高频超声测量掌指关节软骨厚度稳定性的影响因素

目的 探讨影响第2掌指关节（MCP2）软骨厚度（CTh）高频超声测量结果稳定性的因素。方法 对120名健康志愿者分别由不同操作者于不同时间、仪器、参数（频率、增益）及测量时包含或不包含软骨上方亮线（BL）条件下测量右侧MCP2的CTh，并进行统计学分析。结果 包含和不包含BL测量时，右侧MCP2的CTh分别为（0.50±0.09）mm和（0.38±0.09）mm，差异有统计学意义（t=-18.528，P<0.001），二者的变异系数分别为4.44%和5.78%。相同仪器及参数条件下，不同操作者及不同时间，无论包含或不包含BL的测量结果间差异均无统计学意义（P均>0.05）。同一操作者相同参数条件下，采用不同仪器测量时，包含或不包含BL的测量结果间差异均有统计学差异（P均<0.05）。同一操作者相同仪器条件下，采用不同参数测量结果显示，仅相同频率、不同增益条件下不包含BL的测量结果间差异有统计学意义（P<0.05）。无论包含或不包含BL，不同操作者、时间、仪器、参数条件下测量结果间均存在相关性（P均<0.01）。包含BL的测量结果显示，相关系数在不同仪器条件下最小（r=0.619），不同增益条件下最大（r=0.820）。结论 高频超声测量右侧MCP2的CTh时，包含BL较不包含BL的测量结果更稳定。更换超声仪器对测量结果的影响最大，增益变化对测量结果的影响较小。

Impact factors of cartilage thickness measurement stability of metacarpophalangeal joints using high-frequency ultrasound

Objective To investigate the impact factors of stability of high-frequency ultrasound in measurement of cartilage thickness (CTh) of the second metacarpophalangeal joint (MCP2). Methods Under the conditions of different operator, time, instrument, parameters (frequency and gain) and whether including the bright line (BL) above cartilage or not, CTh of the right MCP2 in 120 healthy volunteers were measured with high-frequency ultrasound. Then statistical analysis was performed. Results CTh of the right MCP2 was (0.50±0.09)mm including BL and (0.38±0.09)mm excluding BL, respectively (t=-18.528, P<0.001), and the variable coefficient was 4.44% and 5.78%, respectively. Under the same instrument and parameters, there was no statistical difference between the measurement results of different operators and time, whether including BL or not (all P>0.05). Under the same operator and parameters, there were statistical differences between the measurement results of different instrument, whether including BL or not (both P<0.05). Under the same operator and instrument, there were statistical differences between the measurement results of excluding BL with variable gain and stable frequency (P<0.05). Whether including BL or not, there were correlations between the measurement results of different operator, time, instrument and parameters (all P<0.01). The measurement results including BL showed that the correlation was slight between different instrument (r=0.619) but obvious between different gain (r=0.820), respectively. Conclusion High-frequency ultrasound measurement results of the right MCP2 CTh including BL are more stable than those excluding BL. Instrument has great influence on measurement results, while gain has little effect for measurement.