Clinical Image Testing: CT (Revised 11-10-2022)

Revision History

Every unit that performs diagnostic head/neck, chest, cardiac or abdomen examinations must go through testing for the site to be accredited. Every unit must apply for all modules performed on that unit for a facility to be accredited. Three to four examinations and your facility’s protocol for that examination must be submitted from each unit. The exact number of examinations depends on the number of modules for which the unit is used.

Exams selected for submission include adult and pediatric exams (if applicable), and the head/neck, chest, abdomen, and cardiac modules, with specific exam choices detailed in the table below. The facility may choose which examinations it will submit for accreditation within the accreditation application. For sites that perform only adult CT scanning, clinical images required for submission will be in the modules routinely performed on that unit. For sites that do pediatric scanning (≤ 18 years of age) in addition to adult work, an additional exam performed on a child must also be selected for submission. Sites that perform only pediatric examinations (only patients who are ≤ 18 years of age) will have to submit exams tailored to the pediatric population. Pediatric images should clearly reflect that the site has taken into account the child's age and body habitus in selecting the scanning parameters and contrast dosage (see Image Gently and the FDA Pediatric Imaging webpage).

For units applying for cardiac, at least one CTA examination must be submitted, unless the unit is only used for patients 18 years of age and under, in which case the pediatric cardiac examination is required for the cardiac module.

Clinical images are reviewed by two radiologists, currently in active practice. The requirements used by the accreditation reviewers represent a technical baseline for producing acceptable diagnostic examinations. Although some technical factors are specified and required, facilities should use their own exam protocols and submit their exam protocol along with the studies for evaluation. Examination protocols should apply the principle of minimizing radiation doses to as low as reasonably achievable (ALARA).

The categories for scoring clinical examinations submitted for ACR CT Accreditation are:

• Technique Parameters

• Anatomic Coverage

• Artifacts

• Examination Identification: Missing Information

• Examination Protocols

Technique Parameters and Anatomic Coverage

Upload the primary reconstructed images used for diagnostic interpretation; include the scout(s) and dose report. Do NOT submit the sagittal, coronal and extra thing images unless specifically listed under required series. Please review the detailed criteria for the required series, technique parameters and anatomic coverage for each of the following modules:

Artifacts

Excessive motion artifacts that result in indistinct or "double" contours to organs should be repeated if they significantly degrade the examination quality.

The submitted images should not exhibit excessive noise.

Streak artifacts that compromise diagnostic quality with sections not repeated may be a deficiency. However, internal metallic surgical clips may cause minor streak artifacts that will not be judged as deficient.

Exam Identification and Labeling

Patient and technical data must be displayed on the images or be available in the DICOM header. Do NOT anonymize images. All patient information annotated on clinical examinations will be kept confidential by the ACR, as stated in the Practice Site Accreditation Survey Agreement.

1. Patient name (first and last)

2. Patient age (or date of birth)

3. Gender of patient, date of exam

4. Institution name

5. Left/right labeling

6. Technical parameters:

   • kV

   • mA (or mAs or effective mAs or mAs/slice, as reported by scanner)

   • Rotation time

   • Pitch (if available)

   • Reconstructed image thickness (slice width)

   • Reconstructed filter/kernel

   • Display field of view (FOV)

7. Image number (numbered consecutively based on anatomic location)

8. Table position (scan location)

9. Presence or absence of IV contrast

10. Dose report

Examination Protocol

Facilities are required to submit a copy of their scanning protocols with the images. The facility should submit its protocols in the format that it normally uses on site, but they need to be readily understandable by a reviewer charged with correlating those protocols with the submitted images. There are many published sources of information on scanning protocols and procedures in ACR documents and in radiological journals and textbooks. The ACR does not provide forms for the site’s protocols. These protocols must be submitted on paper (typed) with the provided label affixed to the protocol, or uploaded if electronic submission is selected. A typical protocol should at least include the following elements:

• Indication

• Scanner acquisition settings: routine kV, mA/mAs/effective mAs, collimation (N x T), pitch, rotation time, usage of radiation dose reduction methods (automatic exposure control such as tube current modulation, settings for dose reduction methods, etc.)

• Phase of respiration

• Reconstruction settings: reconstructed image width (slice thickness), reconstruction interval, reconstruction kernel/filter, reconstructed field of view (FOV)

• Anatomical coverage (i.e. lung apices to lung bases, top of diaphragm to iliac crest, etc.)

• IV contrast (with injection rate and scan delay), if applicable

• EKG gating (cardiac studies) policy

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