E2303. Left to Right Shunts: What the Radiologist Needs to Know
  1. Natalie LeCrone; Virginia Commonwealth University Health Systems
  2. Shaimaa Fadl; Virginia Commonwealth University Health Systems
  3. Jonathan Revels; NYU Langone Radiology Associates
  4. Jay Pham; Virginia Commonwealth University Health Systems
  5. John Grizzard; Virginia Commonwealth University Health Systems
Computed Tomography (CT) and cardiac Magnetic Resonance Imaging (MRI) play an important role in detection and evaluation of left-to-right cardiovascular shunts. Imaging studies help delineation of the important anatomical features prior to intervention.

Educational Goals / Teaching Points
1. Discuss different etiologies of left-to-right cardiovascular shunts. 2. Discuss imaging features of left to right cardiovascular shunts. 3. Illustrate the role of imaging in the anatomic and functional evaluation of shunts.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
A left-to-right shunt may be classified as either cardiac shunts or vascular shunts. Examples of cardiac shunts include atrial or ventricular septal defects (ASD or VSD), sinus venosus defect, and unroofed coronary sinus. Examples of vascular shunts include patent ductus arteriosus (PDA), partial anomalous pulmonary venous return (PAPVR), and coronary artery fistula. Although imaging is variable depending on patients age and severity of symptoms, most cases of a left-to-right shunt will be imaged using CT Angiography, Cardiac MR, echocardiography, or a combination of such.

Multiple imaging modalities are used to evaluate left to right shunts, including CT angiography, and Cardiac MR. Imaging plays crucial role in detection and functional evaluation of those shunts as well as preoperative planning.