肝脏的三维可视化及切除术模拟研究

从CT断层数据提取出肝体、动脉、静脉、门静脉和肿瘤,采用轮廓拼接技术重建出肝脏和内部管道,然后利用交互式切割工具对其进行模拟手术切割,开发出一个基于PC的肝脏可视化与模拟切割系统。系统以V isual C++为开发工具,结合可视化类库VTK,用户可通过图形界面调节不透明值并观察肝脏及其内部管道的空间结构,同时实现交互式调节切割平面以模拟肝脏肿瘤切除术。切割面的动态调节与模拟肝切除术的效果图表明针对具体病人的CT数据进行重建可以直观地展示其三维结构,通过切割的模拟有利于术前规划和选择恰当的手术方位以减少对肝实质和血管的伤害。     

头部CT三维重建在鼻窦内翻性乳头状瘤术前规划的应用

目的　通过基于头部CT的三维重建技术,对复杂的内翻性乳头状瘤进行手术规划,为临床推广应用提供参考。　方法　本实验选取一名男性患者,65岁,体重70 kg,身高170 cm,无头部外伤史、手术史、颅脑疾病家族史。行头部CT平扫,排除脑组织器质性疾病。已和患者签署知情同意书。将头部CT图像通过逆向工程软件Mimics 15.0建立三维立体模型,将手术仿真成功的三维模型组件在3-Matic 7.0进行测量,对鼻窦内翻性乳头状瘤患者进行手术规划设计及术后随访观察。　结果　建立了与CT图像测量结果一致的颅骨、鼻窦及肿瘤的三维立体模型;建立了与手术入路一致的仿真鼻部通道的三维模型;确定了复杂鼻部肿瘤的手术方案及预后评估。术中切除肿瘤组织测量结果为X轴最大值为64.78 mm,Y轴71.21 mm,Z轴86.46 mm,总体积为58.88 ml,其形态、大小与术前三维重建测量分析结果基本一致。　结论　根据三维立体模型分析得出的数据设计手术方案,有助于顺利完成手术,对个体化鼻窦肿瘤手术设计具有重要的临床指导意义。     

3D可视化联合3D打印在肝癌大部分肝切除术中的应用

目的:探讨基于3D重建系统软件的肝体积评估和3D可视化、3D打印辅助肝癌大部分肝切除术的应用价值。方法:将符合要求的肝癌行大部分肝切除术患者46例,随机分为观察组和对照组,每组23例。观察组（3D组）患者采用3D可视化技术和3D打印模型进行围手术期规划和指导,主要基于肝体积评估等术前规划和3D可视化分析、3D打印指导肝切除术手术;对照组（CT组）患者采用传统CT资料进行肝体积评估等术前规划、CT二维影像资料指导肝切除术。观察指标:虚拟切除肝体积、实际切除肝体积、残肝体积、标准残肝体积比、手术时间、术中出血量、术后并发症、患者满意度等。结果:3D组与CT组虚拟切除肝体积与实际切除肝体积、虚拟（术前）残肝体积与实际（术后）残肝体积比较,差异均无统计学意义（P>0.05）,相关性分析显示虚拟切除肝体积与实际切除肝体积呈正相关性（3D组r=0.990, P<0.001;CT组r=0.943, P<0.001）。3D组与CT组虚拟残肝体积比、实际残肝体积比比较,差异均无统计学意义（P>0.05）,且相关性分析显示呈正相关性（3D组r=0.931, P<0.001;CT组r=0.902, P<0.001)。3D组术中出血量少于CT组（P<0.05）,3D组患者满意度优于CT组（P<0.05）。两组患者手术时间、术后并发症等比较,差异无统计学意义（P>0.05）。结论:3D重建系统软件和CT软件在评估肝癌大部分肝切除术的肝体积均可行、准确,具有很好的临床应用价值,有助于肝切除术的安全实施。3D可视化联合3D打印在围手术规划可减少手术出血,提高患者满意度,在临床应用中具有潜在优势。     

A technique for noninvasive respiratory gated radiation treatment system based on a real time 3D ultrasound image correlation: a phantom study

This paper proposes a new respiratory gated radiation treatment system that allows real-time tumor localization while avoiding invasive operation to a patient. The proposed system employs a three-dimensional (3D) ultrasound device, a 3D digital localizer, and a real-time image processing system. At the planning time, CT and 3D ultrasound reference data are simultaneously acquired under a breath-hold condition. At the treatment time, ultrasound data on three orthogonal planes are acquired and transferred to the image processing system on a real-time basis. Subsequently, normalized image correlation indices using the reference and the real-time ultrasound data are calculated for the three orthogonal planes after performing real-time coordinate transform using the 3D digital localizer attached to an ultrasound probe. Prior to the system execution, the coordinate transform matrices are partially calculated using an ultrasound calibration phantom and the 3D digital localizer. A trigger pulse to a linac can be generated when the normalized image correlation index exceeds a predetermined threshold level. Experiments have been carried out using a moving-target phantom that simulates a patient respiratory motion. We have observed that the variation of the calculated real-time correlation index synchronizes with the periodical motion of the moving-target, suggesting that real-time localization for a moving tumor is feasible with the proposed system.     

Rh(D)血型不合的肝移植临床分析

背景：血型不合器官移植可能发生严重的排斥反应、移植物抗宿主病及溶血反应。 目的：回顾分析Rh(D)阴性肝癌患者接受Rh(D)阳性供肝移植的方法及疗效,并结合文献复习探讨该方法的可行性。 方法：1 例Rh(D)阴性肝癌患者接受Rh(D)阳性供肝移植过程中,应保证供肝的良好灌洗,尽量减少出血,缩短手术时间,移植中移植后输注适量的异型红细胞及血浆。 结果与结论：肝移植后,受者肝功能恢复正常,未发生急慢性排斥反应及输血相关并发症。随访1年,受者存活良好。说明在无合适供体的情况下,只要供肝得到充分灌洗、移植中控制出血、移植后采用合理的免疫抑制方案,Rh(D)阴性肝病患者移植Rh(D)阳性供肝可达到良好效果。     

Origin of adenocarcinoma in a transplanted liver determined by microsatellite analysis

Inadvertent transmission of neoplastic cells from an organ donor can occur at the time of transplantation. Determination of recipient versus donor origin of a tumor is crucial for patient management. This report illustrates the use of microsatellite (MS) analysis to determine the origin of adenocarcinoma arising in a liver transplant. The study patient was a 42-year-old male who had received a liver transplant for hepatitis C and alcohol-related cirrhosis. At the 1-year follow-up visit, a 1.5-cm liver mass was identified during routine ultrasound of the vascular anastamoses. A liver biopsy showed a moderately differentiated adenocarcinoma. Tumor, donor, and recipient DNA were isolated from the paraffin-embedded liver biopsy, pretransplant donor liver biopsy, and the explant liver tissue, respectively. MS analysis was performed by polymerase chain reaction using 5 markers: D5S346, ACTC, D2S123, D18S34, and TP53. The allelic patterns of tumor DNA were identical to those of donor DNA and were distinct from the DNA profile of the recipient. The use of MS analysis clearly established that the adenocarcinoma was of donor origin.     

基于3D MRI与CT建模的3D打印模型在骶骨肿瘤术前规划中的应用

目的 探索基于3D MRI与CT建模的3D打印模型在骶骨肿瘤术前规划中的应用价值.方法 回顾性分析华中科技大学同济医学院附属同济医院2015年6月至2020年6月收治的接受一期后路肿瘤切除+腰椎-骨盆重建术的骶骨肿瘤患者20例,分为两组,每组10例.其中模型组采用3D MRI与CT建模的3D打印模型辅助术前规划,常规组...     

通过多种技术方法的综合使用优化全脑全脊髓照射技术

全脑全脊髓照射是针对多种癌症的治疗流程中一个重要的组成部分。为了达到最佳的肿瘤控制,需要在靶区体积的确定、重要正常组织的保护、剂量均匀度、射野交接区域以及剂量测定方面都特别注意。本文提出了一种适用于大多数治疗情况的优化了的全脑全脊髓照射治疗技术,以一名因生殖细胞瘤需接受全脑全脊髓照射治疗的17岁男性患者为例,通过综合使用半野衔接技术、扩展半影的射野衔接技术和多叶光拦子野技术,制定临床可实行的治疗计划,大大改善了脊髓靶区内的剂量均匀度,将剂量最大点由处方剂量的124%降低到处方剂量的108%。对仿真人体模进行的实际测量值与计算值的比较表明,测量值和计算值是基本一致的。     

基于3D卷积神经网络的肝脏自动分割方法

原发性肝脏恶性肿瘤是我国高发且危害极大的恶性肿瘤。肝脏手术（如肿瘤切除、活体肝移植等）是各种常见肝脏良恶性疾病的主要治疗方法之一。从医学影像中将肝脏组织准确地分割出来,是计算机辅助肝脏疾病诊断与手术规划中一个基础且至关重要的步骤。针对肝脏分割的特异性及分割难点,提出3D卷积神经网络（3DCNN）肝脏自动分割算法模型。3DCNN基于对体数据的训练能很好地学习到肝脏图像平面与空间信息。通过将深度监督机制无缝地整合到3DCNN中,能够有效解决梯度消失或爆炸的优化问题,加快收敛速度的同时提高分辨能力。最后,将初始分割结果作为先验信息,采用基于多星凸约束的图割算法做进一步的分割优化。实验结果表明该分割模型能够将肝脏组织从腹部CT图像中精确分割。     

Geometric uncertainty of 2D projection imaging in monitoring 3D tumor motion

The purpose of this study was to investigate the accuracy of two-dimensional (2D) projection imaging methods in three-dimensional (3D) tumor motion monitoring. Many commercial linear accelerator types have projection imaging capabilities, and tumor motion monitoring is useful for motion inclusive, respiratory gated or tumor tracking strategies. Since 2D projection imaging is limited in its ability to resolve the motion along the imaging beam axis, there is unresolved motion when monitoring 3D tumor motion. From the 3D tumor motion data of 160 treatment fractions for 46 thoracic and abdominal cancer patients, the unresolved motion due to the geometric limitation of 2D projection imaging was calculated as displacement in the imaging beam axis for different beam angles and time intervals. The geometric uncertainty to monitor 3D motion caused by the unresolved motion of 2D imaging was quantified using the root-mean-square (rms) metric. Geometric uncertainty showed interfractional and intrafractional variation. Patient-to-patient variation was much more significant than variation for different time intervals. For the patient cohort studied, as the time intervals increase, the rms, minimum and maximum values of the rms uncertainty show decreasing tendencies for the lung patients but increasing for the liver and retroperitoneal patients, which could be attributed to patient relaxation. Geometric uncertainty was smaller for coplanar treatments than non-coplanar treatments, as superior-inferior (SI) tumor motion, the predominant motion from patient respiration, could be always resolved for coplanar treatments. Overall rms of the rms uncertainty was 0.13 cm for all treatment fractions and 0.18 cm for the treatment fractions whose average breathing peak-trough ranges were more than 0.5 cm. The geometric uncertainty for 2D imaging varies depending on the tumor site, tumor motion range, time interval and beam angle as well as between patients, between fractions and within a fraction.     

Precise modelling of the eye for proton therapy of intra-ocular tumours

A new method is described that allows precise modelling of organs at risk and target volume for radiation therapy of intra-ocular tumours. The aim is to optimize the dose distribution and thus to reduce normal tissue complication probability. A geometrical 3D model based on elliptic shapes was developed that can be used for multimodal model-based segmentation of 3D patient data. The tumour volume cannot be clearly identified in CT and MR data, whereas the tumour outline can be discriminated very precisely in fundus photographs. Therefore, a multimodal 2D fundus diagram was developed, which allows us to correlate and display simultaneously information extracted from the eye model, 3D data and the fundus photograph. Thus, the connection of fundus diagram and 3D data is well-defined and the 3D volume can be calculated directly from the tumour outline drawn onto the fundus photograph and the tumour height measured by ultrasound. The method allows the calculation of a precise 3D eye model of the patient, including the different structures of the eye as well as the tumour volume. The method was developed as part of the new 3D treatment planning system OCTOPUS for proton therapy of ocular tumours within a national research project together with the Hahn-Meitner-Institut Berlin.     

肝癌肝内血管系统三维重建及整合的X线解剖学研究及临床意义

目的：探讨三维动态增强多层螺旋CT血管造影（three dimensional dynamic contrast enhance muhislice spiral compute tomography angiography，3D DCE MSCTA），以及肝内血管系统重建并与肝癌病灶进行整合技术在临床治疗中的指导作用。方法：对16例肝癌患者采用上腹部3D DCE MSCTA扫描技术采集影像资料，经最大密度投影（maximum intensity projection，MIP）、容积再现（volume rendering，VR）和表面遮盖（surface shaded display，SSD）法重建肝内血管及肝癌病灶，并与三维数字减影血管造影（three dimensional distal subtraction angiography，3D DSA）对照。结果：肝内血管与肿块关系：肝内血管系统主分支未见异常5例，由肝动脉发出供血动脉11例，肝内血管主干受压移位10例，其中门静脉或下腔静脉癌栓3例。MIP法在显示重建血管级数方面高于SSD法，VR法显示图像的立体感优于MIP法和SSD法，3D DSA显示肝动脉及门静脉优于VR、MIP和SSD。结论：肝脏血管系统和肝癌病灶三维重建与整合技术可以较好的显示血管和病灶的立体解剖关系，有助于临床医生确定能否手术及手术的方式、范围。     

Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro‐CT scanning: a feasibility study

Although a full understanding of the hepatic circulation is one of the keys to successfully perform liver surgery and to elucidate liver pathology, relatively little is known about the functional organization of the liver vasculature. Therefore, we materialized and visualized the human hepatic vasculature at different scales, and performed a morphological analysis by combining vascular corrosion casting with novel micro‐computer tomography (CT) and image analysis techniques. A human liver vascular corrosion cast was obtained by simultaneous resin injection in the hepatic artery (HA) and portal vein (PV). A high resolution (110 μm) micro‐CT scan of the total cast allowed gathering detailed macrovascular data. Subsequently, a mesocirculation sample (starting at generation 5; 88 × 68 × 80 mm³) and a microcirculation sample (terminal vessels including sinusoids; 2.0 × 1.5 × 1.7 mm³) were dissected and imaged at a 71‐μm and 2.6‐μm resolution, respectively. Segmentations and 3D reconstructions allowed quantifying the macro‐ and mesoscale branching topology, and geometrical features of HA, PV and hepatic venous trees up to 13 generations (radii ranging from 13.2 mm to 80 μm; lengths from 74.4 mm to 0.74 mm), as well as microvascular characteristics (mean sinusoidal radius of 6.63 μm). Combining corrosion casting and micro‐CT imaging allows quantifying the branching topology and geometrical features of hepatic trees using a multiscale approach from the macro‐ down to the microcirculation. This may lead to novel insights into liver circulation, such as internal blood flow distributions and anatomical consequences of pathologies (e.g. cirrhosis).     

Towards a patient-specific hepatic arterial modeling for microspheres distribution optimization in SIRT protocol

Selective internal radiation therapy (SIRT) using Yttrium-90 loaded glass microspheres injected in the hepatic artery is an emerging, minimally invasive therapy of liver cancer. A personalized intervention can lead to high concentration dose in the tumor, while sparing the surrounding parenchyma. We propose a computational model for patient-specific simulation of entire hepatic arterial tree, based on liver, tumors, and arteries segmentation on patient’s tomography. Segmentation of hepatic arteries down to a diameter of 0.5 mm is semi-automatically performed on 3D cone-beam CT angiography. The liver and tumors are extracted from CT-scan at portal phase by an active surface method. Once the images are registered through an automatic multimodal registration, extracted data are used to initialize a numerical model simulating liver vascular network. The model creates successive bifurcations from given principal vessels, observing Poiseuille’s and matter conservation laws. Simulations provide a coherent reconstruction of global hepatic arterial tree until vessel diameter of 0.05 mm. Microspheres distribution under simple hypotheses is also quantified, depending on injection site. The patient-specific character of this model may allow a personalized numerical approximation of microspheres final distribution, opening the way to clinical optimization of catheter placement for tumor targeting.     

基于数学形态学的CT图像肝脏肿瘤提取研究

目的 肝脏肿瘤的提取是肝脏三维可视化、手术规划和模拟的基础,而当前肿瘤分割存在干预过多和分割效果不佳的问题.方法 本文通过对腹部CT图像进行高斯平滑以去除图像噪声和细密纹理,计算出图像的形态学梯度并用高、低帽变换进行增强,再根据用户选择点计算内部和外部标记符,然后基于控制标记符的分水岭算法分割图像,提取出腹部CT图像中的病变组织.结果 实验结果表明,该算法能够在较少的人工干预下快速分割出肝脏病变组织.结论 该算法实现了腹部CT图像中肝脏病变组织的提取.     

鞍区病变3D打印模型的临床应用观察

目的 探讨根据薄层增强扫描数据制作的鞍区占位性病变3D打印模型在术前制订手术计划和术中指导手术操作中的应用价值。方法 采用前瞻性研究方法,纳入2015年3月—2017年6月解放军福州总医院神经外科15例鞍区病变患者,其中男6例、女9例,年龄40~75岁;垂体腺瘤13例,鞍结节脑膜瘤和颈内动脉床突上段动脉瘤各1例。将CTA、MRI薄层扫描数据输入Mimic软件,建立数字模型,通过3D打印机制作模型。在3D打印模型上分析病变与周围结构的解剖关系、模拟建立手术入路并进行模拟手术操作,确定手术方案。临床采用经单侧鼻孔-蝶窦入路显微手术切除垂体腺瘤13例、开颅手术切除鞍结节脑膜瘤1例、开颅手术夹闭左侧颈内动脉床突上段大型动脉瘤1例,并在手术中进一步参考和验证模型的模拟结果。结果 3D打印模型上,13例垂体腺瘤在经鼻蝶入路视角下,可清晰显示鞍底隆突的形态、蝶窦的大小、气化分型、蝶窦分隔情况和蝶窦后壁形态,还可观察侧壁的骨性隆突;根据影像和3D模型观察结果进行适当地鞍底开窗,外侧缘不累及颈内动脉,上缘达到前海绵间窦,下方显露充分。1例鞍结节脑膜瘤及1例动脉瘤患者病变均与前床突关系密切,术中所见与3D打印模型所见一致。15例患者临床手术均顺利完成,术中、术后无血管及重要脑组织结构损伤、脑脊液漏、感染等并发症发生。结论 3D打印模型可清晰显示鞍区病变与周围骨质、血管的关系,为术前手术方案设计提供了良好、直观的立体解剖结构观察,并可用于模拟手术操作,进而提高手术安全性和成功率。     

混合现实技术在骨与软组织肿瘤精准手术中的应用探索

目的 探讨混合现实技术在骨与软组织肿瘤外科手术治疗中的临床应用价值。方法 选取上海交通大学附属第一人民医院骨科腋窝软组织肿瘤48岁女性住院患者1例,术前行64排螺旋CT平扫和增强扫描、3.0 T MR平扫,获得DICOM原始数据,导入Visual Volume三维重构软件系统,对目标区域各种组织区分后行可视化边缘检测、分割、提取和测算,生成STL格式的三维网格模型,再将三维模型通过Hololens眼镜映射到真实世界形成混合现实三维影像,协助医生在术前进行手术设计、模拟手术操作以及与患者有效沟通,并在混合现实技术引导下行肿瘤切除术。结果 利用基于CT、MRI影像学原始数据的高清重建,在混合现实技术引导下,本例患者手术中可视化清晰显示骨骼、肿瘤组织与周围解剖结构,手术路径清晰,准确定位并于边界外完整切除肿瘤组织;肿瘤周围血管神经保留完整,术后肢体感觉、运动功能良好。术后病理诊断:神经鞘瘤。结论 混合现实技术可在骨与软组织肿瘤术中协助确定肿瘤边界并切除肿瘤,在骨与软组织肿瘤手术的个体化治疗上具有发展潜力。     

Precision targeting of liver lesions using a novel electromagnetic navigation device in physiologic phantom and swine

Radiofrequency ablation of primary and metastatic liver tumors is becoming a potential alternative to surgical resection. We propose a novel system that uses real-time electromagnetic position sensing of the needle tip to help with precision guidance into a liver tumor. The purpose of this study was to evaluate this technology in phantom and animal models. Using an electromagnetic navigation device, instrumented 18 g needles were advanced into radioopaque tumor targets in a respiratory liver phantom. The phantom featured a moving liver target that simulated cranio-caudal liver motion due to respiration. Skin-to-target path planning and real-time needle guidance were provided by a custom-designed software interface based on pre-operative 1 mm CT data slices. Needle probes were advanced using only the electromagnetic navigation device and software display. No conventional real-time imaging was used to assist in advancing the needle to the target. Two experienced operators (interventional radiologists) and two inexperienced ones (residents) used the system. The same protocol was then also used in two anesthetized 45 kg Yorkshire swine where radioopaque agar nodules were injected into the liver to serve as targets. A total of 76 tumor targeting attempts were performed in the liver phantom, and 32 attempts were done in the swine. The average time for path planning was 30 s in the phantom, and 63 s in the swine. The median time for the actual needle puncture to reach the desired target was 33 s in the phantom, and 42 s in the swine. The average registration error between the CT coordinate system and electromagnetic coordinate system was 1.4 mm (SD 0.3 mm) in the phantom, and 1.9 mm (SD 0.4 mm) in the swine. The median distance from the final needle tip position to the center of the tumor was 6.4 mm (SD 3.3 mm, n=76) in the phantom, and 8.3 mm (SD 3.7 mm, n=32) in the swine. There was no statistical difference in the planning time, procedure time, or accuracy of needle placement between experienced and inexperienced operators. The novel electromagnetic navigation system allows probe delivery into hepatic tumors of a physiologic phantom and live anesthetized swine. The system allows less experienced operators to perform equally well as experienced radiologists in terms of procedure time and accuracy of needle probe delivery.     

基于椭圆反射体数学模型的超声刀的研究

本研究基于在椭圆体反射面的作用下能量分布的数学模型研制了一种椭圆聚焦超声换能器,该换能器本身具有X刀、γ刀等三维立体定向治疗设备的旋转治疗特点,基于这种换能器的立体定向热疗设备为超声刀,该设备利用椭圆反向聚焦虚拟了另外一个能量源,能不受辐射源外形的限制,将虚拟的能量源放在肿瘤的位置,并且能避免由于焦点所产生的局部热点、加温面积有限等缺点,通过合理的治疗计划实现理想的适形热疗。