Intravascular photoacoustic and optical coherence tomography imaging dual-mode system for detecting spontaneous coronary artery dissection: A feasibility study

In this work,we present an intravascular dual-mode endoscopic system capable of both intravascular photoacoustic imaging(IVPAI)and intravascular optical coherence tomography(IVOCT)for recognizing spontaneous coronary artery dissection(SCAD)phantoms.IVPAI provides high-resolution and high-penetration images of intramural hematoma(IMH)at different depths,so it is especially useful for imaging deep blood clots associated with imaging phantoms.IVOCT can readily visualize the double-lumen morphology of blood vessel walls to identify intimal tears.We also demonstrate the capability of this dual-mode endoscopic system using mimicking phantoms and biological samples of blood clots in ex vivo porcine arteries.The results of the experiments indicate that the combined IVPAI and IVOCT technique has the potential to provide a more accurate SCAD assessment method for clinical applications.

Vascular Stress Analysis Based on in vivo Intravascular Optical Coherence Tomography Image Segmentation

Identification of carotid artery atherosclerosis is crucial for the diagnosis of the cerebral apoplexy and other vascular diseases.Intravascular optical tomography(IVOCT)has been employed to clinical coronary imaging for several years.Vessel morphological information on IVOCT images together with blood flow information on Doppler OCT(DOCT)images could provide a more accurate internal environment of arteries.Images integrated with fluid-structure interaction(FSI)could obtain the accurate mechanical responses and the quantitative material characters.A porcine carotid artery was imaged with an intravascular system(C7-XR,St.Jude Medical Inc.St.Paul,Minnesota,USA)in vivo,during which 120 images of one section and 600 images of a 5 mm/s pull back were captured within 6 s.Those images were then overlapped with Doppler phase changes to imply the changes in flow profiles.Segmentation and quantification of vessel structure was done in the software(MATLAB 2014b),including specifically the segmentation of lumen,imaging catheter,vessel wall and the guide wire.Appropriate interpolation functions are selected in the coordinate transformation algorithm to have smooth boundaries from images.A set of flow algorithms include image segmentation,three-dimensional/two-dimensional model reconstruction,inversion of material parameters,fitting of experimental velocity data and theoretical derivation based on simulation results is proposed.All steps are programmed to provide a theoretical basis for the future simplified process control.3D-reconstruction FSI model was built in SOLIDWORKS by lofting operation based on the segmentation results.Commercial finite element software(COMSOL 5.3,Sweden)numerically analyzed the entity model to obtain vessel stress/strain and flow shear stress data.Boundary conditions are from the OCT detection.Material of the artery was set to be the modified Mooney-Rivlin constitutive model and the parameters used were adjusted in an algorithm to match an ex vivo experiment.Wall shear stresses(WSS)and vessel deformations were chosen to measure the conditions of the artery and would serve as a target variables for future prediction.Thus,the geometric information together with the data of materials and other mechanical properties are possible to obtain during the imaging process.Segmentation process provided anatomically correct models of a two-layered artery.Numerical simulation permits reliable stress distribution in which the position of catheter and the artery curvature have a neglectable disturbance.Shear stress of the fluid is quite small compared with that of the wall at the same interface,which shows good agreement with the former studies.Moreover,a high flushing speed of 0.1 mps have little impact on the stress distributions and magnitudes,which denotes that the OCT imaging process brings little harm to the vessel.It is the first attempt to combine the OCT imaging and Doppler OCT within a full algorithm and a structural analysis.This study is helpful for the biomechanical property studies of carotid arteries and the development of medical imaging technology.

Pencil-beam scanning catheter for intracoronary optical coherence tomography

Current gradient-index(GRIN)lens based proximal-driven intracoronary optical coherence tomography(ICOCT)probes consist of a spacer and a GRIN lens with large gradient constant.This design provides great flexibility to control beam profiles,but the spacer length should be well controlled to obtain desired beam profiles and thus it sets an obstacle in mass catheter fabrication.Besides,although GRIN lens with large gradient constant can provide tight focus spot,it has short depth of focus and fast-expanded beam which leads to poor lateral resolution for deep tissue.In this paper,a type of spacer-removed probe is demonstrated with a small gradient constant GRIN lens.This design simplifies the fabrica-tion process and is suitable for mass production.The output beam of the catheter is a narrow nearly collimated light beam,referred to as pencil beam here.The full width at half maximum beam size varies from 35.1μm to 75.3μm in air over 3-mm range.Probe design principles are elaborated with probe/catheter fabrication and performance test.The in vivo imaging of the catheter was verified by a clinical ICOCT system.Those results prove that this novel pencil-beam scanning catheter is potentially a good choice for ICOCT systems.

The Application Progress of Skin Imaging Technology in Psoriasis

Skin imaging technologies such as dermoscopy, high-frequency ultrasound, reflective confocal microscopy and optical coherence tomography are developing rapidly in clinical application. Skin imaging technology can improve clinical diagnosis rate, and its non-invasiveness and repeatability make it occupy an irreplaceable position in clinical diagnosis. With the “booming development” of medical technology, skin imaging technology can improve clinical diagnosis rate. Researchers have made significant advances in assisting clinical diagnosis, prediction, and treatment of disease. This article reviews the application and progress of skin imaging in the diagnosis of psoriasis.

Multimodal intravascular imaging technology for characterization of atherosclerosis

Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events.Morphology,composition,and mechanical property of a coronary artery have been demonstrated to be the key characteristics for the identification of vulnerable plaques.Several intravascular multimodal imaging technologies providing co-registered simultaneous images have been developed and applied in clinical studies to improve the characterization of atherosclerosis.In this paper,the authors review the present system and probe designs of representative intra-vascular multimodal techniques.In addition,the scientific innovations,potential limitations,and future directions of these technologies are also discussed.

Neointimal coverage of sirolimus-eluting stents 6 months and 12 months after implantation： evaluation by optical coherence tomography

Optical coherence tomography （OCT） is a new imaging modality with resolution of approximately 10 pm and can be employed to visualize intracoronary characteristics. Sirolimus-eluting stents （SES） are susceptible to late thrombosis due to delayed reendothelialization over the stent struts, which may result in acute myocardial infarction or death. This study was designed to evaluate the re-endothelialization and neointimal coverage of SES with OCT 6 months and 12 months after implantation.Methods A total of 36 patients enrolled in the study underwent OCT examination 6 months （17 patients） and 12 months （19 patients） after SES implantation, The strut apposition to the vessel wall and neointimal coverage on SES struts were evaluated by OCT, Results Forty-six SES and 6561 struts were analyzed, At 6 months, 3041 struts （98.7%） were well-apposed and 39 struts （1,3%） were malapposed, At 12 months, 3434 struts （98,6%） were well-apposed and 47 struts （1,4%） were malapposed, Furthermore, only 4 SES at 6 months （18,2%） and 10 SES at 12 months （41,7%） were fully covered by neointimal growth, The average neointimal thicknesses covering the analyzed struts at 6 months and 12 months were （42±28） μm and （88±32） μm, respectively, There were 1989 struts at 6 months （72,1%） and 1461 struts at 12 months （45,6%） with neointimal thickness 〈100 μm, Conclusions OCT was able to visualize the strut apposition to the vessel wall and neointimal coverage on SES struts, At 6-month and 12-month follow-up examinations most struts were covered with thin neointima, but few of the entire SES showed full coverage. To prevent late-stent thrombosis in the presence of uncovered stent struts, longer dual antiplatelet drugs therapy should be recommended,

局限性硬皮病诊断技术研究进展

局限性硬皮病(LS)是一种主要影响皮肤、皮下脂肪和深层组织的自身免疫性疾病,可能导致严重的功能障碍和外观受损。及时准确的诊断对于患者的治疗和管理至关重要,但目前LS在诊断方面尚存在困难。本文综述了LS诊断领域的最新进展,包括高频超声、磁共振成像、光学相干断层扫描及分子和基因检测等。这些技术提高了诊断的精确性和即时性。高频超声能够精确评估皮肤病变;磁共振成像有助于深层组织受累的评估;光学相干断层扫描和皮肤镜揭示皮肤微小结构变化;分子和基因检测为理解疾病机制及个体化治疗提供新视角。尽管新技术的应用受到成本和设备普及度的限制,但其在改善诊断流程、提供个性化治疗方面有着显著的潜力。未来研究需要进一步探讨这些技术与传统方法的整合及其在LS不同亚型和疾病阶段中的应用。

支架术后即刻冠状动脉光学相干断层扫描结果的临床影响

冠状动脉光学相干断层扫描的分辨率为10μm,它可为术者提供支架贴壁不良、组织脱垂、支架内血栓和支架边缘夹层等支架术后即刻结果,但其对临床预后的影响一直存在争议。现总结既往研究,并就支架术后即刻冠状动脉光学相干断层扫描结果的研究进展及临床影响进行综述。

基于影像的冠状动脉生理学功能评估研究进展

血流储备分数(FFR)已经成为评估冠状动脉狭窄程度、指导血运重建策略以及选择治疗方案的冠状动脉生理学“金标准”。然而,由于FFR评估过程中存在压力导丝侵入性操作、充血药物的使用等诸多因素,其在临床实践中的应用受到限制。随着冠状动脉虚拟生理学的应用,基于冠状动脉影像衍生FFR的技术得以研发,如冠状动脉造影衍生FFR、光学相干断层成像(OCT)衍生的FFR以及血管内超声(IVUS)衍生的FFR。同时这些功能学评估手段的诊断效能不断被大量临床研究证实。本文旨在对基于冠状动脉造影、IVUS和OCT衍生的FFR的诊断效能、临床运用等方面进行综述。

Bioresorbable stent unloading during percutaneous coronary intervention:Early detection and management

In this letter,we comment on a recent case report by Sun et al in the World Journal of Cardiology.The report describes the successful management of a rare complication:The unloading or detachment of a bioresorbable stent(BRS)during percutaneous coronary intervention(PCI)in a male patient.The unloading of BRS was detected via angiography and intravascular ultrasound(IVUS)imaging of the left coronary artery and left anterior descending artery.Although this case is interesting,the authors’report lacked crucial details.Specifically,insufficient information about the type of BRS used,potential causes of BRS unloading,or whether optical coherence tomography(OCT)imaging for coronary arteries was performed before,during,or after PCI.The OCT imaging of coronary arteries before PCI can potentially prevent BRS unloading due to its higher resolution compared to IVUS.In addition,despite detecting myocardial bridging during the PCI,the authors did not provide any details regarding this variation.Here we discuss the various types of BRS,the importance of OCT in PCI,and the clinical relevance of myocardial bridging.

血管腔内超声在下肢动脉疾病中的应用现状与进展

下肢动脉粥样硬化性疾病是临床上较常见的一种周围动脉疾病。目前临床常用的影像学诊断方法主要有超声、计算机断层扫描和动脉造影术等,但这些手段仅能观察到下肢动脉形态学改变,对于动脉腔内病变的评估(如粥样斑块的性质)具有一定的局限性。随着血管腔内超声(Intravascular Ultrasound,IVUS)技术的逐渐成熟以及对下肢动脉粥样硬化性疾病发病机制研究的不断深入,IVUS为临床诊疗方法的选择提供了更好的帮助。本文对IVUS在辅助诊断下肢动脉粥样硬化性疾病中的最新应用进展进行综述,以期促进IVUS技术在临床的应用。

腔内影像技术指导下的PCI精准治疗策略研究进展

腔内影像学作为三维成像,较二维的冠状动脉造影更能准确地反映血管腔内结构及识别病变斑块的性质,因此有助于介入术前支架或球囊类型和置入部位的选择,指导不同类型病变合理的预处理方式,并证实可以优化左主干及慢性完全性闭塞病变介入治疗的策略,最终减少并发症及不良事件的发生。本综述从国内外循证医学证据和指南的角度,介绍了冠脉介入治疗腔内影像学研究在优化经皮冠状动脉介入治疗中的最新进展。

自发性冠状动脉夹层的临床特点及腔内影像分析

目的探讨自发性冠状动脉夹层(SCAD)的临床表现,夹层不同分型在腔内影像中的表现及治疗策略选择。方法纳入2021年8月至2022年8月以急性冠状动脉综合征收住于兰州大学第一医院心内科,经冠状动脉造影联合腔内影像检查[血管内超声(IVUS)或光学相干断层成像(OCT)]明确诊断SCAD的患者20例,收集相关临床资料,术后1~6个月通过门诊及电话随访,术后6个月复查冠状动脉造影联合腔内影像检查(IVUS或OCT),观察夹层及血肿吸收情况,有无新发病变出现及病变延展。结果SCADⅠ型5例(5/20),SCADⅡ型9例(9/20),SCADⅢ型4例(4/20),SCADⅣ型2例(2/20)。药物保护治疗13例(13/20,SCADⅡ型、Ⅲ型),行经皮冠状动脉介入治疗(PCI)7例(7/20,SCADⅠ型、Ⅳ型)。血肿入口和出口均出现明显夹层,血肿内可见斑块破裂,或有机化血栓形成,或SCADⅠ型、Ⅳ型,多采用PCI;血肿入口无夹层,血肿出口也无夹层的病变,管腔内未见斑块,血肿内部呈低回声,可采用药物保守治疗。患者平均随访6个月,药物保守治疗患者中再发急性心肌梗死1例(1/20)。结论SCAD通过腔内影像评估后确定夹层性质,选择适合的治疗策略,可以提高患者整体预后。

一例梅毒感染合并家族性高胆固醇血症的早发心肌梗死

梅毒感染可以引起心血管系统受累,但冠状动脉受累是较为少见的临床表现。家族性高胆固醇血症(FH)是一种因低密度脂蛋白胆固醇(LDL-C)清除障碍导致LDL-C水平显著升高,造成早发严重动脉粥样硬化的常染色体显性遗传疾病。本文报道一例梅毒感染合并FH的青年男性患者,临床表现为急性心肌梗死、高LDL-C血症,冠脉造影及腔内影像检查可见冠状动脉多发瘤样扩张和狭窄,经反复冠状动脉药物球囊扩张后短期内再狭窄,最终植入支架治疗。

自发性右冠状动脉夹层1例

本文回顾1例年轻女性严重自发性右冠状动脉夹层病例,对近年自发性冠状动脉夹层(SCAD)相关文献进行复习,探讨SCAD的病理机制、临床特征及诊疗经验,为今后的临床工作提供诊治经验、减少漏诊及误诊率、改善患者预后。本例患者入院后予双联抗血小板聚集、控制心率、改善心室重构等治疗,发病1个月后复查冠状动脉造影(CAG)显示病变已自行愈合。SCAD可通过CAG、血管内超声及光学相干断层扫描确诊,药物治疗为首选方案。

New Insights into Intravascular Imaging of Coronary Bifurcation Lesions and Left Main Stenosis:What Have We Accomplished?

Coronary bifurcation lesions(CBL)are one of the most challenging lesions to treat in interventional cardiology.Intravascular imaging including intravascular ultrasound(IVUS)and optical coherence tomography(OCT)is paramount for the assessment of lesion characteristics and suboptimal stent results and to improve the outcome of percutaneous coronary intervention(PCI).After upgrading the use of IVUS and OCT by the American College of Cardiology/American Heart Association guidelines,their use has increased.Likewise,there has been significant improvement in image quality and the profile of system(ie,IVUS catheter size).The main indication for the use of IVUS includes:assessment of lesion characteristics,optimization of stent deployment,optimal stent expansion,exclusion of plaque burden>50%,and edge dissection.Intravascular imaging plays a significant role in the assessment and treatment of left main(LM)coronary artery stenosis and CBL.In particular,the use of intravascular imaging for alleviating mechanical issues during stenting and managing stent thrombosis has significantly increased.Overall,a compelling body of evidence has shown that the use of IVUS or OCT during PCI leads to optimal stenting results and mitigates the risk of adverse cardiac events.However,to date,the American College of Cardiology/American Heart Association Guidelines have assigned a Class IIb recommendation for IVUS or OCT,while the European Society of Cardiology Guidelines upgraded it to the Class IIa recommendation.This review summarized the role of IVUS and OCT for the assessment of stenosis and stent optimization in patients with CBL and LM stenosis.In addition,we discuss new insights into the role of IVUS-and OCT-guided stenting in patients with CBL and LM stenosis provided by the ongoing randomized trials.

眼前节成像与生物测量分析系统的最新进展

眼前节成像和生物测量分析系统广泛应用于眼前节疾病的诊断、白内障屈光手术的临床观察、眼前节结构生物参数的测量等。目前国内外许多仪器均能客观地对眼前节进行成像和生物测量,如裂隙灯生物显微镜、超声生物显微镜、光学相干断层扫描等。本次我们就各种最新的眼前节成像和生物测量仪器的原理、各自的特点及其在眼科领域的应用进行综述。

光学相关断层摄影技术观察壁冠状动脉的可行性研究

目的 讨论光学相关断层摄影技术观察壁冠状动脉的可行性。方法 选择36名心肌桥（myocardial bridging,MB）患者（即冠脉造影可见“挤奶现象”的患者）行光学相干断层摄影检查（optical coherence tomography,OCT）及血管内超声检查（intravascular ultrasound,IVUS）,并进一步用猪的心脏作为动物模型以确认与OCT图像相对应的组织学结构。结果 所有患者OCT检测均发现MB节段内一紧邻动脉管壁外的边界清晰、不均质的、低信号梭形区域;且在舒张期更易观察到这一特征性的图像表现。该梭形区域的最大弧度为176.3°±53.1°（106°~287.5°）,最大厚度为（0.41±0.12）mm（0.25~0.69 mm）。所有患者均在且只在肌桥节段外近段血管内检出动脉粥样硬化改变,仅1例患者在肌桥节段内发现了管壁内膜增厚。OCT所发现的梭形区域不同于IVUS图像中代表MB肌束的半月形无回声区域。另外,线性相关分析发现梭形区域弧度与管腔受压迫程度呈负相关（r=-0.403,P=0.004）。进一步的动物模型的组织学检查结果发现这一梭形、低信号区域是位于肌肉与动脉血管之间的结缔组织。结论 在造影和IVUS确诊的MB患者中,OCT检查可在肌桥节段发现一紧邻动脉管壁外的边界清晰、不均质的、低信号梭形区域,进一步组织学检查结果发现这一区域为动脉周围结缔组织,而非IVUS中代表肌束的半月形无回声区域。

应用血管内超声/光学相干断层成像杂交技术研究冠状动脉钙化与斑块回缩的关系

目的:冠状动脉钙化是否与斑块回缩相关尚不清楚。本研究的目的是结合光学相干断层扫描(OCT)和血管内超声(IVUS)评估冠状动脉钙化和斑块回缩(PS)之间的关系。方法:15例患者,16支血管纳入本研究,术后即刻和术后5年联合应用OCT和IVUS评估钙化斑块面积变化和斑块回缩,及二者之间的关系。IVUS检测管腔面积(LA)、血管面积(VA)和斑块/中膜面积(PA)。将斑块/中层回缩(PS)定义为PA相对减少>5%。OCT检测钙化面积、钙化弧度和钙化长度。结果:术后即刻和5年随访时,共有72个OCT和IVUS完全匹配的横断面(共432个图)纳入该研究。72个横截面中,35个横截面在5年随访时显示为PS,37个横截面为非PS。斑块面积的变化分别与OCT测量的钙化面积变化呈负相关(r=-0.29,P=0.004),与OCT钙化弧度变化(r=-0.42,P<0.001),OCT钙化长度变化(r=-0.5,P<0.001)呈负相关,与IVUS测量的钙化弧度变化呈负相关(r=-0.31,P=0.024),而与管腔面积变化呈正相关(r=0.24,P=0.044)。结论:冠状动脉钙化斑块进展使得斑块回缩和管腔扩大。应用IVUS/OCT杂交技术能更好的评估钙化斑块进展和斑块回缩之间的相关性。

光学相干成像与血管内超声在冠状动脉左主干介入治疗中的应用价值比较

目的比较光学相干成像（OCT）与血管内超声（IVUS）在左主干介入治疗中的应用价值。方法回顾性选取2012年4月至2013年12月因左主干病变在首都医科大学附属北京安贞医院行介入治疗的患者60例。根据患者在左主干介入治疗中使用的血管内影像指导方法分为IVUS组（29例）和OCT组（31例），比较2组患者造影及介入治疗结果和随访12个月后的预后，包括死亡、心肌梗死和靶病变再次血运重建等主要心血管不良事件。结果OCT组患者造影剂用量、后扩张次数和贴壁不良反应发生率均明显高于IVUS组[（187±29）ml比（155±20）ml、（3．5±0．3）次比（2．3±0．6）次、77．4％（24／31）比51．7％（15／29）]，差异均有统计学意义（均P〈0．01）。随访12个月后，2组患者病死率、心肌梗死发生率、靶病变再次血运重建发生率比较，差异均无统计学意义（均P〉0．05）。结论与IVUS相比，OCT可发现更多支架贴壁不良反应，增加了后扩张次数，但并未明显改善预后。