Quantitative MR renography using a calibrated internal signal (ERETIC)

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging (MRI)
• Renal Physiology

Background:

• Accurate MR renograms require correcting for MRI system variations.
• Quantitative signal measurement in kidney MRI necessitates a reliable reference signal.
• Existing reference methods have limitations in adjustability and space within the magnet.

Purpose of the Study:

• To evaluate the Electronic Reference To access In vivo Concentrations (ERETIC) method for MR renography.
• To compare the precision of ERETIC against external reference methods.
• To highlight the advantages of ERETIC for in vivo MRI applications.

Main Methods:

• The ERETIC method synthesizes an electronic reference signal using amplitude-modulated RF pulses during MRI acquisition.
• Cortical and medullary kidney signal intensity was monitored post-contrast injection.
• ERETIC's precision was compared to an external tube reference method.

Main Results:

• The ERETIC method demonstrated precision comparable to the external tube reference.
• ERETIC offers significant advantages, including free adjustability to organ characteristics and no space requirement within the magnet.
• Despite intrinsic stability, ERETIC signals are affected by system variations, similar to real NMR signals.

Conclusions:

• ERETIC is a precise and advantageous method for quantitative signal measurement in kidney MRI.
• Its flexibility and ease of implementation on two-RF-channel systems make it a valuable tool for MR renography.
• ERETIC provides a robust alternative for improving the accuracy of dynamic contrast-enhanced MRI studies.