适用于微型CT系统活体成像的新型门控技术

目的微型CT(Micro-CT)具有解剖成像及无损伤的特点,但对软组织分辨率较低,且在活体成像中,动物呼吸和心脏运动会引入伪影。为提高图像质量,本文提出一种新型门控技术。方法门控技术通过检测动物的心肺运动,在其某个生理时相产生门控信号,并触发X射线球管曝光,最终将获得的投影图像用于三维重建。心肺门控系统主要由监控软件,数字信号处理器(DSP),心电(ECG)检测电路及热电偶电路组成。结果在小鼠活体实验中,获取了6组采用不同门控信号得到的CT投影数据。结论实验结果表明,心肺门控技术的使用,极大地提高了小动物在自由呼吸状态下,使用Micro-CT系统进行活体成像的图像分辨率。     

Micro-CT imaging with a hepatocyte-selective contrast agent for detecting liver metastasis in living mice

RATIONALE AND OBJECTIVES: Micro-computed tomography (CT) is a important tool for longitudinal imaging of tumor development. The detection and monitoring of tumors in the liver in live animals using micro-CT is challenging. We evaluated the feasibility of high-resolution micro-CT enhanced with a hepatocyte-selective contrast agent for detecting liver metastases in a live murine model. MATERIALS AND METHODS: Hepatic metastases were induced in 10 BALB/C mice. Two mice each were randomly selected on days 3, 5, 7, 10, and 13 after CT26 colon adenocarcinoma cells were injected into the portal vein; micro-CT imaging was performed at 10 minutes and 4 hours after intravenous administration of a hepatocyte-selective contrast agent at a dose of 0.4 mL/mouse. The attenuation values of the normal liver and the tumors were obtained. The number of metastases was counted and their sizes were measured on the micro-CT images. Gross or histopathologic evaluation was performed for correlating the liver tumors with the micro-CT images. RESULTS: A total of 74 separate tumor sites larger than 300 mum in diameter were detected on pathologic examination of the mice that were sacrificed 7 days after cell injection. On micro-CT, 66 of 74 tumors were detected (83.8%). The smallest tumor detected on micro-CT was 300 mum. There were eight false-negative readings on micro-CT. The sizes of the individual liver metastases measured by micro-CT and on the excised specimen were highly correlated (P < .001). The correlation between the CT scan measurement and the actual measurement was r = 0.8354 (P < .0001). CONCLUSIONS: High-resolution micro-CT enhanced with a hepatocyte-selective contrast agent can be a promising tool for detecting liver metastases in a live murine model.     

部分脾栓塞治疗肝硬化脾功能亢进的临床研究

目的评估部分脾栓塞治疗肝硬化脾功能亢进的临床疗效及价值。方法1988年6月—2004年6月期间对116例肝硬化脾亢患者实施了部分脾栓塞术,观察治疗前后血常规、肝肾和凝血功能,B超及彩色Doppler超声检查明确肝脾大小和门脉系统血流情况,并严密观察病情变化,注意防治并发症。结果本组116例手术均成功(100%),术后随访6~12个月,其血红蛋白含量、白细胞和血小板计数较术前显著增加(P<0.01)并恢复正常,同时其门脉直径、脾血流量和血白蛋白含量较术前改善(P<0.01)。结论部分脾栓塞是治疗肝硬化脾功能亢进的一种疗效较好,有临床应用价值的方法。     

超顺磁性氧化铁（SPIO）对比剂肝脾MR成像的比较研究

目的 比较两种超顺磁性氧化铁（superparamagnetic iron oxide,SPIO)对比剂,Ferumoxides及SHU－555A在肝脾MR成像中的效应。材料与方法 36例已知为肝转移癌患者于SPIO造影前后进行T2WI快速自旋回波成像（T2WI TSE）及T1WI梯度回波快去速相位成像（T1WI FLASH）。扫描伪为1．0T MR机。18例患者行Ferumoxides增强后90分钟进行MR成像;另18例行SHU－55A快速团柱增强,注药后即刻、30秒及480秒行T1WI FLASH成像,10分钟行T2WI TSE成像。测量肝脾、肝转移癌SPIO增强前后的信号强度（signal intensity,SI),计算两种SPIO对比剂在肝脾、肝转移癌增强前后SI变化的百分比（percentage signal intensity change,PSIC)及病灶肝脏对比噪声比（lesion-to-liver contrast-to-noise ratio,CNR)及其变化（ΔCNR）。结果 在T2WI TSE图像上,两种SPIO对比剂造成的肝实质SI下降无显著性差异（P＞0．05）。Ferumoxides引的脾信号下降显著大于SHU－555A（P＜0．05）。两种SPIO对比剂均导致肝实转移癌SNR显著增高。T1WI FLASH图像上,两种对比剂均可导致延迟像上肝脏SI的轻度下降及肝转移癌CNR下降,两者肝脏SIC之间无显著性差异。T1WI上两种对比剂均可导致脾脏SI显著升高,两者脾脏PSIC之间无显著性差异（P＞0．05）。结论 两种SPIO在肝脏的TI及T2增强效应相似,而脾脏的T2增强效应,Ferumoxides强于SHU－555A。     

运动性免疫抑制大鼠肝、脾糖皮质激素受体表达变化探讨

目的:研究运动性免疫抑制时糖皮质激素受体(glucocorticoid receptor,GR)mRNA和蛋白表达变化,探讨GR在运动性免疫抑制发生中的作用。方法:40只SD大鼠随机分为安静对照组(C组,n=10)、中强度运动组(M组,n=10)和过度疲劳运动组(O组,n=20)。后两组分别进行不同强度的8周递增负荷训练,每周训练6天。每周称量大鼠体重。8周训练结束后采血,检测Hb、血睾酮、皮质酮水平,外周血T细胞亚群(CD3+、CD4+、CD8+)、自然杀伤细胞(NK细胞)数量和辅助性T淋巴细胞1、2(Th1、Th2)特异性细胞因子IFN-γ、IL-4水平。之后断头处死动物,采用real time PCR和Western blot方法分别检测大鼠肝、脾GR mRNA和蛋白水平。结果:(1)与安静对照组和中强度运动组相比,过度疲劳运动组大鼠体重从第4周起明显下降(维持至实验结束),Hb、血浆睾酮水平、睾酮/皮质酮比值均显著下降,血浆皮质酮水平显著升高,表明过度疲劳训练组大鼠已发生过度疲劳。(2)8周训练后,与安静对照组和中强度运动组相比,过度疲劳运动组大鼠CD3+细胞、NK细胞数量显著减少、IFN-γ/IL-4比值显著下降,Th1/Th2失衡,但CD4+/CD8+比值无显著性差异,表明运动性免疫抑制大鼠模型建立成功。(3)与安静对照组和中强度运动组相比,8周训练后,过度疲劳运动组大鼠肝、脾GR mRNA和蛋白水平均显著下降;与安静对照组相比,中强度运动组大鼠肝、脾GR mRNA和蛋白水平均无显著变化。(4)相关性分析显示,肝、脾GR mRNA和蛋白水平与血浆GC的相关系数分别为-0.752、-0.613、-0.144和-0.397,均P<0.05。结论:(1)运动性免疫抑制大鼠肝、脾GR mRNA和蛋白表达水平较安静对照组和中强度运动组显著降低。(2)运动性免疫抑制大鼠肝、脾GR mRNA减少和脾GR蛋白水平下降可能与血浆GC升高有关。     

大鼠肝肿瘤模型建立及磁共振新技术表现

目的建立大鼠种植性肝肿瘤模型,并研究磁共振影像学表现。方法(1)选择体重约250~300g SD大鼠50只,将肿瘤细胞混悬液种植到大鼠肝叶中;(2)肝肿瘤形成后进行磁共振各序列(MRI,DWI,MRS,PWI)检查;(3)肿瘤组织送病理学检查及电镜检查;(4)将磁共振与病理学检查对照分析。结果(1)大鼠肝肿瘤种植成功率100%;(2)HE染色肿瘤组织呈岛状,内见小片坏死灶,血管内皮细胞生成因子(VEGF)及增殖细胞核抗原(PCNA)染色表达阳性,CD34染色微血管数增多,电镜清晰显示肿瘤的超微结构;(3)T1WI呈低信号,T2WI及DWI呈高信号,表观弥散系数(apparent diffusion coefficient,ADC)减低;胆碱(Choline,Cho)、肌酸(Creatine,Cr)、谷氨酸(Glutamate,Glx)、乳酸(Lactate,Lac)及脂质(Lipid,Lip)峰均明显增高;PWI示肿瘤血供丰富,最大相对信号强度增减率(MRSI)明显增高,并与VEGF及CD34呈正相关关系。结论肿瘤细胞混悬液种植可成功制备大鼠肝肿瘤模型,磁共振成像检查肿瘤有特异性表现。     

原发性肝癌MnDPDP增强MRI两种T1W成像序列的比较研究

目的 :比较研究原发性肝癌MnDPDP增强MRI两种T1W成像序列的价值。材料和方法 :对36例原发性肝细胞癌(HCC)进行MnDPDP增强MRI前瞻性研究。平扫序列为SET1WI、FSET2W和FMPSPGRT1WI。静脉滴注MnDPDP后5min开始行FMPSPGRT1WI和SET1WI ,每隔5min成像一次直至40min ;并进行延迟24h成像。三位资深MRI诊断医师以盲法分别比较两种T1W图像(SET1WI和FMPSPGRT1WI)的信噪比(S/N)、对比度噪声比(C/N)、病灶的显示率和定性诊断率 ,以及两种T1W图像上HCC的信号强度差异。结果 :(1)MnDPDP增强后不同延迟时间的两种T1W图像之间的S/N±SD均无显著差异(p>0.05) ,而C/N±SD于延迟5min至40minFMPSPGRT1W图像优于SET1W(p<0.01) ;但延迟24hSET1W图像的C/N±SD优于FMPSPGRT1W(p<0.01)。(2)SET1W图像上HCC呈高信号的概率明显高于FMPSPGRT1W(5～40min :58.8 %对21.6 % ;24h :80.4 %对43.3 %)(p<0.005)。(3)SET1W和FMPSPGRT1W的HCC检出率均为92.7 % ;两者的定性率分别为92.7 %(SE)和87.3 %(FMPSPGR)。结论 :MnDPDP增强两种T1WMR图像对HCC的检出率相当 ,定性以SET1W稍优。作者推荐的HCC检查方案为 :(1)10～40min之间成像一次 ,序列为SET1W或(和)FMPSPGRT1W ;(2)延迟24h成像一次 ,序列为SET1W。     

多层螺旋CT与钆贝葡胺增强MRI对肝癌诊断价值比较

目的 比较多层螺旋CT与钆贝葡胺（Gd-BOPTA）增强MRI对肝癌的诊断价值。资料与方法 对19例同组患者依次行多层螺旋CT双期增强扫描、MR平扫及Gd-BOPTA动态、延迟扫描。比较多层螺旋CT动态增强扫描、MR平扫＋Gd-BOPTA动态扫描及联合MRI3种方法病灶检出的敏感性及对肝癌病灶定性诊断的敏感性、特异性和准确性。结果 3组病灶检出的敏感性及对肝癌病灶诊断的准确性以联合MRI组较高,差异有统计学意义。结论 Gd-BOPTA增强MRI对病灶检出的敏感性及肝癌病灶诊断的准确性优于多层螺旋CT。     

磁共振扩散加权与T2加权成像对肝脏局灶性病变检出的比较研究

目的比较磁共振扩散加权成像(diffusion-weighted imaging,DWI)与T2加权成像(T2-weighted imaging,T2WI)对肝脏局灶性病变的检出效能。方法选择T2WI与DWI2种序列均进行了检查的57例患者共79个病灶(45个恶性,34个良性)纳入本次研究。2位读片者采用盲法分别阅读T2WI与DWI图像。第3位读片者测量病灶和邻近肝实质在DWI及T2WI上的信号强度,计算病灶/肝信号强度比(contrast ratios,CR)。比较2种序列之间检出率及CR值的差异。结果2种序列对恶性病灶的检出率之间的差异无统计学意义,T2WI对全部病灶和良性病灶的检出率高于DWI(2位读片者P<0.001)。对于恶性病灶,当在一种序列上检出病灶即计为检出时,则T2WI+DWI的检出率高于DWI(读片者1P=0.008,读片者2P<0.001),但与T2WI之间检出率的差异无显著性。共对46个病灶测量了CR。良性病灶的CR值在T2WI高于DWI(P=0.008),恶性病灶和全部病灶的CR值在2种序列之间的差异无统计学意义。结论DWI对恶性病灶的检出效能低于T2WI,对良性病灶的检出效能也不及...     

Late Gadolinium Hyperintensity of Suspected Colorectal Liver Metastases on Gadofosveset-Enhanced Magnetic Resonance Imaging: A Predictor of Benignity and a Potential Problem-Solving Tool

PurposeLate gadolinium hyperintensity (LGH) is sometimes seen in colorectal liver metastasis (CRLM) and represents a significant diagnostic pitfall due to overlap with LGH in benign hemangiomas; therefore, the objective of this study was to determine the prevalence of LGH and the ability of LGH to differentiate between CRLM and benign lesions with intravascular (gadofosveset) vs extracellular contrast agents (gadobutrol).MethodsPatients with known colorectal cancer and suspected liver lesions were prospectively recruited into this institutional review board–approved, single institution study and received magnetic resonance imaging of the liver with gadofosveset and gadobutrol. The prevalence of LGH for CRLMs and solid benign lesions was determined. Receiver operating characteristics curves were determined for the presence of LGH as a predictor of benignity. The utility of LGH to differentiate between CRLM and solid benign lesions using gadofosveset vs gadobutrol was compared using the generalized estimating equation.ResultsTwenty-five patients with 131 solid focal liver lesions were recruited. The prevalence of LGH of CRLMs was 11.2% (95% confidence interval [CI]: 0.5%–21.8%) with gadofosveset vs 63.7% (95% CI: 45.7%–81.7%) with gadobutrol. The area under the receiver operating characteristic curve for the presence of LGH as a predictor of benignity was 0.86 using gadofosveset vs 0.75 using gadobutrol. Both LGH (P = .003) and the interaction of contrast agent and LGH (P = .003) statistically significantly differentiated CRLM from benign lesions.ConclusionLGH is more common with extracellular than with intravascular contrast agents and is statistically significantly associated with benign lesions rather than metastases.     

Imaging manifestation of conventional and contrast-enhanced ultrasonography in percutaneous microwave ablation for the treatment of uterine fibroids

Objectives

To evaluate the image changes and the relationship between conventional ultrasonography and contrast-enhanced ultrasound (CEUS) in the perioperative period of microwave (MW) ablation for uterine fibroids; to guide clinical ablation therapy and evaluate the efficacy of MW.

Methods

Twenty-nine patients with 31 uterine fibroids were recruited in this study. All patients received conventional ultrasound as well as CEUS examination before, immediately after and 12–24 h after MW, in order to detect variations of echo and characteristics of blood supply. t-Tests were used to compare the hyperecho area on gray-scale ultrasound to immediately after ablation non-enhanced CEUS measurements, as well as to compare the immediately after ablation non-enhanced CEUS measurements to the 12–24 h after ablation measurements.

Results

Immediately after ablation, the average hyperecho area in gray-scale was 82.20 ± 72.32 cm³; the average non-enhancement area was 76.34 ± 70.63 cm³ by CEUS, showing a strong correlation (r = 0.997, P < 0.01) to the hyperecho area in gray-scale. The average non-enhancement area measured by CEUS immediately after ablation was 90.55 ± 74.41 cm³ and average 12–24 h after ablation was 98.29 ± 78.25 cm³; no statistically significant difference was detected between the two time points (P > 0.05).

Conclusions

Measurements made by hyperechoic range on gray-scale ultrasonography is strongly correlated to the no enhancement area by CEUS. The hyperechoic range on gray-scale image can represent the ablated area immediately after MW.     

健脾增免中药对小鼠免疫机能及力竭性游泳运动能力的影响

目的 :观察健脾增免中药对小鼠免疫机能、血睾、血红蛋白、力竭性游泳运动能力的影响。方法 :采用3 H -TdR掺入法、ELISA法 ,12 5I-睾酮测定等。结果 :服用健脾增免中药 4周后 ,高剂量组 (ISSIH)IL-2水平显著高于其它各组 (P <0 0 0 1 ) ,脾细胞数明显高于对照组 (CON) (P <0 0 5 ) ,淋巴细胞对刀豆蛋白 (ConA)的增殖反应显著高于对照组 (P <0 0 1 )及阳性药物组 (PD) (P<0 0 5 ) ;中剂量组 (ISSIM)的淋巴细胞对脂多糖 (LPS)的增殖反应显著高于其它各组 (P <0 0 1 ) ;PD组血清睾酮 (T)显著高于其它各组 (P <0 0 0 1 ) ,ISSIH组T明显高于CON组 (P <0 0 5 )。该中药对体重 (W)、血红蛋白(Hb)无明显影响 ,但可明显延长小鼠力竭性游泳时间。毒性实验表明该药物安全无毒。结论 :健脾增免中药有增强机体免疫力、提高血清睾酮水平和抗疲劳的作用     

口服枸橼酸铁铵在胆胰系MRI中的应用价值评价

目的:评价口服枸橼酸铁铵在胆胰系MRI中的应用价值。方法:对86例怀疑有胰胆管系统疾病的患者行口服枸橼酸铁铵前、后MRCP及常规胆胰系MRI,对服用对比剂前后MRCP图像质量、邻近脏器边缘分辨力及各序列上胃十二指肠腔与肝脏的对比噪声比进行自身对照研究,由资深放射科医生对两组图像进行评价,SPSS统计软件进行统计分析。结果:服用对比剂后TrueFISP及HASTE序列均显示胃、十二指肠腔内信号显著降低,形成阴性对比;而FL2D序列胃、十二指肠腔内信号增强,形成阳性对比;胃十二指肠腔内液体造成的背景高信号被完全抑制,单层法与多层法MRCP图像质量及邻近的肝胆胰等结构边缘分辨力均明显提高。结论:口服枸橼酸铁铵能明显提高胆胰系MRI的成像质量,对诊断胆胰系病变具有重要的临床应用价值。     

3.0 T磁共振正常肝、脾及肾R_2~*及T_2~*值的测量

目的 研究正常成人肝、脾、肾磁共振R_2~*和T_2~*值的正常范围.方法 对85例健康成人进行3.0T磁共振多回波R_2~*扫描,利用R_2~* map和T_2~* map分别测量肝、脾、肾实质及髓质、脊柱旁肌肉的T_2~* 和R_2~*值,再分别计算T_2~*、R_2~*值的肝/肌、肝/脾及脾/肌比值.分析性别、年龄对MR测量参数的影响.结果 男性及女性的脾R_2~* 值分别为(59.42±16.61)Hz和(51.17±15.49)Hz,具有统计学差异(P=0.020,t=2.514);男性和女性的肝/脾T_2~*比值分别为0.87±0.35、0.79±0.33,也具有明显差异(P=0.039,t=2.231);而其余测量参数在性别之间未见统计学差异(P>0.05).所有测量值与年龄之间也未见相关性(P>0.05).肝、脾的R_2~*值及T_2~*值均大于肌肉和肾脏(P<0.05),而肾皮质的T_2~*值为(37.88±15.55)ms,明显大于肾髓质的(28.10±9.01)ms(P=0.021,t=2.315);但R_2~*值在皮、髓质之间未见差异(P>0.05).肝、脾之间的R_2~* 和T_2~*值,以及3个比值(肝/肌肉、脾/肌肉及肾/肌肉)之间均未见统计学差异(P>0.05).结论 利用MR多回波R_2~*技术测得的正常成人肝、脾、肾的T_2~*、R_2~*值及其比值可为组织铁沉积及血氧水平的评估提供界定范围.     

呼吸导航与心电触发对兔肝脏磁共振成像应用比较

目的 比较1.5T磁共振扫描仪(Avanto)在呼吸导航技术和心电触发技术配合下对兔肝脏扫描成像质量的优劣.方法 分别应用呼吸导航技术和心电触发技术配合1.5T磁共振扫描仪对10只新西兰大白兔进行肝脏扫描,在保证图像平均信噪比(SNR)在1±0.1状态下,比较每种检查图像的优劣.扫描序列分别为TSE序列T_1加权、脂肪抑制T_1加权平扫及增强、T_2加权和脂肪抑制质子加权.结果 在心电触发配合下各个序列扫描图像质量均优于在呼吸导航下扫描所得图像,主要表现为前者受运动伪影干扰明显少于后者.结论 在SNR为1±0.1状态下.1.5T磁共振采用心电触发技术扫描兔肝脏所得图像质量优于采用呼吸导航时相同序列扫描所得图像,原因可能和兔的生理特点及2种不同门控方法的敏感度差异有关.     

DWI应用于兔VX2肝癌模型HIFU治疗的价值

目的研究兔VX2肝癌模型在高强度聚焦超声(HIFU)治疗前后肿瘤扩散的变化。材料与方法 45只兔VX2肝癌模型HIFU治疗前及HIFU治疗后1、3、7、14、21天5个观测点进行磁共振扩散加权成像(DWI),观察术后5个观测点肿瘤与术前表观扩散系数(ADC)值的变化,并与病理结果对照分析。结果兔VX2肝癌模型HIFU术后1、3、7、14、21天,ADC图上呈高信号的肿瘤病理为坏死组织,ADC值较术前相应区域升高(P<0.05);术后3、7、14、21天,ADC图上呈混杂信号的肿瘤,高信号区病理为坏死组织,ADC值较术前相应区域升高(P<0.05);而低信号区病理为肿瘤组织,ADC值较术前相应区域无差异性(P>0.05)。结论磁共振DWI ADC值能够准确反映兔VX2肝癌模型HIFU治疗后的肿瘤坏死组织及存活组织,并能够作为HIFU治疗兔VX2肝癌疗效的重要监测手段。     

门脉循环γ照相,B超和肝功能测定对肝硬化诊断的对比研究

本文应用门脉循环γ照相测定门脉分流指数，评估其在肝硬化诊断中的作用，并与Ｂ超和５组肝功能测定进行对比。研究表明，核素门脉分流指数随着慢性肝病的肝纤维化进程不断升高，正常人＜慢性肝炎＜代偿期肝硬化＜失代偿期肝硬化。本法敏感性为９２．３％，Ｂ超为７７．４％，肝功能总体为７０．９％；本法特异性为１００％，准确率９５．１％，阳性预测值１００％，阴性预测值８８．４％。说明门脉循环γ照相是安全、简便，早期诊断肝硬化的可靠方法。     

脂肪肝背景下肝局灶性病变检出率的比较影像学研究

目的 比较超声(uS)、CT、MRI在脂肪肝背景下肝局灶性病变的检出率.方法 回顾性分析129例同时做过US、CT、MRI的肝局灶性病变患者的影像表现,以临床影像综合诊断为参考标准,将其分为脂肪肝组(41例)和非脂肪肝组(88例),以比较两组分别用US、CT、MRI3种检查方法对肝内局灶性病变数目的检出率.结果 US对脂肪肝组和非脂肪肝组肝局灶性病变的检出率分别为52.50％、70.97％(P=0.003);CT对两组病变的检出率分别为70％、85.71％ (P =0.002);MRI对两组病变的检出率分别为88.75％、87.56％(P=0.780).结论 MRI对肝局灶性病变的检出率最高且不受脂肪肝背景的影响,而US和CT在脂肪肝背景下对肝脏局灶性病变的检出率均受到影响.