The many wonders of modern science have allowed medical professionals and surgeons to save patients by fixing heart problems, and the tools they use continue to advance advanced imaging, 3D printing and more—sometimes a combination of the two. In "A CT-optimized protocol for cardiac imaging using 3D printing" by Kamarul Amin Abdullah, University of Sydney, a three-layer study was performed, starting with a 3D printed heart model. Next, it was placed inside the Lungman phantom and scanned, allowing the researchers to reconstruct the data, which could then be measured and compared to determine the potential for dose reduction. Finally, the algorithm was evaluated using "Dose Optimization Studies with Different Intensities and Low Tube Voltages".

Phantoms are often used to refine images such as CT scans, allowing better optimization, assessing quality, and determining radiation doses that occur during use - this has become a growing concern:

"A recent report by the National Council on Radiation Protection and Measurements (NCRP) states that CT examinations contribute 24% of the radiation dose to the U.S. population and have increased by 10% annually since 1993," the researchers said. . "In Australia, radiation doses from CT examinations increased by 36% from 2006 to 2012. Therefore, the increase in radiation doses from CT examinations is a global trend, and CT examinations are now considered to be the largest contributors to population doses."

CT scanning technology is very useful and is now widely used, with increasing use following radiation exposure. Cancer risk is a major concern due to radiation affecting DNA, as well as exposure to the lungs and breasts during the scan. In fact, at organ doses ranging from 42 to 91 mSv for the lungs and 50 to 80 mSv for the breasts of women, the risk of cancer in a 20-year-old woman was 0.7, compared with 0.03% in men. 80.

Reducing cancer risk during exposure is a concern and typical methods of doing so are using the following:
•Tube current reduction
•Tube voltage low
•Treble protocol
•Scan coverage limitation
•Bismuth shielding
•ECG-controlled tube current modulation
•Prospective ECG gating
•Iterative reconstruction algorithm

"Of these, IR algorithms are of particular interest to researchers due to their ability to reduce noise at low exposure factors, thereby reducing dose while maintaining image quality," the researchers said. "Currently, filtered backprojection (FBP) is the most widely used image reconstruction algorithm to reconstruct data into CT images due to its robust and fast algorithm. However, FBP inherently increases image noise and produces Artifacts, so the IR algorithm is used.

Scientists see phantom-based dose optimization approach as ’suitable’ for coronary computed tomography angiography studies. Currently, using patient data causes problems due to the radiation generated while finding enough patients who may have coronary artery disease (CAD). Typical models used in optimization studies are the Catphan series and the American College of Radiology models, which are attractive to research groups because they are both comprehensive and complex. However, a more accurate phantom is required here, and the previously mentioned types do not reproduce the required characteristics very well.

An example of a body phantom is the Catphan® 500 (The Phantom Laboratory, Salem, NY). This phantom is widely used to test the performance of CT scanners. The Specter includes five modules for evaluating image quality; (i) CTP401 for slice width, sensitivity and pixel size,
(ii) CTP528 for line pair and point source spatial resolution,
(iv) Low contrast in sub-slices and above CTP515 slices and (v) image uniformity of CTP486.

The Lungman anthropomorphic chest model comes with a model that mimics a heart, and the surrounding structures and tissues closely resemble real patients, the researchers said. However, heart features are lacking and simulated with only one homogeneous material. "Thus, the lack of CCTA image features can be addressed by replacing the current cardiac insert with a newly designed cardiac insert phantom that can provide an appropriate CCTA image appearance similar to that of a real human heart," state the researchers. They also discuss the advantages of 3D printing in phantom development, as the researchers have investigated ways to make models that mimic different parts of the anatomy. However, so far no 3D printed inserts of the Lungman model have been created.