Purpose: To develop a digital algorithm and validate a semi-quantitative scoring method for surface methylene blue (MB) staining in whole lymph nodes (LN). Methods: Lymph nodes from canine models undergoing sentinel lymph node (SLN) mapping were prospectively assessed ex vivo and photographed. Two blinded observers evaluated all images and assigned a semi-quantitative score based on surface staining (0 – no blue stain, 1 – 1-50% stained, 2 – 51-100% stained). A standard reference for degree of blue staining was based on signal-to-background ratios using computer-based imaging software with an output measurement of percentage of staining of the LN. Agreement between observers was assessed using the Kappa coefficient. Results: 124 lymph nodes were included and demonstrated strong agreement (K = 0.8007, p < 0.0001) between results of semi-quantitative scoring and image analysis. Also, strong interobserver and intraobserver agreement was observed for the scoring system (K = 0.8051, p < 0.0001 and K = 0.9493, p < 0.0001, respectively). Discussion: Agreement between the observer-based scoring system and imaging software illustrates a validated method in assessing MB staining, without the need for analysis software. The use of a semi-quantitative scoring system shows promise for a simple, objective assessment of MB staining in surgery and for future study. Lymph nodes can have variable surface colour, which can make assessment of blue staining challenging for novice observers in certain cases. This study describes a digital algorithm for quantitative analysis of blue staining in LN thereby providing a novel and objective reporting mechanism in scientific research involving SLN mapping.

中文翻译：

---

验证半定量方法以评估前哨淋巴结中亚甲蓝的染色程度

目的：开发一种数字算法并验证整个淋巴结（LN）表面亚甲蓝（MB）染色的半定量评分方法。方法：对前哨淋巴结（SLN）作图的犬模型的淋巴结进行前瞻性评估并拍照。两名视力不佳的观察者评估了所有图像，并根据表面染色（0 –无蓝色染色，1 – 1-50％染色，2 – 51-100％染色）分配了半定量评分。蓝色染色度的标准参考值是使用基于计算机的成像软件基于信噪比进行的，其输出测量值显示LN染色的百分比。使用Kappa系数评估观察者之间的一致性。结果：包括124个淋巴结并显示出强烈的一致性（K = 0.8007，p <0。0001）之间的半定量评分和图像分析。此外，在评分系统中观察者之间和观察者内部的一致性很强（分别为K = 0.8051，p <0.0001和K = 0.9493，p <0.0001）。讨论：基于观察者的评分系统和成像软件之间的协议说明了一种评估MB染色的经过验证的方法，而无需分析软件。半定量评分系统的使用显示了在手术中以及未来研究中对MB染色进行简单，客观评估的希望。淋巴结的表面颜色可能不同，这在某些情况下对新手观察者来说很难评估蓝色染色。