If you have been advised to have an abdominal scan or are trying to work out which type of imaging is right for your symptoms, you are not alone. Abdominal ultrasound and CT scanning are the two most commonly used investigations for abdominal complaints. Still, they work in entirely different ways, carry different risks, and are suited to different clinical questions. Understanding the distinction can help you have a more informed conversation with your clinician and, where appropriate, access the right scan more quickly. At RAD Clinics, we offer a full range of private abdominal ultrasound scans across our clinics in Northampton, Milton Keynes, and St Neots with no GP referral required.
What Is an Abdominal Ultrasound Scan and What Does It Show?
An abdominal ultrasound is a diagnostic imaging procedure that uses low-frequency sound waves to produce real-time images of the organs and structures within the abdomen. It is safe, non-invasive, and involves no ionising radiation, making it the recommended first-line investigation for a wide range of abdominal symptoms in line with British Medical Ultrasound Society (BMUS) guidance.
What Organs and Structures Are Included in an Abdominal Ultrasound?
A standard abdominal ultrasound assesses the liver, gallbladder,bile ducts, spleen, pancreas, kidneys, and abdominal aorta. Depending on the scan variant, the bladder and pelvic organs may also be included. At RAD Clinics, we offer three abdominal scan options to suit your clinical needs:
- Upper abdominal ultrasound: liver, gallbladder, bile ducts, pancreas, spleen, and kidneys
- Full abdominal ultrasound: upper abdominal organs plus the bladder and, where appropriate, pelvic structures
- Upper abdomen & pelvis scan: a combined assessment for patients with both upper and lower abdominal symptoms
Each scan is performed and reported by an experienced HCPC-registered sonographer.
Does an Upper Abdominal Ultrasound Show the Stomach?
The stomach is not routinely assessed during an abdominal ultrasound. Because the stomach contains gas and its walls are thin, it does not image reliably with ultrasound. If gastric pathology is suspected, such as an ulcer or tumour, an upper GI endoscopy or CT is the more appropriate investigation.
What Is the Difference Between an Upper Abdominal Ultrasound and a Full Abdominal Scan?
An upper abdominal scan focuses on the solid organs in the upper abdomen and is the appropriate choice for symptoms such as right upper quadrant pain, suspected gallstones, or abnormal liver function tests. A full abdominal scan extends coverage to include the bladder and lower abdominal structures, making it better suited to patients with more widespread or lower abdominal symptoms. If you are unsure which is right for you, our team can advise at the point of booking.
How Long Does an Abdominal Ultrasound Take?
Most abdominal ultrasound appointments at RAD Clinics take between 20 and 40 minutes, depending on the areas being assessed. A written report from our team is typically available the same day or within 24 hours.
What Is the Difference Between Abdominal Ultrasound and a CT Scan?
Ultrasound and CT are complementary technologies, and they have their own strengths and limitations. Understanding this distinction is key to knowing which investigation is right for your situation.
Ultrasound uses reflected sound waves to build images in real time. It is excellent for assessing solid organs and fluid-filled structures, is safe for repeat use, and carries no radiation risk. CT (computed tomography) uses a series of X-ray measurements processed by a computer to produce cross-sectional images of the entire abdomen. It provides broader anatomical coverage, including the bowel and is not affected by gas or body habitus, but it does involve a significant dose of ionising radiation and is considerably more expensive.
Does a CT Scan Show More Than an Abdominal Ultrasound?
In some respects, yes, but context matters. CT provides better visualisation of the bowel, retroperitoneal structures, and complex pathology across multiple organ systems simultaneously. However, for gallstones, simple cysts, renal pathology, and abdominal aortic aneurysm screening, NICE guidance identifies ultrasound as the preferred first-line modality, and ultrasound is highly accurate for these conditions, quicker to access, and involves no radiation exposure.
Is Abdominal Ultrasound Safe? Does It Use Radiation?
Abdominal ultrasound uses no ionising radiation. Sound waves are entirely safe, with no known adverse biological effects at the frequencies used in diagnostic imaging. This makes ultrasound particularly appropriate for patients who may need repeat scanning, those who are pregnant, and those who are concerned about cumulative radiation exposure. CT, by contrast, delivers a radiation dose equivalent to several hundred chest X-rays and carries a small but measurable increased risk of radiation-induced cancer with repeated use, as acknowledged by Public Health England.
Can Both an Ultrasound and CT Scan Be Needed for the Same Problem?
Yes, and this is common. Ultrasound is frequently the first investigation because it is fast, safe, and widely available. If findings are equivocal, or if further anatomical detail is required, CT may be requested as a follow-on study. At RAD Clinics, our reports include clear recommendations where additional imaging is clinically appropriate.
Can an Abdominal Ultrasound Detect a Hernia?
Ultrasound is a well-established tool for hernia assessment, though its usefulness varies depending on the type of hernia in question. Our dedicated hernia scan service is performed dynamically, with real-time assessment during the Valsalva manoeuvre (bearing down), which significantly increases diagnostic accuracy.
What Type of Hernia Can Abdominal Ultrasound Detect Most Reliably?
Dynamic ultrasound is the imaging of choice for inguinal hernias and abdominal wall hernias (including umbilical and incisional hernias). By scanning while the patient performs a Valsalva manoeuvre, the sonographer can directly visualise herniated tissue passing through a fascial defect, a finding that may not be present at rest. This makes ultrasound particularly valuable for patients with intermittent or position-dependent symptoms where examination alone may be inconclusive.
Can an Ultrasound Miss a Hiatal Hernia?
A hiatus hernia, where part of the stomach protrudes through the diaphragm into the chest, is generally not well demonstrated on standard abdominal ultrasound. Endoscopy (gastroscopy) is the gold standard investigation for suspected hiatus hernia, as it directly visualises the gastro-oesophageal junction. CT can also demonstrate a hiatus hernia incidentally. If your symptoms suggest a hiatus hernia specifically, discuss the most appropriate investigation with your GP or gastroenterologist.
Is a Separate Hernia Scan Better Than an Abdominal Ultrasound for Suspected Groin Hernia?
For suspected inguinal or femoral hernia, a dedicated dynamic ultrasound hernia scan will typically be more diagnostically useful than a standard abdominal ultrasound. This is because a general abdominal scan is not routinely performed dynamically and may not focus sufficient attention on the groin region. If groin hernia is your primary concern, booking a dedicated hernia ultrasound scan is the more targeted approach.
Can an Abdominal Ultrasound Detect Ovarian Cysts and Gynaecological Conditions?
This depends partly on cyst size and the type of scan performed. A transabdominal ultrasound, where the probe is applied to the abdomen, can identify larger ovarian cysts and significant pelvic pathology, but its sensitivity for smaller cysts, endometrial assessment, and early gynaecological pathology is limited.
Will an Abdominal Ultrasound Show Ovarian Cysts?
Larger ovarian cysts (typically those measuring several centimetres or more) are often visible on a transabdominal ultrasound, particularly when the bladder is well-filled and acts as an acoustic window into the pelvis. However, BMUS guidance is clear that transvaginal ultrasound is significantly more sensitive for the detection of smaller ovarian cysts, polycystic ovarian morphology (PCOM), endometrial pathology, and early-stage gynaecological conditions.
What Is the Difference Between a Transabdominal and Transvaginal Ultrasound for Ovarian Cysts?
A transabdominal ultrasound scans the pelvis through the anterior abdominal wall and requires a full bladder. A transvaginal ultrasound uses a slim internal probe positioned close to the pelvic organs, producing substantially higher-resolution images of the ovaries and uterus. The two approaches are complementary and are often used together in a comprehensive pelvic assessment.
Should I Book an Abdominal Scan or a Pelvic Scan if I Have Suspected Ovarian Cysts?
If your primary concern is ovarian cysts, endometriosis, or other pelvic pathology, a dedicated Women’s Health Scan, which includes transvaginal ultrasound, will give you the most clinically useful result. An abdominal or full abdominal scan may detect incidental pelvic findings, but it is not a substitute for dedicated pelvic assessment where gynaecological pathology is the clinical question.
Can an Abdominal Ultrasound Detect Kidney Stones?
Abdominal ultrasound can identify kidney stones and related complications, but its accuracy for this indication depends on where the stones are located. NICE Clinical Guideline identifies ultrasound as the recommended first-line imaging investigation for suspected renal colic.
Is an Abdominal Scan or a Dedicated Renal Scan Better for Kidney Stones?
Ultrasound reliably detects hydronephrosis, the swelling of the kidney that occurs when urine flow is obstructed and can identify stones within the kidney itself, particularly those larger than a few millimetres. However, small stones in the ureter (the tube between the kidney and bladder) can be difficult to visualise with ultrasound due to overlying bowel gas. For patients where ureteric stone disease is the primary clinical question, a dedicated urinary tract scan or KUB ultrasound offers more targeted assessment of the kidneys, ureters, and bladder. CT KUB (non-contrast CT of the kidneys, ureters, and bladder) remains the most sensitive investigation for confirming ureteric calculi where clinical suspicion is high.
What Else Can an Abdominal Ultrasound Show in the Kidneys?
Beyond stones and hydronephrosis, abdominal ultrasound provides valuable assessment of renal cysts, changes in kidney size and echogenicity (which may indicate chronic kidney disease), renal masses requiring further characterisation, and the blood flow within the kidneys when Doppler imaging is applied. It is also used in the routine monitoring of known renal pathology.
How Much Does a Private Abdominal Ultrasound Cost and What Is Included?
For full pricing information, please visit our Fee Guide.
Do I Need a GP Referral to Book a Private Abdominal Ultrasound at RAD Clinics?
No GP referral is required. You can self-refer directly to RAD Clinics for an abdominal ultrasound scan. However, if you have been referred by your GP or a specialist and have relevant clinical information such as blood test results or previous imaging, please bring this to your appointment, as it will help our sonographer and radiologist provide the most useful report.
How Should I Prepare for an Upper Abdominal Ultrasound?
For an upper abdominal scan, you will be asked to fast for four to six hours beforehand. This allows the gallbladder to fill with bile, making it much easier to identify gallstones and assess the bile ducts. You should continue to take any regular medication with a small sip of water. For a full abdominal or pelvic scan, you may also be asked to arrive with a full bladder. Detailed preparation instructions are provided at the time of booking.
How Quickly Will I Receive My Abdominal Scan Report?
At RAD Clinics, reports from our team are typically available the same day or within 24 hours of your scan. You will receive a written report that you can share with your GP or specialist. Where urgent or unexpected findings are identified, our team will contact you directly.
Where Can I Get a Private Abdominal Ultrasound Near Me?
RAD Clinics operates private abdominal ultrasound services across three locations: Northampton, Milton Keynes, and St Neots, serving patients across Northamptonshire, Buckinghamshire, Bedfordshire, and the surrounding areas. To find your nearest clinic or to book a private abdominal ultrasound, visit our contact and booking page.
Common Questions About Abdominal Ultrasound
Is a CT scan more accurate than ultrasound?
A CT scan provides greater detail than an abdominal ultrasound for many abdominal conditions, particularly bowel disease, internal injuries, and small abnormalities. An abdominal ultrasound remains the preferred first-line investigation for many liver, gallbladder, kidney, and pelvic conditions.
What shows up on a CT scan but not ultrasound?
A CT scan detects small bowel abnormalities, tiny kidney stones, internal bleeding, air-filled structures, and certain cancers more clearly than an abdominal ultrasound. CT also provides detailed cross-sectional images of the entire abdomen and pelvis.
Can a CT scan detect all abdominal problems?
No, a CT scan does not detect every abdominal problem. Some conditions require ultrasound, MRI, endoscopy, blood tests, or clinical assessment to reach an accurate diagnosis and guide appropriate treatment.
What cannot be seen on an abdominal ultrasound?
An abdominal ultrasound does not clearly show organs obscured by bowel gas, small-bowel abnormalities, or very small lesions deep within the abdomen. Image quality is also reduced in some patients due to body habitus or overlying intestinal gas.
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