Intermediate
Technical
IVT
navigator
Real-time motion monitoring technique that tracks diaphragmatic position during cardiac MRI to minimize respiratory artifacts.
Full Definition
Navigator techniques in cardiac MRI use rapid, low-resolution images to track the position of anatomical structures, typically the diaphragm, during free-breathing acquisitions. The navigator signal controls image acquisition timing, accepting or rejecting data based on respiratory position to reduce motion artifacts. This allows for high-quality cardiac imaging without breath-holding, particularly valuable for patients who cannot hold their breath or for long acquisition sequences.
Usage
Usage note: Often used in combination with 'gated' (navigator-gated).
In Context
- "Navigator-gated coronary MRA provided excellent vessel visualization without motion artifacts." — Non-invasive coronary imaging report
- "The navigator acceptance window was set to ±5mm to ensure consistent image quality." — MRI protocol parameters
Also known as
respiratory navigator
diaphragmatic navigator
Contrasted with
breath-hold imaging
Don't confuse with
gating
triggering