MRI Essentials is both, a comprehensive teaching tool for orthopedic MRI and a quick reference to pick up facts quickly in every day practice. The basic version provides short and concise paragraphs with simple drawings. It corresponds to the small booklet MR-NOTES.COM by Dr. Fischer, available since 2004. The Pro-version contains in addition more than 4000 MR-cases of outstanding image quality. They illustrate the text, which is still short and concise, focusing on clinically relevant facts. It is the refinement of MRI-ESSENTAILS.COM, an illustrated atlas of orthopedic MRI first published in 2014. The clearly structured app makes of MRI-Essentials an invaluable aid in every day practice.