American College of Physicians: Internal Medicine — Doctors for Adults ®


DynaMed Plus image quiz: CT scan

From the January ACP Internist, copyright © 2017 by the American College of Physicians

This image and answer were derived directly from DynaMed Plus content, which include tables as well as summaries of individual studies. More information on DynaMed Plus is available online and can be accessed online.

© The American College of Physicians

© The American College of Physicians

Which of the following is the most likely cause of the findings in this high-resolution CT scan?

A: Asbestosis

B: Idiopathic pulmonary fibrosis

C: Rheumatoid arthritis

D: Scleroderma

Answer: B. Idiopathic pulmonary fibrosis.

Supporting citations for this topic are online.

Idiopathic pulmonary fibrosis is the most common cause of usual interstitial pneumonia, the type of interstitial lung disease imaged here. Idiopathic pulmonary fibrosis, which commonly affects men aged 50-75 years old, results from a dysregulated response of inflammatory cells to unknown injury resulting in interstitial fibrosis. Similar CT scans may also be seen in patients with known causes of pulmonary scarring such as scleroderma, rheumatoid arthritis, asbestosis, and sarcoidosis but in most patients with usual interstitial pneumonia, as in this patient, the cause of pulmonary scarring is unknown.

Clinical features of a usual interstitial pneumonia pattern include all of the following:

  • subpleural, basal predominance
  • reticular abnormality
  • honeycombing with or without traction bronchiectasis
  • no features inconsistent with usual interstitial pneumonia pattern

Features inconsistent with a usual interstitial pneumonia pattern include any of:

  • upper or midlung predominance
  • peribronchovascular predominance
  • ground glass abnormality more extensive than reticular abnormality
  • profuse bilateral micronodules predominantly in upper lobes
  • multiple, bilateral, discrete cysts away from areas of honeycombing
  • diffuse bilateral mosaic attenuation or air-trapping in ≥ 3 lobes
  • consolidation in bronchopulmonary lobes or segments.



Learn more about DynaMed Plus

DynaMed Plus helps you to:

  • Support your clinical decisions in practice
  • Update your knowledge in all areas of internal medicine
  • Study for the ABIM Certification Exam or the ABIM Recertification Exam

For more information, visit ACP's website on DynaMed Plus.


This is a printer-friendly version of this page

Print this page  |  Close the preview




Internist Archives Quick Links

Not an ACP Member?

Join today and discover the benefits waiting for you.

Not an ACP Member? Join today and discover the benefits waiting for you

ACP offers different categories of membership depending on your career stage and professional status. View options, pricing and benefits.

A New Way to Ace the Boards!

A New Way to Ace the Boards!

Ensure you're board-exam ready with ACP's Board Prep Ace - a multifaceted, self-study program that prepares you to pass the ABIM Certification Exam in internal medicine. Learn more.