MRI Accreditation Checklist: Prepare for Success
United Healthcare’s decision to require MRI accreditation after March 1, 2008, initiated a trend among payers that is likely to gain steam. It has also sent hospitals and freestanding imaging centers scrambling to secure MRI accreditation from the American College of Radiology, which has accredited over to 5,000 MRI units since beginning its MRI program in 1996.
The accreditation process is no cause for panic. A majority of applicants passed on their first attempt, and most of those that did not went on to attain accreditation. So the odds of undergoing a successful accreditation are in your favor. But before initiating the accreditation process, it is important to designate a champion who will accept responsibility for this task and then to give that person the time and support to accomplish it. The following guidelines will help ensure success.
Construct a timeline. Your site’s champion should begin by studying the information on the ACR website and constructing a timeline identifying the anticipated needs for critical stages. Remember that even after you submit your application it may take the ACR up to two months to process it and award accreditation. You may also want to leave at least a two-month cushion in the unlikely event that you fail a portion of the process and need to appeal or resubmit. Presuming a site desires accreditation as of December 1, 2007, it would be wise to submit the application no later than the beginning of October. This also means the application has to be started no earlier than the middle of August since there is only a 45 day window once the application file is opened (once you pay the fee and the accreditation materials are sent to you).
Get the help you need. Parts of the application refer to peer review and to the date of your system’s most recent technical review (physics test). Take questions on peer review to the physicians at your site responsible for clinical interpretation. The MRI scientist or medical physicist who conducts your annual MRI performance testing and assists with your local quality control (QC) program can address the issues on instrument testing. The ACR will not accept an application without proof of an MRI scientist’s or medical physicist’s report on your system dated within twelve months of submission.
Initiate a QC program if you do not have one. Most new sites (and a number of previously accredited sites) have not maintained their QC programs properly and have not had their systems tested. The first step is to find an MRI scientist or a medical physicist with MRI experience to help you get on track. (See sidebar on how to hire an MR scientist or medical physicist.) QC is considered a nuisance by some imaging center personnel, but the alternative is worse. I have tested over 1,000 MRI units in the past twenty years and have encountered problems in about 80% of those systems, including bad head and body coils, poor homogeneity, faulty gradient amplifiers, intermittent RF systems, and monitors that don’t meet specifications. Independent annual testing and on-site quality control can help to identify issues before they become catastrophic.
When your application is accepted, get busy! You have 45 days to complete you submission. The first thing you should do on receipt of your packet and MRAP number is order the ACR MRI phantom from the manufacturer. Phantoms are subject to periodic shortages due to the requirements of the manufacturing process. The paperwork is self-explanatory, but the project leader should distribute appropriate parts to the appropriate people with a deadline.
The most common source of failure is the selection of clinical cases for review. Each applicant must submit an exam of the brain, C-spine, L-spine, and knee. These should demonstrate your standard scan techniques and do not have to include pathology. Be advised that the ACR has requirements for in-plane resolution and slice thickness In the knee, for instance, slice thickness must be less than or equal to 4mm and in-plane resolution is less than or equal to 0.75mm. Remember that in-plane resolution is the field of view (FOV) divided by the acquisition matrix (for example, if you use a 16cm FOV you will have to use phase and frequency matrices exceeding 213 to meet this requirement). If you submit a 5mm-thick knee exam or if it has a resolution greater than 0.75mm, you will fail the clinical portion of the review. Be sure to have the physician selecting the clinical exams verify that all meet or exceed the ACR requirements.
Phantom studies represent another common failure point. The ACR phantom is a plastic cylinder filled with water, salt, and a bit of nickel chloride, with “head” and “chin” engraved on it to ensure proper orientation in the head coil. A pad will minimize vibration and also help in leveling. Although many sites report difficulties in leveling, your physics expert should be able to provide appropriate advice. ACR offers an excellent guide to phantom setup and evaluation, invaluable for any technologist new to the ACR program. It shows what each of the images should look like and how the ACR reviewer will examine them. If your images don’t look like those in the guide you might want to find out why before sending them in. Your submission must contain five phantom studies. These are described in MRI_Site_Scanning_Data_Form.pdf and site_scanning_instructions_phantom.pdf on the ACR website. The first is a sagittal slice through the center that is used for head-foot distance accuracy and for locating the remaining studies. There is an 11-slice T1-weighted series that is used to check geometric distortion, ghosting, resolution, slice thickness, landmark accuracy, image intensity uniformity, and low density contrast detectability. The T2-weighted ACR series also examines slice thickness, landmark accuracy, imaging intensity uniformity, and low-density contrast detectability. ACR also requires applicants to submit phantom studies using the site’s standard brain T1- and T2-weighted protocols. These are modified to use 11 slices of 5mm thickness skip 5mm. Reviewers also consider these exams for slice thickness, resolution, and low-density contrast detectability.
The ACR requires that the clinical exams selected for review must be dated within plus or minus one week of the date on which the phantom studies were done.
Many 8-channel head coils fail portions of the technical testing if you do not use image-correction software. Make sure to employ the normal artifact correction software provided by your vendor (eg, SCIC, Prescan Normalize, CLEAR, etc.) that you use on your clinical exams if your site uses an 8-channel head coil . If you have any questions about this, discuss it with your physics expert and your vendor’s applications specialist.
Check your work carefully, especially the clinical exams. Double-check that the clinical exams you are submitting meet the ACR requirements for resolution and slice thickness. Examine each of your five phantom series according to the test criteria using the instructions detailed in the ACR phantom guide. Questions? Ask your physics expert, or arrange to have him or her do this for you. There is scant likelihood your submission will be rejected if you verify that your clinical and your phantom studies meet requirements.
Sell your staff on the importance of QC. Besides needing it to achieve and maintain accreditation, a QC program can help spot changes in system performance before catastrophic failure or substantial loss of image quality. This can minimize loss of scan time by alerting service to correct the problem promptly. Annual testing and QC can identify problems with system components that may not get regular vendor testing. Some examples include poorly performing specialty coils, monitors that do not meet specifications, substandard magnet homogeneity, geometric distortion, mis-calibrated laser cameras, and ghosting artifacts.
If you approach the process seriously, it is probable that you will get a letter from the ACR noting your successful accreditation for a period of three years. Plan a party, congratulate your champion for his or her efforts, and proudly post your new ACR certificate.
But if you receive a notice of failure, take a deep breath. Read the letter carefully to understand the reasons accreditation was not granted. This is likely to be in only one of the two review areas, clinical or technical. If the failure is due to a clinical issue, discuss the results with your physicians. If one or more of your submitted studies do not meet ACR resolution and/or slice thickness minimums, you will have to change your protocols, resubmit the new studies, and pay the extra fee for resubmission. If the failure is due to the reviewer’s general rejection of your protocols and your physicians believe your methods are adequate, appeal the rejection. Have your physicians author a letter to the ACR explaining why their protocols should be allowed. A second reviewer can be requested to guarantee objectivity in the appeal process. If you win your appeal, you receive accreditation. In the event of a loss, you have the choice to change your protocols and resubmit.
If the failure was of a technical nature contact your physics expert. He or she can help explain the reasons for rejection and assist in a strategy to correct the problems. If the rejection is due to legitimate problems, correct them and resubmit (extra fee for resubmission). If the rejection is not consistent with the information you have submitted, appeal the findings and ask for a second review. Have your physics expert assist you in authoring a letter that points out the reasons why the rejection does not appear to follow ACR analysis and why your data supports passing. If the appeal is granted, toast your success. If it is rejected, rescan the phantom studies, check your results, and resubmit.
ACR accreditation is granted for a period of three years. During this time sites are required to conduct weekly QC, visual checklist, and film densitometry. Annual performance testing is also mandatory. The records of these studies must be available at the site in the event ACR personnel make an unannounced visit, and this does happen, so be prepared. Work with your physics expert to ensure your staff members are conducting exams properly and that they understand the reasons for these efforts. Teach the attitude that such programs demonstrate your excellence and will help to find any problems as early as possible.