Inventors of the Year 2018

Open Innovation

CAIPIRINHA can be used in any kind of MR measurement, which is the beauty of this method.

Peter Jakob and Mark Griswold, Healthineers

Shorter scanning times, improved image quality: With the new parallel imaging method CAIPIRINHA, Mark Griswold, Peter Jakob and their colleagues have taken the technology of magnetic resonance imaging (MRI) a huge step forwards. Siemens Healthineers uses the technique under a license agreement in many MRI scanner models. Both researchers were honored in the Open Innovation category.


Collaborative research is of immense importance to Siemens Healthineers. Substantive progress in the reduction of MR scanning times and in image quality not only requires ingenious ideas but also persistence and patience. Very often it is the result of work by a research group. As in the case of the CAIPIRINHA technique: The acronym stands for Controlled Aliasing in Parallel Imaging Results in Higher Acceleration. To accelerate scanning, the images are composed of separate slices superimposed on top of each other and captured simultaneously. In this way, CAIPIRINHA intelligently refrains from using a certain amount of data, which is subsequently computed with the help of algorithms. “It’s a combined data acquisition and reconstruction method that allows the images that were taken at the same time to be separated again, which greatly improves their quality,” explains Peter Jakob, professor of experimental physics at the University of Würzburg, an internationally renowned talent hotbed for MRI researchers.


Siemens Healthineers and the experts from the University of Würzburg were in regular contact then, as now, to exchange research ideas with each other. “We typically have an idea in which Siemens is interested, and then carry out the research work with the help of doctoral students,” says Jakob explaining the procedure. This was the case with the CAIPIRINHA method.


As part of his doctoral thesis, Griswold invented one of the earliest parallel imaging techniques, the GRAPPA method (GeneRalized Autocalibrating Partial Parallel Acquisition), a predecessor of the CAIPIRINHA method. This also marked the beginning of their collaboration with Siemens Healthineers. “With GRAPPA, Siemens was able to offer the very first commercial parallel imaging method,” says Jakob.


Griswold today researches and teaches at the Case Western Reserve University in Ohio, USA, where, as part of a research project with Siemens Healthineers, he heads a research group for Magnetic Resonance Fingerprinting (MRF), an innovative method for qualitative tissue analysis.