Purpose
The aim of this study is to evaluate the importance of chest CT scans and CT findings in patients with influenza A (H1N1).
The reported imaging findings of radiographs and CT were ground-glass opacity,
consolidation,
nodules,
and interstitial markings [1-5].
However,
a discussion of airway involvement is not present in their description of the radiologic findings.
We examined chest CT findings on the basis of the involvement pattern of lungs,
focusing on the airway or lung parenchyma.
Methods and Materials
1.
Subjects
From September 2009 to January 2010
Of 3511 patients who had microbiologically confirmed influenza A (H1N1) infection,
60 patients (1.7%) underwent chest radiographs and chest CT.
Among the 60 patients,
we excluded 14 patients who had underlying pulmonary disease.
27 men and 19 women,
mean age of 39 years (range,
17 to 81 years)
Positive H1N1 virus infection was confirmed by a real-time reverse transcriptase polymerase chain reaction
2.
Imaging Techniques
1) Chest radiographs
Digital Diagnost system (Philips Medical System)
Posteroanterior/lateral-projection radiographs
100kV,...
Results
Among 46 patients.
9 patients (9/46,
20%) had no abnormality in their CT scans.
The group 3 was predominant group including 21 patients (21/46,
46%),
followed by group 2 (10/46,
22%),
and group 1 (6/46,
13%) (table 1).
Bronchial wall thickening,
often associated with consolidation or ground-glass opacities,
are predominant CT findings.
Even though in patients who have abnormal chest CT findings,
13 patients were normal in their chest radiographs (13/37,
35%).
All of 6 patients in group 1 were predominant (46%,
6/13) compared with...
Conclusion
Diffuse areas of bronchial wall thickening,
often associated with consolidation or groud-glass opacities,
are predominant CT findings in patients with influenza A(H1N1).
If the lesion is limited in airway,
initial chest radiographs are often normal regardless of its distribution.
Therefore,
if influenza A (H1N1) is suspected clinically,
a CT scan is recommended even in patients with normal initial chest radiographs.
References
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Swine-origin influenza a (H1N1) viral infection: Radiographic and CT findings.
AJR Am J Roentgenol 2009;193:1494-1499
Lee EY,
McAdam AJ,
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Fishman MP,
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Swine-origin influenza a (H1N1) viral infection in children: Initial chest radiographic findings.
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