News | October 14, 2011

U.K. Study Links Source-to-Image Distance, Image Quality

October 14, 2011 — A study published in the September/October issue of Radiologic Technology shows increasing the source-to-image distance for direct digital radiography (DR) pelvic examinations reduces radiation dose while maintaining image quality. RT is a journal of the American Society of Radiologic Technologists (ASRT).

Researchers from the United Kingdom investigated distance, dose and image quality for DR pelvic exams, the second most common Bucky procedure in the country.

To perform the study, the researchers positioned an anthropomorphic pelvic phantom for a standard anteroposterior examination. Using a single DR unit with a flat panel detector, they set an initial source-to-image distance of 100 cm and used an antiscatter focused radiation grid. The x-ray beam was collimated for a standard AP pelvic examination and was kept constant throughout the experiment, while source-to-image distance varied from 80-147 cm.

Two exposures were taken in 10-cm intervals to determine image quality, and the experiment was repeated without the grid. A total of 80 images were then sent to a reporting-grade picture archiving and communication workstation for image quality analysis. Researchers calculated the entrance surface dose and effective dose based on distances of 60 cm, 80 cm, 100 cm, 120 cm, 140 cm and 147 cm. 

The research results indicate that by increasing the source-to-image distance, both the entrance surface dose and effective dose decreased when using the antiscatter radiation grid; they decreased further when the grid was removed. At 147 cm, the decrease in entrance surface dose and effective dose when using a grid equated to a 25 percent reduction in radiation dose compared with standard parameters. 

“The optimization of radiation dose for both computed radiography and digital radiography examination is an essential part of radiographic practice,” said Andrew England, BSc(Hons), PgCert, MSc, FHEA, a study author and lecturer for the directorate of medical imaging and radiotherapy at the University of Liverpool. “Our lab-based phantom experiments have indicated that dose reduction is possible without loss of any image quality.” 

In addition, the findings suggest that as source-to-image distance increases, there also may be a minor increase in image quality, although it was determined to be statistically insignificant.     

Based on the study’s outcome, researchers recommended a clinical study involving patients is necessary to confirm the dose reduction potential of increasing source-to-image distances. “It is essential that any improvements to radiographic technique are carefully evaluated in a clinical setting as well as in the lab before we can promote the widespread adaption of any new techniques,” England said.

For more information: www.asrt.org

Related Content

Comparison of Screening Recommendations Supports Annual Mammography
News | Mammography | August 22, 2017
When to initiate screening for breast cancer, how often to screen, and how long to screen are questions that continue...
Sponsored Content | Videos | Digital Radiography (DR) | August 22, 2017
Jared Houk, vice president, imaging business unit, for Agfa HealthCare North America, previews the DR800 at AHRA 2017.
MRI Reveals Striking Brain Differences in People with Genetic Autism

Example images for a control participant , a deletion carrier, and a duplication carrier. In the sagittal image of the deletion carrier, the thick corpus callosum, dens and craniocervical abnormality, and cerebellar ectopia are shown. For the duplication carrier, the sagittal image shows the thin corpus callosum and the axial image shows the increased ventricle size and decreased white matter volume. Image courtesy of the Radiological Society of North America (RSNA).

News | Neuro Imaging | August 09, 2017
August 9, 2017 — In the first major study of its kind, researchers using magnetic...
Clinical Data Supports Use of Xoft System for Endometrial Cancer
News | Brachytherapy Systems | August 03, 2017
Researchers presented clinical data supporting use of the Xoft Axxent Electronic Brachytherapy (eBx) System for the...
brain with chronic traumatic injury
News | Magnetic Resonance Imaging (MRI) | August 02, 2017
Fighters are exposed to repeated mild traumatic brain injury (mTBI), which has been associated with neurodegenerative...
NIH-funded scientists have discovered that Parkinson’s disease increases the amount of “free” water in a particular brain area

NIH-funded scientists have discovered that Parkinson’s disease increases the amount of “free” water in a particular brain area. Image courtesy of David Vaillancourt, Ph.D., University of Florida.

News | Neuro Imaging | July 31, 2017
Scientists at the University of Florida have discovered a new method of observing the brain changes caused by Parkinson...
more healthcare providers and patients are choosing options such as Gamma Knife stereotactic radiosurgery
News | Radiation Therapy | July 31, 2017
Each year, up to 650,000 people who were previously diagnosed with various forms of cancer will develop brain...
"Residual Echo" of Ancient Humans May Hold Clues to Mental Disorders

MRI data shows (left) areas of the skull preferentially affected by the amount of Neanderthal-derived DNA and (right) areas of the brain’s visual system in which Neanderthal gene variants influenced cortex folding (red) and gray matter volume (yellow). Image courtesy of Michael Gregory, M.D., NIMH Section on Integrative Neuroimaging

News | Neuro Imaging | July 26, 2017
Researchers from the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of...
New York Hospital Finds Significant Cost Savings With Toshiba’s Aquilion One CT
News | Computed Tomography (CT) | July 25, 2017
In five years, Kaleida Health’s Stroke Care Center (SCC) at the Gates Vascular Institute in Buffalo, N.Y., has realized...
Overlay Init