Does Pelvic Inflammatory Disease Show on Ultrasound? Signs and Diagnosis Explained

What is Pelvic Inflammatory Disease (PID)?

Pelvic Inflammatory Disease (PID) is a bacterial infection that causes inflammation of the upper female genital tract. It usually spreads upward from an infection in the lower genital tract, such as the vagina or cervix.

PID commonly affects the:

• Uterus
• Fallopian tubes
• Ovaries

It is most often associated with untreated sexually transmitted infections (STIs), particularly chlamydia and gonorrhoea, and can develop in a significant proportion of such cases if left untreated.

Also Read: What are the Symptoms of PCOD?

Risk factors of Pelvic Inflammatory Disease (PID)

Increased chances of PID are associated with: 

• Multiple sexual partners
• Presence of untreated STI
• Previous history of PID
• Is under 25 years of age and sexually active
• Douching (washing out the vagina with fluids)
• The first few weeks following insertion of the Intra-Uterine Device (IUD)

Symptoms of Pelvic Inflammatory Disease

PID is often underdiagnosed due to variations and overlapping of symptoms with other conditions. The major symptoms include:

• Acute pain in the lower abdomen/ pelvis.
• Painful menstruation with heavy bleeding.
• Genital pain during or after intercourse is known as dyspareunia.
• Vaginal discharge.
• Urinary problems accompanied by foul-smelling urine.

Sometimes there are no apparent symptoms, which highlights the importance of regular check-ups and screening.

Does Pelvic Inflammatory Disease show on Ultrasound?

Yes, PID can show up on a transvaginal ultrasound, where the probe is inserted into the vagina to provide detailed real-time imaging. It may help detect subtle changes, such as free fluid in the pouch of Douglas and abnormalities of the reproductive tract, thereby enhancing diagnostic accuracy. In early PID, vague signs such as indistinct uterine borders or enhanced visualisation of pelvic tissues may be seen.

Since transvaginal imaging involves direct contact with the pelvic organs, it can be correlated with physical exams by eliciting pain upon palpation of the involved area.

However, this cannot be detected consistently, particularly in early or mild infections. Hence, ultrasound imaging does not rule out PID and may require additional tests and symptoms to arrive at a final diagnosis.

Also Read: Why Endometriosis Happens

How does Pelvic Inflammatory Disease (PID) look on ultrasound?

Ultrasound may reveal indirect signs of inflammation or complications due to PID. These include:

• Thickened fallopian tubes due to inflammation.
• Fluid-filled by infection (Pyosalpinx/ Hydrosalpinx).
• Tubo-ovarian pockets, where a pus pocket forms between the ovaries and the fallopian tubes.
• Inflammation and thickening of the endometrial layer.

When is an ultrasound required for PID?

An ultrasound is used when symptoms are unclear, severe or when complications are suspected.

It is usually recommended in the following situations:

• Severe or persistent pelvic pain
• To check for complications such as a tubo-ovarian abscess
• When the diagnosis is uncertain
• To rule out other possible conditions

Ultrasound can help distinguish PID from conditions with similar symptoms, such as:

• Ectopic pregnancy (pregnancy outside the womb)
• Ovarian cysts
• Endometriosis
• Appendicitis

Advantages of Transvaginal Ultrasound (TVS)

Transvaginal ultrasound provides various advantages over other imaging modalities, such as:

• Direct and dynamic real-time observation of pelvic structures 
• Spotting characteristic signs of PID
• Does not involve exposure to radiation
• Inexpensive and readily available

Diagnosis using TVS has proven highly accurate, with sensitivity reaching 81%. The imaging capabilities of TVS enable it to identify the disease before complications develop effectively.

How is Pelvic Inflammatory Disease (PID) Diagnosed?

Diagnosis of PID is indicated in all sexually active females, whether they experience abdominal pain and symptoms or not. 

Medical history and physical examination:

• Patterns of pain
• History of past infections
• Sexual history

Pelvic exams:

• Uterine or adnexal tenderness 
• Presence of abnormal discharge

Lab tests:

• Swab tests for Sexually Transmitted Diseases (STIs)
• Blood tests for markers of infections

According to the Centers for Disease Control and Prevention (CDC), diagnostic features are required to enhance the sensitivity and specificity of the diagnosis.

• Oral temperature ≥ 101 F (≥ 38.3° C)
• Mucopurulent discharge from the cervix
• High levels of White blood cells in vaginal secretions
• Increased levels of C-reactive protein
• Increased Erythrocyte sedimentation rate
• Laboratory confirmation of cervical Neisseria gonorrhoeae or Chlamydia trachomatis

Is Pelvic Inflammatory Disease curable?

Yes, PID can be cured if detected early and treated effectively with antibiotics. With timely treatment:

• Infection can be eliminated.
• Symptoms may improve.
• Further complications can be avoided.

Treatment includes:

• Combinations of oral antibiotics.
• Intravenous medications.
• Treatment of sex partners to avoid reinfection.

Patients show improvement within < 3 days of administration of antibiotics.

What happens if Pelvic Inflammatory Disease (PID) is left untreated?

Untreated PID can lead to several complications that may affect the ability to conceive, such as:

• Development of tubo-ovarian abscess and perihepatitis
• Long-term pain
• Scarring of the reproductive organs
• Infertility, regardless of the presence or absence of symptoms
• Tubal damage leading to ectopic pregnancy

It has also been associated with disease recurrence if left untreated.

When should you seek medical advice?

You should seek immediate medical advice if you experience: 

• Persistent pain in the pelvis or abdomen
• Fever with vaginal discharge
• Painful sex
• Foul-smelling discharge

Conclusion

While Pelvic Inflammatory Disease (PID) can sometimes be detected on ultrasound (USG), this depends on the stage of the condition. A normal or inconclusive ultrasound does not rule out PID, which is why diagnosis relies on a combination of symptoms, physical examination and appropriate tests.

What this means for you is that persistent pelvic pain, unusual discharge or fertility concerns should not be ignored, even if initial imaging appears normal. Early evaluation and timely treatment play a key role in preventing long-term complications, including damage to the reproductive organs.

If something feels off, getting it checked sooner rather than later can make a significant difference to your reproductive health and overall well-being.