Published on: • By: Alex Mubajje

Ultrasound Case: Pelvic Inflammatory Disease (PID)

A 28-year-old female presents with lower abdominal pain and fever.

Case Presentation

History

  • Chief Complaint: Lower abdominal pain x 5 days, fever (38.5°C), and vaginal discharge.
  • History of Present Illness:
    • Bilateral lower abdominal pain, worse on the right side.
    • Increased yellowish vaginal discharge.
    • Dyspareunia (pain during intercourse).
    • No urinary symptoms.
  • Past Medical History: Previous chlamydia infection (treated 2 years ago).
  • Sexual History: Multiple partners, inconsistent condom use.

Physical Examination

  • Abdomen: Tenderness in lower quadrants, rebound tenderness on the right.
  • Pelvic Exam: Cervical motion tenderness (CMT), purulent cervical discharge.
  • Vital Signs: Temp 38.5°C, HR 98, BP 110/70.

Clinical Suspicion: Given the history of STIs, multiple partners, fever, and cervical motion tenderness, PID is highly suspected. Ultrasound is requested to assess for complications such as tubo-ovarian abscess or pyosalpinx.

Ultrasound Findings

  • Thickened, fluid-filled tubes: Exhibiting a “cogwheel” or “beads-on-a-string” appearance.
  • Incomplete septations: Visualized within dilated tubes, strongly suggesting pyosalpinx.
  • Free pelvic fluid: Present in the cul-de-sac.
  • Tubo-ovarian complex: Ovary and fallopian tube are adherent but still distinguishable from one another.
  • Hypervascularity: Marked increase in blood flow demonstrated on Doppler imaging due to active inflammation.
Cogwheel sign ultrasound
1. Right fallopian tube: Thickened, fluid-filled fallopian tube demonstrating incomplete septations and marked hypervascularity on Doppler imaging.
Free pelvic fluid ultrasound
2. Free fluid: Anechoic to low-level echo complex free pelvic fluid in the cul-de-sac, indicative of purulent debris/pus.

Final Diagnosis: Pelvic Inflammatory Disease (PID) with Pyosalpinx
Confirmed based on matching clinical findings (fever, CMT, vaginal discharge) alongside key ultrasound features (dilated tubes, hypervascularity, and complex free fluid).

Differential Diagnosis

  • Ectopic Pregnancy: Differentiate by positive β-hCG test and absence of fever; ultrasound typically reveals an adnexal mass displaying a hypervascular “ring of fire” on Doppler.
  • Appendicitis: Presents with acute right lower quadrant (RLQ) pain and fever, but characteristically lacks cervical motion tenderness or purulent vaginal discharge.
  • Ovarian Torsion: Marked by sudden, severe, unilateral pelvic pain; Doppler ultrasound demonstrates absent or severely compromised venous and arterial flow.
  • Endometriosis: Presents with chronic pelvic pain and dysmenorrhea; ultrasound may display static ground-glass endometriomas, but patients lack acute systemic signs like fever.
  • Diverticulitis: Features lower left quadrant (LLQ) pain and fever; distinct because gastrointestinal symptoms predominate.