Ultrasound Does a Great Job
The thyroid gland is an amazing, delicate and very important organ found in the neck, usually just below the Adam’s Apple. Wrapped around the trachea (windpipe), this butterfly-shaped gland secretes hormones that regulate the body’s metabolism and keep the brain, heart, muscles and other organs working properly.
As with other organs in our body, the thyroid sometimes develops unusual growths or doesn’t function normally. Abnormal growths called nodules, which sometimes develop on the thyroid, are actually quite common. They occur in about 15 to 70 percent of all adults, depending upon age, and more than 90 percent are non-cancerous. These nodules are often accidentally discovered when a patient is having an imaging exam such as a CT, PET or MRI, or by “palpation,” when a physician (or patient) actually feels them by touching the neck.
While most thyroid problems are minor, some can be serious, requiring testing and diagnostic imaging to find out if there are cancerous growths and if the thyroid is working properly. Interestingly, thyroid nodules are much more common the older we get, but less likely to be cancerous. Conversely, they are less common in younger individuals, but more likely to be cancerous.
Although blood testing is routinely used to identify an overactive or underactive thyroid, these tests and palpation alone can’t tell whether a growth is cancerous. To get a better look at nodules, doctors usually order an ultrasound test to find out the size, type and number of nodules. In more challenging cases where cancer or other thyroid problems are possible, a biopsy or thyroid scan and uptake tests may be ordered from an imaging center or hospital.
Ultrasound does a great job of showing us thyroid nodules that cannot be felt, and the good news is that most of these pose no health risk at all. However, this is where the expertise of a radiologist is so critical: being able to visualize and gather more precise information about the nodules to help determine if further investigation is needed.
If one or more nodules are detected within the thyroid gland, the radiologist will examine the features of the nodules. Certain characteristics indicate that a nodule is benign (non-cancerous) in nature, and other characteristics raise concerns that a nodule may be a true tumor. In other situations, the radiologist cannot distinguish between benign and malignant lumps with complete certainty.
In many cases, we’ll just watch and wait, with a follow-up ultrasound in another six months or year to see if anything has changed. The vast majority of thyroid cancers are very slow growing and very treatable, so we’re usually looking at a situation that’s much different than with more aggressive cancers such as liver or skin cancer.
Ultrasound alone cannot make a cancer diagnosis or determine if the thyroid is functioning properly. If the radiologist and primary care physician believe further investigation of a potentially cancerous growth is needed, an ultrasound-guided, fine-needle biopsy is usually performed. It is the only non-surgical way to tell the difference between a benign nodule and malignant nodule and is usually the first diagnostic test performed.
Two additional tests for thyroid function are the thyroid scan and iodine uptake. For both tests, a small amount of a radioactive material is given to the patient (injected or swallowed) and absorbed by the thyroid. The radioactive material is used to produce a digitized image of the thyroid gland to evaluate the size, shape and position of the thyroid gland and determine if the gland or any nodules are interfering with its function, resulting in an underactive or overactive thyroid.
Thyroid nodules are very common, usually don’t produce any symptoms and are rarely cancerous. However, it’s always important to get such nodules checked just to be safe. Today’s advanced imaging and diagnostics combined with the expertise of radiologists can help determine the health of the thyroid gland and ensure that any cancers that do develop are identified and treated early.