Robot-Assisted US-Based Vertebral Segmentation for Pedicle Screw Trajectory Identification

NCT05904418 | Completed DMC

• 1 other identifier: W1001
• Study Type: interventional
• Target: 63
• Locations: 1 country
• Sites: 1

Brief Summary

This other clinical trial compares robot-assisted US scanning with handheld US scanning and ground-truth CT data of the lumbar spine in healthy, young volunteers. The main questions it aims to answer are:

• Is a 3D reconstruction of a lumbar spine from robot-assisted US scanning equivalent to or better quality than a 3D reconstruction from handheld US scanning?
• Can a machine learning algorithm automatically segment the bone anatomy from robot-assisted and handheld US scanning to generate 3D lumbar spine reconstructions?
• Can pedicle screw trajectories be identified based on posterior vertebral landmarks of 3D reconstructions of lumbar spines from both robot-assisted and handheld US scanning? Participants will:
• fill out a medical history questionnaire
• get clinically examined
• have an ultra-low-dose (ULD) CT Scan of the vertebra L1 to S1
• have a handheld US scan of the vertebra L1 to S1
• have a robot-assisted US Scan of the vertebra L1 to S1
• fill out a post-study questionnaire

Conditions

Healthy

Keywords

lumbar spine; healthy, young volunteers; handheld ultrasound scan; robot-assisted ultrasound scan; CT scan

Outcome Measures

Primary Outcomes (3)

• Target registration errors between US reconstructions and ground truth CT data

  Evaluating the accuracy of the US reconstructions

  Up to 1 year

• Pedicle screw placement - Trajectory errors in terms of position

  Evaluating the positional accuracy of the Pedicle screw placement

  Up to 1 year

• Pedicle screw placement - Trajectory errors in terms of direction

  Evaluating the directional accuracy of the Pedicle screw placement

  Up to 1 year

Secondary Outcomes (6)

• Gender

  Up to 4 weeks

• Age

  Up to 4 weeks

• Smoking status

  Up to 4 weeks

• BMI

  Up to 4 weeks

• Tegner activity score

  Up to 4 weeks

Study Arms (1)

Young, healthy volunteers

OTHER

1. Medical History (20 minutes) 2. Clinical examination (20 minutes) 3. Clothes changing time (15 minutes) 4. ULD CT scan of the vertebra L1 to S1 (30 minutes) 5. Clothes changing time (15 minutes) 6. Handheld US scan of the vertebra L1 to S1 (20 minutes) 7. Platform changing time (15 minutes) 8. Path planning and robot-assisted US Scan of the vertebra L1 to S1 (40 minutes) 9. Clothes changing time (15 minutes) 10. Volunteer Questionnaire (10 minutes) Total study time per volunteer: 3 Hours 20 minutes

Other: Robot-assisted US Scan of the vertebra L1 to S1; Other: Handheld US scan of the vertebra L1 to S1; Radiation: ULD CT scan of the vertebra L1 to S1

Interventions

Robot-assisted US Scan of the vertebra L1 to S1 OTHER

A standardized robot-assisted US-Scan of the vertebra L1 to the S1 is executed. The two probe trajectories are generated automatically by an optical camera or RedGreenBlue-Depth (RGB-D) camera. Then the robot will scan at two mm/s, automatically following the trajectory. A 6 degrees of freedom (DoF) force sensor (Nano25, Ati Industrial Automation Inc.) was assembled at the US probe. During the scanning, it measures the interaction force and torque between the US probe and volunteers' skin to ensure volunteer safety. The US images and corresponding robot poses are recorded for the reconstruction. A previously developed algorithm is used to obtain a preliminary 3D reconstruction that will be used to adapt the scanning pattern in case of incomplete scanning.

Young, healthy volunteers

Handheld US scan of the vertebra L1 to S1 OTHER

A handheld US-Scan of the vertebra L1 to S1 is executed. An optical marker for an Atracsys Camera is mounted to the US probe to track its position. Simultaneously, the optical tracking allows for standardization of the US-Scan through navigation. The acquired US images and corresponding poses are used to reconstruct the lumbar spines and compared to the ground truth (CT scan). Handheld US scanning will be performed at around two mm/s in two scanning trajectories. The US probe orientation will be adjusted during the scanning by comparing the optical marker orientation with the initial probe orientation. This combination leads to different scanning patterns. For each pattern, the scanning procedure will be repeated three times. At least once per volunteer, each handheld scanning pattern will be performed with a higher manual speed to assess the reconstruction quality with faster scanning. A graphical user interface (GUI) will synchronize and store the data during the scanning.

Young, healthy volunteers

ULD CT scan of the vertebra L1 to S1 RADIATION

A ULD CT scan (CT, Siemens Naeotom Alpha: A-207883-62) of the lumbar spine (L1-S1) is performed at the Swiss Center for Musculoskeletal Imaging (SCMI) at Balgrist Campus, Zurich. The total duration estimate for the CT examination is 30 minutes, whereas the scan takes 15 minutes. The volunteers lie on their abdomen during this procedure to simulate the spine's position during the subsequent US examination. The vertebrae (L1-S1) in the CT Scans are manually segmented with global thresholding and the region growing tool in a standard segmentation software (Materialise Mimics, Leuven, Belgium). The 3D surface models are then exported as Standard Triangle Language (STL) files.

Young, healthy volunteers

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Oral and written informed consent from the volunteer
• Volunteers aged ≥18 y/o and ≤35 y/o
• BMI above or equal to 19 kg/m2 or below or equal to 25 kg/m2
• Proficient in German or English language

You may not qualify if:

• Documented volunteer refusal
• Volunteers in whom CT cannot be performed
• Positive pregnancy test prior to radiology (contraindication to CT)
• Pregnancy
• Chronic pain in the lumbar spine
• Moderate or severe deformity of the lumbar spine
• Any prior intervention to the lumbar spine:
• Chiropractic adjustment therapy
• Injections such as local anesthetics and corticosteroids
• Surgery
• Fracture of the lumbar spine
• BMI below 19 kg/m2 or above 25 kg/m2
• Anatomies, such as subcutaneous fat or tendon, occlude the bony surface or do not allow a clear image in the US scan

Sponsors & Collaborators

• Philipp Fürnstahl: lead
• Swiss Center for Musculoskeletal Imaging: collaborator
• KU Leuven: collaborator

Study Sites (1)

University Hospital Balgrist, Balgrist Campus

Zurich, 8008, Switzerland

Location

Study Officials

• Philipp Fürnstahl, PhD

  Balgrist University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: No masking
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof. Dr. Sc., Assistant Professor in Orthopedic Computer Science

Model Details: All enrolled participants have to go through the previously mentioned interventions

Study Record Dates

• First Submitted: May 3, 2023
• First Posted: June 15, 2023
• Study Start: May 15, 2023
• Primary Completion: June 9, 2023
• Study Completion: June 9, 2023
• Last Updated: June 22, 2023

Record last verified: 2023-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: We plan to make the IPD available within 24 months of data acquisition or after peer-reviewed publication.
• Access Criteria: First we evaluate the access by request. After intellectual property (IP) and publications are completed we will consider open-access for other research group.

Locations

CH (1)