Quantitative mammography contrast threshold test tool.
Med Phys
; 22(2): 127-32, 1995 Feb.
Article
em En
| MEDLINE
| ID: mdl-7565343
ABSTRACT
Mammographic contrast is commonly evaluated by visualizing small objects of varying size or mass divided by projected area. These qualitative contrast determinations are commonly performed by imaging a phantom like the American College of Radiology accreditation phantom at clinical mammographic settings. However, this contrast assessment does not take into account the kVp of the machine. This work describes a quantitative mammography contrast threshold test tool which examines light object contrast on a uniform background for a contrast range of 0.32% to 1.38% at 25 kVp. For this mammography contrast threshold test tool, contrast is defined by delta I/I = loge (psi O/ psi b), where psi O is the target energy flux, and psi b is the background energy flux. Contrast threshold is defined as the lowest contrast value for which the objects are visible. Unlike traditional assessments of mammographic contrast, this measurement of contrast threshold is kVp corrected. The mammography contrast threshold test tool is constructed out of common plastics and provides a quantitative means of assessing contrast threshold for individual mammographic units and total mammographic systems.
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Base de dados:
MEDLINE
Assunto principal:
Mamografia
/
Imagens de Fantasmas
Tipo de estudo:
Diagnostic_studies
/
Qualitative_research
Limite:
Female
/
Humans
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Med Phys
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Estados Unidos