【作者】 胡学梅；

【导师】 胡道予；

【作者基本信息】 华中科技大学 ， 影像医学与核医学， 2008， 博士

【摘要】 第一部分磁共振动态增强在肝脏局灶性病变的临床应用研究目的:利用Propeller LAVA动态增强扫描技术研究肝脏局灶性病变的的强化特点,以探讨其在肝脏局灶性病变中的应用价值。方法:肝脏局灶性病变86例(原发性肝细胞癌51例,周围型胆管细胞癌2例,转移瘤5例,局灶性结节增生3例,血管瘤12例,囊肿7例,炎性病变6例),均行磁共振平扫(轴位T1WI,T2WI)和LAVA动态增强检查。扫描完成后,将LAVA原始图像推入ADW4.2工作站,采用最大信号强度投影、多平面重建和容积再现等重建肝动脉、门静脉和肝静脉。结果:LAVA扫描成功率96.51%。原发性肝细胞癌主要表现为动脉期强化、门脉期和延迟期强化低于肝实质(84/126),动脉期强化、门脉期和延迟期强化与肝实质一致(20/126),动脉期和门脉期与肝实质一致、延迟期强化低于肝实质(14/126),部分病例可见供血动脉(16/126),包膜强化(67/126)且可以显示供血的门脉分支(8/126)和门脉瘤栓(5/49);周围型胆管癌表现为动脉期仅见肿瘤边缘不完整厚薄不均环状强化,门脉期和延迟期亦仅见周边环状强化(3/3);转移瘤表现为动脉期病灶周围环状强化(19/27)或无明显强化(8/27)、门脉期和延迟期均为环状强化,部分病灶仍然低于肝实质。局灶性结节增生各期均明显强化(3/3);血管瘤主要表现为由动脉期到延迟期造影剂由周边向中央填充(45/49);囊肿各期均无强化(34/34);炎性病变呈动脉期轻度环状强化,门脉期和延迟期环状强化更明显。结论:不同肝脏局灶性病变的强化特点各不相同。结合平扫,磁共振动态增强则能提高对肝脏局灶性病变的诊断和鉴别诊断能力。第二部分磁共振弥散加权成像在肝脏局灶性病变的临床应用目的:利用磁共振弥散加权成像技术对肝脏局灶性病变进行定量分析,以探讨其在肝脏局灶性病变中的应用价值。方法:正常肝脏10例和肝脏局灶性病变78例(原发性肝细胞癌28例,周围型胆管细胞癌1例,转移瘤15例,局灶性结节增生6例,血管瘤12例,囊肿11例,肝脓肿5例),采用EPI-SE DWI序列进行扫描,其中10例健康自愿者、10例肝细胞癌、5例局灶性结节增生、8例血管瘤和8例囊肿采用b=400、600、800、1000 s/mm2进行扫描,其余的均采用b=600 s/mm2扫描,扫描时间1分钟55秒。扫描完成后,推入工作站,测量DWI图像的信噪比,病变与肝脏的对比噪声比和病变的ADC值。结果:b值与DWI图像信噪比存在显著负相关关系(r=-0.969,P=0.000),b值与肝癌、局灶性结节增生、血管瘤和囊肿与肝脏的对比噪声比存在显著负相关关系(r=-0.974,-0.921,-0.976,-0.969;P=0.000)。b值与肝癌、局灶性结节增生、血管瘤和囊肿的ADC值存在显著负相关关系(r=-0.784,-0.905,-0.968,-0.814;P=0.000)。当b值选用600 s/mm2时,肝癌、转移瘤、肝脓肿壁、局灶性结节增生、血管瘤和囊肿的ADC值分别为(0.86±0.29)×10-3 mm2/s、(0.91±0.23)×10-3 mm2/s、(1.22±0.49)×10-3 mm2/s、(1.52±0.36)×10-3 mm2/s、(2.39±0.41)×10-3 mm2/s和(3.22±0.17)×10-3 mm2/s。而正常肝脏的ADC值为(1.49±0.11) mm2/s。肝癌和转移瘤的ADC值小于正常肝脏(t=6.0363,7.8699;p=0.000),血管瘤和囊肿的ADC值大于肝脏(t=7.1761,29.1792;p=0.000)。肝脓肿壁和局灶性结节增生与肝脏的ADC值之间无统计学差异。肝癌与转移瘤的ADC值无统计学差异。当ADC值为1.15×10-3 mm2/s时,小于该值为恶性(阳性),大于等于该值为良性(阴性)诊断的一致百分比、敏感度和特异度分别为93.57%,92.23%和95.59%。结论:依据磁共振弥散成像的DWI图像、ADC值及其变化规律,能比较准确的判断肝脏局灶性病变的性质,对其的诊断及鉴别诊断有一定价值。第三部分磁共振波谱分析在肝脏局灶性病变鉴别诊断中的研究目的:分析肝脏局灶性病变的磁共振波谱成像表现,以探讨其在肝脏局灶性病变鉴别诊断中的应用价值。方法:肝脏局灶性病变64例(原发性肝细胞癌28例,周围型胆管细胞癌1例,转移瘤8例,局灶性结节增生6例,血管瘤12例,囊肿7例,肝脓肿2例),应用点分辨选择波谱技术行单体素扫描:TR=1265 ms,TE=144 ms,NEX=8,扫描时间1分11秒,每个患者分别采集病变区域及自体相对正常肝脏谱线。扫描完成后,应用SAGE软件测量谱线中cho峰高、cho峰下面积、lip峰高和lip峰下面积。结果:肝癌的cho峰高和峰下面积明显高于自体非肿瘤组织(t=5.4026,4.7484;P=0.000,0.000),cho峰高/lip峰高和cho峰下面积/lip峰下面积高于自体非肿瘤组织(t=2.5711,2.1455;P=0.015,0.041);转移瘤的cho峰高和峰下面积明显高于自体非肿瘤组织(t=3.6583,8.9184;P=0.008,0.000);局灶性结节增生的lip峰高和峰下面积低于自体正常肝组织(t=-3.6581,-3.1700;P=0.020,0.025);血管瘤的cho峰高、lip峰高和峰下面积均明显低于正常肝组织(t=-4.4629,-5.9614,-3.1663;P=0.001,0.001,0.009),cho峰下面积/lip峰下面积明显高与正常肝组织(t=3.4237;P=0.006);囊肿的cho峰高、cho峰下面积、lip峰高和峰下面积均低于正常肝组织(t=-3.2498,-4.6134,-11.9062,-4.1326;P=0.0015,0.003,0.000,0.006),cho峰高/lip峰高和cho峰下面积/lip峰下面积高与正常肝组织(t=4.9298,2.9594;P=0.003,0.025);脓肿的cho峰低于对照,lip低于对照,cho/lip高于对照。恶性肿瘤组cho峰高、cho峰下面积、lip峰和lip峰下面积明显高于良性病变组(F=-5.2090,-5.4821,-4.9229,-5.4180;P=0.000,0.000,0.000,0.000),有显著统计学差异。结论:磁共振质子波谱能在分子水平无创性地观察到肝脏局灶性病变的代谢异常,cho峰升高是恶性肿瘤的波谱特征,有助于良恶性肿瘤的鉴别诊断。更多还原

【Abstract】 Part I Clincal application value of dynamic contrast enhanced MR scanning in the diagnosis of focal hepatic lesions.Objective: To evaluate Propeller LAVA dynamic contrast enhanced MR scanning in the diagnosis of focal hepatic lesions.Methods: 86 patients with focal hepatic lesions ( 51 hepatocellular carcinomas, 2 intrahepatic peripheral cholangiocarcinomas, 5 metastasises, 3 focal nodular hyperplasias, 12 hemangiomas, 7 hepatic cysts and 6 liver abscesses ) underwent conventional MR scanning ( T1WI and T2WI ) and Propeller LAVA dynamic contrast enhanced MR scanning. After the scanning ,the images were pushed into the workstation ADW 4.2 and then the hepatic artery , portal vein and hepatic vein were reconstructed by maximum intensity projection, multiplanner reconstruction and volume render.Results: 84 of 126 HCC lesions showed strong enhancement in the arterial phase and washout in the portal venous phase and delay phase; 20 of 126 HCC lesions showed strong enhancement in the arterial phase and isointense to the surrounding hepatic parenchyma in the portal venous phase and delay phase; 14 of 126 HCC lesions were observed hypointense to the surrounding hepatic parenchyma only in the delay phase. The feeding artery(16/126), the pseudocapsule (67/126) and tumorthrombus in the portal vein(5/49)were seen in some case of HCC. The intrahepatic peripheral cholangiocarcinomas were observed slightly heterogeneous ring enhancement in the arterial phase and ring enhancement in the portal phase and delay phase. Metastasises were oberserved no enhancedment(19/27) or ring enhancement surrounding thelesions(8/27) in the arterial phase and ring enhancement in the portal enhancement and the delay phase. Focal nodular hyperplasias showed complete homogeneous hyperintense on early and delayed phase. 45 of 49 hemangiomas showed a nodular peripheral enhancement with centripetal filling in delayed phase plasias. The hepatic cysts showed no enhancement. The liver abscesses were observed slightly enhancement in the arterial phase and obvious ring enhancement in the portal phase and delay phase.Conclusions: Various hepatic focal lesions have different enhancement patterns on the dynamic scans. Propeller LAVA dynamic contrast enhanced MR scanning is a useful method in diagnosis of focal liver lesions.Part II Clincal application value of diffusion weighted imaging in the diagnosis of focal hepatic lesions.Objective: To study the differential diagnosis value of diffusion-weighted imaging and apparent diffusion coefficient in focal hepatic lesions.Methods: 10 healthy volunteers and 78 patients with focal hepatic lesions ( 28 hepatocellular carcinomas, 1 intrahepatic peripheral cholangiocarcinoma, 15 metastasises, 6 focal nodular hyperplasias, 12 hemangiomas, 11 hepatic cysts and 5 liver abscesses ) underwent DWI by using a SE-EPI sequence ( b=600 s/mm2 ) . Among of them, 10 healthy wolunteers ,10 hepatocellular carcinomas, 5 focal nodular hyperplasias, 8 hemangiomas, 8 hepatic cysts underwent DWI with four b value ( 400、600、800、1000 s/mm2 ). The scanning time was 1 min 55 s. After the scanning, the signal-to-noise ratio(SNR), contrast-to-noise(CNR) and apparent diffusion coefficient(ADC) value were calculated. Results: There were negative correlation between b value and the SNR of the healthy volunteers ( r = -0.969 ; P = 0.000 ) , between b value and the lesion-liver CNR ( hepatocellular carcinoma, focal nodular hyperplasia, hemangioma, hepatic cyst ;r=-0.974,-0.921,-0.976,-0.969;P=0.000 ), beween b value and the ADC Value of focal hepatic lesion(hepatocellular carcinoma, focal nodular hyperplasia, hemangioma, hepatic cysts ; r=-0.784,-0.905,-0.968,-0.814;P=0.000). when b was 600s/mm2 , the ADC values of primary hepatic carcinoma(PHC), metastasis, focal nodular hyperplasia, hemangioma, hepatic cyst and liver abscess were(0.86±0.29)×10-3 mm2/s、(0.91±0.23)×10-3 mm2/s、(1.22±0.49)×10-3 mm2/s、(1.52±0.36)×10-3 mm2/s、(2.39±0.41)×10-3 mm2/s and(3.22±0.17)×10-37 mm2/s, respectively. And the healthy volunteer was (1.49±0.11) mm2/s. ADC value of the PHC and metastasis was lower than that of the healthy volunteer. ADC value of the hemangioma and hepatic cyst was higher then that of the healthy volunteers. There were no statistic differences among focal nodular hyperplasia, hepatic cyst and the healthy volunteer. Use of a threshold ADC value less than 1.15×10-3 mm2/s for the diagnosis of malignant lesions resulted in sensitivity and specificity of 92.23% and 95.59%, respectively .Conclusions: The focal hepatic lesions can be easily diagnosed and distinguished according to DWI, ADC value and their changing characteristics. So, DWI has an important clinical value in the diagnosis of focal hepatic lesions.Part III Magnetic Resonance Spectroscopy Quantitative Analysis in the Differential diagnosis of focal hepatic lesionsObjective: To evaluate Magnetic Resonance Spectroscopy Quantitative Analysis in the diagnosis of focal hepatic lesions.Methods: 64 patients with focal hepatic lesions ( 28 hepatocellular carcinomas, 1 intrahepatic peripheral cholangiocarcinoma, 8 metastasises, 6 focal nodular hyperplasias, 12 hemangiomas, 7 hepatic cysts and 2 liver abscesses ) underwent conventional MR scanning ( T1WI and T2WI ) and MRS scanning. Localized proton MR spectra with a voxel size of 8 were obtain in the focal hepatic lesions and in the hepatic parenchyma in the same patient as control. After volume-seletive autoshimming of the voxels, the spectra was obtained with a point-resolve spectroscopy technique ( TR=1265 ms, TE=144 ms,NEX=8,scan time 1 min 11 s) with water suppresion. And then the peak value and the area under the peak of cho and lip were caculated.Result: Compared with the hepatic parenchyma ,The peak value and the area under the peak of cho in PHC was higher(t=5.4026,4.7484;P=0.000,0.000),the peak vule and the area under the peak of cho/lip was higher too(t=2.5711,2.1455;P=0.015,0.041);The peak value and the area under the peak of cho in metastasis was higher than the hepatic parenchyma(t=3.6583,8.9184;P=0.008,0.000); The the peak value and the area under the peak of lip in focal hepatic lesions was lower than the hepatic parenchyma(t=-3.6581,-3.1700;P=0.020,0.025); The the peak value of cho and lip and the area under the peak of lip in hemangioma was lowerr than the hepatic parenchyma(t=-4.4629,-5.9614,-3.1663;P=0.001,0.001,0.009), the area under the peak of cho/lip was higher then the hepatic parenchyma(t=3.4237,P=0.006); The cho and lip in hemangioma was lower than the hepatic parenchyma, the cho/lip was higher then the hepatic parenchyma.There was significent statistic difference between the malignant tumor and benign lesions in the peak value and the area under the peak of cho and lip(F=-5.2090,-5.4821,-4.9229,-5.4180;P=0.000,0.000,0.000,0.000).Conclusions: MRS may show the metabolic changes in the focal hepatic lesions noninvasingly, and it is helpful for the differential diagnosis between benign and malignant lesions.更多还原