Ultrasound Imaging Guide: What to Expect, How to Prepare & Understanding Results

Ultrasound imaging, also called sonography, uses high-frequency sound waves to create images of the inside of your body. Unlike X-rays and CT scans, ultrasound uses no radiation, making it one of the safest imaging technologies available.

Think of it like this: The ultrasound machine sends sound waves into your body. These waves bounce off your organs and tissues, creating echoes. The machine detects these echoes and converts them into images that appear on a monitor.

What makes ultrasound special:

• No radiation—completely safe, even for developing fetuses
• Real-time imaging—shows movement (like a beating heart or moving baby)
• Painless and non-invasive—no needles (usually) and no incisions
• Widely available—most hospitals and clinics have ultrasound
• Relatively inexpensive—compared to CT and MRI
• No known risks—when performed by trained professionals

Your healthcare provider may recommend an ultrasound for many reasons:

Common Uses

Abdominal Ultrasound:

• Evaluating the liver, gallbladder, pancreas, spleen, and kidneys
• Diagnosing gallstones
• Finding causes of abdominal pain
• Assessing organ size and structure
• Guiding biopsies of abdominal organs

Pelvic Ultrasound:

• Evaluating the uterus and ovaries in women
• Checking the prostate in men
• Diagnosing fibroids, ovarian cysts, and other gynecological problems
• Finding causes of pelvic pain
• Guiding procedures like egg retrieval for IVF

Pregnancy Ultrasound (Obstetric):

• Confirming pregnancy and due date
• Monitoring fetal growth and development
• Detecting fetal abnormalities
• Determining baby's position
• Evaluating the placenta and amniotic fluid

Breast Ultrasound:

• Evaluating breast lumps found on exam or mammogram
• Distinguishing fluid-filled cysts from solid masses
• Guiding breast biopsies
• Additional imaging for dense breasts

Thyroid Ultrasound:

• Evaluating thyroid nodules
• Guiding thyroid biopsies
• Monitoring thyroid disease

Musculoskeletal Ultrasound:

• Evaluating joint and muscle injuries
• Diagnosing tendon and ligament tears
• Guiding injections
• Finding causes of joint pain

Vascular Ultrasound (Doppler):

• Evaluating blood flow in arteries and veins
• Diagnosing blood clots (DVT)
• Finding blockages in arteries
• Evaluating varicose veins
• Monitoring blood flow after surgery

Other Uses:

• Echocardiogram (heart ultrasound)
• Eye exams
• Skin and soft tissue evaluation
• Guiding numerous medical procedures

Advantages of Ultrasound

Why doctors choose ultrasound:

• No radiation exposure
• Real-time images show movement and function
• Painless and well-tolerated by most patients
• Widely available and relatively inexpensive
• Excellent for certain body parts (like the developing fetus)
• No known harmful effects

Limitations:

• Sound waves don't travel well through bone or gas
• Can't see inside lungs (filled with air)
• Image quality depends on technician skill
• May not see deep structures as well as CT or MRI
• Operator-dependent (quality varies by technician)

Ultrasound exams are generally quick, painless, and straightforward. Here's what typically happens:

Before Your Ultrasound

Arrival and Check-in:

• Arrive 15-30 minutes early for registration
• Bring your ID, insurance card, and referral form
• You may need to change into a hospital gown
• You'll be asked about your medical history and symptoms

Preparation varies by type:

• Abdominal ultrasound: You'll likely need to fast for 8-12 hours
• Pelvic ultrasound: You'll need to drink 32 oz of water before the exam and not urinate
• Other ultrasounds: Often no special preparation needed

During Your Ultrasound

Positioning:

• You'll lie on an exam table, typically on your back
• The technologist may ask you to roll to your side or change positions
• For some exams, you may sit or stand briefly

The Procedure:

1. Gel application: The technologist applies a warm, clear gel to your skin over the area being examined. This gel helps sound waves travel and eliminates air pockets.
2. Transducer: The technologist presses a handheld device called a transducer against your skin and moves it over the area. The transducer sends sound waves into your body and receives the echoes.
3. Image capture: The technologist watches the images on a monitor and captures still images and video clips. You may be able to see the monitor too.
4. Pressure: The technologist may press firmly with the transducer at times. This can be uncomfortable but shouldn't hurt.
5. Breathing instructions: You may be asked to hold your breath briefly or change your breathing to get better images.
6. Duration: Most ultrasounds take 20-60 minutes, depending on what's being examined.

What You'll Feel:

• The gel is usually warm and feels slightly wet
• The transducer pressing against your skin
• Some pressure, which may be uncomfortable at times
• Generally no pain, though certain exams may be briefly uncomfortable

What You'll See:

• The exam room is typically dimly lit
• There's a monitor showing the ultrasound images
• You may be able to watch the images in real-time
• The images are black and white and grainy (this is normal)

Special Types of Ultrasound

Transvaginal Ultrasound:

• A special transducer is inserted into the vagina
• Provides better images of the uterus and ovaries
• Used for certain gynecological problems and early pregnancy
• You'll empty your bladder before this exam
• May be slightly uncomfortable but shouldn't hurt
• Performed with privacy and dignity

Transrectal Ultrasound:

• A special transducer is inserted into the rectum
• Used to evaluate the prostate in men
• Used to guide prostate biopsies
• May be slightly uncomfortable but generally tolerable
• Performed with privacy and dignity

Echocardiogram:

• Ultrasound of the heart
• Performed by a specialized technologist
• You'll lie on your left side
• Electrodes are placed on your chest to monitor your heart rhythm
• Takes about 30-60 minutes

Doppler Ultrasound:

• Special ultrasound that evaluates blood flow
• You may hear swooshing sounds (this is the sound of blood flow)
• Used to evaluate arteries and veins
• Often combined with regular ultrasound

After Your Ultrasound

Immediate post-exam:

• The technologist will wipe off the gel
• You can return to normal activities immediately
• No special recovery period needed
• You can drive yourself home

Getting results:

• A radiologist reviews the images and prepares a report
• Results are typically available within 24-48 hours
• Your referring doctor will contact you to discuss findings
• Emergency ultrasounds are read much faster

Preparation varies significantly depending on what type of ultrasound you're having. Follow your specific instructions carefully.

General Preparation

What to wear:

• Wear comfortable, loose-fitting clothing
• You may need to change into a hospital gown
• Wear two-piece clothing for abdominal or pelvic ultrasounds (easier to expose just your belly)
• Remove all jewelry and piercings in the area being examined

What to bring:

• Photo ID and insurance card
• Doctor's referral or prescription
• List of current medications
• Information about previous ultrasounds or related imaging
• Something to read or do while waiting

Medications:

• Take your regular medications unless told otherwise
• Bring a list of your medications

Specific Preparation by Ultrasound Type

Abdominal Ultrasound:

• Fast for 8-12 hours before the exam
• No food or drink (except small sips of water for medications)
• No gum or mints
• This is critical because eating creates gas in the intestines, which blocks sound waves
• Schedule in the morning so you can fast overnight
• Continue taking medications with small sips of water

Pelvic Ultrasound (Women):

• Drink 32 ounces of water about 1 hour before your exam
• Don't urinate after drinking the water
• A full bladder pushes the intestines out of the way and provides a window to see the pelvic organs
• Arrive with a very full bladder
• The exam may be slightly uncomfortable with a full bladder
• You'll be able to urinate immediately after the exam

Pelvic Ultrasound (Men - Prostate):

• May require a small enema before the exam (follow specific instructions)
• May need to have a moderately full bladder
• No special preparation for some transrectal ultrasounds

Pregnancy Ultrasound:

• First trimester: May need a full bladder (similar to pelvic ultrasound)
• Second and third trimester: Usually no special preparation needed
• Your doctor will give you specific instructions

Breast Ultrasound:

• No special preparation needed
• Don't apply lotion or powder to your breasts or underarms before the exam
• Bring any previous mammogram reports or images

Other Ultrasounds:

• Most other ultrasounds: No special preparation needed
• Fasting for some abdominal organ evaluations
• Specific instructions for specialized exams (ask your doctor)

Special Considerations

Pregnancy and Breastfeeding:

• Ultrasound is safe during pregnancy and breastfeeding
• Tell your doctor if you're pregnant or breastfeeding
• No special precautions needed

Children:

• Pediatric ultrasounds use the same equipment
• Preparation may differ for children
• Distraction techniques may be used
• Parents may be able to stay in the room
• Bring comfort items (toys, blanket)

Patients with Anxiety:

• Ultrasound is generally well-tolerated even by anxious patients
• No enclosed spaces like MRI
• No radiation like CT
• Tell the technologist if you're anxious
• You can see the technologist and often the monitor during the exam

Mobility Issues:

• The exam table may be raised or lowered to accommodate you
• Call ahead if you need assistance
• Most facilities can accommodate patients with mobility challenges

Getting your results can feel stressful. Here's what to expect.

Who Reads Your Ultrasound?

A radiologist—a medical doctor specially trained in interpreting medical images—will carefully analyze your ultrasound images and prepare a detailed report for your referring doctor. Some radiologists specialize in specific types of ultrasound (like breast ultrasound or obstetric ultrasound).

When Will You Get Results?

Turnaround times vary:

• Emergency ultrasounds: Within minutes to an hour
• Routine ultrasounds: Typically 24-48 hours
• Complex cases: Sometimes 3-5 days if special consultation is needed

Your referring doctor will contact you to discuss the results and next steps.

Understanding Your Ultrasound Report

Your report will contain several sections:

Patient Information:

• Your name, age, and the date of the exam
• The reason for the exam (what your doctor is looking for)
• The type of ultrasound performed

Technique Description:

• Technical details about how the exam was performed
• Whether Doppler was used (to evaluate blood flow)
• The specific body parts imaged

Findings:

• Detailed description of what the radiologist sees
• Measurements of any abnormalities found
• Description of organ size and appearance
• Comparison to prior ultrasounds (if available)

Impression/Conclusion:

• The radiologist's interpretation of the findings
• A summary of what's most important
• Recommendations for follow-up if needed

Common Terminology in Ultrasound Reports

Reassuring Terms:

• Normal/Unremarkable: No abnormalities found—this is good news!
• Within normal limits: Everything appears as expected
• No focal lesions: No abnormalities detected in the organ
• Grossly normal: Everything looks normal overall

Terms Describing Findings:

• Hypoechoic: Area appears darker than surrounding tissue (can be normal or abnormal)
• Hyperechoic: Area appears brighter than surrounding tissue (can be normal or abnormal)
• Cystic: Fluid-filled (like a cyst)
• Solid: Not fluid-filled
• Complex: Has both solid and cystic components
• Lesion: Area of abnormal tissue (may be benign or malignant)

Terms That May Need Follow-up:

• Inconclusive: Unable to make a definitive diagnosis—more tests may be needed
• Indeterminate: Unclear findings—additional imaging may be recommended
• Recommend follow-up: The radiologist suggests repeat imaging to monitor something over time
• Clinical correlation recommended: Findings need to be considered along with your symptoms and exam

Ultrasound is one of the safest imaging technologies available.

No Ionizing Radiation

Key safety advantage:

• Ultrasound uses sound waves, not radiation
• No known harmful effects from diagnostic ultrasound
• Safe for developing fetuses
• Safe for children and adults
• Can be repeated as often as medically necessary
• No cumulative risk with multiple exams

Sound Wave Energy

How ultrasound works:

• Uses high-frequency sound waves (above human hearing)
• Sound waves create thermal (heat) and mechanical effects in tissues
• Diagnostic ultrasound uses low energy levels
• No proven harmful effects at diagnostic energy levels

Safety precautions:

• Ultrasound machines are calibrated to use the lowest energy necessary
• Technologists are trained to use ultrasound safely
• Energy levels are monitored during the exam
• Exposure time is minimized

Contrast Materials

Ultrasound contrast:

• Contrast-enhanced ultrasound uses tiny gas-filled bubbles
• Injected through an IV during the exam
• Shows blood flow in greater detail
• Rare allergic reactions (much less common than with CT or MRI contrast)
• Generally very safe
• Not used as often as CT or MRI contrast

Probe Cleaning and Infection Control

Safety between patients:

• Transducers (probes) are cleaned and disinfected between patients
• Single-use probe covers are used for internal exams (transvaginal, transrectal)
• Infection prevention protocols are strictly followed
• Risk of infection is extremely low

Special Considerations

Pregnancy:

• Ultrasound is the imaging of choice during pregnancy
• No known risks to the developing fetus
• Obstetric ultrasound is considered safe
• Used extensively throughout pregnancy

Children:

• No special safety concerns
• No radiation exposure
• Safe for pediatric patients

Repeated Exams:

• No cumulative risk like with radiation-based imaging
• Can be repeated as often as medically necessary
• Your doctor will order exams only when needed

Does an ultrasound hurt?

Most ultrasounds are painless. You may feel some pressure when the technologist presses the transducer against your skin. Internal ultrasounds (transvaginal, transrectal) may be slightly uncomfortable but shouldn't hurt.

How long does an ultrasound take?

Most ultrasounds take 20-60 minutes. The time varies depending on what's being examined and how easily the technologist can get good images.

Can I eat or drink before my ultrasound?

It depends on the type of ultrasound. Abdominal ultrasounds require fasting. Pelvic ultrasounds require a full bladder. Many other ultrasounds have no preparation. Follow your specific instructions.

Why do I need a full bladder for a pelvic ultrasound?

A full bladder pushes the intestines out of the way and provides a clear "window" for the sound waves to see the pelvic organs. It can be uncomfortable, but it's necessary for good images.

Can someone be in the room with me during my ultrasound?

Policies vary by facility and type of ultrasound. Many facilities allow a support person for obstetric ultrasounds. For other exams, ask when scheduling.

Is ultrasound safe during pregnancy?

Yes! Ultrasound uses sound waves, not radiation, making it the safest imaging option during pregnancy. It's used routinely throughout pregnancy.

Why is the gel cold?

The gel should be warm, but sometimes it feels cool on your skin. The gel helps sound waves travel and eliminates air pockets between the transducer and your skin.

Can I see the ultrasound images?

Often yes! Many facilities position the monitor so you can see the images during the exam. The technologist may explain what you're seeing, but they can't provide a diagnosis.

Will I get my results immediately?

Usually not. A radiologist needs to review the images and write a report, which takes 24-48 hours. Your referring doctor will discuss results with you. Emergency ultrasounds are read much faster.

Why is the technologist pressing so hard?

Pressure is sometimes needed to get good images, especially if the area being examined is deep in your body or if you have a thick abdominal wall. It may be uncomfortable, but tell the technologist if it hurts.

Before your appointment:

• Follow preparation instructions carefully (especially fasting or filling your bladder)
• Wear comfortable, two-piece clothing
• Arrive on time to complete paperwork
• Bring previous imaging results if requested

During your appointment:

• Relax as much as possible—tension can make the exam more difficult
• Ask questions if you're unsure about what's happening
• Take slow, deep breaths if you feel anxious
• Let the technologist know if you're uncomfortable

After your appointment:

• The gel wipes off easily, but you may want to wash when you get home
• Return to normal activities immediately
• Follow up with your doctor to get your results
• Keep a copy of your report for your records

• Ultrasound uses sound waves, not radiation, making it one of the safest imaging technologies
• Preparation varies significantly by type—follow your specific instructions carefully
• Most ultrasounds take 20-60 minutes and are painless
• A full bladder is required for pelvic ultrasounds (uncomfortable but necessary)
• Gel is applied to your skin to help sound waves travel
• The technologist may press firmly with the transducer to get good images
• Results are typically available within 24-48 hours and will be discussed with your referring doctor
• Ultrasound is safe during pregnancy and for repeated use

Ultrasound Guides:

• Pelvic Ultrasound: What to Expect
• Abdominal Ultrasound Preparation
• Ultrasound vs MRI: When to Choose Which

Understanding Results:

• Understanding Your Ultrasound Report
• Common Ultrasound Findings Explained

Preparing for an Ultrasound?

Download our free Ultrasound Preparation Guide with detailed instructions, tips, and a preparation timeline for your ultrasound exam.

Download Free Preparation Guide

Disclaimer: This guide is for educational purposes only and does not replace professional medical advice. Always consult with your healthcare provider about which imaging tests are appropriate for your specific situation.