Vena caval flow: assessment with cine MR velocity mapping

Area of Science:

• Cardiovascular Imaging
• Hemodynamics
• Medical Physics

Background:

• Assessing blood flow in the great veins is crucial for diagnosing cardiac conditions.
• Traditional methods may be invasive or lack detailed hemodynamic information.
• Cine magnetic resonance (MR) velocity mapping offers a noninvasive approach to visualize and quantify vena caval flow.

Purpose of the Study:

• To evaluate the utility of cine MR velocity mapping in characterizing superior vena cava (SVC) and inferior vena cava (IVC) blood flow.
• To compare flow patterns in healthy controls with those in patients suffering from right-sided cardiac diseases.

Main Methods:

• Utilized cine MR velocity mapping to analyze SVC and IVC flow in 13 healthy subjects and 13 patients.
• Acquired images with respiratory gating in a subset of controls to assess respiratory influence on flow.
• Correlated flow abnormalities with specific right-sided cardiac pathologies.

Main Results:

• Healthy subjects exhibited distinct systolic and diastolic flow peaks in the SVC, with mean SVC flow at 35% of cardiac output.
• Patients with tricuspid regurgitation showed reduced systolic peaks and retrograde IVC flow.
• Reduced diastolic peaks in patients with pulmonary hypertension, pericardial constriction, and right ventricular dysplasia indicated impaired right ventricular diastolic compliance.
• SVC obstruction was confirmed by absent flow, with retrograde flow observed in the azygos vein.

Conclusions:

• Cine MR velocity mapping is a reliable, noninvasive method for studying vena caval blood flow.
• This technique holds significant potential for investigating various right-sided heart disorders.
• The findings highlight the sensitivity of vena caval flow patterns to specific cardiac pathologies.