Lesson 1, Topic 1
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Limited X-ray Machine Operator

April 11, 2024

Limited X-ray Machine Operator

Learning Objective: Examine the scope, education, and certification requirements of limited x-ray machine operators.

A limited x-ray machine operator (LXMO) is an individual other than a radiologic technologist who performs diagnostic x-ray procedures on selected anatomy. Limited is used because the practice is limited when compared to a certified radiologic technologist. Limited x-ray practice does not involve the following:

• The use of contrast media for imaging blood vessels and abdominal organs
• The operation of complex radiographic equipment, such as computed tomography (CT), magnetic resonance imaging (MRI), mammography, and others.

Limited x-ray machine operators may perform radiographic exams at ambulatory care facilities, chiropractic offices, and hospitals. Limited scope x-ray machine operators prepare patients for exams, explain procedures, give clear instructions during the exam, and practice standards that ensure the highest level of radiation protection and safe operation of the x-ray machine. Limited x-ray machine operator members are certified limited practitioners or hold a restricted state license.


Learning Objective: Describe the educational requirements for a limited x-ray machine operator.

Formal education is required to be eligible for certification as a limited x-ray machine operator. LXMO programs are typically certificate programs designed to prepare graduates for an entry-level position in ambulatory care. Programs emphasize developing clinical skills to train students for a career as a limited x-ray machine operator. Limited x-ray machine operators are restricted in terms of what parts of the body they can image. LXMOs are trained to perform imaging exams of the chest, upper and lower extremities, skull and sinuses, and spine and feet.

FIGURE 37.1  The first clinical radiograph in the United States was taken at Dartmouth College in 1896. From Long BW, Frank ED, Ehrlich RA: Radiography essentials for limited practice, ed 6, St. Louis, 2021, Elsevier.


The American Society of Radiologic Technologists published the Limited X-ray Machine Operator Curriculum to support the education of limited operators of x-ray equipment. The curriculum allows states and faculty flexibility in developing limited curricula to meet the needs of individuals performing diagnostic x-ray procedures within a limited scope.
The LXMO curriculum is divided into specific content areas that represent the essential components of an LXMO program. The curriculum includes a minimum number of hours of didactic instruction and clinical instruction, along with the minimum number of required procedures (TABLE 37.1). Critical thinking must be fostered, developed, and assessed in the education process. The LXMO core curriculum is based on data relevant to today’s healthcare environment and offers a foundation for lifelong learning and transition to general radiography studies. It is designed to meet the needs of individuals performing diagnostic x-ray procedures within a limited scope of practice.


Learning Objective: Discuss the certification requirements for a limited x-ray machine operator.

Students must complete a program to be eligible for the certification examination written by the American Registry of Radiologic Technologists (ARRT) to earn their LXMO certification. LXMO certification means an individual has acquired the necessary training, has taken and passed the Limited Scope ARRT test, and received approval from the state. LXMOs are limited by the type of x-ray examinations they are permitted to perform. For example, limited scope x-ray machine operators who have taken and passed the Limited Scope ARRT extremity module may perform x-rays only on extremities.

TABLE 37.1

Typical Curriculum for a Limited Machine X-ray Operator (LXMO) Program

Anatomic RegionMinimum Hours of Clinical ExperienceMinimum Procedures
• Upper extremity and pectoral girdle
• Lower extremity

The licensure of LXMOs varies from state to state. The majority of states have regulations for those who operate x-ray equipment. Currently, most states have laws requiring some licensure to practice radiography, and at least half of these include provisions for limited x-ray practice. State licensure is separate from ARRT credentialing. Depending on the state, limited x-ray may or may not be allowed. For example, Louisiana prohibits limited x-ray, whereas Missouri has no requirements for certification, and Wisconsin restricts limited x-ray to only the extremities, chest, and spine.
Legal requirements are subject to change, so you must inquire directly to your state’s appropriate agency to determine the following:

• Whether limited x-ray is permitted
• Whether its practice is regulated
• How to obtain the necessary certification.

Each state that regulates limited x-ray has established standards for the scope of practice allowed. There are serious sanctions for practicing radiography outside the boundaries defined by state laws and regulations. Practicing without a valid license or permit or practicing outside the scope of one’s credentials may result in fines, imprisonment, or both. In addition, a license or permit may be suspended or revoked. Employers may also be penalized in their employees practice radiography in violation of regulations. All radiographers and limited operators must be aware of the legal standards that apply to them and ensure that their practice conforms to these standards. The practice of radiography involves a variety of knowledge and skills. Although the scope of practice may be limited, there is no restriction on the knowledge and skill necessary for the practice. In other words, the limited operator is held to the same high standards as a registered radiologic technologist in performing procedures within the permitted scope of practice.


Critical Thinking Application

Susan is a limited x-ray machine operator in Texas. However, she is originally from Wisconsin. Susan wants to move back to Wisconsin to help take care of her mother. Can Susan practice as a limited x-ray machine operator in Wisconsin? If Wisconsin certifies limited x-ray machine operators, will Susan need to take the ARRT certification examination for Wisconsin? Where can Susan locate this information?

FIGURE 37.2  The limited operator explains the procedure to the patient. From Sherer MAS, Visconti PJ, Ritenour ER, Haynes KW: Radiation protection in medical radiography, ed 8, St. Louis, 2018, Mosby.

Typical Duties of a Limited X-ray Machine Operator

Learning Objective: Describe the typical duties of a limited x-ray machine operator.

The limited operator encounters the patient after x-ray procedures are ordered by a provider. Usually, this occurs after the provider has examined the patient. Once the order is placed, the limited operator greets the patient and determines where the patient will need to undress. Many times the patient must change into a gown before radiography. Once the patients are appropriately dressed, they are taken into the x-ray room (FIGURE 37.2).
Then, the limited operator provides a brief explanation and answers any questions about the procedure. Often, the limited operator will have to discuss the examination with a radiographer to ensure that the appropriate x-ray projections will be made and the correct exposure techniques are used. The next step is to assist the patient in the general position required for the x-ray examination. For example, if a hand is to be x-rayed, the patient can be seated at the end of the table (FIGURE 37.3). For a spine examination, the patient may need to lie on the table (FIGURE 37.4). If a chest examination is ordered, the patient will stand at an upright image receptor (IR) (FIGURE 37.5). The limited operator then selects the IR and places it in position. Next, the patient is positioned precisely, and the x-ray tube is aligned with the body part and the IR at a specific distance. The operator sets the technical factors for the examination on the control panel. Final instructions are given to the patient, and the exposure is made. If more than one exposure is needed, the IR is changed, the patient is repositioned, and the steps are repeated until the examination is complete.

FIGURE 37.3  The patient is seated at the end of the x-ray examination table with hand on the image receptor placed on the table. From Long BW, Rollins JH, Smith BJ: Merrill’s atlas of radiographic positioning and procedures, ed 14, St. Louis, 2020, Mosby.

FIGURE 37.4  The patient is lying supine on the examination table.

After ensuring that the patient is safe and comfortable, the operator processes the image. Once the image is viewed on the computer monitor and approved, it is sent for reading and then stored. Depending on the setting, the onsite or offsite radiologist will read the x-ray. In many ambulatory care settings, the treating provider reviews the x-ray and provides initial treatment, which is later evaluated when the final reading is completed.
The patient is returned to an examining room or dressing room. The operator then readies the x-ray room for the next examination and prepares the images for reading. The exact nature of a limited operator’s duties will vary with the place of employment, the size of the staff, and the equipment available.

FIGURE 37.5  Upright vertical Bucky image receptor. From Adler AM, Carlton RR: Introduction to radiologic and imaging sciences and patient care, ed 7, St. Louis, 2020, Saunders.