Dr. Peter Metherall is a registered Clinical Scientist and Chartered Engineer at Sheffield Teaching Hospitals NHS Foundation Trust, UK. As the leader of the new Sheffield 3D Imaging Lab, he is improving the clinical utility of Advanced Visualization and Quantitative Imaging for routine clinical imaging investigations and research applications.
This post is the second in a two-part series.
Can you talk about a specific case where 3D imaging played an important role?
“Low-grade glioma’s grow slowly and the measurement of the lesion size over time is important to identify changes in its growth rate – this is a factor in identifying which patients are at risk of malignant transformation. Traditionally, images were assessed by a simple 2D length measurement but there are a number of problems with such a simple assessment. These include the difficulty in deciding which slice to measure, and as the tumor is such an irregular shape, a 2D measurement is probably meaningless. The 3D Lab introduced a more sophisticated volume measurement to allow us to accurately monitor the tumor size; and by using image registration techniques we are also able to visualize where the growth is occurring. This additional information and a more accurate assessment of growth provides the referring clinician with important information to help identify patients at risk of an early transformation; and who may benefit most from early aggressive therapy.”
In your opinion, how can 3D imaging and printing in hospitals become more available and accessible?
“3D imaging is now a widely accepted method of visualizing medical images. It has taken a surprisingly long time to gain acceptance however, and for a long time it was considered as a gimmick for producing pretty pictures. Gradually the technology gained acceptance in specific applications such as vascular surgery and virtual colonoscopy, and is now used routinely in many CT and MR studies. 3D Printing appears to be going through a very similar path of acceptance, with the added disadvantage that there is an individual cost associated with each model produced. A 3D model used for surgical planning is likely to save operating time and lead to more effective surgery. However, the current costs of 3D Printing are often still perceived to be prohibitively expensive and work is therefore needed to demonstrate the health/economic benefits. Although the quality of consumer 3D Printers is currently not good enough for medical use, the recent growth in their use is likely to help with the general acceptance and understanding of the technology and will encourage 3D Printing in the hospital environment.
The key to an accurate 3D model is always in the quality of the segmentation, and this is determined by the expertise of the person performing the image processing and the software tools they have available. Automated and semi-automated tools are essential to make this a viable task for routine clinical use, and in Sheffield access to the 3D Imaging Lab makes this process much easier.”
What are the (future) goals for 3D Printing at your institution?
“3D Printing is still a relatively a new and underutilized technique at Sheffield. The 3D Lab is very keen to explore new applications and assist other departments to implement this technology. In the past couple of years, the number of applications has steadily increased and each new application often sparks a new idea for another. We are also keen to investigate the clinical impact of using all available 3D technologies, such as volume rendering, surface softcopy models, 3D printing models and virtual reality. Each technology offers distinct advantages and is likely to be more beneficial for specific applications but it is not clear yet which technique is best suited.
The Medical Physics Workshop in the hospital currently only has fairly rudimentary 3D printing capabilities but as the applications develop, investment in more sophisticated equipment will be considered. 3D Printing is developing quickly and so a mixed approach of insource and outsourced manufacturing will probably always be necessary to benefit from the best available technology.”
What benefits (and challenges) do you see in printing models directly at the hospital?
“The benefits of being able to print models directly in the hospital vary considerably depending on the application, and can include better turnaround times, convenience, and better interaction with the end users in the development of new applications and cost. It is not always made clear that the term “3D Printing” embraces a broad range of different technologies and it is currently unrealistic for a hospital to be able to host multiple different printers. Nevertheless, the ability to produce some models directly at the hospital can be useful and as the number of applications and demand grows it will become financially viable.”
What do you see as the main challenges and opportunities for the future of 3D Printing in hospitals?
“If the printing is performed directly in the hospital then capital and revenue costs are clearly a significant challenge. But we also need to remember that the costs are not only for the printer hardware, software and consumables. Depending on the technology used, it will also require staffing and accommodation for a dedicated 3D printing facility. The quality of the 3D-printed model is also an important consideration. 3D-printed implant devices and surgical guides are obviously medical devices and require sterilization, but models printed for surgical planning are also medical devices and their manufacture should conform to the relevant standards and legislation.
3D Printing offers the manufacture of low-volume, bespoke and sometimes complex devices which cannot be manufactured in any other way. This fits perfectly with the emerging theme of personalized medicine, and as the variety of 3D-printed biocompatible materials increases, the future opportunities for 3D Printing are vast.”
What would you advise people who wish to start a 3D imaging lab? What could be their first steps?
“I would advise them to first of all visit a well establish 3D lab to observe their workflow, and see what would be needed to implement at their institution. Then they should perform a survey on Radiologists to identify their different needs. Target a couple of applications which can be implemented easily, but have a measurable impact in terms of productivity and/or clinical benefit. Realistic turnaround times should be agreed. Afterwards, they should perform an analysis of the existing software in the department to identify which software tools are the best for the job. Multiple systems are likely to be needed as no single system exists that is the best of its kind for all 3D Lab tasks. Finally, they would need to obtain funding for dedicated Radiographer/Technologists and Scientist/Engineer time in the Lab.”
Would you like to see more cases in which patient-specific 3D Printing is the optimal way to go? Watch our THINK | Medical 3D Printing orthopedic webinar series to learn how other surgeons use Materialise and Medical 3D Printing to change their patients' lives for the better!
|About Dr. Peter Metherall: Dr. Peter Metherall is a registered Clinical Scientist and Chartered Engineer at Sheffield Teaching Hospitals NHS Foundation Trust and is the lead scientist of the 3D Imaging Lab. He is responsible for the imaging computer systems and has developed image visualization software which has now been licensed commercially. He has received two Chief Scientific Officer awards for innovation in 2005 and 2008. He is currently leading the implementation of the Sheffield 3D Imaging Lab; a new initiative to improve the clinical utility of Advanced Visualization and Quantitative Imaging for routine clinical imaging investigations and research applications.|