ACR Appropriateness CriteriasAcute Respiratory
Illness in Immunocompetent Patients
Jacobo Kirsch, MD,* Jose´ Ramirez, MD,* Tan-Lucien H. Mohammed, MD,w
Judith K. Amorosa, MD,z Kathleen Brown, MD,y Debra Sue Dyer, MD,J Mark E. Ginsburg, MD,z#
Darel E. Heitkamp, MD,** Jean Jeudy, MD,ww Heber MacMahon, MB, BCh,zz
James G. Ravenel, MD,yy Anthony G. Saleh, MD,JJzz and Rakesh D. Shah, MD##;
Expert Panel on Thoracic Imaging
Abstract: Acute respiratory illness is defined as one or more of the
following: cough, sputum production, chest pain, or dyspnea (with
or without fever). The workup of these patients depends on many
factors, including clinical presentation and the suspected etiology.
This study reviews the literature on the indications and usefulness
of radiologic studies for the evaluation of acute respiratory illness
in the immunocompetent patient. The following recommendations
are the result of evidence-based consensus by the American College
of Radiology Appropriateness Criteria Expert Panel on Thoracic
Radiology. Chest radiographs are usually appropriate in (1)
patients with positive physical examination or risk factors for
pneumonia, (2) for the assessment of complicated pneumonia, or
(3) in cases of emerging infections and biological warfare agents
such as severe acute respiratory syndrome, H1N1, and anthrax.
Computed tomography, although having a more limited role, is
usually appropriate (1) in the assessment of complicated pneumo-
nia and (2) in patients with suspected severe acute respiratory
syndrome, H1N1, or anthrax and a normal radiograph.
Key Words: appropriateness criteria, acute respiratory illness,
pneumonia, chest radiograph, computed tomography
(J Thorac Imaging 2011;26:W42–W44)
SUMMARY OF LITERATURE REVIEW
Acute respiratory illness (ARI) is defined as one or
more of the following: cough, sputum production, chest
pain, or dyspnea (with or without fever). The workup of a
patient with ARI, including the need for chest radiography
and computed tomography (CT), depends on many clinical
factors (Table 1).
Benacerraf et al1in a study of 1102 outpatients with
ARI, found patient age, the physical examination, and the
presence or absence of hemoptysis to be important factors.
Only 4% (7 of 175) of patients younger than 40 years of age
with symptoms of ARI and a negative physical examination
had radiographic findings. In a study of 464 patients with
ARI, Heckerling2also found a low incidence (3%) of
pneumonia in patients with negative physical examinations.
In a series of 300 patients with acute cough, Aagaard
et al3found that for patients with a high pretest probability
of pneumonia, a radiograph was not always obtained in
clinical practice, inferring that a negative radiograph would
not alter treatment decisions in these patients. A series by
Basi et al4that included 2706 patients hospitalized with
community-acquired pneumonia (CAP) showed that 911 of
them had radiographs initially interpreted as negative.
These studies call into question the utility of radiographs in
patients with high pretest probability.
Jochelson et al5and Navigante et al6found a low
incidence (4% and 2.3%, respectively) of pneumonia in
febrile, but otherwise asymptomatic, neutropenic patients
with a normal physical examination. Heussel et al7
evaluated the utility of thin-section CT in 87 febrile
neutropenic patients with normal or nonspecific chest
radiographs. Forty-eight percent of the patients had a
normal chest radiograph, but CT findings were suggestive
of pneumonia, impacting therapy in 18% of the patients.
According to the guidelines of the Infectious Diseases
Society of America and the American Thoracic Society,
chest radiography should be obtained whenever pneumonia
is suspected in adults to establish the diagnosis and to aid in
excluding other etiologies.8
The need for chest radiographs in adult patients with
acute asthma is controversial. Petheram et al9found
clinically important radiographic findings in up to 9% of
their patients. However, Findley and Sahn10observed that
Appropriateness Criteria Review
Copyright r 2011 American College of Radiology. Reprinted with
This article is a summary of the complete version of this topic, which is
available on the ACR website at www.acr.org/ac. Practitioners are
encouraged to refer to the complete version.
From the *Division of Radiology, Cleveland Clinic, Weston, FL;
wImaging institute, Cleveland Clinic Foundation, Cleveland, OH;
zDepartment of Radiology, Robert Wood Johnson Medical
Sciences, David Geffen School of Medicine at UCLA, Los Angeles,
CA; JDepartment of Radiology, National Jewish Health, Denver,
CO; zDepartment of Surgery, Columbia University, New York;
JJInstitute of Asthma and Lung Disease, New York Methodist
Hospital, Brooklyn; ##Department of Radiology, North Shore
University Hospital, Manhasset, NY; #Society of Thoracic
Surgeons, Chicago, IL; zzDepartment of Radiology, University
of Chicago Hospital, Chicago; zzAmerican College of Chest
Physicians, Northbrook, IL; **Department of Radiology, Indiana
University, Indianapolis, IN; wwDivision of Diagnostic Radiology
and Nuclear Medicine, University of Maryland Medical Center,
Baltimore, MD; and yyDepartment of Radiology, Medical Uni-
versity of South Carolina, Charleston, SC.
The American College of Radiology (ACR) seeks and encourages
collaboration with other organizations on the development of the ACR
Appropriateness Criteriasthrough society representation on expert
panels. Participation by representatives from collaborating societies
on the expert panel does not necessarily imply society endorsement of
the final document.
Reprints: Department of Quality & Safety, American College of
AMERICAN COLLEGE OF RADIOLOGY
W42|www.thoracicimaging.comJ Thorac Imaging?Volume 26, Number 2, May 2011
99% of their patients either had normal chest radiographic
examinations or showed only slightly prominent markings
or hyperinflation, recommending radiographs only when
pneumonia or pneumothorax is suspected. White et al11
found significant chest radiographic abnormalities in 34%
of adults whose asthma exacerbation warranted admission
to the hospital.
Chronic Obstructive Pulmonary Disease
Sherman et al12studied the chest radiographs of 242
patients with acute exacerbations of chronic obstructive
pulmonary disease, with 14% being abnormal but resulting
in change in management only in 4.5%. They concluded
that the chest radiograph is indicated only if worsening
dyspnea is accompanied by leukocytosis, chest pain, or
Severe Acute Respiratory Syndrome
Severe acute respiratory syndrome (SARS) emerged in
China in late 2002. The etiologic agent is a novel
coronavirus (SARS-CoV). Wong et al13and Paul et al14
described the chest radiographic findings of SARS during
the epidemics. Radiographs were abnormal in 78% to 80%
of patients at presentation. Antonio et al15studied 1373
patients with SARS and found a sensitivity of 82.4% on
initial radiographs, with the initial extent of radiographic
opacification having prognostic value. However, a retro-
spective study by Chan et al16with a cohort of 1311
patients found that the sensitivity (50.3%) of the initial
chest radiograph was much lower than expected previously.
In contrast, the sensitivity of serial chest radiography was
improved to 94.4% with a negative predictive value of
High-resolution chest CT findings of SARS have been
described by Wong et al,17Chan et al,18and Paul et al.14
The most common findings are ground-glass opacities and
crazy paving. Hui et al19suggest that high-resolution chest
CT is useful for early diagnosis of SARS in patients with
Anthrax is endemic in the soil of Texas, Oklahoma,
and the Mississippi Valley. Ninety-five percent of anthrax is
cutaneous, but the inhalational form is the most deadly.
Inhalation of anthrax spores leads to hemorrhagic lympha-
denitis and mediastinitis, sometimes accompanied by
necrotizing pneumonia. The chest radiographic findings
include widened mediastinum and hila, often accompanied
by pleural effusions and parenchymal opacities.
In 2009, a new strain of human influenza A (H1N1)
virus was identified in Mexico that grew to be declared a
level 6 pandemic. A small percentage of patients with H1N1
virus pneumonia may develop acute respiratory distress
syndrome or severe cardiopulmonary failure.20
A review of chest radiograph findings of 97 patients with
proven H1N1 infection by Aviram et al21described an
abnormal radiograph in 40% of patients, showing ground-
glass opacities, often central, or overt patchy consolidations.
Extensive involvement of both lungs was associated with an
adverse prognosis. Abbo et al22reviewed the imaging
characteristics of 123 patients with H1N1 influenza, and up
to 67% of their initial radiographs were negative. On CT
examinations, 90% of patients showed consolidation,
ground-glass opacity, nodules, or a combination of findings.
A study by Agarwal et al23in 222 patients with suspected or
proven H1N1 influenza showed normal chest radiographs in
TABLE 1. Clinical Condition: Acute Respiratory Illness in Immunocompetent Patients
Chest CT With or
Older than age 40y
Dementia, any age
Younger than age 40y, negative physical examination,
and no other signs, symptoms, or risk factors
Younger than age 40y and positive physical examination or
other risk factors
Suspected SARS, chest radiograph normal or equivocal
Suspected anthrax, chest radiograph normal or equivocal
Acute asthma, uncomplicated
Acute asthma and suspected pneumonia or pneumothorax
Acute exacerbation of COPD, “uncomplicated” (no history
of coronary artery disease or congenital heart failure, no leukocytosis,
fever, or chest pain)
Acute exacerbation of COPD with one or more of the following: leukocytosis,
pain, history of coronary artery disease or congenital heart failure
Suspected H1N1, chest radiograph normal or equivocal
Appropriateness criteria scale: 1, 2, and 3, usually not appropriate; 4, 5, and 6, may be appropriate; 7, 8, and 9, usually appropriate.
*In patients without reliable follow-up or with a likelihood of morbidity if disease is not detected initially, a CT may be required in the setting of a negative
wIf pneumonia is not resolving or intervention is contemplated.
zChest x-rays may be normal in a large percentage of patients. If clinical suspicion is present, a chest CT should follow to better assess.
COPD indicates chronic obstructive pulmonary disease; X, not applicable.
J Thorac Imaging?Volume 26, Number 2, May 2011ACR Appropriateness Criterias
r2011 American College of Radiology. Reprinted with Permission.
>58% of patients and bilateral extensive airspace disease in
severely ill patients.
? On the basis of these studies, a chest radiograph seems
warranted in ARI when one or more of the following
are present: older than 40 years of age; dementia; a
positive physical examination; hemoptysis; associated
abnormalities (leukocytosis, hypoxemia); or other risk
factors, including coronary artery disease, congestive
heart failure, or drug-induced acute respiratory failure.
? Chest radiography also seems warranted for any adult
patient with clinical suspicion of pneumonia, although
some clinicians may choose not to perform radiography if
clinical suspicion of respiratory infection is sufficiently high
to warrant treatment if a radiograph was to be negative.
? It seems that in patients with ARI who are younger than
40 years of age, chest radiography is not routinely
indicated unless there are other abnormalities, a positive
physical examination, or other risk factors.
? It also seems that chest radiographic examination is not
indicated in most patients with exacerbations of chronic
obstructive pulmonary disease (including asthma) unless
there is a suspected complication such as pneumonia or
pneumothorax, or unless one or more of the following
are present: leukocytosis, chest pain, edema, or a history
of coronary artery disease or congestive heart failure.
? Chest CT may be warranted in complicated cases of
severe pneumonia and in febrile neutropenic patients
with normal or nonspecific chest radiographic findings.
? In patients with a normal chest radiograph and a high
clinical suspicion of either SARS or H1N1, CT scanning
can be helpful in suggesting the diagnosis.
The ACR Committee on Appropriateness Criteria and its
expert panels have developed criteria for determining appro-
priate imaging examinations for the diagnosis and treatment of
specified medical condition(s). These criteria are intended to
guide radiologists, radiation oncologists, and referring physi-
cians 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 the evaluation of the patient’s condition are
ranked. Other imaging studies necessary to evaluate other
coexistent 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.
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J Thorac Imaging?Volume 26, Number 2, May 2011
r2011 American College of Radiology. Reprinted with Permission.