Question about how to read ultrasounds

what do some of these things mean on right side. im going to the doctors tomorrow and i will ask him if i can remember. but what does

Frq (4.0 MHz)
Gn (36)
S/A (3/1)
D (12.0 cm)
DR (72)
FR (18 Hz)
AO (69%)

just wondering if anyone can help me figure out what those mean or has had experience with it

[AnnieBrooke]

The first one is frequency, 4.0 megahertz.  It applies obviously to the technical specs of the ultrasound itself.  Maybe the others are also technical information regarding the machine or the specifications of the picture-taking, like f-stops are in photography.

[Kim1989]

humm...alright cuz from my last ultrasound everythings the same in the three pictures except Gn, and D, so i was just wondering what all of those ment. alright thanks. that at least expains one.

[mlb1234]

Gn could be "gain" and D could be "diameter" or maybe "depth", not sure but I do think they are all just technical specs like AnnieBrooke said on how the ultrasound is set up.  And nothing to do your measurements.