Preview

Variant: 1 Adult. Acute onset Horner syndrome with or without localizing neurological signs or symptoms. History of recent trauma or painful. Initial imaging.

Procedure	Appropriateness Category
CTA head and neck with IV contrast	Usually Appropriate
CT head without IV contrast and CTA head and neck with IV contrast	Usually Appropriate
MRA head and neck with IV contrast	Usually Not Appropriate
MRA head and neck without and with IV contrast	Usually Not Appropriate
MRA head and neck without IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without and with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without IV contrast	Usually Not Appropriate
MRI cervical spine with IV contrast	Usually Not Appropriate
MRI cervical spine without and with IV contrast	Usually Not Appropriate
MRI cervical spine without IV contrast	Usually Not Appropriate
MRI head and orbits with IV contrast	Usually Not Appropriate
MRI head and orbits without and with IV contrast	Usually Not Appropriate
MRI head and orbits without IV contrast	Usually Not Appropriate
MRI head with IV contrast	Usually Not Appropriate
MRI head with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI head without IV contrast	Usually Not Appropriate
MRI head without IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI neck with IV contrast	Usually Not Appropriate
MRI neck without and with IV contrast	Usually Not Appropriate
MRI neck without IV contrast	Usually Not Appropriate
MRI orbits with IV contrast	Usually Not Appropriate
MRI orbits without and with IV contrast	Usually Not Appropriate
MRI orbits without IV contrast	Usually Not Appropriate
MRI thoracic spine with IV contrast	Usually Not Appropriate
MRI thoracic spine without and with IV contrast	Usually Not Appropriate
MRI thoracic spine without IV contrast	Usually Not Appropriate
CT head with IV contrast	Usually Not Appropriate
CT head without and with IV contrast	Usually Not Appropriate
CT head without IV contrast	Usually Not Appropriate
CT neck with IV contrast	Usually Not Appropriate
CT neck without and with IV contrast	Usually Not Appropriate
CT neck without IV contrast	Usually Not Appropriate

Variant: 2 Adult. Acute onset Horner syndrome with localizing brain or cranial nerve neurological signs or symptoms. No history of trauma. Initial imaging.

Procedure	Appropriateness Category
CTA head and neck with IV contrast	Usually Appropriate
CT head without IV contrast and CTA head and neck with IV contrast	Usually Appropriate
MRA head and neck without and with IV contrast	May Be Appropriate
MRA head and neck without IV contrast	May Be Appropriate
MRI head without and with IV contrast	May Be Appropriate
MRI head without and with IV contrast and MRA head and neck with IV contrast	May Be Appropriate (Disagreement)
MRI head without and with IV contrast and MRA head and neck without and with IV contrast	May Be Appropriate (Disagreement)
MRI head without and with IV contrast and MRA head and neck without IV contrast	May Be Appropriate (Disagreement)
MRI head without IV contrast and MRA head and neck without IV contrast	May Be Appropriate (Disagreement)
MRA head and neck with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without and with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without IV contrast	Usually Not Appropriate
MRI cervical spine with IV contrast	Usually Not Appropriate
MRI cervical spine without and with IV contrast	Usually Not Appropriate
MRI cervical spine without IV contrast	Usually Not Appropriate
MRI head and orbits with IV contrast	Usually Not Appropriate
MRI head and orbits without and with IV contrast	Usually Not Appropriate
MRI head and orbits without IV contrast	Usually Not Appropriate
MRI head with IV contrast	Usually Not Appropriate
MRI head with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without IV contrast	Usually Not Appropriate
MRI neck with IV contrast	Usually Not Appropriate
MRI neck without and with IV contrast	Usually Not Appropriate
MRI neck without IV contrast	Usually Not Appropriate
MRI orbits with IV contrast	Usually Not Appropriate
MRI orbits without and with IV contrast	Usually Not Appropriate
MRI orbits without IV contrast	Usually Not Appropriate
MRI thoracic spine with IV contrast	Usually Not Appropriate
MRI thoracic spine without and with IV contrast	Usually Not Appropriate
MRI thoracic spine without IV contrast	Usually Not Appropriate
CT head with IV contrast	Usually Not Appropriate
CT head without and with IV contrast	Usually Not Appropriate
CT head without IV contrast	Usually Not Appropriate
CT neck with IV contrast	Usually Not Appropriate
CT neck without and with IV contrast	Usually Not Appropriate
CT neck without IV contrast	Usually Not Appropriate

Variant: 3 Adult. Acute or nonacute onset Horner syndrome with localizing spinal cord neurological signs or symptoms. No history of trauma. Initial imaging.

Procedure	Appropriateness Category
MRI cervical and thoracic spine without and with IV contrast	Usually Appropriate
MRI cervical and thoracic spine without IV contrast	May Be Appropriate (Disagreement)
MRI cervical spine without and with IV contrast	May Be Appropriate
MRI cervical spine without IV contrast	May Be Appropriate
MRA head and neck with IV contrast	Usually Not Appropriate
MRA head and neck without and with IV contrast	Usually Not Appropriate
MRA head and neck without IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine with IV contrast	Usually Not Appropriate
MRI cervical spine with IV contrast	Usually Not Appropriate
MRI head and orbits with IV contrast	Usually Not Appropriate
MRI head and orbits without and with IV contrast	Usually Not Appropriate
MRI head and orbits without IV contrast	Usually Not Appropriate
MRI head with IV contrast	Usually Not Appropriate
MRI head with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI head without IV contrast	Usually Not Appropriate
MRI head without IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI neck with IV contrast	Usually Not Appropriate
MRI neck without and with IV contrast	Usually Not Appropriate
MRI neck without IV contrast	Usually Not Appropriate
MRI orbits with IV contrast	Usually Not Appropriate
MRI orbits without and with IV contrast	Usually Not Appropriate
MRI orbits without IV contrast	Usually Not Appropriate
MRI thoracic spine with IV contrast	Usually Not Appropriate
MRI thoracic spine without and with IV contrast	Usually Not Appropriate
MRI thoracic spine without IV contrast	Usually Not Appropriate
CT head with IV contrast	Usually Not Appropriate
CT head without and with IV contrast	Usually Not Appropriate
CT head without IV contrast	Usually Not Appropriate
CT neck with IV contrast	Usually Not Appropriate
CT neck without and with IV contrast	Usually Not Appropriate
CT neck without IV contrast	Usually Not Appropriate
CTA head and neck with IV contrast	Usually Not Appropriate
CT head without IV contrast and CTA head and neck with IV contrast	Usually Not Appropriate

Variant: 4 Adult. Nonacute onset Horner syndrome with localizing brain or cranial nerve neurological signs or symptoms. Initial imaging.

Procedure	Appropriateness Category
MRI head and orbits without and with IV contrast	May Be Appropriate (Disagreement)
MRI head and orbits without IV contrast	May Be Appropriate (Disagreement)
MRI head without and with IV contrast	May Be Appropriate
MRI head without and with IV contrast and MRA head and neck without and with IV contrast	May Be Appropriate (Disagreement)
MRI head without and with IV contrast and MRA head and neck without IV contrast	May Be Appropriate (Disagreement)
MRI head without IV contrast	May Be Appropriate
MRI orbits without and with IV contrast	May Be Appropriate (Disagreement)
MRI orbits without IV contrast	May Be Appropriate
CT head without IV contrast and CTA head and neck with IV contrast	May Be Appropriate
MRA head and neck with IV contrast	Usually Not Appropriate
MRA head and neck without and with IV contrast	Usually Not Appropriate
MRA head and neck without IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without and with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without IV contrast	Usually Not Appropriate
MRI cervical spine with IV contrast	Usually Not Appropriate
MRI cervical spine without and with IV contrast	Usually Not Appropriate
MRI cervical spine without IV contrast	Usually Not Appropriate
MRI head and orbits with IV contrast	Usually Not Appropriate
MRI head with IV contrast	Usually Not Appropriate
MRI head with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI neck with IV contrast	Usually Not Appropriate
MRI neck without and with IV contrast	Usually Not Appropriate
MRI neck without IV contrast	Usually Not Appropriate
MRI orbits with IV contrast	Usually Not Appropriate
MRI thoracic spine with IV contrast	Usually Not Appropriate
MRI thoracic spine without and with IV contrast	Usually Not Appropriate
MRI thoracic spine without IV contrast	Usually Not Appropriate
CT head with IV contrast	Usually Not Appropriate
CT head without and with IV contrast	Usually Not Appropriate
CT head without IV contrast	Usually Not Appropriate
CT neck with IV contrast	Usually Not Appropriate
CT neck without and with IV contrast	Usually Not Appropriate
CT neck without IV contrast	Usually Not Appropriate
CTA head and neck with IV contrast	Usually Not Appropriate

Variant: 5 Adult. Nonacute onset Horner syndrome nonlocalizable, not otherwise specified. Initial imaging.

Procedure	Appropriateness Category
CTA head and neck with IV contrast	Usually Appropriate
MRA head and neck with IV contrast	Usually Not Appropriate
MRA head and neck without and with IV contrast	Usually Not Appropriate
MRA head and neck without IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without and with IV contrast	Usually Not Appropriate
MRI cervical and thoracic spine without IV contrast	Usually Not Appropriate
MRI cervical spine with IV contrast	Usually Not Appropriate
MRI cervical spine without and with IV contrast	Usually Not Appropriate
MRI cervical spine without IV contrast	Usually Not Appropriate
MRI head and orbits with IV contrast	Usually Not Appropriate
MRI head and orbits without and with IV contrast	Usually Not Appropriate
MRI head and orbits without IV contrast	Usually Not Appropriate
MRI head with IV contrast	Usually Not Appropriate
MRI head with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without and with IV contrast	Usually Not Appropriate
MRI head without and with IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI head without IV contrast	Usually Not Appropriate
MRI head without IV contrast and MRA head and neck without IV contrast	Usually Not Appropriate
MRI neck with IV contrast	Usually Not Appropriate
MRI neck without and with IV contrast	Usually Not Appropriate
MRI neck without IV contrast	Usually Not Appropriate
MRI orbits with IV contrast	Usually Not Appropriate
MRI orbits without and with IV contrast	Usually Not Appropriate
MRI orbits without IV contrast	Usually Not Appropriate
MRI thoracic spine with IV contrast	Usually Not Appropriate
MRI thoracic spine without and with IV contrast	Usually Not Appropriate
MRI thoracic spine without IV contrast	Usually Not Appropriate
CT head with IV contrast	Usually Not Appropriate
CT head without and with IV contrast	Usually Not Appropriate
CT head without IV contrast	Usually Not Appropriate
CT neck with IV contrast	Usually Not Appropriate
CT neck without and with IV contrast	Usually Not Appropriate
CT neck without IV contrast	Usually Not Appropriate
CT head without IV contrast and CTA head and neck with IV contrast	Usually Not Appropriate

Prachi Dubey, MBBS, MPH^a; Nitesh Shekhrajka, MBBS^b; Amy F. Juliano, MD^c; Mohit Agarwal, MD^d; Aileen A. Antonio, MD^e; Moises Auron, MD^f; Paul M. Bunch, MD^g; Judah Burns, MD^h; Gregory Compton, MBBS, BAⁱ; Elliott R. Friedman, MD^j; Maria K. Gule-Monroe, MD^k; Mari Hagiwara, MD^l; Vikas Jain, MD^m; Daniel E. Meltzer, MDⁿ; Rohini N. Nadgir, MD^o; Joseph F. Rizzo III, MD^p; Bradley D. Shy, MD^q; Andrew T. Trout, MD^r; Bruno Policeni, MD, MBA^s.

Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when:

There are procedures that are equivalent alternatives (i.e., only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care)

There are complementary procedures (i.e., more than one procedure is ordered as a set or simultaneously wherein each procedure provides unique clinical information to effectively manage the patient’s care).

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please visit https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

The ACR acknowledges the limitations in applying inclusive language when citing research studies that predates the use of the current understanding of language inclusive of diversity in sex, intersex, gender, and gender-diverse people. The data variables regarding sex and gender used in the cited literature will not be changed. However, this guideline will use the terminology and definitions as proposed by the National Institutes of Health.

Appropriateness Category Name	Appropriateness Rating	Appropriateness Category Definition
Usually Appropriate	7, 8, or 9	The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.
May Be Appropriate	4, 5, or 6	The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.
May Be Appropriate (Disagreement)	5	The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.
Usually Not Appropriate	1, 2, or 3	The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table below). Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria^® Radiation Dose Assessment Introduction document.

Relative Radiation Level Designations
Relative Radiation Level*	Adult Effective Dose Estimate Range	Pediatric Effective Dose Estimate Range
O	0 mSv	0 mSv
☢	<0.1 mSv	<0.03 mSv
☢☢	0.1-1 mSv	0.03-0.3 mSv
☢☢☢	1-10 mSv	0.3-3 mSv
☢☢☢☢	10-30 mSv	3-10 mSv
☢☢☢☢☢	30-100 mSv	10-30 mSv
*RRL assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (e.g., region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as “Varies.”

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The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient’s clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient’s condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination