Who reads my CAT scan?

Your doctor orders a CT scan. You skip breakfast, you drink two large containers of bland-tasting white liquid, and you drive to the Imaging Center. After checking in at the front desk, a young lady (the technologist) escorts you to a room with a narrow padded bed. You sit on the bed, and the technologist asks you why you are there (“My doctor ordered this test because I have this pain in my belly.”) She asks if you are allergic to anything (“No”). She discusses the IV contrast (“dye”) and obtains your
permission. She explains that you will lie down on the bed, she will put an IV in your arm vein, and the bed will move until you are partly within the doughnut-shaped device at the end of the bed. She explains you may feel a cool sensation in your arm as the “dye” fluid is injected, or you may feel warmth in various parts of your body; and you should report to the technologist if you feel any burning or pain in your arm, any nausea, any itching or difficulty breathing or swallowing, or any other unusual sensations.

She explains that as the dye is injected, she will ask you to hold your breath, and the bed will steadily move through the doughnut while the “pictures” are taken.

All proceeds as expected. You had a brief generally flushed feeling that passed in less than a minute. The technologist comes in, looks at you, at your arm; then goes out
(“to check the pictures…”). She returns and says “The radiologist will look at your images and send a report to your doctor.”

You depart, relieved that the test is over; but wondering what the “pictures” showed.
After a few days, you have your follow-up appointment with your doctor who tells you, “Your Cat scan was normal except for a few cysts in your kidneys…”

What does it mean? What about my abdominal pain?
Well, most concerned physicians will take the time to explain the implications of the scan to you and then to address the possibilities that remain as a cause for your discomfort.
He or she may also then suggest the next step to elucidate the problem or suggest a
treatment if he or she has formulated a likely diagnosis from all the data (your history, your physical exam, your other lab tests).

So, who is this mysterious radiologist and what did he/ she really do for me?

A Diagnostic Radiologist is trained to interpret a variety of imaging studies – from the
simple radiograph (“xray or plain film”), like a chest xray – to the more complex CT or CAT scans, ultrasounds, MRI’s, mammograms and nuclear medicine studies. Some radiologists perform interventional procedures (eg., angiograms, biopsies) as well.

In the case of the CAT scan, there is usually a radiologist available at or near the facility where your study is performed to prescribe the study, monitor the study if needed, and to
be there in case you have a rare allergic reaction to the “dye” or contrast administered.

After the technologist prepares the final images for review, the radiologist views each of
the usually greater than 100 separate images per study to view the pertinent parts of the body in cross section. In many cases the images can be manipulated on computer to provide different views and different shades of gray to the tissues, to allow for the best evaluation.

After his or her review, the radiologist decides what structures are normal, what features are or may be abnormal, and ultimately tries to put the findings together to come to a conclusion. If the study is not in the normal range, the radiologist provides a “differential diagnosis.” That is, he or she offers a list of possible or likely causes for the findings that
have been observed. Since the radiologist is not fully aware of your history or physical exam or the results of your other lab tests, it is up to your clinical doctor to put all the
pieces of the puzzle together – which may lead your doctor towards or away from the
diagnosis (or diagnoses) offered by the radiologist.

Sometimes the radiologist will suggest additional tests to clarify findings noted on the original CT scan.

For instance, on your abdominal CT, the simple kidney cysts are almost always benign, and therefore almost always an incidental finding. They rarely require further testing.
On the other hand, the fact that the rest of the study was “negative” suggests that the diagnosis lies outside the realm of what CT can diagnose – such as some gastrointestinal problems that may not show up on CT — or the problem is too early in its development or too subtle to recognize at this time.

Your doctor may discuss this with you. And, as the visibility of the practice of radiology evolves, there is an early but growing tendency for some patients to discuss findings with the radiologist.

Most radiologists today in the U.S. (especially if they are board-certified) have undergone
(after medical school) an internship (such as surgery or internal medicine or some combination), a residency (now 4 years) in Diagnostic Radiology, and in some cases
a year or more fellowship in a subspecialty (such as Chest Radiology). They are trained
to know what the best tests are for various diagnoses your doctor is considering, how
best to perform those tests, and how to interpret the tests. The radiologist usually communicates to the referring doctor by written report, but will often
call your doctor if the findings are unusual or urgent.

So, you see, the Radiologist is a Medical Doctor, just like your internist or surgeon; but
his or her training emphasizes imaging the body, and helping your doctor arrive at the
most likely diagnosis, so that the proper treatment can be implemented.

Today, there is an impetus to make the Radiologist more visible – to emerge from behind
the curtain – to allow you, the patient, to appreciate what really goes into (and comes out of) all those imaging procedures that you undergo. Take advantage of this opportunity, especially if you want more information about the studies than your referring physician can offer.

The final decisions and treatment plans offered to you still come from your primary or referring doctor, since he or she is generally better equipped than the radiologist to perform this function.

Malcolm Friedman, M.D.
Diagnostic Radiologist
Hamden, CT – malfmd@gmail.com

Is spiral CT the answer?

DEAR DR. GOTT: My friend told me about a recent news program on television regarding early detection for lung cancer through X-ray. I missed it because I was visiting my father, who is in a nursing home, but I would love to know what this new testing is all about. Can you fill me in on the details?

DEAR READER: I believe the testing you are referring is spiral computed tomography (SCT). These scans are now being performed as a means of early detection for lung cancer in people who smoke or did in the past. Within 12 to 20 seconds, the machine rotates around the patient and creates images that are reconstructed into a three-dimensional model of the lungs.
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