Pattern recognition in medical imaging

最近在模式识别方面的研究表明，计算机可以与人类专家的图像分类和模式分析相提并论，甚至超过它们。现代成像系统在空间和光谱分辨率以及动态范围方面远远超过人眼，因此潜在地允许基于机器的图像模式分析系统执行此类任务。 我们开发、表征和发布的图案分析系统称为WND-Charm。WND-Charm的一个关键特性是它可以提供图像相似度的量化度量。各个图像或图像组之间的定量比较允许建立由图像表示的生理过程的进程的时间进程。计算机能够在没有先验知识的情况下按顺序排列这些图像，这是对过程中形态模式的连续演变被计算机检测到的独立验证。随后，从一个时间点到另一个时间点的变化程度可以用来确定生理过程是平稳和连续的，还是经历了离散的阶段。不连续的过程意味着在过渡阶段存在生物防治，并可能指向医疗干预的关键阶段。 我们发表的工作表明，线虫咽部与年龄相关的肌肉退化(石棺减少)发生在三个不同的阶段。这是对任何生物体中离散的发育后形态状态的第一次表征。观察到肌肉退化是分阶段发生的，这意味着它可能是一个受调控的过程，可能需要采取干预措施来防止或推迟这些转变。我们目前的工作将调查这些阶段是否可以在哺乳动物组织中持续观察到，以及饮食和药物白藜芦醇等干预措施是否会影响这些形态变化的时间或幅度。 我们还发表了我们的研究工作，包括巴尔的摩老龄化纵向研究(BLSA)，调查人类骨关节炎(OA)的进展。我们能够证明，WND-Charm能够诊断膝关节X光片中存在的骨性关节炎，其准确度接近一组训练有素的放射科医生。最近，我们发表了一项工作，即WND-Charm可以预测未来在X光中可检测到的放射学可检测到的骨关节炎的发病情况，这些X射线被评为放射学清晰。我们能够证明，根据一个由三位放射科医生组成的小组打分为无骨性关节炎的X光片，可以用70%的准确率预测未来20年中度骨性关节炎的发展。我们目前在骨性关节炎方面的工作是对来自骨关节炎倡议组织的5000例核磁共振扫描进行分析。 我们对H&E染色的癌活检切片图像的处理工作表明，切片和染色的一致性是医学样本有效图像分析的关键因素。我们对黑色素瘤转移的初步诊断和子分类的成功使我们将这一分析扩展到对几种可用于商业组织微阵列的癌症类型的调查。我们在这项初步调查中取得成功之后，将对前列腺癌的形态/生理学和诊断/预后之间的关系进行更详细的研究，形态和预后之间的联系已经建立起来。

Recent work in pattern recognition has demonstrated that computers can equal or even surpass image classification and pattern analysis by human experts. Modern imaging systems far exceed the human eye in spatial and spectral resolution as well as dynamic range, thus potentially allowing machine-based image pattern analysis systems to perform such tasks. The pattern analysis system we have developed, characterized and published is called WND-CHARM. A key property of WND-CHARM is that it can provide quantitative measures of image similarity. Quantitative comparisons between individual images or groups of images allow the establishment of a time-course for the progression of a physiological process represented by images. An independent verification that the continuous evolution of morphological patterns in a process are detected by the computer is its ability to place these images in order without a priori knowledge. Subsequently, the degree of change from one timepoint to another can be used to determine if the physiological process is smooth and continuous, or progresses through discrete stages. Discontinuous processes imply the presence of biological control at the transitions, and may point to key stages for medical interventions. Our published work has shown that age-related muscle degeneration (sarcopenia) in the C. elegans pharynx occurs in three discrete stages. This was the first characterization of discrete post-developmental morphological states in any organism. The observation that muscle degeneration occurs in stages implies that it may be a regulated process, and may be subject to interventions to prevent or delay these transitions. Our current work will investigate if these stages can be consistently observed in mammalian tissues, and whether interventions such as diet and the drug resveratrol affects the timing or magnitude of these morphological changes. We have also published our work on investigating the progression of osteoarthritis (OA) in the human population comprising the Baltimore Longitudinal Study of Aging (BLSA). We were able to show that WND-CHARM is able to diagnose the existence of OA in knee X-Rays with accuracies approaching that of a panel of highly trained radiologists. More recently, we have published work that WND-CHARM can predict the future onset of radiologically detectable osteoarthritis in X-Rays that were scored as radiologically clear. We were able to show that the development of moderate OA two decades in the future can be predicted with > 70% accuracy from an X-Ray scored as free of OA by a panel of three radiologists. Our current work in OA continues with the analysis of 5000 MRI scans from the Osteoarthritis Initiative. Our work with processing images of H&E-stained sections of cancer biopsies has shown that consistency of sectioning and staining is a key factor in effective image analysis of medical samples. Our initial success diagnosing and sub-classifying melanoma metastases has led us to expand this analysis to a survey of several types of cancers available as commercial tissue microarrays. Our success with this pilot survey will be followed by a more detailed study of the association between morphology/physiology and diagnosis/prognosis in prostate cancer, where a link between morphology and prognosis is already established.