Troubles with cardiac MRI

Operating system: Windows 10
Slicer version: 5.6.1
Hello, I`m new to 3d Slicer and currently having trouble with a cardic mri. After importing the dicom files some volume sequences appear only through thin stripes as in the pictures

If I try to segment an area I can only select a stripe as well (I tried paint and threshold). When I press the show 3d button the same thing happens

How can I fix this? Is the mri itself the problem?