This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Characteristic fallopian tube findings on sonography in pelvic inflammatory disease includes all except 
Select and explain. 
A. Fallopian tube wall thickening., B. Cog-wheel appearance in cross-section., C. Color doppler shows less vascularity., D. Distended tube filled with echogenic fluid.
C: Color doppler shows less vascularity.
Answer: C: Color doppler shows less vascularity. 
Explanation: Color doppler shows marked vascularity with low-impedance blood flow which reflects hyperemia.