Inter-Evaluator Reliability of Sagittal and Rotational Spinal Measurements from 3D Ultrasound Imaging of Healthy Females in Standing with Varying Arm Positions

ABSTRACT

Spinal alignment can be assessed without radiation using three-dimensional ultrasound imaging (3DUS). Reliable measurements could inform the ideal arm position for scoliosis radiographs. This study determined the inter-evaluator reliability of axial vertebral rotation (AVR) measurements and sagittal curve angles in healthy females from 3DUS spinal images in standing with two common radiograph arm positions: Chin and abduction (Abd). Three novice evaluators (R1, R2, and R3) measured images once. The Bland–Altman bias and limits of agreement (LOA) were calculated. T5-T12 kyphosis measurements met our bias and LOA error threshold only for R1 vs R2 in the Chin position [−0.53° (−10.7,9.7)]. The distance between the bias and the LOA also met our acceptable threshold of 5° for all mean AVRTwist, and all but one AVRTwist measurements (R1-R2_Chin = 5.9°). Three lordosis measurements did not meet our acceptable threshold (R1-R2_Chin, R1-R3_Chin, and R2-R3_Abd). The inter-evaluator reliability of novice evaluators was adequate and did not differ significantly between positions.

KEYWORDS:

• ultrasound imaging
• vertebral rotation
• kyphosis
• lordosis
• reproducibility of results

Acknowledgments

We would like to acknowledge the assistance of Sarah Bruha in acquiring the ultrasound image files. We would also like to thank the study participants and their families for their time during the duration of our study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author (EP), upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/1091367X.2024.2347629

Additional information

Funding

The data collection for this work was supported by the Scoliosis Research Society under Standard Research Grant 974124, and the Alberta Spine Foundation under Grant B.Fehr 2022.