CT ABDOMEN AND PELVIS PLAIN

CT ABDOMEN AND PELVIS PLAIN is a computed tomography examination that produces detailed cross-sectional images of the abdomen and pelvis without intravenous contrast. It is also called a non-contrast CT abdomen and pelvis. The word plain indicates that an intravenous contrast agent is generally not administered during the examination.

The scanner uses X-rays and advanced computer processing to create thin images of the internal organs, blood vessel regions, bones and soft tissues. These images can be reconstructed in axial, coronal and sagittal planes, allowing the radiologist to examine the abdomen and pelvis from several anatomical directions.

The scan may display the liver, gallbladder, spleen, pancreas, kidneys, adrenal glands, stomach, bowel, urinary bladder, pelvic organs, major blood vessel regions, lymph-node regions, abdominal wall, spine, pelvic bones and surrounding soft tissues. However, the visibility and characterisation of an abnormality depend on its type because many conditions are assessed more accurately with intravenous contrast, ultrasound, MRI or another dedicated examination.

A plain CT is particularly valuable for detecting most kidney and ureteric stones, calcifications, bowel gas patterns, selected forms of obstruction and some causes of acute abdominal or pelvic pain. It may be recommended when symptoms are severe, when ultrasound findings are inconclusive or when the doctor requires more detailed anatomical information.

Benefits of the Test

• Provides detailed cross-sectional images of the abdomen and pelvis.
• Detects most kidney and ureteric stones with high sensitivity.
• Can identify urinary obstruction and swelling of the kidneys.
• May demonstrate bowel obstruction and abnormal bowel dilatation.
• Helps detect calcification within organs, vessels or abnormal lesions.
• May identify selected causes of abdominal, flank or pelvic pain.
• Usually does not require an intravenous contrast injection.
• Is quick, non-invasive and useful during emergency assessment.
• Allows images to be reconstructed in multiple anatomical planes.
• May provide additional information when ultrasound results are inconclusive.

Why Doctors Recommend This Test

A doctor may recommend CT Abdomen and Pelvis Plain when a patient has severe or persistent abdominal pain, flank pain, pelvic pain, blood in the urine, repeated vomiting, abdominal distension or symptoms suggesting urinary stones. The scan may help determine the location, number and approximate size of kidney or ureteric stones and whether they are causing urinary obstruction.

The examination may also be used when bowel obstruction is suspected. CT can demonstrate dilated bowel loops, abnormal gas patterns, a possible transition point and selected complications. However, oral or intravenous contrast may be required in some patients to answer a specific bowel-related clinical question.

A plain CT may identify calcifications in the urinary tract, gallbladder, pancreas, blood vessels or abnormal lesions. Calcified gallstones may be visible, but many gallstones are not clearly demonstrated on CT and are usually evaluated more effectively with ultrasound.

The scan may also reveal certain hernias, enlarged organs, fluid collections, large masses, fractures or postoperative changes. However, many liver, pancreatic, kidney, bowel and pelvic abnormalities cannot be fully characterised without contrast. The radiologist may recommend contrast-enhanced CT, ultrasound or MRI after reviewing the plain images.

A non-contrast CT may be selected when intravenous contrast is not necessary for the clinical question or cannot be administered. The decision should be based on the patient's symptoms, medical history, previous imaging and the condition being investigated.

Preparation Before Test

Preparation is usually minimal, but the exact instructions depend on the clinical indication and imaging protocol. Fasting may not be required for every plain CT abdomen and pelvis. However, the diagnostic centre may request that the patient avoid food for several hours if additional imaging or contrast could become necessary.

Patients should follow the instructions provided by Focus Diagnostics. Regular medicines can generally be continued unless the referring doctor gives different advice. Patients should not discontinue prescribed medication without consulting a qualified healthcare professional.

Wear comfortable clothing without metal fasteners whenever possible. Jewellery, belts, coins, keys, mobile phones and other metallic objects must be removed from the scanning region because they may produce image artefacts and reduce diagnostic quality. The patient may be asked to change into a gown.

Carry the doctor's referral and provide previous CT, MRI, ultrasound, X-ray, laboratory and surgical records. Comparison with previous studies can help the radiologist determine whether an abnormality is new, stable or changing.

Inform the radiology team if you are pregnant or could be pregnant. Also disclose recent surgery, trauma, fever, known kidney stones, urinary symptoms, bowel symptoms, severe pain or an inability to lie flat. Female patients should provide the date of their last menstrual period when requested.

Because intravenous contrast is not normally used, kidney-function testing and contrast-allergy screening are generally unnecessary. If the protocol is changed to include contrast after medical review, kidney-function assessment, allergy history and additional preparation may be required.

Normal Reporting Time

The actual image acquisition is usually completed within a few minutes. Including registration, preparation, positioning and image-quality verification, the complete appointment commonly takes approximately 10 to 20 minutes. Patients who need assistance or additional imaging may require more time.

The radiologist's report is generally available on the same day or within 24 hours. The exact turnaround time depends on clinical urgency, radiologist availability, comparison with previous examinations and whether further image reconstruction or additional imaging is necessary.

Urgent or critical findings may be communicated to the referring doctor sooner. The CT technologist performs the examination but does not usually provide the final medical interpretation. A qualified radiologist reviews the images and prepares the formal report.

Who Should Take This Test?

This scan may be appropriate for people with suspected kidney or ureteric stones, severe flank pain, unexplained blood in the urine, possible urinary obstruction, persistent abdominal pain or selected causes of pelvic pain. It may also be used when bowel obstruction, calcification, abdominal distension or certain emergency abnormalities are suspected.

People with sudden severe abdominal pain, rigid abdomen, persistent vomiting, inability to pass stool or gas, fainting, blood in vomit or stool, high fever or rapidly worsening symptoms should seek urgent medical attention. These symptoms may represent a medical emergency and should not be managed by waiting for a routine scan appointment.

The examination should be performed on medical advice because it uses ionising radiation. Ultrasound or MRI may be preferred in certain situations, particularly for children, pregnant individuals and patients who require repeated imaging. The referring doctor and radiologist determine which examination is most suitable.

A plain CT is not intended as a routine screening examination for people without symptoms or a clinical indication. It should be selected when the expected diagnostic benefit is greater than the potential radiation risk.

Detailed Information

During the examination, the patient lies on a motorised table, usually on the back. The technologist positions the abdomen and pelvis within the scanning range and performs a planning image. The table then passes through the short circular opening of the CT scanner while images are acquired.

The scanner rotates an X-ray source around the body and records information from multiple angles. Computer software reconstructs this information into thin cross-sectional images. The patient must remain still and may be asked to hold their breath briefly because breathing or body movement can blur the images.

The procedure is non-invasive and painless. The technologist operates the equipment from an adjoining control area and can see, hear and communicate with the patient during the examination. No contrast-related warmth or metallic taste is expected during a routine plain scan because intravenous contrast is not administered.

A non-contrast CT is highly sensitive for most urinary stones. It can show the stone's location, approximate size and density and may demonstrate hydronephrosis or hydroureter caused by obstruction. Some medication-related or unusual stones may be less conspicuous, and the clinical significance of a stone must be determined by the treating doctor.

The examination can demonstrate bowel dilatation, abnormal gas patterns and selected signs of bowel obstruction. It may also show free air, fluid, hernias or large structural abnormalities. Additional contrast-enhanced imaging may be required to evaluate bowel-wall enhancement, inflammation, infection, blood supply or complications.

The liver, pancreas, spleen, kidneys and pelvic organs can be visualised, but many lesions cannot be fully characterised on a plain scan. Intravenous contrast is often required to assess organ enhancement, blood vessels, infection, inflammation, trauma or suspected tumours. Ultrasound may be more appropriate for gallstones, gynaecological conditions and selected superficial structures.

A report stating that there is no acute abnormality generally means the examination did not identify an urgent structural finding that explains the symptoms. It does not exclude every gastrointestinal, urinary, vascular or pelvic condition. Small mucosal lesions, early inflammation and certain functional disorders may not be visible on CT.

Depending on the findings and symptoms, the doctor may recommend contrast-enhanced CT, ultrasound, MRI, endoscopy, colonoscopy, urine analysis, kidney-function tests, liver-function tests or specialist consultation. The report should always be interpreted with the patient's symptoms, medical history and clinical examination.

CT uses ionising radiation. The dose varies according to patient size, scan length, equipment and protocol. Modern scanners use dose-optimisation methods, but unnecessary repeat examinations should still be avoided. Patients should inform the radiology team about recent CT examinations.

Pregnant patients or those who may be pregnant must notify the radiology team before the scan. CT of the abdomen and pelvis is generally avoided during pregnancy unless the expected medical benefit justifies the potential radiation risk and alternative imaging cannot answer the clinical question.

After a routine plain CT, most patients can immediately return to their normal activities, diet and medicines. No special recovery period is usually required. Patients should review the final report with the referring doctor, especially if symptoms persist or worsen.