Report from Stanford MDCT: Pediatric CTA branches out of congenital heart disease

Sixty-four-slice cardiac CT is picking up important incidental findings in pediatric patients with congenital heart disease, and new vascular applications keep popping up on the horizon, according to speakers at the Stanford Multidetector-Row CT Symposium.

Unlike cardiac catheterization and echocardiography, 64-slice CT documents all pathology within a large field-of-view, said Dr. John Haushildt, director of cardiovascular imaging at Children's Hospital and Health Center in San Diego.

Not uncommonly, imagers discover unexpected pathology in children with known or suspected congenital heart disease, sometimes resulting in changes in medical or surgical management, he said. In a retrospective study, researchers analyzed 212 consecutive cases of patients who underwent 64-slice CT after cardiac catheterization (11% of patients) and/or echocardiography (100% of patients). Axial source images, maximum intensity projections, and 3D renderings were assessed.

Sixty-four-slice CT picked up 78 additional unexpected cardiac abnormalities in 51 patients (24% of the patient population). Abnormalities were found most commonly in the coronary arteries, aortic arch, pulmonary arteries, and pulmonary veins.

The MSCT scan changed medical management in four cases of coronary artery abnormalities and two cases of noncoronary abnormalities. In one case, a condition that could have resulted in sudden death was found in a patient with normal echocardiography results and no ECG.

"Further study is needed to evaluate the role of 64-slice CT in the workup and management of patients with congenital heart disease. It finds everything in the field-of-view. Can it become the new gold standard?" Haushildt said.

Even if 64-slice CT did become the gold standard, however, cardiac catheterization would still clearly be necessary in some cases and radiation exposure would need to be considered and minimized, he said.

Catheter digital angiography is invasive and may not yield better results that CTA, according to Dr. Bruce Greenberg, a professor of radiology at the University of Arkansas. Greenberg presented a case in which a patient underwent catheter digital angiography followed by multislice CTA. Two congenital aneurysms were found with digital angiography, and a third calcified aneurysm was found with CTA.

"Again, one wonders, What is the gold standard? Certainly this finding is of interest to the neurosurgeon," he said.

Multislice CTA is taking off in imaging children just as it is in adults, and it could prove useful in many other areas in addition to congenital heart disease, he said. CTA is easier to perform in children than MRA.

Other applications include evaluation of mycotic aneurysms and trauma throughout the body, neuroimaging for cerebral anomalies such as sequestration, chest imaging anomalies, and abdominal imaging for unexplained bleeding, vascular malformations, and tumor vascular evaluation.

Greenberg presented pediatric cases in which CTA picked up a congenital pulmonary airway malformation and myocarditis.

"MDCTA is replacing conventional digital angiography. New vascular applications are on the horizon," Greenberg said.