American College of Radiology
ACR Appropriateness Criteria®

Acute Respiratory Illness in Immunocompetent Patients

Variant 1: Acute respiratory illness in immunocompetent patients with negative physical examination, normal vital signs and no other risk factors. Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest Usually appropriate Moderate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 7 7 0 0 0 1 2 2 1 2 3
References Study Quality
21 (7455106) 4
22 (3718128) 3
23 (16635092) 4
24 (17412152) 2
25 (25785179) 2
26 (18439380) 4
27 (18439353) 4
28 (9224224) 4
CT chest with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 5 4 3 0 0 0 0 0 0
CT chest without IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 3 5 4 0 0 0 0 0 0
US chest Usually not appropriate Strong O 0 mSv O 0 mSv [ped] 2 2 3 4 4 0 0 0 0 0 0
References Study Quality
8 (24184011) 3
9 (21030550) 2
10 (25758182) 2
11 (22700780) 3
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 1 1 6 2 2 1 0 0 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 9 3 0 0 0 0 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 10 2 0 0 0 0 0 0 0
Variant 2: Acute respiratory illnesses in immunocompetent patients with positive physical examination, abnormal vital signs, organic brain disease or other risk factors. Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest Usually appropriate Moderate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 9 0 0 0 0 0 0 1 3 7
References Study Quality
4 (17278083) 4
21 (7455106) 4
22 (3718128) 3
23 (16635092) 4
24 (17412152) 2
25 (25785179) 2
29 (17099198) 4
30 (15336579) 4
31 (16837505) 3
US chest May be appropriate Limited O 0 mSv O 0 mSv [ped] 4 4 2 0 3 2 3 1 0 0 0
References Study Quality
8 (24184011) 3
11 (22700780) 3
CT chest without IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 3 1 4 4 1 1 0 1 0 0
CT chest with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 3 5 2 1 0 1 0 0 0
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 5 1 3 1 1 0 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 7 4 1 0 0 0 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 8 3 1 0 0 0 0 0 0
Variant 3: Acute respiratory illness in immunocompetent patients with positive physical examination, abnormal vital signs, organic brain disease, or other risk factors and negative or equivocal initial chest radiograph. Next Imaging Study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
CT chest without IV contrast Usually appropriate Moderate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 7 7 0 0 0 0 2 2 2 1 4
References Study Quality
4 (17278083) 4
6 (26935360) 2
7 (26168322) 3
32 (18571356) 4
33 (25083953) 3
34 (2785179) 1
24 (17412152) 2
CT chest with IV contrast May be appropriate (Disagreement) Expert Opinion ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 5 6 0 0 4 0 1 2 3 2 0
References Study Quality
4 (17278083) 4
6 (26935360) 2
7 (26168322) 3
24 (17412152) 2
32 (18571356) 4
33 (25083953) 3
34 (2785179) 1
US chest May be appropriate Limited O 0 mSv O 0 mSv [ped] 4 4 1 0 4 3 2 0 1 0 0
References Study Quality
8 (24184011) 3
10 (25758182) 2
11 (22700780) 3
MRI chest without IV contrast Usually not appropriate Limited O 0 mSv O 0 mSv [ped] 2 2 3 6 2 1 0 0 0 0 0
References Study Quality
14 (27811069) 1
MRI chest without and with IV contrast Usually not appropriate Limited O 0 mSv O 0 mSv [ped] 2 2 5 3 1 2 0 1 0 0 0
References Study Quality
14 (27811069) 1
CT chest without and with IV contrast Usually not appropriate Limited ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 1 1 7 2 1 1 1 0 0 0 0
References Study Quality
4 (17278083) 4
6 (26935360) 2
7 (26168322) 3
32 (18571356) 4
33 (25083953) 3
34 (2785179) 1
24 (17412152) 2
Variant 4: Acute respiratory illnesses in immunocompetent patients with pneumonia complicated by suspected parapneumonic effusion or abscess on initial chest radiograph. Next Imaging study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
CT chest with IV contrast Usually appropriate Limited ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 8 8 0 0 0 0 2 2 0 3 4
References Study Quality
6 (26935360) 2
35 (7384467) 4
CT chest without IV contrast Usually appropriate Limited ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 7 7 0 0 0 0 1 3 3 2 2
References Study Quality
6 (26935360) 2
35 (7384467) 4
MRI chest without IV contrast May be appropriate (Disagreement) Expert Opinion O 0 mSv O 0 mSv [ped] 5 4 3 0 0 5 2 2 0 0 0
References Study Quality
14 (27811069) 1
16 (27641778) 2
MRI chest without and with IV contrast May be appropriate (Disagreement) Expert Opinion O 0 mSv O 0 mSv [ped] 5 4 3 0 0 4 2 3 0 0 0
References Study Quality
14 (27811069) 1
16 (27641778) 2
US chest May be appropriate Limited O 0 mSv O 0 mSv [ped] 5 5 0 0 1 0 6 2 3 0 0
References Study Quality
36 (26218493) 4
CT chest without and with IV contrast Usually not appropriate Limited ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 5 3 2 1 0 0 1 0 0
References Study Quality
6 (26935360) 2
35 (7384467) 4
Variant 5: Acute asthma exacerbation in immunocompetent patients, uncomplicated (no suspicion of pneumonia or pneumothorax). Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest May be appropriate Limited ☢ <0.1 mSv ☢ <0.03 mSv [ped] 6 6 0 0 1 0 5 1 3 1 1
References Study Quality
22 (3718128) 3
37 (7297142) 4
CT chest with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 3 4 1 2 0 1 0 0 0
CT chest without IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 4 3 2 1 1 1 0 0 0
US chest Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 2 2 5 3 2 0 1 0 0 0 0
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 1 1 6 3 2 0 0 0 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 10 1 0 0 1 0 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 9 2 0 0 1 0 0 0 0
Variant 6: Acute asthma exacerbation in immunocompetent patients, complicated (suspected pneumonia or pneumothorax). Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest Usually appropriate Limited ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 9 0 0 0 0 0 3 0 2 6
References Study Quality
22 (3718128) 3
37 (7297142) 4
38 (7237908) 3
39 (2060333) 4
CT chest with IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 5 5 0 1 3 1 4 1 1 0 0
CT chest without IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 5 5 0 0 0 0 7 3 1 0 1
US chest May be appropriate Strong O 0 mSv O 0 mSv [ped] 4 4 3 0 2 3 2 1 0 0 0
References Study Quality
8 (24184011) 3
9 (21030550) 2
10 (25758182) 2
11 (22700780) 3
12 (20731700) 2
13 (17316468) 4
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 3 4 1 4 2 0 0 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 2 2 6 2 1 1 1 1 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 2 2 6 2 1 1 1 1 0 0 0
Variant 7: Acute COPD exacerbation in immunocompetent patients, uncomplicated (no chest pain, fever, or leukocytosis, no history of coronary artery disease, or heart failure). Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest Usually appropriate Limited ☢ <0.1 mSv ☢ <0.03 mSv [ped] 8 8 0 0 0 1 2 0 2 2 4
References Study Quality
40 (2818109) 4
CT chest with IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 4 4 3 1 1 2 3 1 0 0 0
CT chest without IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 4 4 2 1 3 4 1 1 0 0 0
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 2 2 5 2 2 2 0 0 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 8 2 1 1 0 0 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 8 2 1 1 0 0 0 0 0
US chest Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 6 1 3 0 0 1 0 0 0
Variant 8: Acute COPD exacerbation in immunocompetent patients with accompanying chest pain, fever, or leukocytosis, or a history of coronary artery disease, or heart failure. Initial imaging.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
Radiography chest Usually appropriate Limited ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 9 0 0 0 0 0 0 1 3 7
References Study Quality
40 (2818109) 4
CT chest without IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 6 6 0 0 1 0 2 4 2 1 1
CT chest with IV contrast May be appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 5 5 0 0 1 0 7 1 3 0 0
US chest May be appropriate Limited O 0 mSv O 0 mSv [ped] 5 5 0 1 2 3 5 1 0 0 0
References Study Quality
10 (25758182) 2
11 (22700780) 3
CT chest without and with IV contrast Usually not appropriate Expert Consensus ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 3 3 4 0 3 0 3 1 0 0 0
MRI chest without IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 7 2 1 1 0 1 0 0 0
MRI chest without and with IV contrast Usually not appropriate Expert Consensus O 0 mSv O 0 mSv [ped] 1 1 7 2 1 1 0 1 0 0 0
Appendix Key

A more complete discussion of the items presented below can be found by accessing the supporting documents at the designated hyperlinks.

Appropriateness Category:The panel’s recommendation for a procedure based on the assessment of the risks and benefits of performing the procedure for the specified clinical scenario.

SOE: Strength of Evidence. The assessment of the amount and quality of evidence found in the peer reviewed medical literature for an appropriateness recommendation.

  • References: The citation number and PMID for the reference(s) associated with the recommendation.
  • Study Quality: The assessment of the quality of an individual reference based on the number of study quality elements described in the reference.

RRL: Relative Radiation Level. A population based assessment of the amount of radiation a typical patient may be exposed to during the specified procedure.

Rating: The final rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Median: The median rating (1-9 scale) for the procedure as determined by the panel during rating rounds.

Final tabulations: A histogram showing the number of panel members who rated the procedure as noted in the column heading (ie, 1, 2, 3, etc.).

Additional supporting documents about the AC methodology and processes can be found at www.acr.org/ac.