In preclinical imaging, magnetic resonance imaging (MRI) can be an attractive alternative to researchers who have previously relied on ultrasound to investigate animal models. Using an ultrasound instrument, animal throughput can be low and operators also need to be highly experienced simply to even find certain organs.
At the Center for Molecular Oncology at Barts Cancer Institute, Queen Mary University of London, researchers have been using preclinical imaging to look at the pharmacokinetics of radiopharmaceuticals, to perform anatomical studies, and to assess treatment responses in mice. The center is fully equipped for radiopharmaceutical development and houses a number of imaging instruments.
One of those instruments is the ICON 1 T MRI from Bruker. In a recent interview, team leader Dr. Jane Sosabowski, explained how the molecular imaging team have been using the ICON to investigate orthotopic pancreatic tumors in mice and described some of the advantages of using this over ultrasound.
The researchers had previously been using ultrasound to investigate these tumors, but preparing the animals and carrying out the imaging had been time consuming. Operators also needed to be highly experienced in ultrasound, even just to find the pancreas, let alone assess any transformation or the extent of that transformation. Almost all of the researchers in the group are biologists who have no background in imaging. The goal therefore became to acquire an instrument that would make things more straightforward for users.
Another goal was to find an instrument with high soft tissue contrast in the abdominal region. A mouse pancreas is a particularly difficult organ to image, explained Sosabowski: “Its shape is defined by the organs around it. We needed something where we would be able to see a difference between the soft tissue of the pancreas, and distinguish that from the intestine in particular, and the spleen and the other tissues that press in on it and define its shape.”
Furthermore, since many orthotopic tumors are buried so deep within the animal, tumor size or shape cannot be assessed and palpitation is very difficult. Sosabowski and team realised they would need to use MRI if they were going to be able to overcome these problems.
Since acquiring the ICON, the team has found implanted pancreatic tumors very easy to see, which allows their imaging to be performed at much shorter scan times.
The ICON has significantly improved animal throughput during experiments, enabling them to get through twice the amount of animals they had previously been able to when using ultrasound. With ultrasound, an experienced operator could get through about ten animals in a day, whereas, now, some users have been able to get through 30 animals in a day.