MONDAY, March 29 (HealthDay News) -- Abnormal findings on an initial chest X-ray in patients infected with H1N1 influenza, particularly extensive involvement of both lungs, may be associated with a worse prognosis, according to research published in the April issue of Radiology.
Galit Aviram, M.D., of Tel Aviv University in Israel, and colleagues retrospectively analyzed clinical outcomes in 97 patients with confirmed H1N1 influenza who underwent frontal chest radiography on admission to the emergency department.
The researchers found that 40 percent of patients had abnormal radiologic findings likely related to influenza infection. More patients with abnormal findings had adverse outcomes compared to patients with normal findings (13 versus 3 percent), although this did not reach statistical significance. Bilateral opacities were found in 62 percent of patients, and multiple lung zones were involved in 72 percent of patients. Opacities in four or more zones and bilateral peripheral opacities occurred with a higher frequency in patients with adverse outcomes compared to patients with good outcomes (multizonal, 60 versus 6 percent; bilateral, 60 versus 15 percent).
"Extensive involvement of both lungs, evidenced by the presence of multizonal and bilateral peripheral opacities, is associated with adverse prognosis," the authors write. "Initial chest radiography may have significance in helping predict clinical outcome but normal initial radiographs cannot exclude adverse outcome."