High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia.
OBJECTIVE
The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia.


METHODS
We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 degrees F (>38 degrees C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision.


RESULTS
The predominant HRCT findings consisted of bilateral ground-glass opacities (n=12), bilateral areas of consolidation (n=2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n=6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients.


CONCLUSIONS
HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.
Marchiori
Edson
E
Fluminense Federal University, Rio de Janeiro, Brazil; Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. edmarchiori@gmail.com
Zanetti
Gláucia
G
Hochhegger
Bruno
B
Rodrigues
Rosana Souza
RS
Fontes
Cristina Asvolinsque Pantaleão
CA
Nobre
Luiz Felipe
LF
Mançano
Alexandre Dias
AD
Meirelles
Gustavo Souza Portes
GS
Meirelles
Gustavo
G
Irion
Klaus Loureiro
KL
D000328:Adult; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult