PID and Endometriosis Imaging

Quick Answer: PID = thick tubal walls, TOA complex, free fluid. Hydrosalpinx = dilated tubular structure with incomplete septa. Endometrioma = ground-glass homogeneous cyst. DIE = hypoechoic nodules in rectovaginal septum.

Pelvic Inflammatory Disease (PID)

Ultrasound is not sensitive for early mild PID—diagnosis is often clinical. Imaging adds value when severe disease or complication suspected.

Worked Scenario: TOA vs Ectopic

Fever, pelvic pain, complex adnexal mass with thick-walled tube. Positive pregnancy test → ectopic first. Negative hCG with fever → TOA more likely—urgent medical/surgical management.

Pyosalpinx vs Hydrosalpinx

Incomplete septa (folds) on cross-section distinguish tubal fluid from ovarian cyst—sausage + folds = tube.

Hydrosalpinx before IVF reduces implantation success—may need salpingectomy or occlusion.

Endometriosis Imaging

Endometrioma

• Homogeneous low-level internal echoes ("ground glass")
• No papillary vascular solid areas (if present, think neoplasm)
• Often bilateral

Deep Infiltrating Endometriosis (DIE)

Hypoechoic nodules in:

• Rectovaginal septum
• Uterosacral ligaments
• Bowel wall ("mushroom sign"—loss of wall layers)

Tenderness with probe pressure supports clinical correlation. US maps lesions for surgeon—does not replace ASRM surgical staging.

Fitz-Hugh-Curtis Syndrome

Perihepatitis in PID—right upper quadrant pain, perihepatic adhesions ("violin string"), perihepatic fluid on RUQ ultrasound. Overlap content but appears in registry clinical vignettes.

PID vs Other Causes of Pelvic Pain

Post-Treatment Follow-Up

TOA may shrink on antibiotics—document size trend. Residual hydrosalpinx may persist after PID—infertility implication.

Exam Traps

• Early PID with normal US called "rules out PID" (false—clinical diagnosis stands)
• Endometrioma vs hemorrhagic cyst without follow-up plan
• Hydrosalpinx mistaken for ovarian cyst (look for folds, separate from ovary)
• Endometrioma with solid papillary nodule still called endometrioma (think malignancy)
• Missing TOA in febrile patient with complex adnexal mass

PID and endometriosis items reward tubal morphology recognition—when you see a sausage-shaped fluid collection with incomplete septa, think fallopian tube first.

Clinical Diagnosis vs Imaging in PID

Mild PID often has normal pelvic ultrasound—negative imaging does not exclude diagnosis. Severe PID and TOA show imaging findings. Sonographer supports but does not replace clinical criteria (cervical motion tenderness, fever, discharge). Report complex adnexal mass with thick-walled tube in febrile patient as suspicious for TOA.

Tubo-Ovarian Abscess Management Imaging

TOA may require drainage (transvaginal or CT-guided) vs surgery. Ultrasound documents size, complexity, and response to antibiotics on follow-up. Ruptured TOA shows free fluid, debris, peritoneal irritation—surgical emergency.

Fitz-Hugh-Curtis and Upper Abdominal Pain

Perihepatitis in PID causes right upper quadrant pain—perihepatic adhesions ("violin string sign") on RUQ ultrasound. Registry clinical vignette: young woman with PID symptoms and RUQ pain—answer links Fitz-Hugh-Curtis not cholecystitis alone.

Deep Infiltrating Endometriosis (DIE) Mapping

DIE sites: uterosacral ligaments, rectovaginal septum, rectosigmoid wall, bladder. Bowel endometriosis shows hypoechoic nodule distorting wall layers with "mushroom" sign. Tenderness with probe pressure supports diagnosis. Maps surgical approach—does not replace histology.

Superficial vs Ovarian Endometriosis

Superficial peritoneal endometriosis is not reliably seen on standard ultrasound—laparoscopy gold standard. Endometrioma is ovarian manifestation—homogeneous ground-glass cyst. Do not report "no endometriosis" when only endometrioma was excluded.

PCOS Overlap (Recognition)

Polycystic ovary morphology: ≥20 follicles per ovary (2–9 mm) or ovarian volume >10 cc with peripheral distribution—requires clinical hyperandrogenism or oligo-anovulation for PCOS diagnosis. Sonographer describes morphology; clinician diagnoses PCOS.

Chronic Pelvic Pain Differential

Ultrasound rules in structural causes; normal scan does not explain all chronic pain.

Hydrosalpinx Before IVF

Hydrosalpinx reduces IVF implantation—may need salpingectomy or proximal occlusion. TOA appears as complex adnexal mass merging tube and ovary with fever and thick tubal walls.

Endometrioma vs Malignancy

Endometrioma shows ground-glass homogeneous echoes without solid vascular nodules. Solid papillary projections in adnexal mass require malignancy workup, not endometrioma label alone.

PID vs Ruptured Cyst

Ruptured hemorrhagic cyst causes acute pain and free fluid often without fever. PID/TOA more often includes fever, thick-walled tube, and complex inflammatory mass. Cogwheel sign is thickened fallopian tube cross-section with incomplete septa.

Deep Endometriosis Sites

Deep infiltrating endometriosis may involve rectovaginal septum, uterosacral ligaments, and bowel wall with hypoechoic nodules—tenderness with probe pressure supports clinical correlation.

Hydrosalpinx Recognition

Hydrosalpinx appears as sausage-shaped tubular fluid with incomplete septal folds, separate from ovary. Chronic PID may leave hydrosalpinx affecting IVF outcomes—document on baseline infertility imaging before embryo transfer.

Endometrioma Follow-Up

Endometrioma typically persists on follow-up unlike hemorrhagic cyst which often resolves in 6–8 weeks. Solid papillary nodule within cystic mass requires malignancy workup, not routine endometrioma surveillance.