Measurement of normal left heart dimensions using optimally oriented MR images

Area of Science:

• Cardiovascular Imaging
• Medical Physics

Background:

• Establishing normal reference values for cardiac dimensions is crucial for diagnosing cardiovascular conditions.
• Magnetic resonance imaging (MRI) offers detailed anatomical visualization of the heart.

Purpose of the Study:

• To establish normal values for left heart dimensions using electrocardiographically gated magnetic resonance imaging (MRI).
• To validate MRI measurements against two-dimensional echocardiography (2DE) for cardiac imaging accuracy.

Main Methods:

• Electrocardiographically gated MRI was performed on 16 healthy subjects using a 0.6-T superconducting magnet and spin-echo pulse sequence.
• Cardiac images were acquired along the long and short axes of the left ventricle, comparable to 2DE planes.
• Left heart dimensions (ventricular diameters, wall thicknesses, atrial diameter) were measured at end diastole and end systole using both MRI and 2DE.

Main Results:

• A strong correlation was found between MRI and 2DE measurements (r = 0.97, p < 0.0001).
• Individual measurements also showed high agreement between the two imaging modalities (p < 0.001).
• No significant differences were observed in the mean values obtained by MRI and 2DE.

Conclusions:

• Standardized MRI technique, with image planes aligned to intrinsic cardiac axes, yields measurements comparable to 2DE.
• This study provides reliable normal values for left heart dimensions determined by MRI.
• MRI is a validated tool for accurate assessment of cardiac morphology.