Lobes and Fissures

Table of Contents

Table of Contents

Published January 2021

Brandon Fainstad, MD1

1 Assistant Professor, Department of Medicine, University of Colorado


  1. Identify the minor and major fissures using a CXR with multiple pleural effusions 

Teaching Instructions

Plan to spend 5-10 minutes familiarizing yourself with the animations of the PowerPoint and the key findings of this chest X-ray. 

Instructions: Present the image either by expanding the window (bottom right) in a browser or downloading the PowerPoint file (downloading is recommended).  Have the image pulled up in presenter mode before learners look at the screen to avoid revealing the diagnosis.  Ask a learner to provide an overall interpretation.  Then advance through the animations to prompt learners with key questions and reveal the findings, diagnosis, and teaching points.  You can go back to prior graphics and questions by using the back arrow or scrolling back on the mouse wheel.

Official CXR Read: Sternotomy wires with two prosthetic valves.  Right middle and lower lobe airspace opacities with parapneumonic effusions in the right-sided fissures and subpulmonic space along with a small effusion in left costo-phrenic sulcus. 

Diagnosis: Right middle lobe pneumonia and parapneumonic effusions

Teaching: The focus of this talk is on the identification of lobes and fissures.  The right has a minor fissure seen on both AP and lateral views while the left does not have a minor fissure.  The major fissure for either side is best seen on the lateral view and differentiated by whether or not the fissure extends all the way to the diaphragm (right) or stops at the mediastinum (left). 

Presentation Board

Take Home Point

  1. The right minor fissure is well visualized on both anterior and lateral views.  There is no left minor fissure. 
  2. The right and left major fissures are differentiated by the silhouette sign of the left major fissure and mediastinum. 


Goodman, L. R. (2019). Felson's Principles of Chest Roentgenology E-Book: A Programmed Text. Netherlands: Elsevier Health Sciences.

Brandon Fainstad


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