What it is (overview)

A CT Pelvis without IV Contrast (also called a CT scan of the pelvis without contrast) is a type of diagnostic imaging test that uses X-rays and computer processing to create detailed, cross-sectional pictures of the pelvic region. The pelvis includes important structures such as the bladder, parts of the bowel/rectum, pelvic bones, blood vessels, lymph nodes, and—depending on sex—uterus and ovaries or the prostate and seminal vesicles. Because it captures thin “slices” of the body, CT can show internal anatomy more clearly than a standard X-ray.

“Without IV contrast” means no contrast dye is injected into a vein. This is sometimes preferred if contrast is not needed for the clinical question, if you have a history of contrast allergy, or if there are concerns about kidney function. Even without contrast, a CT pelvis can be very helpful for evaluating abdominal or pelvic pain, certain types of bleeding, stones, bone injury, bowel problems, and some masses.

What the results mean in plain language: A radiology specialist (radiologist) reviews the images and looks for signs of problems such as abnormal swelling, fluid collections, enlarged organs, bowel inflammation, enlarged lymph nodes, fractures, or visible masses. A “normal” result means the pelvic organs and bones appear typical, with no clear signs of an acute problem. An “abnormal” result does not automatically mean cancer—findings can reflect infection, inflammation, benign cysts, constipation, injury, or other non-cancer causes. Your clinician will interpret the report in context with your symptoms, exam, and other tests.

When & why it's usually done

Doctors commonly order a CT scan of the pelvis without IV contrast to quickly and accurately evaluate symptoms or conditions involving the pelvic organs. It may be used in emergency, inpatient, or outpatient settings, especially when a detailed look at internal structures is needed.

This test is often ordered for:

Symptoms that need further evaluation

Persistent or severe lower abdominal pain or pelvic pain, especially when the cause is unclear; pelvic pressure; unexplained tenderness; or symptoms that suggest a problem involving the bowel, bladder, or reproductive organs.

Urinary tract concerns

Evaluation of suspected urinary stones (that may be near the bladder), certain causes of blood in the urine (hematuria), urinary retention, or complications related to the bladder or urinary tract—particularly when contrast dye is not advisable.

Bowel and rectal symptoms

Assessment of suspected bowel obstruction, significant constipation with complications, diverticular disease affecting the lower bowel, or other causes of rectal/pelvic discomfort. (In some bowel conditions, IV contrast may be preferred, but non-contrast CT can still provide important information depending on the situation.)

Possible mass, tumor, or enlarged lymph nodes

When there is concern for a pelvic tumor or abnormal growth based on symptoms, physical exam, or another imaging test. A non-contrast CT can identify many masses and structural abnormalities; your clinician may recommend additional imaging (such as CT with contrast, MRI, or ultrasound) for further characterization.

Infection, inflammation, or abscess (selected cases)

To look for fluid collections, inflammatory changes, or complications from infection when IV contrast can’t be used or when the clinical question can be answered without it.

Injury or trauma

Evaluation after a fall, car accident, or other trauma to look for pelvic fractures, bleeding, or organ injury. (In trauma, contrast-enhanced CT is often preferred when safe and available; however, non-contrast imaging may be used in certain circumstances.)

Pre-operative or post-treatment assessment

To help plan procedures or evaluate complications after surgery in the pelvic region, such as unexpected pain, swelling, or suspected fluid collection.

Common diseases related to it

• Pelvic fractures and other pelvic bone injuries
• Urinary tract stones (including stones near the bladder or distal ureter)
• Bladder disorders (e.g., bladder wall thickening, bladder distention/retention, suspected structural abnormalities)
• Diverticulitis affecting the lower colon (selected cases)
• Bowel obstruction or severe constipation with complications
• Appendicitis (when the appendix is low in the pelvis or as part of broader abdominal/pelvic evaluation)
• Pelvic inflammatory conditions (where visible inflammatory changes or fluid collections may be present)
• Abscess or abnormal pelvic fluid collection (selected cases)
• Enlarged pelvic lymph nodes (which may occur with infection, inflammation, or cancer)
• Pelvic masses and tumors (benign or malignant), including involvement of reproductive organs or surrounding tissues
• Prostate enlargement or other prostate-related structural concerns (limited evaluation on non-contrast CT)
• Gynecologic conditions such as uterine fibroids or ovarian cysts (often better characterized by ultrasound or MRI, but may be seen on CT)

Health goals where it may help

• Finding the cause of ongoing or severe abdominal pain or pelvic pain to guide timely treatment
• Supporting medical diagnosis of bladder, bowel, or pelvic bone problems when symptoms are unclear
• Evaluating possible tumors or pelvic masses and helping determine next steps in care
• Monitoring known pelvic conditions over time (when your clinician determines CT is appropriate)
• Assessing complications after pelvic surgery or procedures to improve recovery planning
• Helping guide decisions about referral to specialties such as radiology, urology, gynecology, gastroenterology, or oncology
• Reducing delays in care by providing fast, detailed CT scan imaging of the pelvis when contrast dye is not an option