Uncategorized Normal P-A Chest X-ray NORMAL PA to BRONCHUS RATIOThe pulmonary artery and bronchus travel together and there are 3 basic regions where the relationship is best visualisedIn the upright position, the ratio of the size of the pa to the bronchus is 1.2:1, in the mid lung zone it is 1:1, and in the upper lungs it is .8 :1Ashley Davidoff MD Where to Look NORMAL PA to BRONCHUS RATIOThe pulmonary artery and bronchus travel together and there are 3 basic regions where the relationship is best visualisedIn the upright position, the ratio of the size of the pa to the bronchus is 1.2:1, in the mid lung zone it is 1:1, and in the upper lungs it is .8 :1Ashley Davidoff MD Normal Ratios, Lower, Mid and Upper Lung Zones NORMAL PA to BRONCHUS RATIOThe pulmonary artery and bronchus travel together and there are 3 basic regions where the relationship is best visualisedIn the upright position, the ratio of the size of the pa to the bronchus is 1.2:1, in the mid lung zone it is 1:1, and in the upper lungs it is .8 :1Ashley Davidoff MD