冠状动脉粥样硬化斑块的磁共振成像研究进展

急性冠状动脉综合征系由粥样硬化易损斑块的破裂进而血栓形成所致，因此，在斑块破裂之前进行冠脉管壁及斑块成像，并预测斑块稳定性，对于降低急性冠脉综合征的发生率具有重要意义。与其它影像学检查技术相比，MR成像优势明显，具有很大潜力。本文就冠脉粥样硬化斑块MR成像原理，以及目前冠脉粥样硬化斑块成像序列、MR对比剂研究现状进行综述，并探讨其对斑块成分的判定以及斑块稳定性评价的应用前景。     

直肠癌的磁共振成像诊断及其分期的临床应用

探讨直肠癌磁共振成像诊断及分期的临床应用价值。直肠癌磁共振成像既可以分析肿瘤浸润肠壁的深度和范围，还可判断是否有淋巴结和远处脏器转移，并且很好地预测环状切缘。经研究证明，直肠癌磁共振成像诊断分期与术后病理诊断具有密切的相关性。故直肠癌磁共振成像检查对选择合理的治疗方案、手术方式及判断预后均具有重要的价值。     

超声造影谐波成像在老年肛瘘患者术前评估中的应用

目的 分析超声造影谐波成像在老年肛瘘患者术前评估中的应用价值。方法 选取河北省中医院2021年1～7月收治的60例老年肛瘘患者作为研究对象，均拟行肛瘘切除术治疗，术前行超声造影谐波成像检查，评估患者肛瘘等级，以手术结果作为“金标准”,检验超声造影谐波成像评估肛瘘类型与手术检查结果的符合率，评估超声造影谐波成像评估肛瘘不同等级与手术检查结果的一致性。结果 纳入的60例肛瘘患者，经手术检查出Ⅰ级12例，Ⅱ级10例，Ⅲ级14例，Ⅳ级18例，Ⅴ级6例。经手术检查出主瘘管20例，分支瘘管8例，内口18例，脓肿14例；超声造影谐波成像评估肛瘘类型与手术检查结果的符合率为91.67%;超声造影谐波成像评估肛瘘不同等级与手术检查结果的具有强一致性(Weighted Kappa系数值=0.914)。结论 超声造影谐波成像用于老年肛瘘患者术前评估中具有一定价值，评估肛瘘不同类型与手术检查结果相比具有较高符合率，评估肛瘘不同等级手术检查结果相比具有强一致性。     

CT灌注成像在脑缺血中的应用进展

CT灌注成像技术在急性缺血性脑血管病超早期能帮助确定缺缺血病灶的部位，范围和程度，对临床超早期溶栓治疗具有重要指导意义，文章介绍了CT灌注成像的基本原理，成像方法和在脑缺血中的应用。     

Xe-CT在缺血性脑血管病诊治中的应用

目前，临床上用于脑血流灌注功能成像的检查方法主要有CT灌注成像、正电子发射体层摄影（PET）、单光子发射体层摄影（SPECT）、MRI波谱、弥散及灌注成像等，但由于设备昂贵，成像时间长以及具有核放射性等缺点，在一定程度上限制了这些检查方法的推广和普及心。而Xe—CT能够重复地提供量化的局部或整体的脑血流数据及脑血管储备、侧枝循环等情况，且脑血流图像直接与大脑的解剖结构相关联，对缺血性脑血管病的诊断及治疗具有重要意义。     

磁共振在乳腺癌新辅助治疗疗效评估与预测中的应用进展

新辅助治疗（NAT）是乳腺癌综合治疗的重要组成部分。目前，NAT疗效评估的金标准是组织病理学，但其需要术后标本，存在明显滞后性。准确评估和预测NAT疗效对及时改进治疗方案、确定精准的手术计划具有重要价值。已有多种影像学检查方法被用于乳腺癌NAT疗效评估与预测，其中磁共振（MR）检查因其优越的软组织分辨力和多方位、多参数成像特点，成为准确性最高的影像学手段。传统MR成像可从肿瘤长径、体积和退缩模式等形态学改变来评估与预测NAT疗效。近年来随着MR功能成像技术不断更新迭代，动态对比增强磁共振成像、扩散加权成像及体素内不相干运动扩散加权成像、酰胺质子转移成像、磁共振波谱成像等MR功能成像从不同维度实现了对乳腺癌NAT疗效的早期预测，进一步提高了MR成像对NAT疗效的早期预测能力。     

功能性磁共振成像技术在移植肾中的应用

外科技术发展和免疫抑制剂的应用使肾移植术后一年生存率达到90％以上，但术后多种原因仍可导致移植肾功能不全，及早发现病因并合理治疗可以避免肾功能的丧失，延长移植肾的存活时间。磁共振成像（MRI）具有多方位及多参数成像、无创伤性、无放射性及优越的软组织对比等特点，结合功能性磁共振成像（functional MRI，fMRI）可以对移植肾同时获得结构和功能信息，较其他影像检查方法更具有优势。     

冠状动脉CT血管成像指导经皮冠状动脉介入治疗临床研究进展

冠状动脉CT血管成像是评估冠状动脉狭窄程度的无创影像学手段。随着冠状动脉CT血管成像技术不断完善，其可提供斑块性质、血管周围脂肪组织衰减指数、血流储备分数及心肌灌注等大量信息，对经皮冠状动脉介入治疗具有重要指导意义。     

三维超声成像诊断颈动脉粥样硬化中风的临床价值

对经二维彩色多普勒超声检查存在颈动脉粥样硬化脑血管患者进行三维超声检查，并与二维彩色多普勒成像进行比较。结果颈动脉粥样硬化的三维超声图像可显示多种形态的粥样斑块的立体形状及表面特征，在斑块内部的组织结构及表面形态等方面的成像明显优于二维成像。对斑块性质显示更准确，增加了颈动脉粥样硬化中风预报的可靠性，具有重要的临床应用价值。     

MRI及MRA在诊断老年糖尿病患者脑梗死中的价值

近年来，随磁共振技术的发展，磁共振成像（MRI）及磁共振血管成像（MRA）具有无创伤性及三维观察的特点，所以在应用其了解糖尿病人脑梗死方面具有很大优越性。缺血性脑血管病，尤其是腔隙性脑梗死，发病多在60—70岁，可见年龄因素是脑血管病不可干预的危险因素。本文选取了一组老年糖尿病患者进行头部MRI及MRA检查，以期对不同情况下糖尿病与脑梗死情况进行初步评估。     

Main pancreatic duct, common bile duct and sphincter of Oddi structure visualized by optical coherence tomography: An ex vivo study compared with histology

BACKGROUND: Optical coherence tomography has been proposed to obtain high-resolution imaging of tissue structure of GI tract. Up till now, the optical coherence tomography appearance of the common bile duct, main pancreatic duct and sphincter of Oddi wall structure has not yet been defined. AIMS: To compare, in a prospective study, optical coherence tomography images of pancreato-biliary ductal system with histology and identify the optical coherence tomography pattern of the normal wall structure of the ducts. METHODS: Multiple sections of non-neoplastic segments of five consecutive ex vivo human pancreatic specimens were investigated by optical coherence tomography scanning within 1h of resection. Sixty optical coherence tomography images were compared with the corresponding histological findings. RESULTS: Optical coherence tomography appearance of normal common bile duct, main pancreatic duct and sphincter of Oddi is characterized by a differentiated three-layer architecture with a regular surface and a homogeneous back-scattered signal, corresponding to the single layer of epithelial cells, the connective-muscular layer and the muscular or acinar structure, respectively. Optical coherence tomography and histology findings were concordant in all cases. CONCLUSIONS: Optical coherence tomography was able to provide in real-time images of wall structure of the normal common bile duct, main pancreatic duct and sphincter of Oddi that are similar to those obtained by histology. These results suggest that optical coherence tomography could enable high-resolution images to be obtained from the pancreato-biliary system during an ERCP procedure.     

Optical coherence tomography compared with histology of the main pancreatic duct structure in normal and pathological conditions: An ‘ex vivo study’

BACKGROUND AND STUDY AIMS: Optical coherence tomography permits high-resolution imaging of tissue microstructures by a probe inserted into the main pancreatic duct through a standard ERCP catheter. The aim of this study was to compare optical coherence tomography images of the main pancreatic duct with histology and identify the optical coherence tomography pattern of the normal and pathological structure of the main pancreatic duct. PATIENTS AND METHODS: Multiple sections of neoplastic and non-neoplastic segments of 10 consecutive surgical pancreatic specimens obtained from patients with pancreatic head adenocarcinoma were investigated by optical coherence tomography scanning within 1h of resection. One hundred optical coherence tomography findings were then compared with the corresponding histopathological diagnoses. RESULTS: Main pancreatic duct wall architecture appeared at optical coherence tomography investigation as a three-layer structure with a different back-scattered signal from each layer. Optical coherence tomography imaging was concordant with histology in 81.8% and 18.75% of sections with normal tissue and chronic inflammatory changes. The K statistic between the two procedures was equal to 0.059 for non-neoplastic main pancreatic duct wall appearance. In all neoplastic sections optical coherence tomography showed a subverted layer architecture with heterogeneous back-scattering of the signal and was concordant with histology. CONCLUSIONS: Optical coherence tomography provided images of main pancreatic duct wall structure that were concordant with histology in 100% of cases in presence of neoplastic ductal changes and did not have false-positive or negative results. Optical coherence tomography images were also concordant with histology in about 80% of cases with normal main pancreatic duct structure; however, the differential diagnosis between normal tissue and chronic pancreatitis or dysplastic changes appeared very difficult.     

What is the role of accreditation in the era of competency-based specialist training - A perspective from the United Kingdom

Optical coherence tomography is an exciting light-based imaging modality with a much higher axial resolution as compared with intravascular ultrasound. The diagnostic value of optical coherence tomography resides in its ability to provide information on the stent interaction with the vessel wall at the level of individual struts. Chief clinical implications include evaluating strut neointimal coverage and strut malapposition following coronary stenting. This Editorial covers the basics of optical coherence tomography, its established and potential clinical implications, probable caveats and downsides, in addition to a future perspective, all in view of the late-breaking peer-reviewed literature.     

Diagnostic accuracy of optical coherence tomography and intravascular ultrasound for the detection and characterization of atherosclerotic plaque composition in ex-vivo coronary specimens: a comparison with histology

BACKGROUND: Both intravascular ultrasound and optical coherence tomography have been purported to accurately detect and characterize coronary atherosclerotic plaque composition. The aim of our study was to directly compare the reproducibility and diagnostic accuracy of optical coherence tomography and intravascular ultrasound for the detection and characterization of coronary plaque composition ex vivo as compared with histology. METHODS AND RESULTS: Intravascular ultrasound (20 MHz) and optical coherence tomography imaging was performed in eight heart specimens using motorized pullback. Standard histology using hematoxylin-eosin and van Gieson staining was performed on 4 mum thick slices. Each slice was divided into quadrants and accurately matched cross-sections were analyzed for the presence of fibrous, lipid-rich, and calcified coronary plaque using standard definitions for both intravascular ultrasound and optical coherence tomography and correlated with histology. After exclusion of 145/468 quadrants, we analyzed the remaining 323 quadrants with excellent image quality in each procedure. Optical coherence tomography demonstrated a sensitivity and specificity of 91/88% for normal wall, 64/88% for fibrous plaque, 77/94% for lipid-rich plaque, and 67/97% for calcified plaque as compared with histology. Intravascular ultrasound demonstrated a sensitivity and specificity of 55/79% for normal wall, 63/59% for fibrous plaque, 10/96% for lipid-rich plaque, and 76/98% for calcified plaque. Both intravascular ultrasound and optical coherence tomography demonstrated excellent intraobserver and interobserver agreement (optical coherence tomography: kappa=0.90, kappa=0.82; intravascular ultrasound: kappa=0.87, kappa=0.86). CONCLUSION: Optical coherence tomography is superior to intravascular ultrasound for the detection and characterization of coronary atherosclerotic plaque composition, specifically for the differentiation of noncalcified, lipid-rich, or fibrous plaque.     

Optical Coherence Tomography in Inflammatory Bowel Disease: Prospective Evaluation of 35 Patients

Purpose  Optical coherence tomography is a technique using infrared light in tissues of the gastrointestinal tract and human colon affected by inflammatory diseases. We evaluated whether there are specific patterns of optical coherence tomography for inflammatory bowel disease and compared the technique performance to the histology. Methods  Optical coherence tomography was performed in 35 patients (18 men; 31 ulcerative colitis, 4 Crohn’s disease). The images were obtained from affected and normal colon at endoscopy. Two biopsies of the sites visualized were taken. Two endoscopists scored the images, and two pathologists, blind to the endoscopy and optical coherence tomography, performed the histologic evaluation. Results  Three optical coherence tomography patterns were identified: 1) mucosal backscattering alteration, 2) delimited dark areas, and 3) layered colonic wall. Compared with the histology, mucosal backscattering alteration was the most effective in recognizing the disease in patients (P = 0.007 in colon segments affected, and P < 0.001 in normal segments). The sensitivity and specificity have been 100 and 78 percent, respectively. Conclusions  The in vivo optical coherence tomography correctly detected inflammatory bowel disease features in affected and apparently normal colon, and allowed to discriminate patterns for active ulcerative colitis and Crohn’s disease.     

Visualization of coronary atherosclerotic plaques in patients using optical coherence tomography: comparison with intravascular ultrasound

OBJECTIVES: The aim of this study was to evaluate the feasibility and the ability of intravascular optical coherence tomography (OCT) to visualize the components of coronary plaques in living patients. BACKGROUND: Disruption of a vulnerable coronary plaque with subsequent thrombosis is currently recognized as the primary mechanism for acute myocardial infarction. Although such plaques are considered to have a thin fibrous cap overlying a lipid pool, imaging modalities in current clinical practice do not have sufficient resolution to identify thin (< 65 microm) fibrous caps. Optical coherence tomography is a new imaging modality capable of obtaining cross-sectional images of coronary vessels at a resolution of approximately 10 microm. METHODS: The OCT images and corresponding histology of 42 coronary plaques were compared to establish OCT criteria for different types of plaques. Atherosclerotic lesions with mild to moderate stenosis were identified on angiograms in 10 patients undergoing cardiac catheterization. Optical coherence tomography and intravascular ultrasound (IVUS) images of these sites were obtained in all patients without complication. RESULTS: Comparison between OCT and histology demonstrated that lipid-rich plaques and fibrous plaques have distinct OCT characteristics. A total of 17 IVUS and OCT image pairs obtained from patients were compared. Axial resolution measured 13 +/- 3 microm with OCT and 98 +/- 19 microm with IVUS. All fibrous plaques, macrocalcifications and echolucent regions identified by IVUS were visualized in corresponding OCT images. Intimal hyperplasia and echolucent regions, which may correspond to lipid pools, were identified more frequently by OCT than by IVUS. CONCLUSIONS: Intracoronary OCT appears to be feasible and safe. Optical coherence tomography identified most architectural features detected by IVUS and may provide additional detailed structural information.     

Optical coherence tomography. Initial experience in patients undergoing percutaneous coronary intervention

Optical coherence tomography is a new intracoronary diagnostic technique that has a higher resolution than other techniques, such as intravascular ultrasound. We used optical coherence tomography to study outcomes after stent implantation in six patients who had undergone percutaneous coronary intervention, and in whom angiography showed normal results after revascularization. Material was observed to protrude through the stent struts in all patients, small dissections were seen at the stent edges in four patients, and there was incomplete stent apposition in four patients. In two patients, small amounts of thrombus were observed to form around the tomography catheter. With optical coherence tomography, it was possible to detect areas in which the results of percutaneous coronary intervention were suboptimal, despite a satisfactory appearance on angiography.     

Application of optical coherence tomography in the treatment of coronary bifurcation lesions

Optical coherence tomography (OCT) is a novel intravascular imaging modality with excellent resolution. We report the application of OCT in 3 coronary bifurcation interventions, in which OCT allowed optimization of the final procedural result, by detecting a dissection, intracoronary thrombus and by confirming complete ostial coverage by a stent.     

Optical coherence tomography in pediatric patients: A feasible technique for diagnosing celiac disease in children with villous atrophy

Background and aimCeliac disease is a common condition with many atypical manifestations, where histology serves as the “gold standard” for diagnosis. A useful new technique, optical coherence tomography, can depict villous morphology in detail, using light waves. This study examined the correlation between the sensitivity and specificity of optical coherence tomography in pediatric patients undergoing esophago-gastro-duodenoscopy for the diagnosis of celiac disease.Materials and methodsA total of 134 children were prospectively enrolled, 67 with a serological suspicion of celiac disease (group 1) and 67 with negative histology for celiac disease (group 2). During a diagnostic esophago-gastro-duodenoscopy we acquired multiple images and films in the four quadrants of the second part of the duodenum, and biopsies were taken in the area where optical coherence tomography had been done. Three patterns of villous morphology were considered: pattern 1 = no atrophy (types 0, 1 or 2 of the Marsh classification); pattern 2 = mild atrophy (type 3a or 3b); pattern 3 = marked atrophy (type 3c).ResultsThe diagnosis of celiac disease was histologically confirmed in all 67 children with positive antiendomysium and/or antitransglutaminase antibodies. Optical coherence tomography correlated with pattern 1 histology in 11/11 cases, pattern 2 in 30/32 (93.8%) and pattern 3 in 22/24 (91.6%). Sensitivity and specificity were 82% and 100%. In the control group there was 100% concordance between optical coherence tomography and histology. The overall concordance between optical coherence tomography and histology in determining patchy lesions was 75%.ConclusionOptical coherence tomography could be a helpful diagnostic tool in children with mild or marked villous atrophy for diagnosing celiac disease during upper gastrointestinal (GI) endoscopy, avoiding biopsies. However, duodenal biopsies are mandatory if the optical coherence tomography shows normal villous morphology in patients with positive antibodies.     

OCT-guided stenting of a spontaneous coronary artery dissection

We present the case of a 67 year-old patient that presented to our institution with acute and severe chest pain. Optical coherence tomography high-resolution images of the coronary lumen, allowed us to confirm diagnosis of spontaneous coronary artery dissection, guide treatment, and verify the results of our intervention.