This patient does not have testicular torsion, but has epididymitis, likely secondary to a sexually transmitted disease (GC, chlamydia, etc).
Epididymitis
Epididymitis is the number one cause of acute scrotal pain and is due to the inflammation of the epididymis, usually due to bacterial invasion. Most commonly this infection stems from Chlamydia and Neisseria gonorrhea. Symptoms include acute scrotal pain, discharge and may include fever or dysuria.
On ultrasound, acute epididymitis is diagnosed by a hypoechoic epididymis or an epididymis that appears darker grey than the testicle itself. Color doppler shows increased blood flow in the epididymis.