In the past two decades, perhaps no field of medicine has evolved quite so fast or dramatically as radiology. Fueled by new technologies, ever-faster and smarter computers, and cutting-edge techniques, radiology is at the forefront of diagnostics, intervention and, perhaps most notably, biomedical research. And nowhere is that evolution more apparent than in the Johns Hopkins Department of Radiology and Radiological Science, where several groups are providing radiological tools to advance research in a wide variety of disciplines across the institution.
Zaver Bhujwalla, Ph.D., director of the MRB Molecular Imaging Service Center and vice chair of research for the department, is particularly proud of the newest acquisition in the service center, a positron emission tomography-magnetic resonance (PET-MR) scanner, which combines the best of PET and MR to provide scans that are unparalleled in their accuracy and spatial resolution. This PET-MR machine, available for the first time at Johns Hopkins, is designed for research studies with animal models.
PET, by itself, is great for detecting radio tracers at very low concentrations to look at molecular expression of receptors, antigens and more. But PET lacks in spatial resolution, exactly where MRI excels. With PET-MR, it is possible to measure metabolism, perfusion and diffusion, among other spatially significant information, to gain further insights into multiple disease processes.
“With the combination of PET-MR,” Bhujwalla says, “you get structural, functional and molecular information.” The instrument will be available through the service center to all faculty members at Johns Hopkins to advance their research, she notes.
“With PET-MR, we can now see how changes in molecular pathways affect function in a molecular-functional approach. That improves understanding across many areas, ranging from cardiovascular disease to cancer to neurology,” says Bhujwalla.
Not far from the MRB Molecular Imaging Service Center satellite facility, Kristine Glunde, Ph.D., inaugural director of the new Applied Imaging Mass Spectrometry (AIMS) Service Center, is equally proud to discuss impressive new technology, known as matrix-assisted laser desorption/ionization, or MALDI, imaging. It is a form of mass spectrometry, and while MALDI itself is not new to Johns Hopkins, MALDI’s tissue imaging capabilities are.
Having worked in the field for 15 years, Glunde says that MALDI imaging has finally arrived at a point where it now allows for consistently reproducible, high-spatial-resolution, high-throughput and, most importantly, much faster MALDI tissue imaging, which stands to have a profound impact on biomedical research.
“MALDI imaging lets us see actual molecules in the tissue,” she adds. It can detect the presence and location of a drug in the tissue or whether the molecular composition of a tissue has been affected by disease or treatment. “Plus, we’re able to image several biomolecules in one shot,” Glunde says. “MALDI imaging is highly multiplexed with great spatial resolution too.”
The AIMS Service Center is making this impressive new technology available to all faculty members at Johns Hopkins. Glunde and her team are already working with faculty members in tissue engineering, oncology, biological chemistry, pathology, neurology and radiology to advance their research projects.
Rebecca Krimins, D.V.M., was recently selected to direct the Express Radiology Research Lab, another of the radiology department’s research-specific initiatives. The “express” in the lab’s name refers to the efficiency with which the facility can deliver data, allowing researchers to move research more quickly into clinical trials.
A research team often consists of multiple faculty members from across departments and can include residents, students, industry personnel and experts from other universities. Simply getting the entire team assembled to be present at any one time is a feat in itself. “Our lab understands these operational complexities, so we collaborate with a researcher and work around their schedule,” Krimins says.
The lab is open to researchers in disciplines across Johns Hopkins who need advanced imaging, such as CT, ultrasound, PET-CT or magnetic resonance imaging. This includes the vast array of medical specialists working on all Johns Hopkins campuses who are designing new equipment or procedures that require radiological imaging.
“You provide the objective; we provide the imaging equipment. We’re here for everyone at Johns Hopkins,” says Krimins, who is a veterinary anesthesiologist by training. Since studies in her lab frequently involve large-animal models, her expertise ensures animal safety and comfort as well as compliance to university, state and federal regulations.
For Krimins, the big message about the Express Radiological Research Lab is its mission: By expediting animal studies, the lab more quickly delivers diagnostics, equipment and therapies that can be translated into practical medical applications to help those who suffer from injury or disease — be it a cruciate ligament tear or cancer.