News | October 24, 2014

ASTM International Standard Aids in Measurement of X-Ray Focal Point Size

October 24, 2014 — The quality and resolution of X-ray images depends on the characteristics of the focal point, the area that is struck by electrons and from which the resulting X-rays are emitted. A new ASTM International standard will allow users to determine the effective focal spot size of an X-ray source.

The new standard is ASTM E2903, Test Method for Measurement of the Effective Focal Spot Size of Mini and Micro Focus X-ray Tubes. X-ray tube manufacturers will find the standard helpful when supplying customers with focal spot size, or for quality control.

Additionally, “knowledge of focal spot size is very important to practitioners of digital radiography because magnification principles need to be applied to compensate for the limited spatial resolution of digital X-ray image detectors,” said ASTM member David Fry, research and development engineer, Los Alamos National Laboratory. 

Fry explains that, in radiography, the blurring of image edges is a function of the geometry of the setup and the focal spot size.

“Digital images are also blurred by the pixel size and X-ray to light conversion screens,” Fry said. “Digital images are thus blurred by combination of focal spot size, geometry and digital detector characteristics.”

Results generated from the use of ASTM E2903 can be used to establish source-to-object and object-to-image detector distances appropriate for maintaining the desired degree of geometric unsharpness or maximum magnification possible, or both, for a given radiographic imaging application. ASTM standard practices E2698 and E2033 for radiographic examination using digital methods require knowledge of focal spot size.

ASTM E2903 was developed by Subcommittee E07.01 on Radiology (X and Gamma) Method, part of ASTM Committee E07 on Nondestructive Testing. E07.01 encourages all interested parties to participate in its standards-developing activities. The subcommittee is particularly interested in feedback on how ASTM E2903 is being applied, as well as additional data for refinement of the standard’s precision and bias statement.

For more information: www.astm.org

Related Content

SCCT Releases New Guideline for CT Use During TAVR
News | Computed Tomography (CT) | January 08, 2019
The Society of Cardiovascular Computed Tomography (SCCT) has released a new expert consensus document for computed...
A CT calcium scoring image showing calcified plaques in coronary vessel segments. The higher the calcium content of the vessels, the high risk the patient is for a heart attack event. CAC exam

A CT calcium scoring image showing calcified plaques in coronary vessel segments. The higher the calcium content of the vessels, the higher risk the patient is for a heart attack event. Image courtesy of Canon Medical Systems.

Feature | Computed Tomography (CT) | October 17, 2018 | Dave Fornell, Editor
A picture is worth a thousand words, and to patients concerned about their health, detailed images of the coronary an
Abdominal Aortic Calcification May Signal Future Heart Attack

Image from computed tomography (CT) colonography shows segmented abdominal aortic calcification measured with semiautomated CT tool on coronal image. Within region of interest over aorta selected by user, tool automatically segments and quantifies aortic calcification (shown in blue). 

Image Credit: O’Connor S D, Graffy P M, Zea R, et al. Does nonenhanced CT-based quantification of abdominal aortic calcification outperform the Framingham Risk Score in predicting cardiovascular event sin asymptomatic adults? Radiology doi: 10.1148/radiol.2018180562. Published online Oct. 2, 2018. © RSNA.

News | Computed Tomography (CT) | October 12, 2018
Computed tomography (CT)-based measures of calcification in the abdominal aorta are strong predictors of heart attacks...
Siemens Healthineers Announces First U.S. Install of Somatom go.Top CT
News | Computed Tomography (CT) | September 17, 2018
September 17, 2018 — The Ohio State University Wexner Medical Center in Columbus recently became the first healthcare
Key Patient Preparations for a CT Scan
News | Computed Tomography (CT) | September 05, 2018
The Center for Diagnostic Imaging (CDI) in Miami recently released a list of important preparations patients should...
Videos | Computed Tomography (CT) | July 25, 2018
A discussion with Patricia Dickson, LRT(CT), director of imaging and outpatient services, Capital Cardiology Associat
Videos | Computed Tomography (CT) | July 23, 2018
Ed Nicol, M.D., FSCCT, MBA, head of cardiac CT, Royal Brompton Hospital, London, and chair of the Society of Cardiova
Videos | Computed Tomography (CT) | July 17, 2018
An interview with Patrick Serruys, M.D., Ph.D., Imperial College London, principal investigator of the SYNTAX III Tri
Overlay Init