Dear All,

I hope this message finds you well.

I am a first-time user of MRIcron and am currently exploring its functionalities for ROI drawing. Despite reviewing the forum discussions, I still have some uncertainties regarding the import issue with NifTI and “undo” option, and I would greatly appreciate your insights on the following queries:

Q1: When importing a NIfTI file, I encountered the message: "Integer required: Multi-volume file, please select volume to view. [1..2]". However, my dataset only contains a single DICOM folder with multiple DCM files. Could you please clarify what selecting [1] or [2] means in this context? How does this choice impact my workflow?

Q2: While drawing the ROI, I chose the "autoclose pen" option, but mistakes are inevitable at times. I noticed that I can only undo one step, which makes it challenging when multiple errors occur, as I have to restart the drawing process entirely. Is there a way to increase the number of undo steps to improve error tolerance?

I greatly appreciate your guidance on these matters,  and I look forward to your advice.

Warm regards,

Hua Song

Fudan University, Shanghai, China

If you are just starting out, you may want to try the more modern MRIcroGL.. While I am glad that my MRIcron software has provien robust and popular, modern tools can better use contemporary hardware.

WIth regards to MRIcron:

1. If you load a 4D time series, MRIcron will ask you to select which 3D volume you wish to view. A single DICOM series can contain many 3D volumes (e.g. fMRI data is a 4D time series, and DTI is a collection of 3D volumes sensitized to different directions). You can either select the time series when you open a dataset, or use fslsplit to convert a single 4D NIfTI file to a series of 3D NIfTI files. With either option, I would start by using the MRIcron Import/ConvertDicomToNifti menu item to convert all of your DICOMs to NIfTI images. This will reduce the number of files (as it seems your data is in classic DICOM) and given them meaningful file names.
   
2. I agree, the drawing undo only has a single step, so you will want to be careful with each iteration. If you are using a MacOS or iOS device, you can try out our "NiiVue" application where the drawing mode allows multiple undos. We hope to release NiiVue for other operating systems soon.