Did you know that over 80 million ultrasounds and CT scans are performed each year in the United States alone? Selecting the appropriate body imaging technique can make a significant difference in diagnosing and managing your health condition.
At Smart Scan Medical Imaging, we want you to feel fully informed and supported throughout your care journey. Understanding the differences between ultrasound and CT scans, including how they work, when they’re used, and how they compare to MRI, can help you make the best decision for your health needs. Book your appointment today.
Keep reading to learn when ultrasound and CT imaging are typically used, and why MRI at Smart Scan might be the ideal choice for your imaging needs.
Understanding Ultrasound
Ultrasound is a non-invasive diagnostic imaging technique that uses high-frequency sound waves to produce real-time images of structures inside the body. It’s commonly used to evaluate soft tissues and blood flow without exposing patients to radiation.
This type of imaging is ideal for examining organs such as the liver, kidneys, bladder, and reproductive system, as well as assessing fetal development during pregnancy. It can also help detect fluid buildup, cysts, or blockages in the body.
How does it work?
Ultrasound imaging uses a handheld device called a transducer that emits sound waves into the body. These waves bounce off internal structures and return to the transducer, which then converts them into images on a monitor. This real-time view allows providers to assess motion and function, such as blood flow or fetal heartbeat, on the spot.
Because it doesn’t use ionizing radiation, ultrasound is considered safe for a wide range of patients, including children and those who are pregnant.
Conditions best suited for ultrasound
Ultrasound is typically recommended for:
- Pelvic pain, especially in women
- Pelvic inflammatory disease (PID)
- Acute pelvic pain in non-pregnant and pregnant patients
- Monitoring pregnancy and fetal development
- Diagnosing gallstones, kidney stones, or urinary issues
- Evaluating blood vessels (Doppler ultrasound)
- Guiding fluid drainage or tissue biopsies
This diagnostic imaging method is often the first step when evaluating soft tissue concerns or fluid-filled structures.
Understanding CT Scans
A CT scan (short for computed tomography) is a highly advanced body scanning type that combines multiple X-ray images taken from different angles to generate detailed cross-sectional images of the body. It’s especially useful for evaluating internal injuries, detecting disease, and guiding treatment decisions.
CT scans are more comprehensive than traditional X-rays and offer sharper, more defined images—especially useful in urgent or complex diagnostic cases. While they involve ionizing radiation, the diagnostic benefit often outweighs the risk when used appropriately.
How does it work?
During a CT scan, the patient lies on a motorized table that moves through a circular scanner. As the scanner rotates, it captures a series of X-ray images. A computer then compiles these into detailed, 3D representations of internal organs, bones, and tissues.
In some cases, a contrast agent (or contrast dye) may be used to highlight certain areas, such as blood vessels or inflammation, improving the accuracy of the scan.
Conditions best suited for CT scans
CT scans are ideal when more detailed images are needed, particularly for:
- Acute abdominal pain and suspected internal bleeding
- Head injuries and trauma
- Detection and monitoring of cancer, tumors, or infections
- Evaluation of chest pain, lung conditions, or pulmonary embolism
- Assessing complex bone fractures or spinal problems
- Guiding procedures such as biopsies or tumor ablations
The ability to create detailed images compared across multiple angles makes CT ideal for comprehensive internal evaluation.
Ultrasound vs. CT Scans: Key Differences
While both ultrasound and CT scans are essential diagnostic imaging techniques, they differ significantly in how they work, what they show best, and how they are used in medical care. Understanding these key differences can help you better understand why your provider might choose one over the other—or recommend both for a more complete evaluation.
Resolution (Image Detail)
One of the most important distinctions between the two imaging techniques is their level of image resolution.
- CT scans provide extremely detailed, cross-sectional images of internal structures, including bones, organs, and blood vessels. They are ideal for detecting small abnormalities, complex anatomy, or subtle signs of disease.
- Ultrasounds, on the other hand, excel at visualizing soft tissues and fluid-filled structures in real time but offer less spatial resolution than CT. They are not as effective for imaging air-filled or bony areas due to sound wave interference.
If your provider needs high-definition imaging to evaluate deeper or more complex areas, a CT scan is typically preferred. For real-time views of soft tissue or movement (like blood flow), ultrasound may be the better fit.
Safety
When considering any diagnostic imaging technique, radiation exposure is an important factor.
- Ultrasound imaging is completely free of radiation, making it the safest option, especially for children, pregnant patients, or individuals needing multiple scans.
- CT scans use ionizing radiation, which is carefully calibrated and controlled to minimize risk. While the amount is small, it’s always considered in balance with the potential benefit of obtaining accurate diagnostic information.
Ultrasound is considered safer overall due to the absence of radiation. CT scans are used when the benefit of detailed imaging outweighs the minimal radiation exposure.
Cost and Accessibility
Cost is another practical consideration when comparing CT scans versus ultrasounds.
- Ultrasounds are typically more affordable and widely available. The machines are portable and can even be used at the bedside for patients who cannot be transported easily.
- CT scans, while more expensive, offer a higher degree of diagnostic accuracy for certain conditions and are most often used in hospitals or advanced imaging centers.
Ultrasounds are generally more accessible and budget-friendly. CT scans, though higher in cost, deliver detailed images that may be critical in diagnosing complex issues.
When Both May Be Used
In some cases, your provider may recommend both ultrasound and CT to obtain a full picture. For example:
- A patient with acute abdominal pain might receive an ultrasound scan to rule out gallbladder disease, followed by a CT scan if the cause remains unclear.
- A woman experiencing acute pelvic pain may undergo an ultrasound to assess reproductive structures, with a CT added to evaluate surrounding organs or complications.
Using both imaging techniques allows radiologists to correlate findings and provide a more accurate diagnosis.
How Providers Decide Between Ultrasound and CT
Choosing between a CT scan and an ultrasound depends on your symptoms, medical history, and what your provider needs to see. Each imaging type has specific strengths based on the area of the body being examined and the urgency of the situation.
Here’s how providers typically decide:
- For soft tissue concerns or pregnancy-related imaging: Ultrasound is often the preferred first step. It’s ideal for evaluating reproductive organs, monitoring fetal development, and examining conditions like pelvic inflammatory disease or ovarian cysts. The lack of radiation exposure makes it a safer choice for these situations.
- For suspected trauma, internal bleeding, or infection: CT scans provide highly detailed images that help assess injuries to organs, bones, or blood vessels, especially in emergency settings. When the cause of acute abdominal pain is unclear or a comprehensive internal view is needed quickly, CT is often the best option.
- When real-time imaging is required: In procedures such as fluid drainage or biopsies, ultrasound provides live imaging that allows providers to visualize needle placement and surrounding anatomy on the spot.
- When maximum image clarity is essential: If your provider needs to examine areas that are difficult to visualize (e.g., deep-seated organs or complex bone structures), a CT scan may be ordered to capture detailed images compared to what ultrasound can provide.
Choosing between an ultrasound, CT, or MRI depends on your symptoms, medical history, and diagnostic goals. At Smart Scan, we specialize in MRI, offering a safe, detailed imaging option when real-time views of soft tissues, joints, brain, spine, and other areas are needed.
When MRI May Be a Better Choice
While ultrasound and CT scans are excellent diagnostic tools, there are times when an MRI (Magnetic Resonance Imaging) offers the best clarity and detail, especially for soft tissue, brain, spine, and joint imaging.
MRI provides high-resolution images without any radiation exposure, making it a safe and powerful tool for diagnosing a wide range of conditions, including:
- Brain and spinal cord issues
- Soft tissue injuries, such as ligament and tendon tears
- Joint and musculoskeletal disorders
- Tumor detection and monitoring
- Complex abdominal or pelvic conditions where more precise imaging is needed
At Smart Scan Medical Imaging, we currently specialise exclusively in advanced MRI services at our Eau Claire, Weston, and Madison locations. While we do not offer ultrasound or CT scans at this time, our GE Voyager 1.5T Wide Bore MRI scanner provides superior image quality with a comfortable patient experience. If your doctor recommends MRI, Smart Scan delivers safe, accurate, and patient-focused imaging care.
Why Choose Smart Scan?
At Smart Scan, we focus on accuracy, safety, and patient comfort using trusted technology and clinical expertise. Here's what sets us apart:
- Comfort-Focused Technology: Our GE Voyager 1.5T Wide Bore MRI scanner features a more open, spacious design than traditional machines, helping to ease claustrophobia and create a more relaxed experience.
- Expertise You Can Trust: Our subspecialty-trained radiologists bring years of advanced training and experience to every diagnosis, providing you with confidence and peace of mind.
- Compassionate Care: From check-in to post-scan support, our team is dedicated to creating a calm, welcoming environment where your questions and concerns are always heard.
- Timely and Accurate Results: We understand the stress that waiting can bring. That’s why we prioritize delivering clear, accurate imaging results as efficiently as possible.
We understand that medical imaging can be stressful, so we prioritize your comfort and safety. Our team provides clear, supportive guidance from scheduling your appointment to sharing your results.
Choose Confidence in Diagnostic Imaging at Smart Scan
Every diagnostic decision begins with selecting the right imaging. At Smart Scan Medical Imaging, we currently specialise exclusively in advanced MRI services at our Eau Claire, Weston, and Madison locations. While we do not offer ultrasound or CT scans at this time, our GE Voyager 1.5T Wide Bore MRI scanner provides superior image quality with a comfortable patient experience.
Schedule your MRI imaging appointment inEau Claire, Weston, or Madison today. Call (855) 694-3300 or request an appointment online to get started with care you can trust.
