A new study led by Indian origin scientist has found that patients with severe H1N1 infection are at an increased risk of developing life-threatening condition called pulmonary emboli, where one or more arteries in the lungs become blocked.
"The high incidence of pulmonary embolism is important. Radiologists have to be aware to look closely for the risks of pulmonary embolism in severely sick patients," said Dr Prachi P. Agarwal, M.D., assistant professor of radiology at the University of Michigan Medical School and lead author of the study.
"The majority of patients with H1N1 that undergo chest X-rays have normal radiographs. CT scans proved valuable in identifying those patients at risk of developing more serious complications as a possible result of the H1N1 virus," added Agarwal.
The study was conducted over 66 patients diagnosed with the H1N1 flu of which 14 severely ill and required Intensive Care Unit admission.
All 66 patients underwent chest X-rays for the detection of H1N1 abnormalities. Pulmonary emboli were seen in CT scans on five of the 14 ICU patients.
Another important finding is that initial chest radiographs were normal in more than half of the patients with H1N1, said co-researcher Dr Ella Kazerooni, director of U-M's division of cardiothoracic radiology and professor of radiology.
"These findings indicate that imaging studies would have to be repeated in severely ill patients to monitor disease progression.
"It's important to heighten awareness not only among the radiologists, but also among the referring clinicians," Kazerooni added.
The study is published in the American Journal of Roentgenology.