast-enhanced and DWI had accuracy of 97.9% in differential diagnosis. Conclusion: Combined with ADC value and signal features, DWI of liver can provide additional important information in differentiating SHCC from hepatic hyperplastic nodules.Part IVInitial investigation of HCCs on its Correlation between DWI and HCCDifferentiations, PCNA expressionObjective: To investigate the correlations between ADC value of HCC on DWI and tumor differentiation and PCNA expression.Materials and methods: 27 HCCs cases with 29 lesions confirmed by pathology were collected in this study. The DWI of liver were performed with mSENSE technology under b value 500sec/mm² for all cases, the ADC value of HCC were calculated on ADC mapping. The pathological examination with HE stain for cell differentiation, irnmunohistochemistrical exams for PCNA were performed. All lesions were also divided according to Edmondson grading into two groups: group one （high differentiation） including Edmondson grade I, I-II and II; group two （lowdifferentiation） including Edmondson grade II-II1, III, III-IV and IV; The all 29 leisons were quantitatively evaluated N/C area ratio, immunohistochemistrically for PCNA positive index. The correlation between ADC value and cell differentiation PCNA expression were analyzed.Results: Hyperintensity was demonstrated on DWI for all HCC lesions. The ADC value of HCC lesions was 0.86-1.69X10^-3mm²/sec. According to the Edmondson grade, there was 14 high-differentiated lesiosns and 15 low-differentiated lesions. There was no significant difference in ADC value between high-differentiated and low-differentiated lesions（p=0.913）. There were no significant correlations between ADC value and the tumor N/C area ratio（r=0.149） and PCNA index（r=0.364）. Conclusion: At the DWI of liver with b value 500sec/mm², ADC value of HCC may not be used to evaluate the tumor cell differentiation and invasion in vivo study.更多还原