Chlamydia is a vaginal infection. It may or may not reach very high in the genital tract to cause extensive infection. PID is pelvic inflammatory disease. That infection may have ascended via genital tract from outside (many bacteria can cause). Or it may be blood borne , that means blood has transferred bacteria from some other infected organ of the body , or it may come from adjacent organ. PID can be diagnosed by ultrasound but getting infection of Chlamydia today and expecting that the diagnosis can be confirmed by sonography, well that doesn't happen.

Ultrasound can detect pid

PID moreover is clinical examination but however you can do ultrasound