For example, an ultrasound cannot show actual structures, only soft tissues. For larger areas of soft tissues, joints, bones, muscles, or cartilage, an MRI is a better diagnostic tool. If the doctor needs a detailed look of the entire arm, hand, or ankle, they typically order an MRI.
An ultrasound exam offers the benefit of producing images quickly and in real time, so movement can easily be observed on ultrasound. MRI images can provide greater detail, but these images are time consuming to capture are typically static.
The magnetic fields that change with time create loud knocking noises which may harm hearing if adequate ear protection is not used. They may also cause peripheral muscle or nerve stimulation that may feel like a twitching sensation. The radiofrequency energy used during the MRI scan could lead to heating of the body.
MRI is slightly, but significantly more sensitive than ultrasound for erosive disease, while ultrasound is more sensitive to detect tenosynovitis. Ultrasound and MRI are comparably sensitive to detect synovitis.
Because sound waves echo differently from fluid-filled cysts and solid masses, an ultrasound can reveal tumors that may be cancerous. However, further testing will be necessary before a cancer diagnosis can be confirmed.
An ultrasound can miss small tumours: "It takes millions of cells to make a tumor big enough to show up on an imaging test."
An example of early signs that may not show up on ultrasound are tiny calcium deposits called microcalcifications. Ultrasound may be used if you: Have particularly dense breast tissue. A mammogram may not be able to see through the tissue.
“When structures are not very deep, or superficial, ultrasound can show images with higher resolution/detail than MRI,” Dr. Forney notes. The tendons in the fingers are often seen in greater detail with ultrasound compared with MRI, for example.
An MRI provides a clearer picture of abnormal tissues. It is a better scan for looking at ligaments and tendons, your spinal cord, and other soft tissues. A CT scan can give you a higher-quality picture of bones and is better for diagnosing chest and lung problems as well as detecting some cancers.
The bottom line is that not all pain is able to be detected on an x-ray or MRI. That does not mean that there is nothing there that needs to be treated or diagnosed. In fact, it means that it is possibly a precursor to something going really wrong and then eventually needing surgery because it eventually winds up torn.
An MRI machine uses powerful magnets that can attract any metal in your body. If this happens, you could get hurt. It can also damage equipment that's implanted in your body -- a pacemaker or cochlear implant, for instance. Also, metal can reduce the quality of the MRI image.
Since the MRI machines are magnets, it is best to not apply deodorants, antiperspirants, perfumes, or body lotions before the examination. These items contain metals that might interfere with the magnetic field inside the MRI machine and cause you to have distorted images and wrong results.
Some patients occasionally experience a tingling sensation or feel hot from being in the MRI scanner. These effects only last a short while and should ease as soon as the scan is over. You're given a squeeze alarm which can alert the Radiographers if you have any concerns during your scan.
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 technology is most closely associated with pregnancy, but it is very effective at helping physicians diagnose muscle, tendon, and soft tissue injuries.
Furthermore, MRI can also detect subclinical muscle inflammation such as in amyopathic DM (34), in which up to 100% of patients have muscle inflammation on WB MRI, or in amyopathic ASyS patients where muscular inflammation is frequently observed (28).
WHEN IS MRI ORDERED? MRI is often ordered when more detail is needed or the cause of symptoms is unclear on other types of imaging, such as X-ray, ultrasound, and computed tomography (CT). It can help diagnose diseases of the brain, spine, skeleton, abdomen, and soft tissues.
The MRI scan is used to investigate or diagnose conditions that affect soft tissue, such as: Tumours, including cancer. Soft tissue injuries such as damaged ligaments. Joint injury or disease.
MRI (Magnetic Resonance Imaging)
Muscle, tendons, nerves, brain. Some Pros: Creates an excellent picture, no radiation exposure. Some Cons: Takes a longer time (e.g. up to 40 mins), expensive, may not be accessible to people in the country.
An MRI may be able help identify structural lesions that may be pressing against the nerve so the problem can be corrected before permanent nerve damage occurs. Nerve damage can usually be diagnosed based on a neurological examination and can be correlated by MRI scan findings.
Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI.
It is a versatile imaging technique with a high sensitivity of 93% for detecting focal nerve lesions. Ultrasound can assess the structural integrity of the nerve, neuroma formation and other surrounding abnormalities of bone or foreign bodies impeding the nerve.
Ultrasound imaging can help determine the composition of lumps, distinguishing between a cyst and a tumour. Also known as sonography, it involves the use of high-frequency, real-time sound waves to create an image.
Ultrasound technology cannot find ulcers, but other types of diagnostic tests can. Doctors usually request a test for the bacteria that causes stomach ulcers, an x-ray series or an endoscopy.
Based on the heterogeneity of stiffness between different tumor tissues, ultrasound elastography can distinguish between benign and malignant tumors by detecting the modulus of elasticity (10).