ABSTRACT
Acute viral bronchiolitis (AVB) is an obstructive lung disease which frequently develops in infants and the most common functional involvement is a V/Q ratio change caused by small airway obstruction. We report a case showing the redistribution of pulmonary blood flow by multiple perfusion scan defects in an infant with AVB. A 15 month-old male infant visited ER due to respiratory difficulty. He manifested decreased lung sound in the left lung field, hyperinflation of the left lung on chest x-ray, and metabolic acidosis in blood gas analysis. A perfusion scan showed multiple perfusion defects of both lungs without the evidence of pulmonary embolism on a following cardiac CT and echocardiography. Human Rhinovirus PCR in a nasopharyngeal aspirate was positive. With supportive care, the symptom was resolved in 4 days. AVB can show multiple perfusion defects by the redistribution of pulmonary blood flow of which the direction is opposite to the usual distribution of pulmonary blood flow in children.