Calcium pyrophosphate crystal size and characteristics.
Calcium pyrophosphate crystal size and characteristics.
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DOI：
10.1016/j.ocarto.2020.100133
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发表时间：
2021-03-01
期刊：
影响因子：
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通讯作者：
FitzGerald, John D
中科院分区：
文献类型：
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作者：
Zell, Monica;Aung, Thanda;FitzGerald, John D
目的：研究补偿偏光显微镜（CPLM）下焦磷酸钙（CPP）的晶体大小和形态特征。其次，描述只能通过数字增强CPLM图像看到的CPP晶体，并通过先进的成像技术证实。方法：采集16例关节抽吸者临床实验室鉴定的pcp阳性滑液标本。四名评级员使用一种标准化的协议来描述晶体形状、双折射强度和颜色。晶体专家证实了cplm可视化晶体识别。在晶体测量中，采用了高通线性滤光片来提高数字图像的分辨率和线分辨能力。该过程确定了在CPLM下评分者未见的额外增强晶体。单次计算偏振光显微镜（SCPLM）进一步证实了增强晶体的存在。结果：在932个经CPLM鉴定的疑似晶体中，569个符合纳入标准，其中293个（51%）为CPP晶体。175个晶体中，118个（67%）为棒状（中位面积3.6 mum2[范围，1.0-22.9 mum2]）， 57个（33%）为菱形（中位面积4.8 mum2[范围，0.9-16.7 mum2]）。仅经过数字图像增强后可见的晶体比cplm识别的晶体更小，双折射更少。结论：较小且双折射较弱的CPP晶体更难识别。可能有一群较小的，双折射较少的CPP晶体，通常无法被CPLM检测到。描述不可见晶体的特征可能有助于未来开发新的晶体鉴定方法。
OBJECTIVE: To describe the characteristics of calcium pyrophosphate (CPP) crystal size and morphology under compensated polarized light microscopy (CPLM). Secondarily, to describe CPP crystals seen only with digital enhancement of CPLM images, confirmed with advanced imaging techniques.METHODS: Clinical lab-identified CPP-positive synovial fluid samples were collected from 16 joint aspirates. Four raters used a standardized protocol to describe crystal shape, birefringence strength and color. A crystal expert confirmed CPLM-visualized crystal identification. For crystal measurement, a high-pass linear light filter was used to enhance resolution and line discrimination of digital images. This process identified additional enhanced crystals not seen by raters under CPLM. Single-shot computational polarized light microscopy (SCPLM) provided further confirmation of the enhanced crystals' presence.RESULTS: Of 932 suspected crystals identified by CPLM, 569 met our inclusion criteria, and 293 (51%) were confirmed as CPP crystals. Of 175 unique confirmed crystals, 118 (67%) were rods (median area 3.6 mum2 [range, 1.0-22.9 mum2]), and 57 (33%) were rhomboids (median area 4.8 mum2 [range, 0.9-16.7 mum2]). Crystals visualized only after digital image enhancement were smaller and less birefringent than CPLM-identified crystals.CONCLUSIONS: CPP crystals that are smaller and weakly birefringent are more difficult to identify. There is likely a population of smaller, less birefringent CPP crystals that routinely goes undetected by CPLM. Describing the characteristics of poorly visible crystals may be of use for future development of novel crystal identification methods.