"The findings are variable1-3:"
"The TWIST score can be calculated to determine the need for ultrasound 8."
"normal gray-scale and Doppler US if the torsion is partial or intermittent"
"elevated resistive index (RI >0.75) 3"
"normal gray-scale and Doppler US if the torsion is partial or intermittent"
"torted testis due to increased intra-testicular pressure"
"Initially, torsion is sufficient only to obstruct venous outflow (incomplete torsion, less than 360 degrees), resulting in the gradual increase in intratesticular pressure and resistance. Over time and with additional twisting of the cord (greater than 360 degrees), arterial inflow is also obstructed; blood flow ceases when torsion exceeds 540 degrees, and viability decreases with time 1-3,14."