ITKReadWrite5DImage.cxx

using PixelType = unsigned short;
constexpr unsigned int Dimension = 5;

using ImageType = itk::Image< PixelType, Dimension >;
using ReaderType = itk::ImageFileReader< ImageType >;

ReaderType::Pointer reader = ReaderType::New();
using InputImageType = itk::Image<PixelType, Dimension>;
reader->SetFileName("d:/pynrrd_test.nrrd");
reader->Update();
ImageType::ConstPointer image = reader->GetOutput();

using WriterType = itk::ImageFileWriter< ImageType >;
WriterType::Pointer writer = WriterType::New();
writer->SetFileName("d:/ith5DWriteTest.nrrd");
writer->SetInput(image);
writer->Update();

To keep the RGBA component, the first two rows need to be modified to:

using PixelType = itk::RGBAPixel<unsigned short>;
constexpr unsigned int Dimension = 4;