犬正常腰椎间盘的动态增强MRI特征

【摘要】 目的：研究犬正常腰椎间盘的动态增强MRI特点。方法：选取2岁龄健康杂种犬6只,麻醉后,对腰椎进行常规MRI T1WI、T2WI及X线片检查,排除退变或畸形腰椎间盘。MRI常规扫描结束后,静脉注射对比增强剂（钆喷酸葡胺）,并在注射增强剂后2min、5min、10min、30min、1h、1.5h、2h、2.5h、3h、3.5h、4h行T1WI扫描。动态扫描结束后,选取每个腰椎间盘的上下椎体、上下终板、上下周围髓核及中央髓核为感兴趣区,分别测量增强前及注射增强剂后各时间点腰椎各感兴趣区的信号强度值,计算增强率,绘制时间-信号曲线及峰值出现时间,观察感兴趣区的信号变化特点。结果：注射对比增强剂后5min、1h、1h、1.5h,正常犬腰椎椎体、终板区域、周围髓核、中央髓核分别达到第1个峰值,信号增强率分别为（172.7±14.6）%、（197.6±39.5）%、（234.2±56.3）%、（253.5±37.3）%。注射对比增强剂后3.5h各区域信号强度达到达到第2个峰值,信号增强率分别为（122.5±18.2）%、（164.7±36.0）%、（200.6±23.6）%、（220.9±15.2）%。各感兴趣区的第2个峰值均低于第1个峰值,差异均有统计学意义（P<0.05）。结论：犬正常腰椎间盘的动态增强MRI表现具有“终板延迟”现象及“双峰”特征。     

近红外荧光分子成像在裸鼠卵巢癌移植瘤模型中的应用

目的观察近红外荧光吲哚七甲川菁染料IR-783在裸鼠卵巢癌移植瘤模型中对肿瘤的特异靶向作用。方法采用卵巢癌细胞株SKOV-3创建卵巢癌裸鼠模型,将IR-783注入15只裸鼠体内,之后采用MaestroTM2.10活体成像系统分别在30min、1h、6h、24h、48h观察染料的肿瘤特异靶向作用及其在荷瘤裸鼠体内的代谢分布。结果图像分析软件测得肿瘤平均体积(16.34±3.35)cm3,游标卡尺测得为(15.56±1.85)cm3(P=0.79);注射后30minIR-783主要分布于肝脏、心脏、肾脏和肺,6h肿瘤荧光强度达到峰值,注射后48h肿瘤部位仍存在少量荧光信号。结论近红外荧光染料IR-783可无创、准确、直观地反映裸鼠卵巢癌移植瘤的生长。     

肝癌围手术期肝脏储备功能检测进展——(文献综述)

正确把握肝癌围手术期肝脏储备功能已成为肝外科的重要课题,本文从肝脏能量代谢,药物代谢、蛋白质代谢、氧代谢和肝有效血流量、功能肝切除率、肝纤维化率、肝细胞膜糖蛋白受体量等方面介绍了评价肝储备功能的一些新方法,这些方法在一定程度上能从各个侧面反映出肝脏功能的储备量,比 Child 氏分级法更精确,具有临床实用性,使肝癌围手术期处理具有预见性。     

菲立磁增强磁共振在肝脏局灶性病变中的诊断作用

目的 研究菲立磁增强磁共振在肝脏局灶性病灶中的灵敏性和特异性。方法 对54例临床或其他检查怀疑肝脏占位病变的病人进行平扫、菲立磁增强扫描,分析增强前后图像上病灶和肝脏的信号强度的变化。结果 平扫T2W像上,原发性肝癌和肝转移瘤信号稍高于肝脏或为中等信号。肝硬化再生结节为等信号或稍低信号。菲立磁增强后原发性肝癌和转移瘤显示为中等或明显高信号;肝硬化再生结节仍显示为等或低信号。结论 菲立磁增强磁共振对肝脏局灶性病变有较高的特异性和敏感性。     

3.0T磁共振3DF AME动态增强序列对肝脏局灶性病变的诊断价值

目的：探讨3.0T磁共振3D FAME动态增强序列对肝脏局灶性病变的诊断价值。方法：对65例肝脏局灶性病变（原发性肝细胞癌30例,胆管癌4例,转移瘤8例,肝血管瘤12例,肝囊肿11例）相继进行MR常规平扫及3D FAME序列多期动态增强扫描,包括肝动脉期、门静脉期、平衡期及延迟期,观察病灶各期的强化特征,并利用动态强化自动分析软件及时间-信号强度曲线分析各种病变的曲线类型。结果：不同的肝脏局灶性病变具有特征性的强化方式,时间-信号强度曲线较客观反映不同病变的血流动力学特性。肝细胞癌的时间-信号强度曲线分为3种类型：Ⅰ型（速升速降）、Ⅱ型（速升缓降）、Ⅲ型（缓升缓降）,30例肝细胞癌中60.0%（18/30）表现为Ⅰ型曲线类型,26.7%（8/30）表现Ⅱ型曲线类型,13.3%（4/30）表现Ⅲ型曲线类型。肝血管瘤的动态增强曲线分为2种类型：Ⅰ型（缓升平坦型）、Ⅱ型（速升平坦型）,12例血管瘤中66.7%（8/12）表现为Ⅰ型曲线类型,33.3%（4/12）表现Ⅱ型曲线类型。4例胆管癌动态增强曲线为缓慢上升型。转移瘤表现为2种强化方式,2例（25.0%）表现为早期周边环状强化,6例（75.0%）表现为轻度强化。11例肝囊肿增强扫描各期均无强化。结论：3D FAME动态增强序列有助于肝脏局灶性病变的定性诊断。     

MRI VIBE序列动态增强对肝脏局灶性病变的诊断价值

目的 探讨MRI快速梯度回波的三维容积式插入法屏气检查（three-dimensional volumetric interpolated breath—hold examination，3D-VIBE）序列动态增强扫描对肝脏局灶性病变的诊断价值。方法 对51例CT及US检查未明确诊断的肝脏局灶性病变病例相继进行常规自旋回波（spin—echo，SE）T2W、2DGRET1W平扫和3D-VIBE序列的钆剂增强多期（动脉早期、动脉晚期和门静脉期）扫描，分别观察各种病灶在平扫和多期增强扫描各时相的信噪比（SNR）、对噪比（CNR）、信号强度和强化规律，并与临床、手术病理结果等对照。结果 各种类型的肝脏局灶性病变的SNR和CNR，信号强度及强化特点存在不同程度的差异。结论 MRI3D-VIBE序列动态增强对肝脏各种局灶性病变具有重要的定性诊断及鉴别诊断价值。     

P选择素在肾病综合征并发深静脉血栓中的作用及犬血栓模型磁共振分子成像观察

目的 观察P选择素在肾病综合征（NS）并发深静脉血栓形成（DVT）中作用，探讨P选择素靶向对比剂及分子磁共振成像（MRI）在DVT犬模型早期诊断应用的可行性。 方法 （1）选择我院2005年至2006年间住院NS患者41例，根据核素深静脉造影检查有无伴发DVT，再分为DVT组和无DVT组，检测患者血中P选择素含量。（2）选择健康成年毕格犬，建立DVT模型，并按造模即刻、1 h、3 h采血并取静脉损伤节段，行血管组织和血中P选择素含量检测。（3）利用研制的抗P选择素单抗，制成P选择素靶向对比剂，结合体外犬静脉损伤节段血管MRI，进行犬活体内观察。 结果 （1）NS患者血P选择素水平较健康组显著增高（P < 0.01），DVT组又较无伴DVT组明显增高（P < 0.01）。（2）模型犬血P选择素水平较对照犬显著增高（P < 0.05），且于受损血管内膜及血栓形成部位明显表达。（3）制备的MRI对比剂，体外可明显增强犬离体受损血管与血栓部位显像信号。体内于犬静脉损伤局部注射对比剂30 min，MRI即显示高于周围肌肉显影的血管信号；1 h可见附壁血栓增强信号；至3 h随血栓形成增大而持续强化，实验组对比度噪声比 （CNR）值与对照组比较，差异有统计学意义（11.51±2.32比2.71±0.86，P < 0.01），且显示了与P选择素表达一致的信号强化效果。另从犬损伤部位远心端注射对比剂30 min至1 h，也显示了上述成像效果；2 h至4 h血栓信号由明显上升渐见趋缓，延迟24 h信号强度减弱，实验组CNR值与对照组间差异也有统计学意义（10.40±2.15比1.93±0.57，P < 0.01）。此外，该对比剂对实验犬的生命体征及心、肺、肝、肾等脏器均无明显影响。 结论 P选择素参与NS合并DVT。利用P选择素单抗MRI对比剂，可在活体内早期定位显像及反映血栓形成状态，为DVT早期诊断提供了一种可行方法。     

不同细胞因子体外诱导骨髓间充质干细胞定向肝细胞分化的研究

肝脏损伤修复过程是一个多步骤、多因子、涉及多种信号相互作用的精确而有序的复杂过程，肝脏损伤后骨髓间充质干细胞（BMSCs）参与肝脏再生就是以上因素综合作用的结果。我们模拟体内多种细胞因子协同作用进行体外诱导，观察体外不同细胞因子对BMSCs定向肝细胞分化率的影响，探讨提高诱导分化率的最佳条件。     

MRI检测胶原进行肝脏纤维化分期的方法建立

目的检测和比较多种影像学方法在肝脏纤维化分期诊断中的应用。方法构建CCl4诱导的小鼠肝脏纤维化模型,用钆为基础的MRI探针EP-3533团注,在处理前后用多种影像学方法进行诊断,并对结果进行比较。结果在EP-3533团注增强信号后,肝脏肌肉对比噪声比发生明显变化,并且与肝脏胶原沉积程度呈现明显正相关;其变化也与肝脏纤维化Ishak评分呈现正相关;但是其他影像学方法所得参数不能精确反映肝脏纤维化程度。结论我们建立了基于肝脏胶原影像学进行肝脏纤维化分期诊断的小鼠模型,为更好的检测肝纤维化病人病情提供了更加准确的方法。     

磁共振间质淋巴造影诊断前列腺癌盆腔淋巴结转移的安全性和可行性研究

目的 评估欧乃影介导的磁共振间质淋巴造影诊断前列腺癌盆腔淋巴结转移的可行性和安全性。方法 对30例确诊为前列腺癌的患者于双侧腹股沟及阴囊根部皮下真皮层内注射欧乃影,通过三维增强磁共振淋巴造影增强扫描,采用兴趣区法测量造影后各组淋巴结的信号强度,绘制不同延迟时间引流区域淋巴结信号强度的时间-信号强度曲线,定性和定量分析以评估淋巴管及淋巴结增强造影效果。结果 皮下注射欧乃影后,欧乃影迅速吸收进入淋巴系统,引流区域各组淋巴结显示清晰。皮下注射对比剂9min后腹股沟淋巴结信号强度达到峰值,而髂内、外淋巴结则于注射后11min达到最大信号强度;各组淋巴结间的峰值信号强度有明显差异。常规MRI扫描辨认淋巴结19枚,欧乃影静脉注射增强扫描辨认淋巴结21枚,磁共振间质淋巴造影共辨认淋巴结162枚。常规扫描辨认可疑转移淋巴结6枚,欧乃影静脉注射增强扫描辨认可疑转移淋巴结6枚,磁共振间质淋巴造影辨认可疑转移淋巴结26枚。常规和增强磁共振不能检出的〈1.0cm的转移淋巴结可通过磁共振间质淋巴造影检出。结论 经腹股沟及阴囊根部皮下注射欧乃影磁共振间质淋巴造影术诊断前列腺癌盆腔淋巴结转移安全、可行,该注射途径对盆腔淋巴结的显影更加全面。     

Cervical pedicle screw guiding jig,an innovative solution

Pedicle screws are one the commonest used modality in spinal instrumentation. However, the method of pedicle screw fixation in cervical spine as compared to thoracic and lumbar spine is still technically demanding because it carries the risk of catastrophic damage to the surrounding neurovascular structures We have utilized virtual planning and 3D (3-dimension) printing to develop a patient specific jig to guide the accurate placement of pedicle screws. A patient with bifacetal dislocation C7 over D1 classified as flexion-distraction injury type 3 who was planned for decompression and fusion by posterior instrumentation at C6, C7, D1 and D2 was selected. A CT scan with 1?mm cuts was used to produce DICOM images of the same. Using these DICOM images virtual planning was done on MIMICS and 3 MATICS software to create patient specific jigs. These jigs were then 3D printed using a 3D printer and used for accurate placement of pedicle screws intra-operatively after adequate sterilization. Our procedure is low cost but high technology based. It is simple, accurate, and very cost effective. The technology transfer is very easy and can be adopted easily.     

3.0T磁共振下肢动脉3D CE-MRA对比剂用量

目的探讨使用3.0TMR仪并行采集快速扫描技术进行腹部至下肢动脉三维对比增强磁共振血管成像（3DCE-MRA）中减少对比剂用量的可行性。方法 30例怀疑下肢动脉狭窄的患者按就诊顺序平均分为A、B两组,使用3.0T磁共振扫描仪行腹部至下肢动脉3DCE-MRA,钆浓度为0.5mmol/ml,A、B两组的使用剂量分别为40ml和20ml。比较两组患者三站图像最大密度投影（MIP）图像质量及原始增强图像末端腹主部动脉、股动脉及腘动脉的信号强度（SI）、信噪比（SNR）和对比噪声比（CNR）。结果 A、B两组所有三站动脉的MIP图像质量均符合诊断要求,差异无统计学意义（P〉0.05）,B组小腿静脉污染比A组略轻,但差异无统计学意义;A、B两组末端腹主部动脉的SI、SNR及CNR差异无统计学意义。A组股动脉及腘动脉的SI、SNR及CNR均略高于B组,差异有统计学意义（P〈0.05）。结论采用3.0TMR仪行腹部至下肢动脉3DCE-MRA,使用20ml钆对比剂获得的图像质量可满足临床诊断。     

颈动脉小剂量对比剂三维增强磁共振血管成像

目的探讨使用小剂量对比剂进行颈动脉三维增强磁共振血管成像（3DCE-MRA）的可行性。方法将50例疑似颈动脉狭窄的患者分为三组：A组20例,B组10例,C组20例,均行颈动脉3DCE-MRA检查,所用钆对比剂（钆浓度0.5mmol/ml）剂量分别为20ml、15ml和12ml。比较三组患者颈动脉三维最大密度投影（MIP）重建后的图像质量及原始图像颈动脉的信号强度（SI）、信噪比（SNR）和对比噪声比（CNR）。结果三组患者颈部动脉的MIP图像质量差异无统计学意义（P〉0.05）;颈动脉SI分别为779.62±127.97、834.30±147.27、797.28±145.07（P=0.600）;SNR分别为152.45±26.83、175.98±31.49、159.74±31.82（P=0.137）;CNR分别为139.17±25.77、162.78±30.07、146.70±31.78（P=0.124）。结论使用小剂量（12ml）对比剂可行颈动脉3DCE-MRA。     

The protective effect of intratympanic dexamethasone on cisplatin-induced ototoxicity in guinea pigs.

OBJECTIVE: The purpose of this study was to investigate the effectiveness of intratympanic dexamethasone injection as a protection agent against cisplatin-induced ototoxicity. STUDY DESIGN AND SETTING: The four groups of guinea pigs were injected as follows: 1) cisplatin, 2) intratympanic dexamethasone, 3) cisplatin following intratympanic dexamethasone, and 4) cisplatin after intratympanic saline. Before and 3 days following injections, the ototoxic effect was measured with distortion product otoacoustic emissions (DPOAEs). RESULTS: The DPOAEs amplitudes and signal-to-noise ratio (SNR) values at 1 to 6 kHz frequencies for group 1 animals after injections significantly decreased over those before injections (P < 0.05). In group 2, there were no significant differences in DPOAE amplitude and SNR values between before and after intratympanic dexamethasone injections (P > 0.05). Considering group 3, there were also no significant differences in DPOAEs amplitudes and SNR values before and after of dexamethasone and cisplatin injections (P > 0.05). CONCLUSIONS: Intratympanic dexamethasone injection did not cause any ototoxic effect; in contrast, it might have a significant protective effect after cisplatin injection.     

A novel technique for three-dimensional reconstruction for surgical simulation around the craniocervical junction region

Performing surgeries on the craniocervical junction presents a technical challenge for operating surgeons. Three-dimensional (3D) reconstruction and surgical simulation have improved the efficacy and success rate of surgeries. The aim of this study was to create a 3D, digitized visible model of the craniocervical junction region to help realize accurate simulation of craniocervical surgery on a graphic workstation. Transverse sectional anatomy data for the study were chosen from the first Chinese visible human. Manual axial segmentation of the skull base, cervical spine, cerebellum, vertebral artery, internal carotid artery, sigmoid sinus, internal jugular vein, brain stem, and spinal cord were carried out by using Photoshop software. The segmented structures were reconstructed in 3 dimensions with surface and volume rendering to accurately display 3D models spatially. In contrast to conventional 3D reconstruction techniques that are based on computed tomography and magnetic resonance imaging Digital Imaging and Communications in Medicine (DICOM) inputs and provide mostly osseous details, this technique can help to illustrate the surrounding soft tissue structure and provide a realistic surgical simulation. The reconstructed 3D model was successfully used in simulating complex procedures in the virtual environment, including the transoral approach, bone drillings, and clivus resection.     

基于CT的直肠癌新辅助化疗后病理完全缓解预测模型的初步探索--DACCA数据库的联合研究

目的初步探索基于CT影像组学特征建立的决策树模型对局部进展期直肠癌(LARC)患者行单纯新辅助化疗疗效的评估价值。方法回顾性分析四川大学华西医院肠癌数据库(DACCA)中2016年10月至2019年3月期间符合本研究纳入和排除标准的244例单纯新辅助化疗后行根治性手术的LARC患者的临床及CT检查的DICOM格式图像资料。利用ITK-SNAP软件选取肿瘤最大层面并对影像感兴趣区域进行勾画。使用计算机随机分配软件将200例患者纳入训练集,44例患者纳入测试集。利用MATLAB软件读取DICOM格式图像并提取和筛选影像组学特征,进而用降维后得到的影像组学特征进行机器学习并建模。通过绘制受试者操作特征曲线并计算曲线下面积(AUC)来评估模型预测单纯新辅助化疗后对病理完全缓解(pCR)的效能。结果根据术后病理肿瘤退缩分级(TRG)患者被分为pCR组(TRG0,28例)和非pCR组(TRG1~TRG3,216例)。最终获得13个影像组学特征即6个灰度特征(均值、方差、标准差、偏离度、峰态、能量)、3个纹理特征(对比度、相关性、同质化)及4个形状特征(边界长度、直径、面积、形状参数)。基于CT的决策树模型预测LARC患者新辅助化疗后效果的AUC值为0.772 [95%CI(0.656,0.888)],对于非pCR的预测准确度较高(97.2%),但对于pCR的预测准确度较低(57.1%)。结论在本次初步探索中,基于CT的决策树模型在判断LARC患者新辅助化疗后pCR上较同质研究的预测效能低,通过分析后将进一步从优化算法、继续拓展数据集、挖掘更多影像组学特征值等方面优化模型,从而最终实现pCR的精准预测。     

低注射速率、低剂量对比剂3D-DSA脑血管造影

目的探讨低注射速率、低剂量对比剂3D-DSA脑血管造影的的可行性。方法连续收集疑似动脉瘤患者51例行3D-DSA脑血管造影,选择DynaCT 5sDSA成像,均采用非离子型对比剂碘普罗胺注射液(370mgI/100ml),导管尖端均位于平枢椎水平,按对比剂注射速率随机分为A组(1.5ml/s,n=18)、B组(2.0ml/s,n=18)、C组(3.0ml/s,n=15)。计算C臂锥形束CT轴位图像颈内动脉岩段(C2段)和眼段(C6段)、大脑中动脉水平段(M1段)、大脑前动脉水平段(A1段)的噪声、SNR及CNR,由2名医师对连续减影图像、VR及MIP重组图像的图像质量进行评分后行统计学分析。结果 B、C组与A组噪声的差异均无统计学意义(P均0.05)。A组与B组比较,M1、A1段的SNR、CNR差异均有统计学意义(P均0.05),C2、C6段SNR、CNR差异均无统计学意义(P均0.05);A组与C组比较,C2、C6、M1及A1段的SNR、CNR差异均有统计学意义(P均0.05)。3组间大脑中动脉、大脑前动脉连续减影图像及VR、MIP图像的图像质量主观评分差异均无统计学意义(P均0.05),均可充分显示颅内动脉瘤情况。结论 3D-DSA脑血管造影中实施个性化低注射速率、低剂量对比剂注射方案可行,能够降低患者碘摄入量及血管破裂出血风险。     

动物奶油低密度CT造影剂的制备及其在消化道出血中的应用

目的 利用简单易得的原料制备一种新型的胃肠道低密度造影剂,从而实现对消化道出血的准确显示及定位。方法 以可食用淡奶油和黄原胶为原料,在约7℃的温度条件下,经搅拌机以160~260转/分搅拌约5分钟后制得低密度造影剂。然后在不同温度下测试其稳定性、在CT扫描图像上观察其均匀性并测量CT值、比较其与血凝块的密度差异,最终利用猪小肠、盐水袋和混入肝素的血浆模拟消化道出血,比较其与水对出血灶的显示及定位效果,从而探究该低密度造影剂在消化道出血中的应用价值。结果 该低密度造影剂在室温（25℃）、冰箱冷藏室温度（2℃~4℃）下均表现出良好的稳定性;由CT扫描图像观察到其均匀性较高,测得CT值范围为-500~-700 Hu,与血凝块的密度差异明显;与水相比,该低密度造影剂对出血灶的显示、定位有明显的优势。结论 以可食用淡奶油和黄原胶制得的胃肠道低密度造影剂具有良好的稳定性和较高的均匀性,可以准确显示并定位出血灶,对于消化道出血的诊断具有重要的临床价值。     

Automated registration of intraoperative CT image data for navigated skull base surgery.

OBJECTIVES: With a new intraoperative computed tomography (CT) imaging system, patient-to-image registration without any invasive registration markers is possible. Furthermore, registration can be performed fully automatically. The accuracy of this method for skull base surgery was investigated in this study. METHODS: We employed a phantom study design. A phantom skull was equipped with 33 target markers in the regions of the anterior and lateral skull base. CT image data were acquired with an intraoperative CT suite. Image data were transferred as DICOM data to the navigation system, and registration was performed automatically. For registration, the position of the patient and the position of the CT gantry were monitored in the imaging process, using the infrared camera of a navigation system. Using the pointing device of the navigation system, the target markers were identified. The accuracy was measured as the spatial difference of the target markers in image space and on the phantom. RESULTS: Accuracy was always sufficient for image-guided surgery of any region of the skull base, with an average target registration error of below 1.2 mm. In contrast to traditional non-invasive registration methods, there was no difference in registration accuracy between the anterior skull base and the lateral skull base. CONCLUSIONS: Fully automated registration based on a tracked CT gantry is a robust and accurate registration method for skull base surgery.     

No evidence for blood flow redistribution with isoflurane or halothane during acute coronary artery occlusion in fentanyl-anesthetized dogs

The present study examines the postulate that isoflurane, in contrast to halothane, causes redistribution of blood flow away from an ischemic myocardial region through vasodilation of adjacent normally perfused myocardium. The study was performed in open-chest dogs anesthetized with fentanyl; ischemia was induced by occlusion of the left anterior descending coronary artery. At 0.6% alveolar concentration, isoflurane increased transmural blood flow to 125% of control values (P less than 0.05) in the normal region without concomitant changes in blood flow to the ischemic region or in the endocardial/epicardial flow ratio in the ischemic region. The evidence excludes either transmural steal or regional redistribution phenomena. Myocardial blood flow variables returned to control values at 1.8% isoflurane, and no blood flow redistribution effects were evident. In contrast, whereas halothane 0.4% caused no significant effect on myocardial blood flows, an alveolar concentration of 1.2% decreased transmural blood flow to normally perfused left ventricle to 70% of control (P less than 0.05). Regional myocardial oxygen consumption in the normal and ischemic areas decreased at higher alveolar concentrations and was unchanged at the lower concentrations for both agents. Myocardial lactate production from the ischemic region was unchanged with either agent, suggesting that, in terms of metabolic changes, neither agent worsened ischemia during sustained occlusion of the left anterior descending coronary artery. The present data show no evidence for worsening of myocardial ischemia with either isoflurane or halothane. Isoflurane causes a relatively greater increase in perfusion compared to myocardial oxygen consumption of normally perfused myocardium; nevertheless, sufficient coronary vascular reserve remains in the native collateral circulation so that myocardial metabolic supply-and-demand relationships during ischemia are not further compromised.