The paper, STIR: software for tomographic image reconstruction release 2 (Phys. Med. Biol. 57 867), describes an open source software library, implemented in C++, for reconstruction and processing of PET images. STIR is designed for use with many different algorithms and scanner geometries, and is portable to various computing platforms.

This second release of STIR in 2012 enhanced its flexibility and modular design and included additional features such as Compton scatter simulation, an additional iterative reconstruction algorithm and parametric image reconstruction.

"This was a major new release preparing STIR for the future," explained first author Kris Thielemans from University College London. "STIR 1.x was restricted to image reconstruction of static PET data using a small number of algorithms. STIR 2.0 provided a framework that would allow handling of dynamic or gated data, potentially of other modalities, and introduced 'objective functions' allowing introduction of many more optimization algorithms."

The redesign enabled the introduction in the ensuing years of many new capabilities, such as inclusion of motion correction within reconstruction, for example, and the integration of a SPECT reconstruction library. STIR is now on release 3.0, and the team is currently planning for the next releases, which will include support for time-of-flight PET reconstruction and other upgrades created by a number of STIR developers. "The design introduced in version 2.0 has served us well for five years, but it is becoming apparent that a new refresh will be needed," said Thielemans.

The popularity of this winning research paper is likely down to the considerable number of users of the STIR library. "Many people use STIR to reconstruct their data, either simulated or acquired, and STIR provides the framework for reconstructing data from any typical PET scanner, thus it has become the main software used by hundreds of researchers worldwide," explained co-author Charalampos (Harry) Tsoumpas from the University of Leeds. "Notably, it has been also used by a few start-up companies, in their products or to provide the gold standard to improve their proprietary software."

Thielemans emphasized the importance of STIR being open source software, that's freely downloadable and extendable by anyone. "I think that has been crucial for its success," he told medicalphysicsweb.

Rotblat medal

The PMB citations prize is marked with the presentation of the Rotblat medal, named in honour of Sir Joseph Rotblat, PMB's second and longest-serving editor. This year, the medal was presented to Kris Thielemans by PMB board member Steve Meikle at the STIR Users' & Developers' Meeting at the recent IEEE Nuclear Science Symposium and Medical Imaging Conference in Atlanta.

"Physics in Medicine & Biology is a prestigious and one of the leading journals in medical physics; having the award for the most cited paper is fulfilling and reconfirms that we are in good track serving our scientific society," said Tsoumpas. "Personally, it feels even more special because of the award being named after Sir Joseph Rotblat for whom I have great respect, not only for his contributions in PMB, but also for his constant and courageous fight against nuclear weapons, for which he obtained the Nobel Peace Prize only 22 years ago. Sir Joseph's activities, as summarised in his words 'Above all, remember your humanity', are truly inspirational to me."

• The winner of the 2017 Physics in Medicine & Biology citations prize is: STIR: software for tomographic image reconstruction release 2 Kris Thielemans, Charalampos Tsoumpas, Sanida Mustafovic, Tobias Beisel, Pablo Aguiar, Nikolaos Dikaios and Matthew W Jacobson Phys. Med. Biol. 57 867