Correction of intensity nonuniformity in MR images of any orientation

Detection of Focal Longitudinal Changes in the Brain by Subtraction of MR Images

“…It is also possible to perform a bias field correction as a postprocessing step, but again this is based on a number of assumptions about the nature of the field and its stability. 8,9 The algorithm described in the current work circumvents these issues by correcting the bias field in subtraction images rather than in the source images themselves.…”

A review of Methods for Bias Correction in Medical Images

“…Several phantom based approaches have been proposed and investigated in the past years (Condon, Patterson, Wyper, Jenkins, & Hadley, 1987;Tofts et al, 1994;Davenel et al, 1999;Moyher, Vigneron, & Nelson, 1995;Tincher, Meyer, Gupta, & Williams, 1993), but none of them have been widely used in practice because of the frequent and time-consuming acquisitions of the phantom images. To deal with that problem, the author in (Wicks, Barker, & Tofts, 1993) proposed a correction matrix to transform the estimated phantom from just one or two orientations to images of any orientation, and therefore the number of phantom acquisitions can be reduced. Besides, there also exist many studies aim at mathematically modeling the bias field (Tincher et al, 1993;Condon et al, 1987), and then fit the model to the phantom image.…”

Interleaved k-NN Classification and Bias Field Estimation for MR Image with Intensity Inhomogeneity

“…Generally speaking, bias correction methods are classified into two classes: prospective methods [4], [5] and retrospective methods [6], [7]. The former avoid intra-scan intensity inhomogeneity due to special hardware and have been employed in correcting intensity inhomogeneity caused by MR's canner.…”