Low-dose Whole Body Computed Tomography Scanning

NCT ID: NCT03425032

Last Updated: 2018-11-27

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 520 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2016-09-30
• Study Completion Date: 2018-01-31

Brief Summary

Computed tomography represents the mainstay for diagnosing various diseases in the whole body. Over the past decade, enormous efforts were undertaken by both CT manufacturers and radiologist to reduce the radiation dose to patients. Today, the dose is significantly lower that it was before the era of multislice CT and iterative reconstruction methods. The X-ray beam originating from the tube in a CT system contains a spectrum of different energies, whereby the "harder" beams with higher energy penetrate the patient better, and the "softer" beams will be absorbed through the patient's tissues. Recent research has been shown that the radiation dose can be further reduced by improved primary beam filtering in CT. This study is intended to compare the radiation dose in clinically indicated, routine CT examination while maintaining a diagnostic image quality, on a new CT system with modified primary beam filtering.

Detailed Description

At the Joint Department of Medical Imaging (JDMI), the investigators periodically adjust the radiation dose and modify the clinical imaging protocols in order to continuously optimize image quality in CT. The investigators have formalized the process of radiation dose adjustments by implementing a CT dose committee that meets on a monthly basis and reviews imaging protocols (SOP). The committee includes radiologists, technologists, vendor representative (if needed), managers and the radiation protection officer. Part of the review is the investigator's in-house developed Coral image quality review program as well as the clinically used radiation dose monitoring software (Radiometric).

Part of the evaluation study of the new CT system is to monitor 520 patients who will undergo a clinically indicated CT scan on the new system. Identical to standard-of-care (SOC) quality insurance, the investigators will use the existing monitoring software (Radiometric, JDMI) in order to capture the data in the existing database. The investigators will also capture quality data through the existing CT image quality feedback tool. After installation of the new CT system, the investigators will maintain the radiation dose as currently applied in the standard JDMI wide imaging protocols and examine 20 patients on the new system; radiation dose and image quality feedback will be recorded in the identical fashion to standard operating procedures (CT image quality and radiation dose committee). Subsequently, the investigators will drop the dose by approx. 10% for each scanning protocol and scan the subsequent 250 patients while concurrently analyzing the impact on the collective dose to the patient population. Based on the expected increase in image noise, the investigators will calculate the possible additional dose reduction in percent and modify all protocols accordingly for the subsequent 250 patients. This step-down approach ensures that no CT scan will be performed with too little dose, and that all CT scans remain diagnostic.

Conditions

Computed Tomography; Image Quality

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Interventions

CT scanner

Regular CT imaging of the abdomen and pelvis

Intervention Type: DEVICE

Other Intervention Names

Genesis TSX-350A CT scanner

Eligibility Criteria

Inclusion Criteria

• Patients who are clinically scheduled for a CT of the body (any part, or a combination of different parts).

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Health Network, Toronto

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Patrik Rogalla

Role: PRINCIPAL_INVESTIGATOR

UHN

References

Zhang G, Marshall N, Jacobs R, Liu Q, Bosmans H. Bowtie filtration for dedicated cone beam CT of the head and neck: a simulation study. Br J Radiol. 2013 Aug;86(1028):20130002. doi: 10.1259/bjr.20130002. Epub 2013 May 31.

Reference Type: RESULT

PMID: 23728948 (View on PubMed)

Mail N, Moseley DJ, Siewerdsen JH, Jaffray DA. The influence of bowtie filtration on cone-beam CT image quality. Med Phys. 2009 Jan;36(1):22-32. doi: 10.1118/1.3017470.

Reference Type: RESULT

PMID: 19235370 (View on PubMed)

Tkaczyk JE, Du Y, Walter D, Wu X, Li J, Toth T. Simulation of CT dose and contrast-to-noise as function of bowtie shape. Proc SPIE 2004;5368:403-410

Reference Type: RESULT

Other Identifiers

16-5477

Identifier Type: -

Identifier Source: org_study_id