When attempting to load the NIfTI file images, a pop-up message indicates that a "large image downsample" has occurred and that an adjustment in the preferences must be completed to load all volumes. Currently, this makes the sagittal and coronal views of the images look blurry (attached image). Could anyone give me directions on how to alter this in the preferences (which setting to alter) to be able to load all volumes?

Thank you in advance.

Hello,
 What version are you using? If you are using the pre-release (v1.2.20200707) https://github.com/rordenlab/MRIcroGL12/releases/tag/v1.2.20200707 you can change this by going to the Preferences window and setting the "Reduces volumes larger than ..." If you are using an older version of v1.2, you can select Preferences and press the "Advanced" button to edit the text file, in this case the value you want to edit is "MaxVox=560". The default setting is 560 which will work for all modern graphics cards. If you have a discrete graphics card with 8Gb of RAM, you can set this to 1024. This will stop the downsampling of large data.

Unfortunately, while changing this will hide the warning, in your case it will not make the resulting image look much better. In your example, the image has a exceptionally high in-plane resolution, but very thick slices. These thick slices make the image look blurry in the slice (head-foot) direction. This is an inherent property of your anisotropic image, any tool must interpolate this low resolution dimension. In future, you may want to consider acquiring isotropic images. For Siemens the classic 3D T1 sequence is referred to as "MP-RAGE" and the 3D T2 sequence is "SPACE" - both can provide outstanding isotropic images.

Thank you for your help and the advice, luckily the data is from a pilot and things can be altered.

Hello,
I have same problem in loading fMRI image. MRIcroGL only loads 409 volume of total 600 volume. I am using "MRIcroGL 1.2.20211006 GTK2 x86-64 LLVM" on ubuntu 20.04. In Help menu by selecting Prefernces, I can not find "Reduces volumes larger than ...", and also in advanced mode I have no "MaxVox=560" element in it. Why is it like that? How can I solve this issue?

Uncheck "Only initial volumes (load 4D series faster)"

Thank you so much Chris, it works well.