3DUS Examination of the Effect of Arm Position on the Spine Alignment Adolescent Idiopathic Scoliosis (AIS)

University of Alberta


Adolescent idiopathic scoliosis (AIS) is a 3D spine deformity with lateral curvature, vertebral rotation, and sagittal changes. Clinicians detect progression using x-rays every 6 months during growth. Many centres have recently acquired low-dose stereo-radiographic systems to simultaneously acquire a frontal and a sagittal image of the spine. To obtain a good x-ray image that shows both the front and side view of the spine, the arms must be elevated, and this has shown to affect the sagittal angles.

We have a poor understanding of how to best capture the best habitual standing image of the spine. It is currently unclear which arm positions used during imaging best represent the habitual standing image of the spine. Capturing the hands in the same image will help avoid unnecessary x-ray radiation exposure and simplify patient flow. Spinal alignment can be quantified repetitively using non-invasive 3D ultrasound (3DUS) imaging to propose the most accurate arm position for radiography.

The objective of this research is to find which arm positions could be used to acquire simultaneous frontal and lateral radiographs that best represent habitual standing posture as measured using the angle of vertebral rotation (AVR), frontal, and sagittal curve angles extracted from 3DUS images; and do any of the positions simultaneously allow for skeletal maturity assessment in healthy populations?

Roles and Responsibilities

We are looking for patients with diagnosis of AIS to attend a 1-hour 3DUS scan that will help us understand the best imaging position for x-rays for future patients with AIS.

During the scans, patients will be explained the impact of their time and the possible outcomes from this project – most notably, the goal to reduce radiation exposure to future patients with AIS. During the scans, patients will be asked which positions are most comfortable for them. This may possibly influence our results by eliminating positions that are uncomfortable for patients to hold for a duration of time.

Time Commitment

Patients are asked only to come to the University of Alberta for a one-time visit that will last approximately 1 hour in total.

The start date of this project was July 2021 and the completion date is anticipated for July 2023.


In addition to free parking, patient participants will be offered $10 token of appreciation.

Approved by the Health Research Ethics Board at University of Alberta Pro00111811

For more information or to apply, please connect with
Brianna Fehr
Eric Parent

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