mriToolbox - Home


This website hosts several tools that may be helpful for those doing work in the field of Magnetic Resonance Imaging. Currently, the tools include a database of normative T1 and T2 measures, an Ernst angle calculator, tools for basic online parametric fitting, and a tool to estimate image contrast in T1-weighted MPRAGE imaging. Hopefully you find these tools useful or at least interesting. Please let me know if you do!

Available Tools


MRI contrast can be estimated by providing the relative proton density, T1, T2, and other pulse sequence parameter values. The Contrastinator tool provides a simple way to estimate the contrast between two tissue types for gradient recalled echo (GRE) and spin echo (SE) sequences for T1-weighted and T2-weighted imaging.

Go to this tool »

Ernst Angle Calculator

The Ernst angle is the optimal flip angle for a spoiled gradient recalled echo (GRE) which maximizes the MR signal for a given T1 and TR. This tool will help you calculate the Ernst angle.

Go to this tool »

Parameter Database

This tool aims to be a comprehensive database of normal in vivo T1 and T2 relaxation parameters for a wide range of human tissues and organs. These parameters are only listed from peer-reviewed journal articles and are linked via their PubMed ID (PMID). The tool allows you to search the database for specific regions of the body, e.g., "brain", "liver", etc.

Go to this tool »

Parameter Fitting

This tool allows you to perform parameter mapping or curve fitting to canonical MRI signal equations. You may calculate diffusion weighted imaging (DWI), relaxometry (T1 relaxation, T2 relaxation, T2* relaxation)] parameters directly from your browser. The fitting is performed using non-linear least squares.

Go to this tool »

T1 MPRAGE Simulator

This is a simulator for T1-weighted MPRAGE acquisitions for two tissue types using the extended-phase graph algorithm. This can be used to optimize contrast between gray and white matter in T1-weighted brain images.

Go to this tool »

News / Changelog

9/14/2023 The Contrasatinator tool is available to provide pulse sequence parameter suggestions to optimize contrast between two tissues.
9/13/2023 All plotting now uses Chart.js.
8/23/2023 10 years later, the look and feel of the site has been updated! Stay tuned for more updates.
5/12/2013 The Ernst Angle Calculator and Parameter Fitting tools will now remember the values you have entered between visits.
1/17/2013 Added the Ernst angle calculator.
12/6/2012 Just a few small improvements.
11/3/2012 The Parameter Fitting tool has been updated. The T1 IR (imperfect 180) has been improved and should be more robust. Thanks Sam!.
04/30/2012 Bug fix. (Thanks Albert!) The MPRAGE Simulator was interpreting the Proton Density inputs as Integers only.
04/29/2012 Plotting is now totally client-side by making use of GChart. This should be more compatible with various devices (e.g., Android) and not rely upon on active Internet connection.
12/11/2011 Updates to the web page.
11/3/2011 Now available. A few of the tools are online now. Let me if you have fun with them.


I created this site to help provide some useful magnetic resonance imaging physics tools to the world. I would love to know if they have helped you in any way! I am currently a faculty member in the Department of Radiology at the University of Wisconsin. You can find me on LinkedIn or at my research group's webpage.

These tools were created using Bootstrap, Chart.js, and Java/GWT.