Quick Start

Install

Anaconda

We recommend using the mrd Anaconda package, which can be installed using conda:

$ conda install ismrmrd:mrd

CMake

If you use CMake, you can include MRD within your C++ project using CMake's FetchContent feature. CMake will download and include the SDK directly from Github.

In your project CMakeLists.txt, declare a dependency on MRD one of two ways:

1. Using the full MRD repository by specifying either a git tag or commit hash

FetchContent_Declare(
    mrd
    GIT_REPOSITORY https://github.com/ismrmrd/mrd.git
    GIT_TAG {tag -or- commit hash}
    SOURCE_SUBDIR cpp
    FIND_PACKAGE_ARGS
)

2. Using only the C++ source code for a given MRD release (smaller download, fewer files)

FetchContent_Declare(
    mrd
    URL https://github.com/ismrmrd/mrd/releases/download/{tag}/mrd-cmake-src.tar.gz
)

Then, tell CMake to fetch the mrd source, include its headers, and link with the mrd library:

FetchContent_MakeAvailable(mrd)

include_directories("${mrd_SOURCE_DIR}")

add_executable(myrecon main.cpp)
target_link_libraries(myrecon PRIVATE mrd_generated)

Dependencies

The MRD source code is generated using yardl and requires the dependencies listed here.

These dependencies are automatically installed by the mrd conda package.

Reading and Writing MRD streams

To read and write MRD streams, start with the following example:

#include "mrd/binary/protocols.h"

int main(void) {
  mrd::binary::MrdWriter w("test.bin");

  mrd::Header header;
  // Populate Header
  // ...

  w.WriteHeader(header);

  unsigned int nreps = 2;
  for (unsigned int r = 0; r < nreps; r++) {
    mrd::Acquisition acq;
    // Populate Acquisition
    // ...

    w.WriteData(acq);
  }
  w.EndData();
  w.Close();

  mrd::binary::MrdReader r("test.bin");

  std::optional<mrd::Header> header_in;
  r.ReadHeader(header_in);

  mrd::StreamItem v;
  while (r.ReadData(v)) {
    if (!std::holds_alternative<mrd::Acquisition>(v)) {
      continue;
    }

    auto acq = std::get<mrd::Acquisition>(v);
    // Process Acquisition
    // ...
  }
  r.Close();

  return 0;
}

Examples

See cpp/mrd-tools and cpp/mrd-tools/CMakeLists.txt in the MRD repository for example programs using the MRD library.

These tools are also installed as command-line executables when mrd is installed from Anaconda.

For example, to generate a cartesian Shepp-Logan phantom:

$ mrd_phantom --coils 8 --matrix 256 --repetitions 2 --oversampling 2 > phantom.bin