A group of researchers in Canada have been utilizing 3D printed anatomically correct organ models to improve medical imaging and reduce the exposure of patients to radiation. It is critical that patients treated with radiation aren’t exposed to addition, harmful, radiation. The researchers point out how important it is to use the minimize radiation while maximizing data collected.
Human based mannequins (Phantoms) are tools used for training medical professionals and targeting for X-ray, however, phantoms are limited and costly to produce traditionally.
“There has been a particular lack of modular anthropomorphic abdominal phantoms that allow the user to remove and replace the organs to replicate different pathologies, and if required, to place foreign bodies such as dosimeters or surgical devices inside the abdominal cavity,” explain the researchers. “Advances in 3D printing technology have increased the range of possibilities in the creation of innovative models for medical purposes.”
With the benefits of 3D printing these phantoms become more available, the models can be created accurately and be removable. There are a few things to consider thought, structural properties, mechanical properties, and how the material interacts with the X-rays. The 3D model, dubbed CASMER, took multiple steps to complete and required input from:
- Biomedical engineers
The phantom was made out of a hallow polycarbonate shell with Clear Flex® urethane rubber as the muscles, fat made of modeling beeswax, and a skeleton made of off the shelf parts.
“The polycarbonate shell was confirmed to minimally attenuate the X-ray radiation from the CT scan, and was transparent to visible light, which facilitated visualization of the internal structures during phantom manufacture and testing,” stated the authors.
Every hallow cavity was filled with attenuating material for greater accuracy.
“To fill the 3D printed organ shells with the agar, distilled water and fiber solution, a 250 mL syringe was inserted into a small opening in the organ shell,” stated the researchers.
The researcher stated that structural accuracy was important but not as important as radiological accuracy (how close to real organs does the material react to x-ray) a radiologist had to thoroughly review the images. The researchers stated that during the project, both the small and large bowel were the most challenging to segment:
“The CT scan data that was available was suboptimal for segmentation and 3D printing of the bowel. Therefore, the decision was made to utilize an artistic rendering of the large and small bowel that could be more easily scaled to fit within the phantom cavity. Considerable editing of the shell was necessary to make a continuous hollow channel from the gastric sphincter all the way to the anus. Four threaded plugs were also created to allow access to the interior of the bowel for the purposes of adding radiopaque material to simulate obstructions and other material normally found in the digestive tract.”
“CASMER will be available for training medical radiation technology (MRT) students in cross sectional anatomy of the abdomen and for radiation dosimetry calculations,” concluded the researchers. “We will also explore 3D printing of pathologies within organs to facilitate training in performing image guided procedures.
O’Neal, Bridget. “CASMER: Medical Imaging Mannequin Features 3D Printed Organ Models – 3DPrint.Com: The Voice of 3D Printing / Additive Manufacturing.” 3DPrint.Com | The Voice of 3D Printing / Additive Manufacturing, 27 Feb. 2020, 3dprint.com/263525/casmer-medical-imaging-mannequin-features-3d-printed-organs/.