By using a photon-counting computed tomography (PCCT) algorithm to acquire digital non-contrast (VNC) photos from coronary computed tomography angiography (CCTA), radiologists might be able to cut back radiation dosing by almost 20 % compared to standard non-contrast CT for coronary artery calcium scoring (CACS).
For the retrospective examine, not too long ago revealed in Radiology, researchers in contrast VNC photos from a PCCT algorithm (PureCalcium) for CCTA versus true non-contrast (TNC) photos from CCTA to establish any variations in CACS evaluation. The 170-patient cohort (imply age of 63) included 111 sufferers with Agatston scores greater than 0, in accordance with the examine.
The researchers discovered the median Agatson scores have been 4.8 for the VNC photos and a couple of.7 for the TNC photos and famous “glorious” settlement on plaque classification between VNC and TNC photos. Noting that the acquisition of TNC photos accounted for 19.7 % of the whole imply dose-length product for the CCTA examination, the examine authors urged that PCCT-derived VNC photos could also be a viable different.
Right here one can see comparative examples of non-contrast coronary artery calcium scoring (left photos), PureCalcium photos obtained from coronary CT angiography (CCTA) (center photos) and contrast-enhanced CCTA (proper photos). The highest photos reveal delicate coronary artery calcifications in a 70-year-old male affected person and the underside photos present reasonable coronary artery calcifications in a 72-year-old feminine affected person. (Photographs courtesy of Radiology.)
“PureCalcium photos from routine CT angiography might obviate the necessity for a devoted calcium scoring scan, providing complete info on calcium burden and plaque composition on a single scan whereas decreasing radiation publicity,” wrote lead examine writer Nina P. Haag, M.D., who’s affiliated with the Division of Radiology, Neuroradiology and Nuclear Medication at Johannes Wesling College Hospital and Ruhr College Bochum in Minden, Germany, and colleagues.
In an accompanying editorial, Hajime Sakuma, M.D., Ph.D., famous that improved dose effectivity and better spatial decision are a few of the benefits of PCCT in distinction to energy-integrating detector (EID) CT. Dr. Sakuma stated the examine’s findings with VNC photos acquired with PCCT from CCTA photos are promising for potential discount of radiation dosing for CCTA.
“These outcomes recommend that VNC photos from contrast-enhanced coronary CTA reconstructed with an up to date model of the PureCalcium algorithm can remove the necessity for a separate non-contrast CAC scan, which may cut back the radiation dose of the traditional coronary CTA protocol by a imply of 19.7% + 8.8,” famous Dr. Sakuma, a professor and chair of the Division of Radiology at Mie College Hospital in Japan, and chair of the Japanese Society of Cardiovascular Radiology.
Three Key Takeaways
- Decreased radiation dosing. Using a photon-counting computed tomography (PCCT) algorithm to generate digital non-contrast (VNC) photos from coronary computed tomography angiography (CCTA) can lower radiation publicity by almost 20% in comparison with standard non-contrast CT for coronary artery calcium scoring (CACS). This discount in radiation dose affords a major benefit in scientific observe, significantly for sufferers requiring repeated imaging research.
- Correct plaque evaluation. The examine demonstrated “glorious” settlement on plaque classification between VNC and true non-contrast (TNC) photos, indicating that PCCT-derived VNC photos can present dependable evaluation of coronary artery plaque burden. Regardless of some misclassifications, significantly in distinguishing between no plaque burden (P0) and minor plaque burden (P1), the general accuracy charge for plaque burden classification utilizing VNC photos was 74 %. Nevertheless, an intensive visible evaluation of CCTA photos might additional refine plaque burden classification accuracy, particularly in circumstances of no or minor plaque burden.
- Complete imaging with single scan. PCCT-derived VNC photos from routine CT angiography might remove the necessity for a separate non-contrast calcium scoring scan, providing complete info on calcium burden and plaque composition in a single scan. This streamlined strategy not solely reduces radiation publicity however might improve workflow effectivity by consolidating imaging protocols. It suggests a possible paradigm shift in coronary imaging observe, whereby PCCT may turn into integral for each diagnostic and prognostic assessments of coronary artery illness (CAD).
The examine authors identified that use of the VNC photos had a 74 % accuracy charge (125/170 sufferers) with the classification of plaque burden. Particularly, 20 sufferers who had a CAD-RADS P0 classification have been misclassified as having CAD-RADS P1 classifications primarily based on VNC photos, in accordance with the examine authors. Additionally they famous the usage of VNC photos led to 14 sufferers with a CAD-RADS P1 classification being misclassified with CAD-RADS P0 classifications.
“Whereas most misclassifications occurred at charges not more than random, PureCalcium CACS misclassified considerably extra sufferers as having minor plaque burden (P1) as a substitute of no plaque burden (P0),” famous Haag and colleagues. “When the PureCalcium CACS is used for sufferers with no or minor plaque burden, an intensive visible evaluation of CCTA photos might refine and enhance the accuracy of plaque burden classification, however this was not systematically evaluated in our examine,”
(Editor’s be aware: For associated content material, see “Rising Ideas with ICM Discount and Photon Counting for Coronary CT Angiography,” “Examine Examines Photon-Counting CT for CAD Detection in Sufferers Having TAVR Procedures” and “Examine: Photon-Counting CT Improves Accuracy of Coronary Stenosis Evaluation.”)
Past the inherent limitations of a single-center retrospective examine, the researchers acknowledged a scarcity of exploration of interscan reliability between photon-counting CT and energy-integrating detector CT, and analysis of variations between PureCalcium and TNC photos with respect to iterative reconstruction and reconstruction kernel degree. Additionally they conceded that sufferers with greater Agaston scores have been underrepresented within the examine cohort.
