**9.5.2 Computed tomography**

High-resolution CT (HRCT) scanning is more sensitive than standard chest radiography and is highly specific for diagnosing emphysema and outlines bullae that are not always observed on radiographs. CT can visualise whether the emphysema is centriacinar or panacinar(Hasegawa et al.,2006;Nishino et al.,2010;Washko et al.,2008 as cited in Shapiro SD,2010). A CT scan is not indicated in the routine care of patients with COPD but is helpful when the patient is being considered for a surgical intervention such as bullectomy or lungvolume reduction surgery(Fishman et al,2003 as cited in Shapiro SD,2010).
