Associate Professor of Pulmonary and Critical Care Medicine
University of Michigan Health System
Ann Arbor, Michigan

Question: Should I order routine (ie, every 6 or 12 months) follow-up HRCT studies for my patients with IPF?

Answer: HRCT plays a pivotal role in the diagnosis of diffuse parenchymal lung disease and, in some cases, can supplant the need for a surgical lung biopsy. That said, the role of regular HRCT follow-up is less clear. Few longitudinal studies are available and most show some change in ground glass and/or interstitial abnormalities with weak correlations with survival.1-3 Differences in HRCT patterns have also been reported between treatment arms in clinical trials; however, the details of analysis were not clearly specified.4 There is also recent heightened awareness about the possible radiation risks associated with the increased numbers of CT scans.5 With these thoughts in mind, we do not recommend routine follow-up HRCT studies to monitor patients with IPF. We do perform follow-up CT studies when there is a change, particularly an abrupt change, in clinical status to look for evidence of infection (especially in patients on immunosuppressive therapy), pulmonary edema, pulmonary embolism, malignancy, or acute exacerbation of IPF.

  1. Xaubet A, Agusti C, Luburich P, et al. Pulmonary function tests and CT scan in the management of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. 1998;158:431-436.
  2. Hartman TE, Primack S, Kang EY, et al. Disease progression in usual interstitial pneumonia compared with desquamative interstitial pneumonia. Assessment with serial CT. Chest. 1996;110:378-382.
  3. Nagao T, Nagai S, Hiramoto Y, et al. Serial evaluation of high-resolution computed tomography findings in patients with idiopathic pulmonary fibrosis in usual interstitial pneumonia. Respiration. 2002;69:413-419.
  4. Azuma A, Nukiwa T, Tsuboi E, et al. Double-blind, placebo-controlled trial of pirfenidone in patients with idiopathic pulmonary fibrosis. Am J Resp Crit Care Med. 2005;171:1040-1047.
  5. Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Eng J Med. 2007;357:2277-2284.