Mathison Blaine A, Kohan Jessica L, Walker John F, Smith Richard Boyd, Ardon Orly, Couturier Marc Roger
ARUP Laboratories, Salt Lake City, Utah, USA.
Techcyte, Inc., Lindon, Utah, USA.
J Clin Microbiol. 2020 May 26;58(6). doi: 10.1128/JCM.02053-19.
Intestinal protozoa are responsible for relatively few infections in the developed world, but the testing volume is disproportionately high. Manual light microscopy of stool remains the gold standard but can be insensitive, time-consuming, and difficult to maintain competency. Artificial intelligence and digital slide scanning show promise for revolutionizing the clinical parasitology laboratory by augmenting the detection of parasites and slide interpretation using a convolutional neural network (CNN) model. The goal of this study was to develop a sensitive model that could screen out negative trichrome slides, while flagging potential parasites for manual confirmation. Conventional protozoa were trained as "classes" in a deep CNN. Between 1,394 and 23,566 exemplars per class were used for training, based on specimen availability, from a minimum of 10 unique slides per class. Scanning was performed using a 40× dry lens objective automated slide scanner. Data labeling was performed using a proprietary Web interface. Clinical validation of the model was performed using 10 unique positive slides per class and 125 negative slides. Accuracy was calculated as slide-level agreement (e.g., parasite present or absent) with microscopy. Positive agreement was 98.88% (95% confidence interval [CI], 93.76% to 99.98%), and negative agreement was 98.11% (95% CI, 93.35% to 99.77%). The model showed excellent reproducibility using slides containing multiple classes, a single class, or no parasites. The limit of detection of the model and scanner using serially diluted stool was 5-fold more sensitive than manual examinations by multiple parasitologists using 4 unique slide sets. Digital slide scanning and a CNN model are robust tools for augmenting the conventional detection of intestinal protozoa.
肠道原生动物在发达国家导致的感染相对较少,但检测量却出奇地高。粪便的手动光学显微镜检查仍是金标准,但可能不够灵敏、耗时且难以保持检测能力。人工智能和数字玻片扫描有望通过使用卷积神经网络(CNN)模型增强寄生虫检测和玻片解读,从而彻底改变临床寄生虫学实验室。本研究的目的是开发一种灵敏的模型,该模型可以筛选出阴性的三色染色玻片,同时标记潜在的寄生虫以便人工确认。在深度CNN中将传统原生动物训练为“类别”。根据标本可用性,每个类别使用1394至23566个样本进行训练,每个类别至少有10张不同的玻片。使用40倍干镜物镜自动玻片扫描仪进行扫描。使用专有的网络界面进行数据标记。使用每个类别10张不同的阳性玻片和125张阴性玻片对模型进行临床验证。准确性通过与显微镜检查的玻片水平一致性(例如,是否存在寄生虫)来计算。阳性一致性为98.88%(95%置信区间[CI],93.76%至99.98%),阴性一致性为98.11%(95%CI,93.35%至99.77%)。该模型在包含多个类别、单个类别或无寄生虫的玻片上显示出极好的可重复性。使用连续稀释粪便时,该模型和扫描仪的检测限比多位寄生虫学家使用4套不同玻片进行的手动检查灵敏5倍。数字玻片扫描和CNN模型是增强肠道原生动物传统检测的强大工具。