Recommendations on Standards for the Design of Medical Diagnostic Equipment for Adults with Disabilities, Advisory Committee Final Report

5.8.3 Breast Platform Recommendations

Description: In addition to providing knee and toe clearance at the breast platform (see 5.8.2 Knee and Toe Clearance Recommendations under Breast Platforms), the height of the breast platform is also critical to ensuring that mammography equipment is accessible to patients seated in a wheelchair. The proposed provision addresses the low and high heights that must be provided.

NPRM Proposed Provision: M303.4.1 Breast Platforms. The height of the breast platform shall be 30 inches high minimum and 42 inches high maximum above the floor when in use by a patient seated in a wheelchair

5.8.3.1 Breast Platform Height Recommendations

The Committee recommends decreasing the minimum height of the top of the breast platform to 26 inches above the floor. The upper height range for the breast platform was not controversial and remained as proposed. The final version of the criteria must clarify that the specified height range is a minimum range of travel.

Rationale for the recommendation

The subcommittee expressed conflicting perspectives on the minimum breast platform height with members either choosing to support the 26-inch or 28-inch minimum. While all other subcommittee decisions were by group consensus, the group required a formal vote on this issue. Although the subcommittee vote was for 28 inches, during the final public meeting, the full Committee supported the 26-inch minimum by a strong majority.

According to industry, equipment currently manufactured ranges anywhere between 25 and 28 inches for the lowest measurement of the breast platform. There were various reasons cited for each of the positions. Recommendations from accessibility experts who developed mammography protocols for women with disabilities identified a need for a breast platform height of 24 inches. Because this recommendation evolved from technologist experience on equipment with less knee space, disability advocates supported the rationale for 26 inches as the minimum. One member cited the diversity of body types and sizes for persons with disabilities as the rationale for the 26 inches. Another member emphasized the importance of considering patients of short stature in addition to considering patients seated in a wheelchair.

Many industry organizations supported the 28-inch minimum. Reasons cited included providing more flexibility for manufacturers and concern that the lower minimum could result in more leg injuries as the technologist lowered the breast platform so close to the lap of the patient using a wheelchair. Members disagreed with limiting the height as the method of minimizing the risk of injury since this could happen at any height depending upon the height of the knees of the person. Informal input from some technologists indicated no problems with imaging patients with disabilities at 28-inch minimum heights.

One member expressed support for the lower height in order to facilitate the Magnified Cranio Caudal (hereinafter “Mag”) view for person needing magnified views of tissue. Mag views require the breast to be located at a specific position in between the x-ray tube and the breast platform. To capture this view, providers place an accessory, often called a “Mag Stand”, on the breast platform, as shown in Figure 5.8.3.1. The provider will then position the patient’s breast on top of the mag stand so that the breast is at the correct position between the x-ray tube and the breast platform. The height of the mag stand can vary between 6 inches and 10 inches, depending on the characteristics of the x-ray beam and the degree of magnification desired. Since the technologist places this accessory on top of the breast platform, it effectively increases the height and thickness of the breast platform. Beginning with a lower breast platform height could help more patients to have access to the mag view. However, the more significant barrier to patients imaged from a seated position is the increased overall size of the platform (from lap to breast) during a mag view, since it would require the patient to have a very tall torso.

Figure 5.8.3.1 Illustration of an example mag stand on top of the breast platform.
(SOURCE: Hologic, Inc.)