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	Normal Chest Radiograph

The NIOSH B Reader Program


Need for a Reader Proficiency Program

In 1949, the International Labour Office (ILO) promulgated standards for systematically describing and recording radiographic appearances of certain abnormalities caused by the inhalation of dusts. The principle intent of the standards was to achieve uniformity in assessing pneumoconiosis across readers. However, it was found that readers, despite employing the classification scheme, still disagreed with each other and with themselves to an excessive degree (Felson 1973). As a consequence, NIOSH concluded that a proficiency program was needed to provide a pool of qualified readers. The NIOSH B Reader Program began in 1974, although it was not until 1978 that the B reader examination was given extensively (Attfield 1992).

Objective of the B Reader Program

The B Reader examination was originally developed to identify physicians qualified to serve in national pneumoconiosis programs directed at coal miners and others who suffer from dust-related illness. This originally included epidemiologic research on coal workers’ pneumoconiosis and the compensation of coal miners with pneumoconiosis under programs processed by government agencies (Morgan 1979). The original intent of the B Reader Program still exists, but B Readers are also now involved with epidemiologic evaluation, surveillance, and worker monitoring programs involving many types of pneumoconioses. The B Reader Program aims to ensure competency in radiographic reading by evaluating the ability of readers to classify a test set of radiographs, thereby creating and maintaining a pool of qualified readers having the skills and ability to provide accurate and precise ILO classifications.

B Reader Applications

B Readers, through their demonstrated proficiency in classifying radiographs of the pneumoconioses, are appropriate choices for research, surveillance, and worker monitoring programs and activities. NIOSH has employed B Readers in many epidemiologic and other research studies for nearly 30 years, as have many other organizations.

Physicians who classify chest radiographs for certain federal surveillance programs may be required to be B Readers. For example, in the NIOSH Coal Workers’ X-ray Surveillance Program, physicians who classify radiographs for the program are required to be B Readers for the second and any later readings of each radiograph ( 42 CFR 37 ). The Asbestos Medical Surveillance Program (AMSP) , administered by the Navy and Marine Corps Public Health Center (NMCPHC), requires that the second reader of each radiograph be a B Reader. B Readers also have important roles to play in epidemiologic research, government programs, and contested proceedings.

Use of B Readers alone is not sufficient for adequate data quality. Their use should be augmented by the adoption of good technical practices to provide information of the highest quality.

Becoming a B Reader

Exam Description and Approval Process

The examination consists of the classification of 125 chest radiographs over a period of 6 hours. The test is scored on the basis of a total possible score of 100 points, with a passing score being 50 or more points. There are six sections to the examination: small opacities (3 sections), large opacities, pleural abnormalities, and other abnormalities. Scoring is weighted towards parenchymal abnormalities (60%). From 1987 to 1990, about 47% of readers passed the examination. An individual who fails the examination must wait ninety days before retaking it (Wagner 1993). B readers must be retested every four years to retain their status (see Maintaining B Reader Status below).

Reader Training

NIOSH strongly recommends pre-test preparation for examination participants to assure familiarity with the ILO Classification System and associated Roentgenographic Interpretation Form .

The NIOSH Self Study Syllabus is offered in several formats from NIOSH.

Calendar of Events

Examinations are offered monthly at the NIOSH Appalachian Laboratory for Occupational Safety and Health. For scheduled dates, please call (888) 480-4042 or email

* See B Reader Information for Medical Professionals for more information.

Maintaining B Reader status

Readers must retest every four years to maintain their B Reader status; testing can be done any time within the fourth year. The retest is very much like the original approval examination, except readers are required to classify only fifty radiographs. A reader who fails the retest must take and pass the original approval examination before the end of their four-year approval period expires in order retain their B Reader status. There is no waiting period between failing the retest and taking the original approval examination. B Readers who do not retest before expiration of their approval automatically become A Readers.

New Developments Impacting the B Reader Program

Digital Radiography

Conventional film screen chest radiography has been widely applied in assessing lung health in dust-exposed workers for decades, but this technique is being replaced by digital radiography systems. NIOSH is currently assessing the equivalency of traditional radiography and digital radiography with respect to pneumoconiosis classification using conventional and digital images from patients with a spectrum of dust-related lung disorders and chest pathology. See Digital Radiography for more information.

2011 ILO Revisions

The ILO revised its Classification System in 2011. To assure adherence to this new system, NIOSH has modified the B Reader examinations and related training activities and materials, including the Self-Study Syllabus . See New ILO Revisions for more information.

Syllabus Online and Compact Disc

The NIOSH Self-Study Syllabus is now available electronically to increase availability of the Syllabus to each test taker.

Comments or Concerns

Comments or Concerns about the B Reader Program

The B Reader Program welcomes any comments or concerns about the Program, the examination, or this Web site. Our goal is to serve all persons who interact with this Program and continuously improve the information that we provide. Please use any of the following contact methods:

Call the Program office at (888) 480-4042

Email us at

Mail the Program at:

National Institute for Occupational Safety and Health
Coal Workers' Health Surveillance Program
1095 Willowdale Road - M/S LB205
Morgantown, WV 26505

Comments or Concerns about Specific B Readers

The purpose of the B Reader Program is to train licensed physicians in use of the ILO Classification System and to assess their ability to apply the ILO Classification System in classifying chest radiographs for the presence and severity of changes potentially associated with exposure to dusts such as asbestos, silica, and coal mine dust. Use of a medical license in order to commit fraud is a violation of the conditions that accompany the medical license. Therefore, complaints about a specific B Reader should be referred to the appropriate State medical licensing board, as these boards are the bodies responsible for assuring the competence and integrity of licensed physicians. Contact information for each State’s medical licensing board can be found on the Federation of State Medical Boards (FSMB) Web site .


Felson B, Morgan WKC, Bristol LJ, et al. Observations on the results of multiple readings of chest films in coal miners' pneumoconiosis. Radiology 1973;109:19-23.

Attfield MD, Morring K. An investigation into the relationship between coal workers’ pneumoconiosis and dust exposure in U.S. coal miners. Am Ind Hyg Assoc J 1992; 53:486-92.

Morgan RH. Proficiency examination of physicians for classifying pneumoconiosis chest films. Am J Roentgenology 1979;132:803-08.

Wagner GR, Attfield MD, Parker JE. Chest Radiography in Dust-Exposed Miners: Promise and Problems, Potential and Imperfections. Occupational Medicine: State of the Art Reviews 8(1); 127-141, 1993.

More Information

Federal Mine Safety and Health Act of 1977, Public Law 91-173

Specifications for Medical Examinations of Underground Coal Miners. 42 CFR 37

Asbestos Medical Surveillance Program, Navy and Marine Corps Public Health Center (NMCPHC)

Safety and Health Topics: Asbestos. Occupational Safety and Health Administration

NIOSH Coal Workers' Health Surveillance Program (CWHSP)

Roentgenographic Interpretation Form
En Español
(OMB 0920-0020) (CDC/NIOSH 2.8) (December 2009)
This form must be completed by the A or B Reader that interprets a chest radiograph for NIOSH as part of the Coal Workers' X-ray Surveillance Program. Mail the completed form to the address on the form. Do NOT send this form electronically to NIOSH. Print/Copy as a double-sided form.

American College of Radiology (ACR)

Federation of State Medical Boards (FSMB)

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