Figure 18b. PLCH in a 52-year-old physician with a long history of cigarette smoking and worsening cough. (a-c) High-resolution CT scans (lung window; obtained at cranial to caudal levels) at the time of diagnosis show nodules and cysts that predominantly affect the upper and middle lung zones. (d-f) High-resolution CT scans (lung window; obtained at cranial to caudal levels) taken 3 years following cessation of smoking show marked improvement with near resolution of previously seen nodular and cystic lesions and evidence of centrilobular emphysema.