Pros and Cons of Ultrasound-Guided Injections
The Pros and Cons of Ultrasound-Guided Injections
- 1 The Pros and Cons of Ultrasound-Guided Injections
- 2 The procedure offers greater accuracy but still draws debate
- 3 How Ultrasound-Guided Injections Are Performed
- 4 The Debate Over Ultrasound-Guided Injections
- 5 Alternative Procedures
- 6 Ultrasound for Cancer
- 7 Does Ultrasound Therapy Really Work?
- 8 How Ultrasound Works
- 9 Heating Effects of Ultrasound
- 10 Does Ultrasound Speed Healing?
- 11 Can Ultrasound Hurt?
- 12 The Placebo Effect
- 13 Bottom Line
- 14 General Ultrasound
- 15 What is General Ultrasound Imaging?
- 16 What are some common uses of the procedure?
- 17 How should I prepare?
- 18 What does the equipment look like?
- 19 How does the procedure work?
- 20 How is the procedure performed?
- 21 What will I experience during and after the procedure?
- 22 Who interprets the results and how do I get them?
- 23 What are the benefits vs. risks?
- 24 What are the limitations of General Ultrasound Imaging?
The procedure offers greater accuracy but still draws debate
Jonathan Cluett, MD, is a board-certified orthopedic surgeon with subspecialty training in sports medicine and arthroscopic surgery.
Slobodan Vasic / Getty Images
Orthopedic surgeons often use injections to treat a variety of conditions. Commonly injected medications include cortisone, local anesthetics, and joint lubricants such as hyaluronic acid. In some cases, delivering an injection is not as easy as it sounds. Some require you to hit the target just right, often with the slimmest margin of error.
Joint injections, for example, need to be administered within the joint space and not the surrounding soft tissue. Similarly, tendon injections should be administered in the tendon sheath, the structure covering the tendon, and not the tendon itself.
Traditionally, injections were given «blind,» requiring a doctor to have a certain degree of experience, delicacy, and anatomical know-how. Even then, there was no guarantee of success. These days, orthopedists largely avoid the hit-or-miss approach by using guided technologies such as ultrasound.
How Ultrasound-Guided Injections Are Performed
One of the most commonly used devices for image-guided injections is the ultrasound. Until recently, they were used infrequently in an orthopedist office, either because they were cumbersome or costly (or both). Today, newer portable models offer the ease, accuracy, and resolution needed for a broader range of orthopedic procedures.
Ultrasound-guided injections are performed much in the same way as traditional injections. To ensure the images come in clear, an ultrasound gel will be applied directly to the skin. The gel acts as a conductive medium that creates a tight bond between the skin and the ultrasound probe. This ensures the reflected sound waves have minimal interference.
The probe, also known as a transducer, is then placed near or adjacent to the targeted tendon or joint. Once the doctor has identified the anatomic landmarks on the monitor, the injection will be delivered using a standard needle and syringe.
The ultrasound also allows you to visualize fluids so that you can see if the medication is being distributed exactly where you need it to be.
The Debate Over Ultrasound-Guided Injections
There has been an ongoing debate as to whether ultrasound-guided injections are worth all the fuss. Much of the dissent comes from insurers and private payors who question the value of a tool that may add $100 or more to a bill. Others, meanwhile, wonder if greater impetus should be placed on proper injection training rather than offering technological shortcuts to doctors.
Despite some validity to the arguments, the simple fact remains that there are numerous anatomically difficult parts of the body that even experienced doctors may cringe about. Consider, for example, the value of an ultrasound in performing a lumbar puncture (spinal tap) on an elderly patient with extensive osteoarthritis.
The same thing applies to people with joint disorders. If there is the long-term or acute damage, an otherwise «simple» injection can turn challenging for not only for the doctor but the person undergoing the procedure.
Ultrasounds are not necessarily the best tool to guide injections for every particular situation. In some situations, other imaging modalities can be used to assist with injection guidance. For example, x-ray machines and CAT scanners are routinely used for injection guidance in some situations.
Also, there are certain types of injections which may not benefit from imaging guidance at all. This is a subjective great debate among physicians. Some physicians will argue that the only reason why imaging guidance is used is that it is yet another means to bill insurance companies for a service. I think that most clinicians agree that imaging guidance certainly has a role, but it is unclear exactly which injections are worth the added cost of imaging guidance
A Word From Verywell
There is no minimizing the impact of out-of-pocket medical costs for people who are either uninsured or underinsured. If you have serious financial concerns, don’t be afraid to question the cost of any medical procedure being offered to you.
If you are scheduled to have an ultrasound-guided injection, ask your doctor if the technology is really needed. Explain your concerns, keep an open mind, and make an informed choice based on the information given to you. It is your right as a patient.
Ultrasound for Cancer
Other names for this test: ultrasonography, sonography, and sonogram
An ultrasound helps doctors look for tumors in certain areas of the body that don’t show up well on x-rays. Doctors often use them to guide a needle during a biopsy. Ultrasounds are usually quick and most don’t require special preparation. They’re often done as an outpatient.
Ultrasound is commonly used to monitor pregnant women and their unborn babies.
What does it show?
An ultrasound machine creates images called sonograms by giving off high-frequency sound waves that go through your body. As the sound waves bounce off organs and tissues, they create echoes. The machine makes these echoes into real-time pictures that show organ structure and movement and even blood flow through blood vessels. The images can be seen on a computer screen.
Ultrasound is very good at getting pictures of some soft tissue diseases that don’t show up well on x-rays. Ultrasound is also a good way to tell fluid-filled cysts from solid tumors because they make very different echo patterns. It’s useful in some situations because it can usually be done quickly and doesn’t expose people to radiation.
Ultrasound images are not as detailed as those from CT or MRI scans. Ultrasound cannot tell whether a tumor is cancer. Its use is also limited in some parts of the body because the sound waves can’t go through air (such as in the lungs) or through bone.
Doctors often use ultrasound to guide a needle to do a biopsy (taking out fluid or small pieces of tissue to be looked at under a microscope). The doctor looks at the ultrasound screen while moving the needle and can see the needle moving toward and into the tumor.
For some types of ultrasound exams, the transducer (the wand that sends out the sound waves and picks up echoes) is pushed against and moved over the skin surface. The sound waves pass through the skin and reach the organs underneath. In other cases, to get the best images, the doctor must use a transducer that’s put into a body opening, such as the esophagus (the tube connecting the throat and the stomach), rectum, or vagina.
Special ultrasound machines, known as Doppler flow machines, can show how fast and in which direction blood flows through vessels. This is helpful because blood flow in tumors is different from that in normal tissue. Some of these machines make color pictures. Color Doppler has made it easier for doctors to find out if cancer has spread into blood vessels, especially in the liver and pancreas.
How does it work?
An ultrasound machine has 3 key parts: a control panel, a display screen, and a transducer, which usually looks a lot like a microphone or a computer mouse. The transducer sends out sound waves and picks up the echoes. The doctor or ultrasound technologist moves the transducer over the part of the body being studied. The computer inside the main part of the machine analyzes the signals and puts an image on the display screen.
The shape and intensity of the echoes depend on how dense the tissue is. For example, most of the sound waves pass right through a fluid-filled cyst and send back very few or faint echoes, which makes them look black on the display screen. But the waves will bounce off a solid tumor, creating a pattern of echoes that the computer will show as a lighter-colored image.
How do I get ready for the test?
For most ultrasounds, no preparation is needed, but it depends on what’s being studied. Your doctor or nurse will give you instructions about any steps to take before your test. Depending on the organ being studied, you may need to not eat, take a laxative, or use an enema. If you’re having an abdominal (belly) ultrasound, you might need to drink a lot of water just before the study to fill your bladder. This will create a better picture because sound waves travel well through fluid.
What is it like having the test?
Ultrasound can be done in a doctor’s office, clinic, or hospital. Wear comfortable clothes. Depending on the body part to be studies, you may need to change into a hospital gown.
Most often you will lie down on a table. Your position will depend on the body part to be studied. The technologist will put a water-based gel on your skin and move the transducer over the area to be checked. The gel both lubricates the skin and helps conduct the sound waves. The gel feels cool and slippery. If a probe is used, it will be covered with gel and put into the body opening. This can cause pressure or discomfort.
During the test the technologist or the doctor moves the transducer as it’s firmly pressed to your skin. You may be asked to hold your breath during the scan. The operator may adjust knobs or dials to increase the depth to which the sound waves are sent. You may feel slight pressure from the transducer.
After the test the gel is wiped off your skin. It does not stain your skin or your clothing.
How long does it take?
An ultrasound usually takes 20 to 30 minutes. The length of time depends on the type of exam and how hard it is to find any changes in the organs being studied.
What are the possible complications?
Ultrasound is a very safe procedure with a low risk of complications.
Does Ultrasound Therapy Really Work?
Therapeutic ultrasound is a treatment modality often used in physical therapy. It has been used historically to improve circulation and tissue healing, but research has called into question its efficacy. Does ultrasound really work, and is it an important component of your rehab program after an injury?
If you have an injury such as bursitis, tendonitis, or arthritis you may require physical therapy to help decrease pain and improve function. Your physical therapist may choose to apply therapeutic ultrasound to your injured body part as part of your rehabilitation program.
How Ultrasound Works
Therapeutic ultrasound is a treatment that has been used in physical therapy clinics for over 50 years. It provides heat to injured body parts that lie deep within your body that cannot be heated with a standard hot pack alone. Ultrasound is also thought to improve cellular function by making microscopic gas bubbles near your injury expand and contract rapidly, a process called cavitation. This expansion and contraction are thought to speed up the healing process in your injured body part.
How is ultrasound produced? An electrical charge is applied to a crystal, creating a piezo-electric effect. This produces ultrasonic waves. These sound waves cannot be heard, but they are able to pass in through your skin and to tissues, heating them and causing cavitation.
But does ultrasound really work? Does ultrasound really provide heat to the deep tissues in your body, and does this heating have a positive effect on helping your injury heal better or faster?
Heating Effects of Ultrasound
A published overview of therapeutic applications of ultrasound confirms that it certainly does heat your body parts when applied correctly. It also heats parts of your body that are deep and located outside of the reach of standard hot packs. So if you have an injury and your physical therapist feels that heat may be required to help your condition, ultrasound is a good choice to use.
Does Ultrasound Speed Healing?
Studies about using ultrasound to help speed healing are not so positive. There are many studies that compare ultrasound use to sham (fake) ultrasound. These studies indicate that people who receive an ultrasound for an injury do not have a speedier, healthier recovery or a better outcome.
For example, in a study on the use of ultrasound for knee arthritis, some of the study participants received the ultrasound treatment, while other study participants received sham ultrasound. There were no differences in the recovery of patients in either group.
There is one positive study on the use of ultrasound in the treatment of shoulder pain. A 2001 review of studies for treatments for shoulder pain gave ultrasound a grade of “A” (benefit demonstrated) for the use of ultrasound in the treatment of one specific shoulder condition. This was for the treatment of calcific tendinitis in the shoulder. This painful condition limits shoulder range of motion and causes pain when moving your arm.
Can Ultrasound Hurt?
Ultrasound is a pretty safe and innocuous treatment in physical therapy. There are some instances where ultrasound should absolutely not be used, such as over body parts with cancer and in young children, but for the most part, it can be used safely to heat-injured parts of your body.
Since many studies show that ultrasound offers very little to help speed healing in your injured body part, some physical therapists feel that ultrasound can “hurt” by making you feel like you need it to get better.
Treatments that do not actively involve you in your care may make you feel like you have very little control over the management of your injury. This puts responsibility for your care in your physical therapist’s hands and not your own.
The Placebo Effect
Many physical therapists continue to use ultrasound and many feel that it adds positive outcomes in the treatment of many conditions. But is it really the placebo effect?
The placebo effect is a phenomenon where you perceive an improvement in your condition simply because something is being done to you. Your physical therapist tells you that ultrasound treatments can make you better, and therefore you start to feel better after receiving the treatments.
If your condition improves because of the placebo effect, that is fine. But some professionals argue that using the placebo effect in the treatment of conditions is unethical.
In general, ultrasound is a safe treatment that has been used in physical therapy for many years. It provides heat to deep structures in the body, and it is thought that this heat helps improve that way that your body heals.
Studies may not really support the use of ultrasound in physical therapy. Still, it is commonly used and you may come across it if you go to physical therapy, so you should have some idea about what it is and what it can (and can’t) do.
If your PT decides to use ultrasound as part of your rehab program, you may wish to question if it is absolutely necessary for you.
If you do receive an ultrasound, you should also be actively involved in your physical therapy plan of care. You should make sure that your physical therapist helps you understand your condition and that he or she offers you strategies that you can apply to help improve your condition independently.
A Word From Verywell
Ultrasound may be a treatment modality that you are exposed to during your physical therapy treatments. Research calls into question its efficacy, so if your PT does use it, be sure to understand the goals of treatment and the necessity of the treatment.
Ultrasound imaging uses sound waves to produce pictures of the inside of the body. It is used to help diagnose the causes of pain, swelling and infection in the body’s internal organs and to examine a baby in pregnant women and the brain and hips in infants. It’s also used to help guide biopsies, diagnose heart conditions, and assess damage after a heart attack. Ultrasound is safe, noninvasive, and does not use ionizing radiation.
This procedure requires little to no special preparation. Your doctor will instruct you on how to prepare, including whether you should refrain from eating or drinking beforehand. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown.
What is General Ultrasound Imaging?
Ultrasound is safe and painless. It produces pictures of the inside of the body using sound waves. Ultrasound imaging is also called ultrasound scanning or sonography. It uses a small probe called a transducer and gel placed directly on the skin. High-frequency sound waves travel from the probe through the gel into the body. The probe collects the sounds that bounce back. A computer uses those sound waves to create an image. Ultrasound exams do not use radiation (as used in x-rays). Because images are captured in real-time, they can show the structure and movement of the body’s internal organs. They can also show blood flowing through blood vessels.
Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions.
Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats the sound wave data into 3-D images.
A Doppler ultrasound study may be part of an ultrasound examination.
Doppler ultrasound is a special ultrasound technique that evaluates movement of materials in the body. It allows the doctor to see and evaluate blood flow through arteries and veins in the body.
There are three types of Doppler ultrasound:
- Color Doppler uses a computer to convert Doppler measurements into an array of colors to show the speed and direction of blood flow through a blood vessel.
- Power Doppler is a newer technique that is more sensitive than color Doppler and capable of providing greater detail of blood flow, especially when blood flow is little or minimal. Power Doppler, however, does not help the radiologist determine the direction of blood flow, which may be important in some situations.
- Spectral Doppler displays blood flow measurements graphically, in terms of the distance traveled per unit of time, rather than as a color picture. It can also convert blood flow information into a distinctive sound that can be heard with every heartbeat.
What are some common uses of the procedure?
Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following illness.
Ultrasound is used to help physicians evaluate symptoms such as:
Ultrasound is a useful way of examining many of the body’s internal organs, including but not limited to the:
Ultrasound is also used to:
- guide procedures such as needle biopsies, in which needles are used to sample cells from an abnormal area for laboratory testing.
- image the breasts and guide biopsy of breast cancer (see the Ultrasound-Guided Breast Biopsy page .
- diagnose a variety of heart conditions, including valve problems and congestive heart failure, and to assess damage after a heart attack. Ultrasound of the heart is commonly called an «echocardiogram» or «echo» for short.
Doppler ultrasound images can help the physician to see and evaluate:
- blockages to blood flow (such as clots)
- narrowing of vessels
- tumors and congenital vascular malformations
- reduced or absent blood flow to various organs, such as the testes or ovary
- increased blood flow, which may be a sign of infection
With knowledge about the speed and volume of blood flow gained from a Doppler ultrasound image, the physician can often determine whether a patient is a good candidate for a procedure like angioplasty.
How should I prepare?
Wear comfortable, loose-fitting clothing. You may need to remove all clothing and jewelry in the area to be examined.
You may be asked to wear a gown during the procedure.
Preparation for the procedure will depend on the type of examination you will have. For some scans your doctor may instruct you not to eat or drink for as many as 12 hours before your appointment. For others you may be asked to drink up to six glasses of water two hours prior to your exam and avoid urinating so that your bladder is full when the scan begins.
What does the equipment look like?
Ultrasound scanners consist of a computer console, video display screen and an attached transducer. The transducer is a small hand-held device that resembles a microphone. Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out inaudible, high-frequency sound waves into the body and then listens for the returning echoes. The principles are similar to sonar used by boats and submarines.
The technologist applies a small amount of gel to the area under examination and places the transducer there. The gel allows sound waves to travel back and forth between the transducer and the area under examination. The ultrasound image is immediately visible on a video display screen that looks like a computer monitor. The computer creates the image based on the loudness (amplitude), pitch (frequency) and time it takes for the ultrasound signal to return to the transducer. It also takes into account what type of body structure and/or tissue the sound is traveling through.
How does the procedure work?
Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an object, it bounces back, or echoes. By measuring these echo waves, it is possible to determine how far away the object is as well as the object’s size, shape and consistency. This includes whether the object is solid or filled with fluid.
In medicine, ultrasound is used to detect changes in the appearance of organs, tissues, and vessels and to detect abnormal masses, such as tumors.
In an ultrasound exam, a transducer both sends the sound waves and records the echoing waves. When the transducer is pressed against the skin, it sends small pulses of inaudible, high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids and tissues, the sensitive receiver in the transducer records tiny changes in the sound’s pitch and direction. These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor. One or more frames of the moving pictures are typically captured as still images. Short video loops of the images may also be saved.
Doppler ultrasound, a special ultrasound technique, measures the direction and speed of blood cells as they move through vessels. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and creates graphs or color pictures that represent the flow of blood through the blood vessels.
How is the procedure performed?
For most ultrasound exams, you will lie face-up on an exam table that can be tilted or moved. Patients may be turned to either side to improve the quality of the images.
After you are positioned on the examination table, the radiologist (a physician specifically trained to supervise and interpret radiology examinations) or sonographer will apply a warm water-based gel to the area of the body being studied. The gel will help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin that can block the sound waves from passing into your body. The transducer is placed on the body and moved back and forth over the area of interest until the desired images are captured.
There is usually no discomfort from pressure as the transducer is pressed against the area being examined. However, if scanning is performed over an area of tenderness, you may feel pressure or minor pain from the transducer.
Doppler sonography is performed using the same transducer.
Rarely, young children may need to be sedated in order to hold still for the procedure. Parents should ask about this beforehand and be made aware of food and drink restrictions that may be needed prior to sedation.
Once the imaging is complete, the clear ultrasound gel will be wiped off your skin. Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain or discolor clothing.
In some ultrasound studies, the transducer is attached to a probe and inserted into a natural opening in the body. These exams include:
- Transesophageal echocardiogram. The transducer is inserted into the esophagus to obtain images of the heart.
- Transrectal ultrasound. The transducer is inserted into a man’s rectum to view the prostate.
- Transvaginal ultrasound. The transducer is inserted into a woman’s vagina to view the uterus and ovaries.
What will I experience during and after the procedure?
Most ultrasound exams are painless, fast and easily tolerated.
Ultrasound exams in which the transducer is inserted into an opening of the body may produce minimal discomfort.
If a Doppler ultrasound study is performed, you may actually hear pulse-like sounds that change in pitch as the blood flow is monitored and measured.
Most ultrasound examinations are completed within 30 minutes, although more extensive exams may take up to an hour.
When the examination is complete, you may be asked to dress and wait while the ultrasound images are reviewed.
After an ultrasound examination, you should be able to resume your normal activities immediately.
Who interprets the results and how do I get them?
A radiologist, a doctor trained to supervise and interpret radiology exams, will analyze the images. The radiologist will send a signed report to the doctor who requested the exam. Your doctor will then share the results with you. In some cases, the radiologist may discuss results with you after the exam.
Follow-up exams may be needed. If so, your doctor will explain why. Sometimes a follow-up exam is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. A follow-up exam may also be done to see if there has been any change in an abnormality over time. Follow-up exams are sometimes the best way to see if treatment is working or if an abnormality is stable or has changed.
What are the benefits vs. risks?
- Most ultrasound scanning is noninvasive (no needles or injections).
- Occasionally, an ultrasound exam may be temporarily uncomfortable, but it should not be painful.
- Ultrasound is widely available, easy-to-use and less expensive than most other imaging methods.
- Ultrasound imaging is extremely safe and does not use radiation.
- Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
- Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn babies.
- Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration.
- Standard diagnostic ultrasound has no known harmful effects on humans.
What are the limitations of General Ultrasound Imaging?
Ultrasound waves are disrupted by air or gas. Therefore, ultrasound is not an ideal imaging technique for the air-filled bowel or organs obscured by the bowel. Ultrasound is not as useful for imaging air-filled lungs, but it may be used to detect fluid around or within the lungs. Similarly, ultrasound cannot penetrate bone, but may be used for imaging bone fractures or for infection surrounding a bone.
Large patients are more difficult to image by ultrasound because greater amounts of tissue attenuate (weaken) the sound waves as they pass deeper into the body and need to be returned to the transducer for analysis.
Ultrasound has difficulty penetrating bone and, therefore, can only see the outer surface of bony structures and not what lies within (except in infants who have more cartilage in their skeletons than older children or adults). For visualizing internal structure of bones or certain joints, other imaging modalities such as MRI are typically used.