The Three Planes / Views I like to start this section by highlighting the famous short story of blind men and the elephant. For those of you who aren’t familiar with the story, you can read it here. In summary, each blind man encounters different part of the elephant. One man felt the elephant’s leg
The Hounsfield Unit, Window Level & Width The Hounsfield Unit The Hounsfield Unit (HU) is a way to (quantitatively) measure tissue density. More dense structure absorbed more radiation = image is brighter e.g. bone (+1000 HU) Less dense structure absorbed less radiation = image is darker e.g. air (-1000 HU) The reference point is water,
The Blind Men & the Elephant Poem by John Godfrey Saxe (1872) I. It was six men of IndostanTo learning much inclined,Who went to see the Elephant(Though all of them were blind),That each by observationMight satisfy his mind. II. The First approached the Elephant,And happening to fallAgainst his broad and sturdy side,At once began to bawl:“God
Lobar Collapse What’s normal ? For further details on the normal CXR please see specific section here. For quick revision, in the normal CXR where both lungs are fully expanded, (because of the difference in tissue density) you should be able to see all sides border of the lungs, including the normal cardiomediastinal contour. The
Pulmonary Embolism What’s normal ? For further details on CTPA please see specific section on CTPA and CT angiogram. In summary, the contrast helps to enhance the outline of the vessels. The normal CTPA has continuous flow of hyper-attenuated contrast within the vasculature of pulmonary artery (PA) and its branches. Figure 1: CT chest without
Endotracheal Tube (ETT) The optimal position of ETT can be assessed with CXR. The idea is that you want the tip to be just in between the carina and the vocal cord. Most sources recommend to position the tip of the ETT about 5-7 cm from the carina. Although personally, I try not go higher