Advance Knobology for B-Mode Imaging - Focal Zone
Focal Zone
Focal Zone:
The narrowest part of the ultrasound beam profile when it is emitted from the transducer. In this region, the pulse waves are concentrated resulting increased beam intensity (energy/area).
Effects:
At the focal zone, the pulse waves are concentrated resulting increased beam intensity (energy/area).
Since the beam profile is narrowed, the beam width is, also, reduced. This improves lateral resolution which is dependent on beam width.
After the beam profile diverges, the beam width increases and intensity of the beam reduces. The former will reduce lateral resolution and latter will result in reduce Harmonic Wave generation (discussed later in this module).
Since the beam profile is narrowed, the beam width is, also, reduced. This improves lateral resolution which is dependent on beam width.
After the beam profile diverges, the beam width increases and intensity of the beam reduces. The former will reduce lateral resolution and latter will result in reduce Harmonic Wave generation (discussed later in this module).
Take Home Messages:
- Know how to change and locate the the Focal Zone on your system
- Center the Focal Zone to the structure of interest
- If you CANNOT change the Focal Zone on your system, change the depth so that the structure of interest is in the middle of the screen.