Interventional Radiology: Digital Subtraction Techniques

Temporal subtraction is a computer-assisted technique where an image obtained at one time is subtracted from an image obtained at a later time to enhance the pattern of contrast media.

The variables required for temporal subtraction are the same patient position, same anatomy, same radiographic distance, and same exposure factors.

The purpose of temporal subtraction is to visualize certain information on an angiogram by removing non-essential structures, thereby allowing for better visualization of the opacified vessels.

<p>The mask is the preliminary image, recorded before the introduction of the contrast agent, which serves as the reference for subsequent subtraction.</p> Signup and view all the answers

<p>Temporal subtraction enhances the visualization of contrast media by eliminating non-essential structures and highlighting the opacified vessels in the subsequent images.</p> Signup and view all the answers

<p>The different types of digital subtraction mentioned in the text are temporal subtraction, energy subtraction, and hybrid subtraction.</p> Signup and view all the answers

<p>An exact copy of the base film, but with the densities reversed.</p> Signup and view all the answers

<p>Attenuation differences of the various types of tissue and the iodine in the contrast.</p> Signup and view all the answers

<p>Diapositive mask + Angiogram film</p> Signup and view all the answers

<p>Switching kilovoltage during exposures and changing filtration system.</p> Signup and view all the answers

<p>Reduction of motion artifacts.</p> Signup and view all the answers

<p>To subtract the contrast films and highlight structures with radiographic contrast.</p> Signup and view all the answers

<p>Because details are visible due to density differences.</p> Signup and view all the answers

<p>Serial mask mode, continuous mask mode, time interval difference, and postprocessing subtraction.</p> Signup and view all the answers

<p>The difference between densities in adjacent areas.</p> Signup and view all the answers

<p>To highlight structures with radiographic contrast and remove confusing shadows.</p> Signup and view all the answers