Pediatric Congenital Heart Disease – Anomalous Coronary Arteries

SOMATOM Definition Dual Source Scanning

Suzu Kanzaki MD, Masahiro Higashi MD, Hiroaki Naito MD PhD
Department of Radiology, National Cardiovascular Center, Osaka, Japan
 |  2008-10-17

History

A 3-year-11-month-old girl was referred to the pediatric cardiology department of our center for detailed examination and treatment of her congenital heart disease. Light cyanosis and heart murmurs were first noticed when she was examined at age 3, after having contracted influenza. Examinations by transthoracic echocardiography and catheter angiography lead to a diagnosis of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (MAPCA). We took an ECG-gated, cardiac Dual Source CT scan to help confirm the diagnosis.
 

Diagnosis

The same findings as obtained by echocardiography were also seen on the DSCT images, which were of excellent quality: a ventricular septal defect of about 10 mm diameter, an overriding of the aorta and pulmonary atresia. DSCT could confirm the MAPCA as seen on angiography, and the relative positions of MAPCA, trachea and bronchi could be easily identified from the volume rendered images. The DSCT images revealed a single coronary artery that was not clearly seen on angiography. The DSCT images further revealed that all major coronary arteries originated from the left sinus of Valsalva.
 

Comments

With DSCT, isotropic volume data with high spatial resolution could be acquired. DSCT images have sufficiently high image quality to allow diagnosis of cardiac and vascular morphologies even for pediatric patients. DSCT can therefore complement echocardiography and angiography and provide valuable information, particularly for surgical treatment planning. The scan could be performed after only lightly sedating the patient by oral medication before the scan. A bolus of 18 mL iodinated contrast agent (370 mgI/mL) was injected. The patient's height was 93 cm, body weight was 12 kg, and mean heart rate during the scan was 123 bpm. This scan was performed shortly after installation of the Dual Source CT at our center, we have become able to reduce the dose to pediatric patients by about 2/3.

Examination Sequence Protocol

Scanner SOMATOM Definition
Scan area Thorax
Scan length 100 mm
Scan direction Cranio-Caudal
Scan time 3 s
kV 100 kV / 100 kV
Effective mAs 280 mAs /rot
Rotation time 0.33 s
Slice collimation 0.6 mm
Reconstructed slice thickness 0.6 mm
Increment 0.5 mm
Kernel B25f
Temporal resolution: 83 msec (Heart rate independent)
Spatial Resolution: 0.33 mm isotropic

The information presented in this case study is for illustration only and is not intended to be relied upon by the reader for instruction as to the practice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Systems to be used for any purpose in that regard.


The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The source for the technical data is the corresponding data sheets. Results may vary.