Abstract

Objective

To determine inter- and intra-reader reproducibility of shear wave elastography measurements for musculoskeletal soft tissue masses.

Materials and methods

In all, 64 patients with musculoskeletal soft tissue masses were scanned by two readers prior to biopsy; each taking five measurements of shear wave velocity (m/s) and stiffness (kPa). A single lesion per patient was scanned in transverse and cranio-caudal planes. Depth measurements (cm) and volume (cm³) were recorded for each lesion, for each reader. Linear mixed modelling was performed to assess limits of agreement (LOA), inter- and intra-reader repeatability, including analyses for measured depth and volume.

Results

Of the 64 lesions scanned, 24 (38%) were malignant. Bland-Altman plots demonstrated negligible bias with wide LOA for all measurements. Transverse velocity was the most reliable measure—intraclass correlation (95% CI) = 0.917 (0.886, 1)—though reader 1 measures could be between 38% lower and 57% higher than reader 2 [ratio-scale bias (95% LOA) = 0.99 (0.64, 1.55)]. Repeatability coefficients indicated most disagreement resulted from poor within-reader reproducibility. LOA between readers calculated from means of five repeated measurements were narrower—transverse velocity ratio-scale bias (95% LOA) = 1.00 (0.74, 1.35). Depth affected both estimated velocity and repeatability; volume also affected repeatability.

Conclusion

This study found poor repeatability of measurements with wide LOA due mostly to intra-reader variability. Transverse velocity was the most reliable measure; variability may be affected by lesion depth. At least five measurements should be reported with LOA to assist future comparability between shear wave elastography systems in evaluating soft tissue masses.

中文翻译：

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剪切波弹性成像测量对肌肉骨骼软组织肿块的阅读器间和阅读器内重现性

摘要

目的

为了确定剪切波弹性成像测量对肌肉骨骼软组织肿块的读者之间和读者之间的可重复性。

材料和方法

总共有64位肌肉骨骼软组织肿块患者在进行活检之前由两名阅读器进行了扫描；每次测量剪切波速度（m / s）和刚度（kPa）五次。在横断面和颅尾平面中对每位患者的单个病变进行扫描。对于每个阅读器，记录每个病变的深度测量值（cm）和体积（cm ³）。进行线性混合建模以评估一致性极限（LOA），阅读器间和阅读器内重复性，包括对测得的深度和体积的分析。

结果

在扫描的64个病变中，有24个（38％）是恶性的。布兰特-奥特曼（Bland-Altman）图显示，对于所有测量而言，具有宽广的LOA的偏差可忽略不计。横向速度是最可靠的度量标准-类内相关性（95％CI）= 0.917（0.886，1）-尽管阅读器1的度量值可能比阅读器2的度量值低38％至57％（比例误差（95％LOA） = 0.99（0.64，1.55）]。重复性系数表明大多数分歧是由于阅读器内部的可重复性差所致。通过五次重复测量计算得出的阅读器之间的LOA较窄-横向速度比比例偏差（95％LOA）= 1.00（0.74，1.35）。深度会影响估计的速度和可重复性；体积也影响可重复性。

结论

这项研究发现，由于阅读器内部的变异性，具有广泛LOA的测量的可重复性差。横向速度是最可靠的测量方法。病变深度可能会影响变异性。LOA至少应报告五个测量值，以帮助将来在评估软组织肿块时剪切波弹性成像系统之间的可比性。