A limited scope operator (LSO) is an individual who has taken and passed a required test and has approval by the X-ray Certification Unit pursuant to 2.4.5.1 to operate x-ray systems and to conduct specified radiographic examinations of the chest, extremities, skull, hip/pelvis and spine/sacrum and abdomen.
A limited scope x-ray machine operator cannot perform radiologic procedures involving the administration or utilization of contrast media, bone densitometry, fluoroscopy to include c-arms, mammography, computed tomography, or radiation therapy.
Colorado requires the registration and biennial renewal of limited scope operators.
Limited scope operator requirements
Please see below for the list of requirements needed to register as a limited scope operator.
Didactic education requirement
Part 2, Appendix 2D, Section 2D.2.1
- The student must complete at least 80 hours of classroom training in the following topics: basic x-ray physics (20 Hours), radiobiology (3 Hours), radiation protection (6 Hours), principles of exposure (15 Hours), procedures and processing (4 Hours), and anatomy and positioning (32 Hours).
Clinical requirement
Part 2, Appendix 2D, Section 2D.2.2 and 2D.2.3
- The student must complete at least 480 hours of clinical experience under direct supervision of a qualified trainer (supervisor is physically present in the room during the procedure). No more than 160 hours may come from non-clinical, laboratory experience. During the clinical experience the student must perform at least four of each of the following imaging exam procedures: skull, sinuses, facial bones, cervical spine, thoracic spine, lumbar spine, chest, ribs, clavicle, shoulder, humerus, elbow, forearm, wrist, hand, hip/pelvis , femur, tibia/fibula, ankle, foot, and flat plate abdominal images.
ARRT testing requirement
Part 2, Appendix 2D, Section 2D.2.4
- The student must obtain a passing score on the American Registry of Radiologic Technologists (ARRT) examination for the Limited Scope of Practice in Radiography.
- A passing score is a score of at least 75% correct on the core module and an average score of at least 75% correct on the radiographic procedures modules for chest, extremities, skull/sinuses, and spine.
- The student will have three attempts to obtain a passing score on the ARRT examination. Each attempt requires an additional application fee and testing fee.
Timing requirement
Part 2, Section 2.4.5.1 (2)(c)
- Applicants must submit the application for registration as a limited scope operator within one year upon completion of the requirements of 2D.2.1 and within 90 calendar days upon completion of the requirements of 2D.2.2 and 2D.2.3.
Failure to pass the ARRT test within three attempts
Part 2, Section 2.4.5.1 (2)(d)
- If an applicant cannot achieve a passing score per 2D.2.4 within three attempts, the applicant must restart the training required by 2D.2.1, 2D.2.2, and 2D.2.3.
Registration renewal requirement
Part 2, Appendix 2D, Section 2D.2.5
- Every two years registrants must renew their registration and submit 24 continuing education hours in the areas of radiology, radiation safety, radiography, and similar fields.
LSO application
Submit the limited scope operator application
Instructions for applying for registration as a limited scope operator
- Complete the online application (The required R-70 & R-71 forms are now combined into the current online application).
- Attach all supporting documentation for your education and clinical experience.
- Application for registration must occur within one year of completing didactic education training.
- Application for registration must occur within 90 days of completing your clinical training.
- Submit the non-refundable $60 application processing fee.
- Refer to the online application for additional information on how to make this payment.
- Upon approval, we will email you a letter with instructions and next steps on how to complete the testing portion with ARRT.
- Additional testing fees apply.
- If you need to retake the LSO ARRT exam, please complete the application linked above. Please note: additional application fees and testing fees apply to each attempt.
Transfers from out-of-state
- Complete the application linked above.
- Attach all applicable documents for equivalency review- state license, state ARRT test scores, education transcripts and certificate/degree, and supporting documentation for completion of your clinicals.
Renewal of registration
- To renew, complete the online application linked above (The required R-90 form is now combined in the current online application).
- Registrant must submit evidence of 24 continuing education hours and pay the $60 application fee.
What procedures can a limited scope operator perform?
- X-ray procedures include skull, chest, hip/pelvis, spine/sacrum, abdominal flat plate images, upper extremities, and lower extremities.
- A limited scope x-ray operator cannot perform procedures involving the administration or utilization of contrast media, bone densitometry, fluoroscopy, mammography, computed tomography, or radiation therapy procedures.
I am already a registered limited scope operator in another state (other than Colorado); does my limited scope registration automatically carry over from state to state?
- No, it may not directly transfer because states may have different requirements for limited scope operators. For instance, the educational and clinical training requirements may vary. Please complete the online application and include all supporting documentation including, but not limited to: state license, state ARRT test scores, education transcripts and certificate/degree, and supporting documentation for completion of your clinicals. The X-ray Certification Unit may request additional documentation and testing.
Is there a certificate from the department once the x-ray operator registers?
- No, we will email an approval letter. As of 02/12/2020, the unit no longer prints certificates with the state seal. The approval letter contains your registration number and expiration date. Verification of registration is available on our website on the X-ray registration verification page.
Can a limited scope operator perform fluoroscopy or CT procedures?
- No, limited scope x-ray machine operators cannot perform radiologic procedures involving the administration or utilization of contrast media, bone densitometry, fluoroscopy, mammography, computed tomography, or radiation therapy.
Are rural areas of the state who have limited scope operators given any special considerations in the regulations?
- No, all limited scope operators must meet the same requirements.
Can I pay for my application fees electronically?
- Yes, you can make online payments via credit/debit card or electronic check (additional processing fees apply). The X-ray Certification Unit will email you your invoice once your application is up in the queue for processing. This can take up to 7-10 business days, but can occur more quickly depending on the volume of business.
What is required to meet the 480 hours of clinical training and who can provide this training?
- Students can complete training in a medical office or in a medical setting under a qualified trainer. Qualified trainers include a physician, a radiologic technologist, a formal instructor employed by a training or education facility, or a Colorado registered limited scope operator.
Does all the clinical training for limited scope operators need to be under direct supervision?
- Yes, you need 480 hours of clinical training under direct supervision of a qualified trainer. Direct supervision means the supervisor is present in the facility and immediately available to furnish assistance and direction to the supervisee throughout the performance of a procedure. Only 160 hours can be in laboratory training.
How can I obtain the 80 hours of didactic education?
- There is a variety of methods to acquire the 80 hours of didactic education. Methods include structured and documented training programs. These include accredited educational institutions and various online courses.
Educational resources for x-ray machine operators
What is acceptable documentation of education & clinical training?
- Some examples of acceptable documentation for proof of education include copies of training certificates or school transcripts. Documentation for clinical exams includes signed verification from a qualified trainer of completion of clinical exams (ex: signed checklist). A letter from your clinical supervisor attesting to the completion of the requirements in Appendix 2D.2.2 and 2D.2.3 is also acceptable to document the completion of the clinical exams. Please ensure the letter is on facility letterhead, dated, and signed by your clinical supervisor. Please submit all other supporting documentation to the unit for review.
How long after training ends does a limited scope operator have to register with the department?
- You must apply within one year upon completion of the didactic (classroom) education requirements and (90) calendar days upon completion of the clinical requirements.
Does CDPHE conduct the limited scope operator test?
- No, third-party testing centers administer the American Registry of Radiologic Technologists (ARRT) Limited Scope Operator test.
How long does it take to get results of the ARRT limited scope x-ray operator examination?
- It can take up to 4-6 weeks to receive your exam results from the x-ray unit. Once you take the ARRT test, CDPHE will receive your test scores by mail via the post office. After receipt, we will email you a letter with your results. We do not give results to employers or over the telephone.
If I fail the limited scope x-ray operator exam, can the test be taken over again?
- Yes, you have up to three attempts to pass the ARRT exam for limited scope operators. You must complete the three attempts within two years of your application term end date. A passing score is 75% on the core section and a cumulative score of 75% on the additional sections. Additional application fees and testing fees apply to each attempt. You may continue to train under direct supervision while retesting.
I passed all but two sections of the test do I need to retake the entire exam?
- No, you do not need to retake the entire exam. You can choose to retake just the sections that you need. However, it does not negatively affect you to retake the other modules because we take the highest score earned of the three attempts for each section. In some instances, applicants prefer to take only the modules needed. In other instances, applicants choose to retake the whole test in the hopes of scoring higher in the sections they are stronger in to help with their cumulative average. Please note: additional application and testing fees apply for each attempt.
I am already a registered limited scope operator in the State of Colorado, how do I renew my registration?
- To renew, complete the online application, attach your documentation of your 24 continuing education hours, and pay the $60 application processing fee.
What type of continuing education is required for Colorado registered limited scope x-ray operators?
- Limited scope operators can obtain continuing education in any subject directly related to radiology. Limited scope x-ray operators must maintain a minimum of 24 continuing education units every two years in the areas of radiology, radiation safety, radiography and similar fields. Continuing education units must conform to guidelines equivalent to the most current version of the ARRT® Education Requirements for Obtaining and Maintaining Certification and Registration.
If someone fails to renew with the department as a limited scope operator, will they lose their limited scope status with the state?
- Yes, failure to renew will result in loss of registration.
Additional information
Please contact CDPHE X-ray Certification Unit at: cdphe.hmxraycomments@state.co.us or call 303-692-3448.