New research into “Black Bone” MRI scanning presents a novel technique for incorporating this into 3D printing. The results come from a research project written by authors from the University of Oxford and published by the British Institute of Radiology.
MRI scans have already proved useful for 3D printing surgical models, as recently shown with Texan biotechnology startup SiMMo3D. The company use MRI and CT scans to create digital models which they can then 3D print using their Stratasys printer. Moreover, we recently spoke to an expert about the use of scanning for creating 3D models. We interviewed to Dr. Saleem Abdulrauf, a neuroscience expert working with Stratasys Direct Manufacturing, for some insight into his experience with the technology.
Combining the two methods of scanning is often necessary to create a detailed 3D digital model. However, on the back of this new research, CT scanning may not need to be used in favour of the “Black Bone” MRI scanning.
What is “Black Bone” MRI scanning?
CT scans have been associated with ionizing radiation and thus MRI scans are preferred. Despite this, CT scans have increased detail and therefore application for creating 3D models. To counteract this, Black Bone MRI scanning was evaluated by researchers as an alternative approach that is free from radiation. A paper published in the British Radiology journal from 2012 concluded that “Black Bone” MRI scans offer “a radiation-free method of imaging the head and neck.”
The term Black Bone when referencing MRI scans is associated with the way the scanned images are created. The Black Bone approach is a ‘gradient echo MRI sequence’, this means the scanning procedure involves a different way of pulsing the object, or body, with magnetic waves. This approach minimizes the contrast between soft tissue “to enhance the bone-soft tissue boundary.” The researchers believed this would have significant improvement over conventional MRI scanning while avoiding issues of ionizing radiation with CT scans.
In order to test their hypothesis, the research team assessed the use of Black Bone scanning on both adult and infant patients. Following this, they used a cube phantom test to consider the accuracy of the approach. This testing evaluated the differences between the Black Bone approach and the CT scans, as well as the 3D printed objects produced. The researchers explain,
Measurements of the cube phantom and 3D printed models demonstrated sub-millimetre discrepancy.
According to the paper,
The feasibility of producing anatomical 3D models has been demonstrated, thus offering a potential non-ionising alterative to CT for the craniofacial skeleton.
This research, therefore, may pave the way for new approaches into producing the files required for 3D printing surgical models. The technique is becoming increasingly popular for planning complex surgery as it allows the surgeons to have a physical structure to understand and manipulate in their hands. With accuracy of course being very important for the surgical models, the Black Bone approach seems viable for future techniques. While also mitigating the impact of ionizing radiation.
Featured image shows a 3D printed model of toddler skull. Image via Evening Standard