Cardiac CT is becoming an increasingly valuable tool for heart imaging, but it does face challenges, particularly when it comes to reimbursement, according to a presentation delivered May 4 at the annual American Roentgen Ray Society (ARRS) meeting in New Orleans.
Cardiac CT's applications are legion, said presenter Dr. Sandeep Hedgire of Massachusetts General Hospital in Boston.
"Cardiac CT [offers so much] in the day-to-day life of the cardiovascular imager," he said. "[Its applications range] from calculating coronary calcium scores and the evaluation of coronary arteries to evaluating pulmonary veins in patients with arrythmias, [assessing] cardiac masses or the myocardium, integrating cardiac devices, evaluating [heart] structure and function in patients with congenital disease, and evaluating pericardial diseases."
New developments in the field of cardiac CT fall into four categories, Hedgire told session attendees: practice patterns and training; guidelines and reimbursements; technology; and new clinical applications.
Practice patterns and training. The use of coronary CT has increased in out-of-hospital settings by 355% over the past nine years, according to Hedgire. With this increased volume comes a need to establish trained cardiac CT readers, both increasing the pool of eligible readers and boosting their proficiency. "Practice patterns are changing, and we need to emphasize training in the next generation of the field," Hedgire said.
Guidelines and reimbursement. Professional societies such as the American Heart Association, the American College of Cardiology, the American Society of Echocardiography, and the Society of Cardiovascular Computed Tomography have published guidelines for evaluating and diagnosing chest pain using cardiac CT.
At the same time, reimbursements for cardiac CT exams have decreased over the past five years after increases in 2017, Hedgire noted, citing data from a study published in February 2021 in Radiology: Cardiothoracic Imaging.
| Changes in Medicare technical component payment for cardiac CT scans | ||||
| Exam | 2017 | 2018 | 2019 | 2020 |
| CT of heart structure with contrast | 11.9% | -4.6% | -20.2% | -9.7% |
| CT of heart with contrast for congenital heart disease | 11.9% | -4.6% | -20.2% | -9.7% |
| CT of heart blood vessels with grafts with contrast | 11.9% | -4.6% | -20.2% | -9.7% |
"Guidelines have evolved. Even though reimbursements are down, we need to brace for higher volume in the coming years," he said.
Technology advances and new clinical applications. As cardiac CT technology has advanced, the radiation dose per exam has decreased, so that a typical mean dose for cardiac CT is now 3.4 mSv, Hedgire said. He outlined the following leading-edge cardiac CT technology and applications:
- Photon counting CT. Hedgire cited a study published in February in Radiology that demonstrated that the use of a photon-counting CT system for coronary CT angiography (CCTA) improves image quality and diagnostic confidence among readers compared with conventional CT.
- Fractional flow reserve derived from coronary CT angiography (FFRct). This technique produces a 3D anatomical model with values that indicate the level of blood vessel blockage.
- Cardiac CT for preprocedure planning of transcatheter edge-to-edge tricuspid valve repair (TTVR).
| Values on FFRct that indicate coronary vessel blockage | |
| FFRct value | Interpretation |
| >0.8 | Normal |
| 0.8 to 0.76 | Borderline |
| ≤0.75 | Abnormal |
Of course, cardiac CT will also be supported and refined by artificial intelligence (AI), Hedgire said.
"[AI] offers faster postprocessing, improves image noise, and can be time saving, and CNN [convolutional neural networks] and ML [machine learning] will change how we acquire and report images," he noted.
The bottom line for cardiac CT is that it's primed to become a valuable tool for cardiac assessment, according to Hedgire.
"[Cardiac CT] technology continues to evolve, and new clinical applications will continue to aid clinical care," he concluded.
