Technology Created for Small Sample Multimodal Imaging

Wawryzniec Dobrucki with the microPET/SPECT/CT scanner in the Beckman Institute basement.
Wawryzniec Dobrucki with the microPET/SPECT/CT scanner in the Beckman Institute basement.

Beckman Institute researchers Ling-Jian Meng and Wawrzyniec Dobrucki are teaming up to create a novel imaging modality that could add even more nuclear and magnetic resonance imaging capabilities in the Biomedical Imaging Center and elsewhere.

Beckman Institute researchers Ling-Jian Meng and Wawrzyniec Dobrucki are teaming up to create a novel imaging modality that could add even more nuclear and magnetic resonance imaging capabilities in the Biomedical Imaging Center and elsewhere.

Meng is an Assistant Professor in the Department of Nuclear, Plasma and Radiological Engineering, while Dobrucki is an adjunct assistant professor in the Department of Bioengineering and head of BIC’s Molecular Imaging Laboratory. They have been working together on a project that is using newly-developed detector inserts for positron emission tomography (PET) imaging toward creation of a novel imaging modality for small animal models.

Meng has a research focus on developing new nuclear imaging techniques such as sensors based on room temperature detectors. Dobrucki has research interests in multimodal imaging and, particularly, imaging strategies for assessing angiogenesis in animal models for studies of disease. This project is developing novel semiconductor detector technology for ultrahigh resolution small-animal PET imaging.

Dobrucki works with the MIL’s multimodal microPET/SPECT/CT scanner, which combines nuclear imaging modalities, X-ray Computed Tomography (CT), Single Photon Emission CT (SPECT) and Positron Emission Tomography (PET). The PET modality can image resolutions of 2 mm which, Dobrucki said, is not good enough for imaging specimens such as heart tissue from a mouse. Meng said the use of small-pixel semiconductor detectors will provide high resolution for samples from small animal models.

“I would say that the target resolution we would like to achieve in PET images is between 0.3 and 0.5mm, which is regarded as ultrahigh resolution in PET imaging,” Meng said. He added that his group is developing “proof-of-concept detection systems for preliminary imaging studies, which would also allow a direct comparison against a state-of-art commercial PET system currently installed at MIL.”

As for their roles, Dobrucki said that Meng is “developing the hardware and I’m developing the applications and agent radio tracer we will use with them.”

Meng said the semiconductor-based PET detection system could also be used inside MRI scanners for simultaneous due-modality PET/MRI studies. That would enable images from the two modalities to be superimposed, providing visualization of anatomical (MRI) and functional (PET) features of samples.

Dobrucki said the first phase in the project was to develop a small ring detector and “test it using phantoms to see how it works, acquire the performance of the system. Now we are moving this to imaging and using tissue.”

Meng is also applying the technology toward developing an MRI-compatible SPECT system, which he expects to be completed this fall.

The project has been supported by the Department of Energy (DOE) and the National Institute of Biomedical Imaging and Bioengineering (NIBIB).