VIDEO: Congenital heart imaging with cardiac CT

 

Renee Bullock-Palmer, MD, FACC, FAHA, FASNC, FASE, FSCCT, director of non-invasive cardiac imaging, director of the Women's Heart Center, Deborah Heart and Lung Center, Brown Mills, New Jersey, and clinical associate professor, Thomas Jefferson University, discusses the use of cardiac computed tomography (CT) to image congenital heart patients. She spoke to Cardiovascular Business at the 2022 Society of Cardiovascular Computed Tomography (SCCT), where she presented a session on the topic.

"As the population of patients with adult congenital heart disease has grown, we are seeing a lot of these patients entering into the adult cardiology clinics, and they are presenting to the CT imagers," Bullock-Palmer said. "So I think cardiac CT is increasing playing a bigger and important role for these patients."

She said many of these patients also will not qualify for MRI, which is the preferred imaging modality for congenital heart. She said this is often because these patients have MRI incompatible devices implanted such as ICDs or pacemakers. Patients also may have limited access to Cardiac MRI or be claustrophobic. In some instances, cardiac CT may have better spacial resolution than cardiac MR when assessing the coronary arteries, coronary anomalies and stents, including pulmonary stents and pulmonary valves, Bullock-Palmer explained. 

Often in congenital patients, an imaging study needs to be customized to the clinical question being asked because of septic nature of each patient's anatomical anomalies and prior surgeries, she said. 

"They can be porporri of patients, ranging from very simple ASDs, or they can be very complex single ventricle Fontan patient," Bullock-Palmer said. "So we use the adult congenital heart disease (ACHD) classification system, which is based on anatomy and physiology classifications.

The anatomy is graded as simple, moderate complex and great complexity. The physiological stages follow the New York Heart Association functional classifications, with Class I being no hemodynamic sequelae and Class IV being severe hypoxemia or cyanosis.

"At our center we do see a good mix of these patients," she said. "Usually we use CT for the very complex cases when MRI is unavailable or not possible. For the simple cases, we usually do not see those on CT because those cases can be assessed using echo. This is particularly true for atrial septal defects (ASDs) and ventricular septal defects (VSDs)."

Bullock-Palmer said CT is often used for structural heart procedure planning to size the anatomy and create a table of measurements used by surgeons or interventionists implanting transcatheter devices or valves. There pre-procedural workups are done for Tetralogy of Fallot, Fontan procedures and pulmonary valve replacements. Sometimes 3D modeling is done to help surgeons and interventionalists better understand the complex anatomy and use as a reference during the procedure.

Advanced visualization software used to help automate measurements and create specific views of the anatomy can be problematic in congenital patients because it was designed around and validated using normal patient anatomy imaging. Congenital patients are often missing parts of the normal cardiovascular anatomy, or vessels and cardiac anatomy are not located where they should be normally, which usually causes issues with automated software. So, she warns imagers will likely have to spend more time post-processing these exams. 

"Most times I am having to change were the contours are, and that is important, because you do not want to give inaccurate information to the referring physician. This is especially important for information on left ventricular or right ventricular volumes and function," she said. "For example, in a Fontan patient where there is only a single ventricle, the software is going to try and find the other ventricle, and most time it is going to give you inaccurate information. So you have to go through manually in each of the phases to fix the contours."

If it is too difficult to assess, she said she has sometimes given a visual estimate that ventricular function is reduced and suggest the patient should undergo an echo or MRI assessment. 

Find more SCCT and cardiac CT coverage

Dave Fornell is a digital editor with Cardiovascular Business and Radiology Business magazines. He has been covering healthcare for more than 16 years.

Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com

Around the web

Ron Blankstein, MD, professor of radiology, Harvard Medical School, explains the use of artificial intelligence to detect heart disease in non-cardiac CT exams.

Eleven medical societies have signed on to a consensus statement aimed at standardizing imaging for suspected cardiovascular infections.

Kate Hanneman, MD, explains why many vendors and hospitals want to lower radiology's impact on the environment. "Taking steps to reduce the carbon footprint in healthcare isn’t just an opportunity," she said. "It’s also a responsibility."