Learning objectives
To be familiarwith the mainultrasound settings available on current machines
Tounderstand how altering these settings will change the images that we acquire (for better and for worse)
To identify how we can apply the above,
specifically to renal transplant ultrasound
To recognise that inappropriate machine settings can mimic pathology in otherwise normal renal transplants
Background
The physics of ultrasound can be complex and many of us rely on renal presets on our machines to give us the best images and spectral Doppler studies.
However,
there are many settings that we can alter manually to further optimise our diagnostic accuracy.
We review the main B-mode,
colour-flow and spectral Doppler ultrasound parameters and discuss how some of these settings can be adjusted to improve our sensitivity at identifying common post-operative complications of renal transplants.
Findings and procedure details
Brightness (B) Mode Ultrasound
B-mode involves the acquisition of cross-sectional images using ultrasound waves that are reflected differentially by various tissues and organ boundaries.
Echoes are depicted topographically according to their positions within the scanned tissues,
giving us a good representation of anatomy and pathology.
There are several parameters that allow us to optimise our B-mode images.
Power
Power simply alters the strength of the ultrasound waves and is often set to the maximum by default.
Many ultrasound machines do not allow alteration of the...
Conclusion
Our review demonstrates that there are multiple ultrasound settings that can be used together to produce a significant improvement in our renal transplant studies.
Specifically,
we have shown that suboptimal colour-flow and Doppler settings can produce results that mimic severe transplant pathology,
particularly in the immediate post-operative period.
References
Allan P L et al.
Clinical Ultrasound.
3rd Edition.
London: Churchill Livingstone; 2011.
Allisy-Roberts P J and Williams J.
Farr’s Physics for Medical Imaging.
2nd Edition. Philadelphia: Elsevier Saunders; 2008.
pg147
Platt JF et al.
Distinction between obstructive and nonobstructive pyelocaliectasis with duplex Doppler sonography. AJR 1989; 153: 997-1000