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

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
Zebra Medical Vision Announces FDA 510(k) Clearance of Coronary Calcium Algorithm
Technology | Computed Tomography (CT) | July 12, 2018
Zebra Medical Vision has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for its Coronary...
IAC Awards First CT Accreditation for a Mobile Stroke Unit
News | Computed Tomography (CT) | July 09, 2018
The Intersocietal Accreditation Commission (IAC) recently recognized the University of Tennessee Health Science Center...
FFR-CT may soon replace invasive angiography for coronary lesion assessment. #EuroPCR 

Anexample of a clinical case of CT-FFR, which can derive the FFR numbers for their entire coronary tree using a noninvasive CT scan.

Feature | Computed Tomography (CT) | May 29, 2018
May 29, 2018 — Results from the innovative SYNTAX III Revolution Trial [1] underline the effectiveness of evolving no
James Min Named Editor-in-Chief of Journal of Cardiovascular Computed Tomography
News | Computed Tomography (CT) | May 01, 2018
James K. Min, M.D., FSCCT, has been selected for a five-year term as the new editor-in-chief of the Journal of...
FDA Clears Siemens' Somatom go.All, go.Top CT Scanners
Technology | Computed Tomography (CT) | April 18, 2018
April 18, 2018 — The U.S.
Canon Medical Systems' Aquilion Precision CT Receives FDA Clearance
Technology | Computed Tomography (CT) | April 13, 2018
Canon Medical Systems USA Inc. this week received U.S. Food and Drug Administration (FDA) clearance for the Aquilion...
FDA Clears Siemens Somatom Edge Plus CT System
Technology | Computed Tomography (CT) | April 04, 2018
April 4, 2018 — The U.S.
Overlay Init