Uniformity (Bias) Correction - Introduction

The Uniformity Correction tool is used to correct intensity non-uniformity, typically found on MRI scans when using surface receiver coils or other tightly-fitting coils such as head, neck and knee coils. This non-uniformity is often known as the "bias field", and while exact correction is not possible without a detailed mapping of the coil properties, an approximate correction often improves the uniformity markedly.

The Uniformity Correction tool works on the principal that the introduction of image non-uniformities leads to a blurring of the image intensity histogram. Thus, correction of the non-uniformity involves finding the bias field that will create the sharpest intensity histogram when corrected. The bias field is modelled as a smooth polynomial surface, the order of which is selectable by the user.

To start the Uniformity Correction tool, select it from the Toolkits menu:

This brings up the Uniformity Correction tool:

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