Intraepidermal nerve fiber density (IENFD) measurements in skin biopsy are performed manually by 1–3 operators. To improve diagnostic accuracy and applicability in clinical practice, we developed an automated method for fast IENFD determination with low operator-dependency. Sixty skin biopsy specimens were stained with the axonal marker PGP9.5 and imaged using a widefield fluorescence microscope. IENFD was first determined manually by 3 independent observers. Subsequently, images were processed in their Z-max projection and the intradermal line was delineated automatically. IENFD was calculated automatically (fluorescent images automated counting [FIAC]) and compared with manual counting on the same fluorescence images (fluorescent images manual counting [FIMC]), and with classical manual counting (CMC) data. A FIMC showed lower variability among observers compared with CMC (interclass correlation [ICC] = 0.996 vs 0.950). FIMC and FIAC showed high reliability (ICC = 0.999). A moderate-to-high (ICC = 0.705) was observed between CMC and FIAC counting. The algorithm process took on average 15 seconds to perform FIAC counting, compared with 10 minutes for FIMC counting. This automated method rapidly and reliably detects small nerve fibers in skin biopsies with clear advantages over the classical manual technique.

中文翻译：

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在皮肤活检中定量表皮内神经纤维的自动化方法与手动方法相比的优势

皮肤活检中的表皮内神经纤维密度 (IENFD) 测量由 1-3 名操作员手动执行。为了提高临床实践中的诊断准确性和适用性，我们开发了一种自动化方法，用于快速确定 IENFD，且操作员依赖性低。用轴突标记 PGP9.5 对 60 个皮肤活检标本进行染色，并使用宽视野荧光显微镜进行成像。IENFD 首先由 3 名独立观察员手动确定。随后，图像在其 Z-max 投影中进行处理，并自动描绘皮内线。IENFD 是自动计算的（荧光图像自动计数 [FIAC]），并与相同荧光图像上的手动计数（荧光图像手动计数 [FIMC]）和经典手动计数 (CMC) 数据进行比较。与 CMC 相比，FIMC 在观察者之间的变异性较低（类间相关性 [ICC] = 0.996 对 0.950）。FIMC 和 FIAC 表现出高可靠性（ICC = 0.999）。在 CMC 和 FIAC 计数之间观察到中到高 (ICC = 0.705)。算法过程执行 FIAC 计数平均需要 15 秒，而 FIMC 计数需要 10 分钟。这种自动化方法可以快速、可靠地检测皮肤活检中的小神经纤维，与传统的手动技术相比具有明显的优势。