vessel dropout
Sudden loss of vascular signal or visualization on imaging studies, often due to technical factors.
Full Definition
Vessel dropout refers to the sudden loss or absence of vascular signal or contrast opacification in a vessel segment that should normally be visualized on imaging studies. This phenomenon can result from various factors including flow-related signal loss, motion artifacts, inadequate contrast timing, vessel compression, or actual pathological occlusion. In MR angiography, vessel dropout commonly occurs due to turbulent flow, in-plane saturation effects, or susceptibility artifacts. Distinguishing between artifactual vessel dropout and true pathological findings requires careful analysis of multiple imaging planes and sequences, and may necessitate additional imaging or alternative techniques for clarification.
Usage
Usage note: Always consider technical factors before diagnosing pathological occlusion.
In Context
- "Apparent vessel dropout in the distal right vertebral artery was attributed to flow-related signal loss rather than occlusion." — MRA interpretation
- "Repeat imaging with different parameters was performed to distinguish vessel dropout from true stenosis." — Quality assurance report