An aften ignored setting during sonography:

One of the most prominent settings control on any ultrasound machine is the gain knob. Yet, this happens to be one of the most unused. This knob in conjunction with the TGC or Depth gain is very useful. A good example is the female child. Here, transabdominal ultrasound to image the ovaries and small uterus can be a real pain. But lower the gain or Depth gain, and you should be able to see the ovaries, even if very small. It works in most cases.


Observe the images of the thyroid here:
With high gain settings, the margins of the thyroid and fine detail are lost. With too low gain, most of the thyroid becomes poorly visible. Optimal gain settings show both internal and marginal details. Another observation: when Color Doppler imaging is switched on, the overall gain goes down.. the gain has to be increased to compensate for this.

Sonography of fetal kidneys with Autosomal recessive Polycystic kidney disease

This fetal kidney shows typical features of ARPKD (autosomal recessive polycystic kidney disease) also called infantile polycystic kidney disease. This congenital disease of the kidney can be present from as early as fetal stage and may be detected as late as in childhood.
The fetal kidneys in this case show minute cysts with grossly hyperechoic kidneys.
Read more at: http://www.ultrasound-images.com/fetal-urogenital.htm

Sedimenting echoes in urinary bladder:

Sediment producing echogenic debris in the urinary bladder can be caused by a number of factors.
Excessive amounts of Phosphate crystals in the urine is one cause. It can also be due to pyuria or pyogenic material in the urine secondary to urinary tract infection; sometimes it may be caused by hematuria (blood in urine) or chyluria following filariasis. Other causes include uricosuria (uric acid excess) or increase in oxalate crystals. This ultrasound image shows debris in the distended urinary bladder, gravitating to the dependent part.
This ultrasound image is courtesy of Dr. Ravi Kadasne, UAE.
For more sonographic images of the urinary bladder visit: http://www.ultrasound-images.com/urinary-bladder.htm
Case-2:
Here is a nice real time B-mode ultrasound video clip showing freely mobile particles in the urinary bladder:

                                                                                  

This patient has active urinary tract infection with cystitis. The particulate matter in the urinary bladder are the result of debris- both pyogenic material and phosphate crystals floating within the urine.

This is a still image of the same case (as the video above):                                                                                

 Fine particles are seen throughout the urine in the bladder.