Ordinary chest X-rays show distinctive disease patterns of avian flu in humans that are good predictors of patient survival, according to University of Oxford investigators. Their findings indicate that patients with more severe X-ray appearances would benefit from aggressive treatment earlier, giving them a better chance of survival.

"On chest X-rays in patients with avian flu, the most common abnormality we found was multifocal consolidation, which usually represents pus and infection in patients with fever and a cough. We also discovered that the severity of these findings turned out to be a good predictor of patient mortality," said Nagmi Qureshi, a fellow of thoracic radiology at the University of Oxford in England.

The investigators studied 98 X-rays of 14 patients admitted to Ho Chi Minh City Hospital in Vietnam after testing positive for avian flu. They assessed the X-rays for features commonly seen in chest infection and then looked for associations between X-ray appearances and mortality. Of the 14 patients studied, nine patients died and five survived, claims a Radiological Society of North America (RSNA) release.

Three of the five patients who survived underwent computed tomography (CT) exams after discharge from the hospital. CT images showed that even though the patients' respiratory symptoms had abated, the abnormal appearance of the lungs persisted, suggestive of scar tissue formation.

Dr. Qureshi described the findings as similar to what was seen previously in patients with severe acute respiratory syndrome (SARS). "The appearance of multiple accumulations of infection in the lung is found in both avian flu and SARS. However, additional abnormalities we discovered in avian flu patients including fluid in the space surrounding the lungs, enlarged lymph nodes and cavities forming in the lung tissue were absent in patients with SARS,” Dr. Qureshi said.

The influenza virus that causes avian flu is highly unstable and prone to mutations. While common in birds, some experts warn that this virus could mutate and become contagious between humans, leading to a possible pandemic. Avian flu in its current form does not typically infect humans hence there is little or no immune protection against it in the human population.

RSNA is an association of more than 38,000 radiologists, radiation oncologists, medical physicists and related scientists committed to promoting excellence in radiology through education and by fostering research, with the ultimate goal of improving patient care.