4D-CT在立体定向放射治疗中对内靶区体积和剂量的影响

目的:探究肺癌在三维立体定向放射治疗（SBRT）中利用4D-CT测量的肿瘤运动对内靶区（ITV）的体积和剂量影响。方法:在6例肺癌患者中共探究了两种ITV的定义方法。第一种是将10个呼吸时相的4D-CT序列的所有肿瘤区（GTV）进行合并所得到的区域（ITVall）;第二种是在自由呼吸CT中的GTV加上从4D-CT测量到的肿瘤在前后（AP）、左右（LR）和颅尾（CC）方向上的运动距离所得的区域（ITVmotion）。最后分析了两种ITV在靶区体积和剂量上的区别。结果:在体积上,ITVmotion对ITVall的平均比值为2.36;对于这两种不同的ITV,它们的PTV覆盖非常接近。肺平均剂量（Dmean）随着ITV的减小而减小,ITVall的Dmean比ITVmotion少77.4 cGy。结论:由于SBRT治疗的肿瘤尺寸相对较小,因此两种ITV的剂量学差异不显著。考虑到产生ITVall所需的工作量和时间,ITVmotion会是一个不错的选择。     

Four-dimensional tractography animates propagations of neural activation via distinct interhemispheric pathways

ObjectiveTo visualize and validate the dynamics of interhemispheric neural propagations induced by single-pulse electrical stimulation (SPES).MethodsThis methodological study included three patients with drug-resistant focal epilepsy who underwent measurement of cortico-cortical spectral responses (CCSRs) during bilateral stereo-electroencephalography recording. We delivered SPES to 83 electrode pairs and analyzed CCSRs recorded at 268 nonepileptic electrode sites. Diffusion-weighted imaging (DWI) tractography localized the interhemispheric white matter pathways as streamlines directly connecting two electrode sites. We localized and visualized the putative SPES-related fiber activation, at each 1-ms time window, based on the propagation velocity defined as the DWI-based streamline length divided by the early CCSR peak latency.ResultsThe resulting movie, herein referred to as four-dimensional tractography, delineated the spatiotemporal dynamics of fiber activation via the corpus callosum and anterior commissure. Longer streamline length was associated with delayed peak latency and smaller amplitude of CCSRs. The cortical regions adjacent to each fiber activation site indeed exhibited CCSRs at the same time window.ConclusionsOur four-dimensional tractography successfully animated neural propagations via distinct interhemispheric pathways.SignificanceOur novel animation method has the potential to help investigators in addressing the mechanistic significance of the interhemispheric network dynamics supporting physiological function.     

3D reconstructions, 4D imaging and postprocessing with CT in musculoskeletal disorders: Past,present and future

Three-dimensional (3D) imaging and post processing are common tasks used daily in many disciplines. The purpose of this article is to review the new postprocessing tools available. Although 3D imaging can be applied to all anatomical regions and used with all imaging techniques, its most varied and relevant applications are found with computed tomography (CT) data in musculoskeletal imaging. These new applications include global illumination rendering (GIR), unfolded rib reformations, subtracted CT angiography for bone analysis, dynamic studies, temporal subtraction and image fusion. In all of these tasks, registration and segmentation are two basic processes that affect the quality of the results. GIR simulates the complete interaction of photons with the scanned object, providing photorealistic volume rendering. Reformations to unfold the rib cage allow more accurate and faster diagnosis of rib lesions. Dynamic CT can be applied to cinematic joint evaluations a well as to perfusion and angiographic studies. Finally, more traditional techniques, such as minimum intensity projection, might find new applications for bone evaluation with the advent of ultra-high-resolution CT scanners. These tools can be used synergistically to provide morphologic, topographic and functional information and increase the versatility of CT.     

时间-空间相关成像技术评估中孕期胎儿心功能的初步研究

目的 评估时间-空间相关成像( STIC)技术在中孕期胎儿心功能检查中的应用.资料与方法 110例孕20～27+6周胎儿常规超声筛查心脏无异常,用STIC技术扫描获得胎儿心脏整个心动周期的容积数据,存盘后采用体器官计算机辅助分析软件(VOCAL)进行脱机分析,手动描画出心室舒张末期容积(EDV)、收缩末期容积(ESV).计算心室的每搏量(SV)、心排血量(CO)、射血分数(EF),评价SV、CO、EF与孕龄的相关性.结果 110例胎儿中,94例(85.5％)获得满意的心脏容积数据.左、右心室SV从孕20周的(0.33±0.06) ml和(0.40±0.07) ml增加至孕27+6周的(1.13±0.11) ml和(1.29±0.11) ml,左、右心室CO从孕20周的( 49.66±8.10) ml/min和(59.96±9.43) ml/min增加至孕27+6周的(163.51±17.68) ml/min和(187.57±15.98) ml/min;左、右心室SV和CO随孕龄增加而增加,与孕龄呈正相关(左心室SV及CO r=0.93,P＜0.05.右心室:SV r =0.95,P＜0.05; CO r=0.94,P＜0.05).左、右心室EF分别为(49.48±4.12)％和(51.07±4.00)％,与孕龄无明显相关性(r=0.02、0.04,P＞ 0.05).结论 STIC技术能较为准确客观地测量胎儿心室容积,评价胎儿心功能,有望成为胎儿心功能检查的一种新方法.     

骨折固定的四维空间事件

文题释义： 骨折固定的磨盘效应：硬组织小间隙在受到剪切或旋转应力产生微动时,由于表面的粗糙不平可以产生类似磨盘的磨损效应,产生对间隙内组织的碾挫以及硬组织自身的磨损,骨折断端可以产生间隙内缺血以及微骨折等。 内固定物的四维空间漂移：当骨骼发生穿骨固定后,骨骼与固定装置共同承担应力,这会在四维空间上导致一系列形态变化,包括骨骼的形态和内固定的相对位置发生改变,将内固定物与骨骼的相对位置发生的缓慢变化称为内固定物的四维空间漂移。 背景：骨折的固定方式和手术操作对骨折愈合的最终结局产生十分重要的影响,但有关骨折愈合的不良结局是手术操作与其后伴发的一系列四维空间事件共同作用的结果。 目的：探讨骨折愈合的四维空间事件。 方法：检索中国知网和Medline数据库;中文检索词为骨折愈合,股骨骨折,应力遮挡,骨折与血供;英文检索词为Fracture healing,femoral fracture,stress shielding,fracture and blood flow。检索符合骨折愈合过程四维空间事件的相对宏观的事实描述,包括逻辑的支持证据和反驳证据。结合文献复习对骨折固定后主要的四维空间事件进行分析。 结果与结论：骨折固定后主要的四维空间事件包括血运潮汐、力学脉冲与生物学脉冲、硬组织小间隙的磨盘效应、应力遮挡效应以及内固定物的四维空间漂移效应等。骨折及手术创伤后伴发长达数月的超代偿血运潮汐,因此骨折术后宏观上并不缺血,但硬组织小间隙在不稳定状态下会发生磨盘效应,造成骨折间隙内的碾挫损伤以及骨折间隙内的微观缺血。固定过于坚强导致的应力遮挡效应是取内固定后再骨折以及骨骼萎缩变细的重要原因。钢板固定螺钉的微小轴向漂移可能具有重要的理论意义,具有“智能性”轴向动力化效应,可使钢板分担的应力随着骨折的愈合逐步降低。对骨折愈合四维空间事件的探讨将为骨折愈合及牵拉成骨的调控提供基本的逻辑基础。 ORCID: 0000-0002-7545-0511(刘振东) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Visual diagnosis in utero: Prenatal diagnosis of Treacher-Collins syndrome using a 3D/4D ultrasonography

ObjectiveWe present a case with prenatal diagnosis of Treacher-Collins syndrome in which micrognathia and other facial and ear abnormalities were described using a three- and four-dimensional (3D/4D) ultrasonography in utero.Case reportA 39-year-old Japanese pregnant woman was referred because of polyhydramnios at 29 weeks' gestation. Conventional ultrasonography showed a hypoplastic mandible on the sagittal section of fetal head. Continuous observation using a 3D ultrasonography additionally demonstrated bilateral downslanting palpebral fissures with symmetry and macrostomia as well as micrognathia. Both ears were microtia and no polydactyly or missing fingers were found.ConclusionThe advantage of the rendering mode of 3D images covering entire face including ears and limbs was enhanced by a continuous observation, so called 4D ultrasonography, under a condition of polyhydramnios, providing visual diagnosis in utero.     

四维超声在胎儿先天性心脏病诊断中的应用与进展

四维超声在胎儿心脏中的应用具有多种模式，可以为临床提供更多的先天性心脏病形态结构的信息，本文就四维超声在胎儿先心病中的应用与进展作一综述。     

四维应变技术评价冠心病患者PCI术前后左室舒张功能的研究

目的 应用四维应变成像 (4D-SI) 技术评价冠心病患者PCI术前后左室舒张功能。方法 根据疑似冠心病患者行冠脉造影术及左心导管检查结果,选取44例患者分为病例组：冠心病并左室舒张功能不全患者(需行PCI术)26例;对照组：冠心病并左室舒张功能正常18例。分别采集对照组及病例组PCI术前、术后3个月的常规超声心动图检测指标,测量左室舒张末期容积 (LVEDV) 、左室收缩末期容积 (LVESV) 、左室射血分数 (LVEF) ;运用 4D-SI 技术测得收缩末期纵向应变(GLS)、径向应变(GRS)、面积应变(GAS)、圆周应变(GCS)、纵向应变显像舒张指数(LSI-DI)、面积SI-DI (ASI-DI)、 径向SI-DI(RSI-DI)、圆周SI-DI(CSI-DI)。 结果 1.病例组GLS、GCS、GAS、GRS、LSI-DI、CSI-DI、ASI-DI、RSI-DI均小于对照组(P＜0.05);病例组术后3月各参数均大于病例组术前(P＜0.05);2. ROC 曲线分析结果显示LSI-DI的曲线下面积(AUC)0.921,截值为50.107%,灵敏度和特异性分别为89.2%、81.3%;ASI-DI的AUC 0.887,截值为49.233%,灵敏度和特异性分别为86.4%、79.1%。 结论 PCI术可有效改善冠心病患者左心室舒张功能,4D-SI的相关指标在一定程度上可评价冠心病患者左室舒张功能受损及PCI术后左室舒张功能的改善情况。     

Dynamic assessment of the tricuspid annulus in a healthy Asian population: A four-dimensional echocardiography study

Background

Tricuspid annulus (TA) geometry and function reference values are limited, especially for Asian populations. We aimed to explore TA using four-dimensional echocardiography (4DE) in a healthy Asian population.

Methods

A total of 355 healthy Asian volunteers (median age 34 years; 52% males) were prospectively enrolled. TA geometry and function were analyzed using 4DE throughout the cardiac cycle.

Results

The TA area, perimeter, and dimensions were smallest at end systole (ES) and largest at late diastole (LD). Normal TA parameters at end diastole (ED) in different sex and age groups were obtained. TA areas, perimeters, and dimensions in males were significantly larger than those in females at ED; BSA-indexed perimeters and BSA-indexed dimensions in males were significantly smaller than those in females at ED. TA parameters correlated well with tricuspid valve (TV) tenting, right ventricle (RV), and right atrium (RA) parameters.

Conclusions

Reference values of TA parameters were obtained by 4DE in an Asian population. Quantitative data on TA geometry and function are essential for TA pathology and therapeutics.