Factors affecting colour Doppler regurgitant jet size
| Factor | Relation to or effect on colour jet size | |
|---|---|---|
| LA, left atrium, LV, left ventricle. | ||
| Direct, jet size increases as factor increases; Inverse, jet size decreases as factor increases. | ||
| Effects on measured or displayed flow velocities | ||
| Haemodynamic effects | LA compliance | Direct |
| LA pressure | Inverse | |
| LV systolic function | Direct | |
| LV pressure | Direct | |
| Instrument settings | Colour gain | Direct |
| Wall filter | Inverse | |
| Transducer frequency | Direct | |
| Pulse repetition frequency | Inverse | |
| Other factors affecting colour jet size | ||
| Transducer position | Relative to direction of flow | Doppler angle effects |
| Inadequate alignment to jet | Underestimation of true jet size | |
| Jet eccentricity | Coanda effect (see text) | Reduced jet dimensions |