This is a normal testis with an adjacent enlarged and hypervascular head of the epididymis (label says 'sag RT EPI') consistent with inflammation or epididymitis. There is also thickening of the scrotal skin. This is a Doppler image showing that there is an abnormal amount of vascular flow in this inflamed region. The red and blue colors do NOT indicate arterial and venous structures, but direction (based on the scale on the left of the image-red is toward the transducer and blue is away).