Image Processing Toolbox makes a sample 3-D MRI chest scan data set available as an optional feature. This volumetric data set is used by the example Segment Lungs from 3-D Chest Scan.
To obtain this data set, download it using the Add-On Explorer.
Select Get Add-ons from the Add-ons drop-down menu on the MATLAB® desktop. The Add-on Explorer opens.
In the Add-On Explorer, search for the data package Image Processing Toolbox Image Data. The data package is a MathWorks Optional Feature.
Click the data package in the search results. On the data package page, click Install. Follow the instructions presented by the installer.