Electron Density  
Phantom
• Evaluate CT scan data 
• Correct for inhomogeneities
• Document relationship between CT number and  
  tissue electron density
• Simulate indicated tissue within the diagnostic     
  energy range
• Quickly assess distance registration
Correlate CT Number and Tissue Electron Density 
Because CT scans are used to correct for tissue 
inhomogeneities in radiation therapy treatment planning, 
it’s important to obtain a precise relationship between 
CT number (in Hounsfield units) and electron densities. 
The CIRS Model 062M, Electron Density Phantom, 
enables precise correlation of CT data to electron 
density of various tissues, and is manufactured from 
CIRS tissue equivalent materials.
Tissue Equivalent Technology
The Model 062M consists of two nested disks made 
from Plastic Water®-LR. The disks can represent both 
head and abdomen configurations. Nine different tissue 
equivalent electron density plugs can be positioned at 
17 locations within the scan field. Included is a vial plug 
that can be filled with any fluid. Optional distance marker 
plugs enable quick assessment of the CT scanner’s 
distance measurement accuracy.
Improved Accuracy
Physicists performing treatment planning need 
accurate tools to evaluate CT scan data, correct for 
inhomogeneities and to document the relationship 
between CT number and tissue density. To improve 
the accuracy of your treatment planning, consider 
the CIRS Model 062 Electron Density Phantom.