Use appropriate codes for residual urine ultrasounds

AUA recommends 51798 any time ultrasound is performed to check for residualurineQ We use the BVI-3000 BladderScan from Diagnostic Ultrasound for residualurine. They show a shadow of amount left in the bladder on a printed report.Is this still considered a non-image? Is there any way we can use 76775using the BVI-3000?