Medical & Dental

3D printed kidneys predict the body’s capacity for radioactive material

3D printed organs are increasingly used as educational aids. Patients’ MRI scans are being used by the likes of Stratasys Direct Manufacturing and Whiteclouds to make brain models to assist surgeons and medical students. Phantom kidneys have also been explored for educational purposes, namely in November’s edition of The Journal of the Biomedical Engineering Society as reported by 3DPI last month. Now, new model kidneys made by a team of researchers at the University of Würzburg in Germany take this modeling up a notch by using 3D printed artifices in the administering of nuclear medicines.

3D printed phantom kidneys Figure via: Tran-Gia et al.
3D printed phantom kidneys Figure via: Tran-Gia et al.

Reverse radiology

Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) scans are used to uncover problems in our bones, brains and hearts among other things. In order to get a clear image of these organs and bones, a patient must however ingest some radioactive liquids, typically technetium-99m or iodine-123.

Moving image of a whole-body positron emission tomography (PET) scanBy Jens Maus ( – Own work, Public Domain, Link

As a specialist practice, the volume of liquid used for this procedure is highly controlled in order to minimize any radiation caused to the patient. It’s a tricky balance to achieve, and the very problem Johannes Tran-Gia and his team in Würzburg are hoping to solve.

Publication in The Journal of Nuclear Medicine

Tran-Gia worked with Susanne Schlögl and Michael Lassmann on a paper titled Design and Fabrication of Kidney Phantoms for Internal Radiation Dosimetry Using 3D Printing Technology for The Journal of Nuclear Medicine earlier this year. Explaining their findings in a summary on, Tran-Gia said,

This research shows a way of producing inexpensive models of patient-specific organs/lesions for providing direct and patient-specific calibration constants. This is particularly important for imaging systems suffering from poor spatial resolution and ill-defined quantification, such as SPECT/CT.

The result of the research was the production of four different sized (Newborn, 1 year-old, 5 year-old and adult) phantom kidneys.

CAD models of 4 sizes of kidney. Figure via: Tran-Gia et al.
CAD models of 4 sizes of kidney. Figure via: Tran-Gia et al.

Waterproof and refillable, the kidneys could be re-used to determine the adequate amount of radioactive material to transmit an image to a SPECT or CT scan. They were made on a Renkforce RF1000 FFF 3D printer, using Voltivo ExcelFil transparent PLA.

The 3D print in action. Figure via: Tran-Gia et al.
The 3D print in action. Figure via: Tran-Gia et al.

Speaking again to, Tran-Gia comments:

Although in our study the kidneys were modeled as a relatively simple one-compartment model, the study represents an important step towards a reliable determination of absorbed doses and, therefore, an individualized patient dosimetry of other critical organs in addition to kidneys.

Tran-Gia and his co-authors concluded that 3D printing the kidneys is a ‘promising prototyping technique for geometry-specific calibration of SPECT/CT systems’ and for its low cost and high resolution, the method holds great potential for applications in Nuclear Medicine.

Featured image shows the 3D printing of a phantom kidney on the Renkforce RF1000. Figure via: Tran-Gia et al.