The left paratracheal reflection

A surprisingly common mediastinal reflection that has received minimal attention in the literature is the left paratracheal reflection (LPR). It was seen in approximately 30% of cases in review of several hundred normal posteroanterior radiographs of the chest. The LPR is produced when the lung anterior to the left subclavian artery contacts the mediastinum in a paratracheal coronal plane. The lung may border the left common carotid artery, left paratracheal mediastinal fat, or, rarely, the left tracheal wall. The LPR is illustrated and its radiographic appearance correlated with the appearance on conventional tomograms, CT scans, and anatomic specimens. As well, pathologic processed altering the normal reflection is shown