Digital pathology: current status and future perspectives

During the last decade pathology has benefited from the rapid progress of image digitizing technology. The improvement in this technology had led to the creation of slide scanners which are able to produce whole slide images (WSI) which can be explored by image viewers in a way comparable to the conventional microscope. The file size of the WSI ranges from a few megabytes to several gigabytes, leading to challenges in the area of image storage and management when they will be used routinely in daily clinical practice. Digital slides are used in pathology for education, diagnostic purposes (clinicopathological meetings, consultations, revisions, slide panels and, increasingly, for upfront clinical diagnostics) and archiving. As an alternative to conventional slides, WSI are generally well accepted, especially in education, where they are available to a large number of students with the full possibilities of annotations without the problem of variation between serial sections. Image processing techniques can also be applied to WSI, providing pathologists with tools assisting in the diagnosis-making process. This paper will highlight the current status of digital pathology applications and its impact on the field of pathology.     

颈椎椎弓根技术在下颈椎疾患应用的临床疗效观察

[目的]探讨颈椎椎弓根内固定技术在下位颈椎疾患应用的临床疗效。[方法]回顾2000年8月~2007年8月对118例患者,置入490枚椎弓根螺钉治疗下颈椎疾患,其中颈椎骨折脱位81例,颈椎病合并椎管狭窄21例,颈椎黄韧带骨化11例,颈椎后突畸形2例,强直性脊柱炎3例。术前应用图像存储传输系统(简称PACS),采用X线片及64排CT片,对患者下位颈椎椎弓根的冠状位、矢状位、横断位进行精确测量,得出椎弓根的长度、宽度、高度、向内侧倾斜、向头侧倾斜角度的数据值,以指导术中选钉及置钉。术中应用自行研制的颈椎椎弓根定位导向器,准确定位入钉点及角度,打孔、置钉、固定。[结果]术后102例患者获13~65个月随访,平均随访时间18.95个月。采用JOA评分标准[1],结果:优82例,良15例,可3例,差2例,优良率95.01%。术后X线及CT示固定节段稳定,颈椎椎体高度和生理曲度维持良好,内固定位置良好,无植骨块脱出或钢板、螺钉松动、断裂等并发症,无脊髓及椎动脉损伤。2例患者植骨块吸收未融合,融合率为97.04%。[结论]下颈椎椎弓根螺钉技术是相对安全的操作,可用于需从后路固定的颈椎疾患病例,可维持良好的颈椎生理曲度,远期临床效果满意。     

T-PACS系统在构架新型医学教学体系中的应用

T-PACS教学系统是在放射信息系统(RIS)和医学影像存档与传输系统(PACS)的基础上,建成的用于医学影像学教学的多媒体网络教学系统.应用T-PACS系统终端进行影像学的教与学,是构建医学教学新体系的重要环节.由于其具有实用、高效、资源共享等优势,可将多种影像手段、多学科的知识综合示教,让学生对医学影像学知识有更直观的认识,从而对医学教学新体系的构建起到积极的意义.     

Interoperative fundus image and report sharing in compliance with integrating the healthcare enterprise conformance and web access todigital imaging and communication in medicinepersistent object protocol

AIM:To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS) framework in conformance with digital imaging and communication in medicine (DICOM) and health level 7 (HL7) protocol to realize fundus images and reports sharing and communication through internet.METHODS: Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE) Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO) protocol, which contains three tiers.RESULTS:In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME) type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images.CONCLUSION:Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.     

PACS在颈椎后方结构测量及其临床意义

目的　利用图像存储传输系统(PACS)结合CT片测量颈椎后方解剖学结构,为临床颈椎椎弓根置钉提供资料。 方法　利用PACS结合CT片,由5名脊柱外科医师对2000例正常人颈椎椎弓根的矢状位及横断为进行精确测量,得出椎弓根的长度、宽度、高度、向内侧倾斜、向头、尾侧倾斜角度的数据值, 并分别计算各节段左右侧椎弓根测量值的均值和标准差,进行统计学分析。 结果　寰椎入钉点距离一般在后弓中点旁开17～20 mm,在C2～7各椎弓根均有髓腔,C2～7椎弓根的高度大于宽度,C3、C4椎弓根直径最小,仍可置入3.5 mm的螺钉。寰枢椎螺钉在矢状面入钉角向头侧倾斜为正角,下颈椎螺钉向尾侧倾斜为负角,C4接近水平, C5～7负角逐渐增大, C7可达-19°左右。在横断位上测量的椎弓根的进钉角度显示,其中C2最小,下颈椎椎弓根具有变异性,术前利用CT片通过PACS进行精确测量,指导术中准确选钉与安全置钉具有指导性意义。 结论　应用PACS系统结合CT片术前测量,能够指导术中安全置入颈椎椎弓根螺钉,明显减少并发症,是一种值得推广的方法。     

应用螺旋CT分层扫描及PACS图像分析技术在枢椎个体化置钉手术中的应用

[目的]探讨高速螺旋CT分层扫描及影像存档和通信系统(picture archiving and communication system,PACS)图像分析技术在枢椎个体化置钓手术中的应用价值.[方法]60例共120侧枢椎椎弓根,术前接受螺旋CT分层连续扫描,根据椎动脉孔及椎弓根扫描结果判断椎弓根类型,并测量椎弓根长度,内倾角等指标,为手术提供参考.[结果] 120侧枢椎椎弓根经CT薄扫后,其椎动脉孔分型为:Ⅰ型70侧、Ⅱ型20侧、Ⅲ型18侧、Ⅳ型12侧.选择其中的100侧椎弓根实施螺钉固定,术后CT钉道扫描显示97枚螺钉位于椎弓根管内,位置良好;3枚椎弓根螺钉偏外,指向或进入椎动脉孔.未出现偏向椎管的病例.置钉总成功率97％,置钉失误率3％.[结论]①基于枢椎椎动脉特征型的椎弓根分类判断方法对于判断枢椎椎弓是否适合置钉具有重要价值;②术前对患者枢椎椎弓根进行螺旋CT分层扫描后,测量相关数据,判断枢椎椎弓根的类型,并进行术前钉道设计与测量有助于提高枢椎椎弓根螺钉的置钉成功率.     

PACS在中医院校影像科实习带教中的运用

医学影像学是一门实践性很强的学科;图像存储与传输系统( Picture archiving and communication system,PACS)为影像诊断学的临床教学提供了便捷而行之有效的方法,便于教学资料的使用和管理,便于学生的自主学习及个体化教学辅导,还便于新的教学模式的探索和应用;在中医院校学生的临床教学中优势更为明显.     

The effect of Gaussian noise on pneumonia detection on chest radiographs,using convolutional neural networks

IntroductionChest X-rays (CXR) with under-exposure increase image noise and this may affect convolutional neural network (CNN) performance. This study aimed to train and validate CNNs for classifying pneumonia on CXR as normal or pneumonia acquired at different image noise levels.MethodsThe study used the curated and publicly available “Chest X-Ray Pneumonia” dataset of 5856 AP CXR classified into 1583 normal, 4273 viral and bacterial pneumonia cases. Gaussian noise with zero mean was added to the images, at 5 image noise variance levels, corresponding to decreasing exposure. Each noise-level dataset was split into 80% for training, 10% for validation, and 10% for test data and then classified using custom trained sequential CNN architecture. Six classification tasks were developed for five Gaussian noise levels and the original dataset. Sensitivity, specificity, predictive values and accuracy were used as evaluation performance metrics.ResultsCNN evaluation on the different datasets revealed no performance drop from the original dataset to the five datasets with different noise levels. Sensitivity, specificity and accuracy for the normal datasets were 98.7%, 76.1% and 90.2%. For the five Gaussian noise levels the sensitivity, specificity and accuracy ranged from 96.9% to 98.2%, 94.4%–98.7% and 96.8%–97.6%, respectively. A heat map was used for visual explanation of the CNNs.ConclusionThe CNNs sensitivity maintained, and the specificity increased in distinguishing between normal and pneumonia CXR with the introduction of image noise.Implications for practiceNo performance drops of CNNs in distinguishing cases with and without pneumonia CXR with different Gaussian noise levels was observed. This has potential for decreasing radiation dose to patients or maintaining exposure parameters for patients that require additional radiographs.     

Tumor and Ablation Margin Visibility during Cryoablation of Musculoskeletal Tumors: Comparing Intraprocedural PET/CT Images with CT-Only Images

PurposeTo compare tumor and ice-ball margin visibility on intraprocedural positron emission tomography (PET)/computed tomography (CT) and CT-only images and report technical success, local tumor progression, and adverse event rates for PET/CT-guided cryoablation procedures for musculoskeletal tumors.Materials and MethodsThis Health Insurance Portability and Accountability Act (HIPAA)–compliant and institutional review board–approved retrospective study evaluated 20 PET/CT-guided cryoablation procedures performed with palliative and/or curative intent to treat 15 musculoskeletal tumors in 15 patients from 2012 to 2021. Cryoablation was performed using general anesthesia and PET/CT guidance. Procedural images were reviewed to determine the following: (a) whether the tumor borders could be fully assessed on PET/CT or CT-only images; and (b) whether tumor ice-ball margins could be fully assessed on PET/CT or CT-only images. The ability to visualize tumor borders and ice-ball margins on PET/CT images was compared with that on CT-only images.ResultsTumor borders were fully assessable for 100% (20 of 20; 95% CI, 0.83–1) of procedures on PET/CT versus 20% (4 of 20; 95 CI, 0.057–0.44) of procedures on CT only (P < .001). The tumor ice-ball margin was fully assessable in 80% (16 of 20; 95% CI, 0.56–0.94) of procedures using PET/CT versus 5% (1 of 20; 95% CI, 0.0013–0.25) of procedures using CT only (P < .001). Primary technical success was achieved in 75% (15 of 20; 95% CI, 0.51–0.91) of procedures. There was local tumor progression in 23% (3/13; 95% CI, 0.050–0.54) of the treated tumors with at least 6 months of follow-up. There were 3 adverse events (1 Grade 3, 1 Grade 2, and 1 Grade 1).ConclusionsPET/CT-guided cryoablation of musculoskeletal tumors can provide superior intraprocedural visualization of the tumor and ice-ball margins compared with that provided by CT alone. Further studies are warranted to confirm the long-term efficacy and safety of this approach.