Is posterior acoustic shadowing the only sonographic sign for diagnosing an echogenic focus within the renal sinus as a stone?
No
Echogenic focus (white arrow) was noticed incidentally while scanning the left kidney, with faint associated posterior shadowing.
Colour Doppler was applied for verification of a stone, it showed the diagnostic twinkling artifact / colour comet-tail artifact. The stone measured ± 5.5 mm.