On 2014 Apr 07, Anders von Heijne commented:

This is an interesting and important discussion. However, the cited paper by Geurts et al from 2005, that compares 3D FLAIR and 3D DIR, reports on older versions of both sequences, with scan times around 15 minutes and with rather poor image quality in the published images. Modern versions using parallell imaging renders much better image quality with higher GM-WM contrast. 3D FLAIR is also much better in showing cortical lesions than comparable 2D sequences, if not quite as good as 3D DIR. The most pragmatic approach is then, in my opinion, to use modern 3D FLAIR, with reconstructed 3mm consecutive images in three orthogonal planes for monitoring MS patients, allowing for the best trade off between scan time and detection of WM and GM lesions. 3D DIR has its place in the diagnostic phase of neuroinflammation in order to optimize the process of differential diagnosis.

On 2014 Apr 07, Anders von Heijne commented:

This is an interesting and important discussion. However, the cited paper by Geurts et al from 2005, that compares 3D FLAIR and 3D DIR, reports on older versions of both sequences, with scan times around 15 minutes and with rather poor image quality in the published images. Modern versions using parallell imaging renders much better image quality with higher GM-WM contrast. 3D FLAIR is also much better in showing cortical lesions than comparable 2D sequences, if not quite as good as 3D DIR. The most pragmatic approach is then, in my opinion, to use modern 3D FLAIR, with reconstructed 3mm consecutive images in three orthogonal planes for monitoring MS patients, allowing for the best trade off between scan time and detection of WM and GM lesions. 3D DIR has its place in the diagnostic phase of neuroinflammation in order to optimize the process of differential diagnosis.