Paradoxical vocal cord PET uptake

Large lung tumor adjacent to the aortic arch, extending to the aorto-pulmonary window and the expected location of the left recurrent laryngeal nerve. On plain CT, there are features of left sided vocal cord palsy, with paramedian position of the cord and enlarged laryngeal ventricle (arrow). No increased PET uptake is seen in the paralyzed cord, consistent with absence of tumor there. There is increased PET uptake in the normal cord (arrow), secondary to increased physiological activity as a compensatory mechanism.