13-18 Probes and Biopsy 
 
Image of the biopsy target and the actual position of 
the biopsy needle: 
Diagnostic ultrasound systems produce tomographic 
plane images with information of a certain thickness 
in the th
ickness direction of the transducer. (That is 
to say, the information shown in the images consist 
all the information scanned in the thickness direction 
of the transducer.) So, even though the biopsy 
needle appears to have penetrated the target object 
in the image, it may not actually have done so. When 
the target for biopsy is small, dispersion of the 
ultrasound beam may lead to image deviate from the 
actual position. Pay attention to this. Image deviation 
is shown as the figures below:
 
 
The biopsy needle appears to reach the target object in 
the image 
 
Dispersion of the ultrasound beam 
To avoid this problem, note points below: 
Do not rely only on the echo of the needle tip on the 
image.  Pay careful attention to the target object, 
which should shift slightly when the biopsy needle 
comes into contact with it. 
Before you perform the biopsy, please evaluate the 
size of the object and confirm if the biopsy can be 
carried out successfully. 
 
CAUTION: 
When using the needle-guided bracket wear sterile gloves to 
prevent infection.