Skip to main content
This site will look better in a browser that supports web standards, but it is accessible to any browser or Internet device.

TOOLS
» Time Constants

An understanding of time constants allows easier understanding of MRI signal equations. This tool allows you to build up the equations describing the change of magnetisation in basic pulse sequences.

« Tools List

Time Constant Tool: Introduction

Answer this...

What is the time constant of an exponential?

Answer: The time constant of an exponential is simply the denominator of the fraction to which e is powered.

A simple exponential decay may be defined in general form as

f(t) = A·e-t/τ

where f is a function of time (t), A is the peak amplitude (a scalar) and τ is the time constant of the exponential. The time constant is the denominator of the fraction to which e is powered.

In MRI, T1, T2 and T2* are time constants.

Navigate below to the first equation in the list: exp (x/400).

Further reading on this topic:
Books: Q&A in MRI p29-30

Navigate through the tool...
  1. Introduction.
  2. exp (x/400)
  3. exp (-x/400)
  4. 1 - exp (-x/400)
  5. 1 - 2·exp (-x/400)

Other sections of this tool:

Remember, T1, T2 and T2* are time constants.

« Back to Tools list

 
(This page: http://www.revisemri.com/tools/timeconst/)