Diagnostic Radiology

Discovered in November 1895 foot x-ray , by Wilhem Conrad Roentgen x-rays have been one of the primary diagnostic tools of medicine for almost a hundred years. The main stay of Radiology, plain x-rays and most fluoroscopy (basically a method of taking x-rays similar to taking videos) have been combined to form what is commonly called Diagnostic Radiology, or Routine Diagnostic Radiology. This includes x-rays of the skeleton, and various Contrasted studies such as G.I.'s (Gastrointestinal), Myelograms, Venagrams, Arthrograms, and IVP's.

The most commonly performed x-ray is a Chest x-ray, which commonly consists of a PA, or frontal view, and a Lateral, or side view. One thing that does confuse a lot of patients about these is the PA, or frontal view, since the patient is facing away from the x-ray tube when this one is taken. Truthfully, referring to this as a frontal view is not correct, and most technologists only use this term because it is a term that they feel their patients will understand. The reason the patient is facing the chest board instead of the x-ray tube for this view is to place the heart closer to the x-ray film, thus reducing the magnification of the heart to a point where fairly accurate measurements of the heart can be obtained. These measurements are used to check for various heart conditions, such as CHF (congestive heart failure) and Cardiomegaly (basically an enlarged heart). A chest x-ray will also demonstrate a number of lung problems including such problems as: Bronchitis, Pneumonia, Asthma, Pneumothorax (air trapped between the lungs and the chest wall), and fluid in the lungs as a result of CHF. The lateral, or side view of the chest is obtained to see whether a problem is located nearer to the front of the chest or the back, and to see if there is anything behind the heart that would not show up on the PA view. The Technologists doing your x-rays will normally take the films after telling you to take in a deep breath and hold it. This expands the lungs to their fullest and pushes the diaphragm down, making it easier for the Radiologist who will read your x-rays to see everything.

The second most common x-ray exam is of the abdomen or stomach, often referred to as a KUB. Perhaps the most common question I hear about this exam is how can an x-ray show anything in the abdomen when x-rays are only good for seeing bones. Certainly it is a valid question considering what most patients have been told about x-rays, and it is true that x-rays do not do a good job of demonstrating what is commonly referred to as "soft tissue". What makes a KUB work as a x-ray is that it is the difference in tissue densities that determines what shows up on a x-ray, and since there is a big difference in density between the fat that covers many internal organs as a sort of shock absorbing protective cover, and the muscles surrounding them, there is enough difference on the completed x-ray to enable the doctor to distinguish some things. Add to this the fact that many problems will cause air, which shows up as a black object on x-rays, to be trapped in the intestines and they can be even more helpful in evaluating what is going on. The difference in gas patterns (air in the stomach and/or intestines) between when you, the patient is lying down and standing up can also be helpful. And of course some stones, such as large kidney stones or certain types of gall stones will also show up.

Still, many things in the abdominal area will not show up on plain x-rays, which is why exams like Upper G.I.'s, Barium Swallows, BE's (short for Barium Enema), Small Bowel Follow Through (SBFT for short), and IVP's often follow up the plain films taken of the abdomen when you are first treated. For more information on any of these exams, please follow the indicated link.

The most common group of x-rays however, are still the skeletal x-rays everyone thinks of when they think of x-rays at all. Just about any part of the skeleton can be x-rayed somehow or other, though some portions are more complicated than others. For instance, since the bones in the wrist tend to form a C shape when viewed along the axis of the arm, at least three pictures are normally taken to adequately show any fractures or breaks, and some facilities routinely take four pictures. Yet once a broken wrist is set in a cast, only two pictures are normally taken, partly because the material the cast is made out of will hide any small or subtle detail, and partly because the doctor is mainly interested in alignment at this point since he or she already knows what is wrong. The neck, or cervical spine is even more complicated. If the patient is in bad shape, often only a front view and a side or lateral view will be obtained. Yet this is deceiving to even say this, because the top two bones in the neck are hidden behind the jaw when viewed from the front, three pictures, not two, are the minimum number needed to see everything. In addition to that, since the bottom bone in the neck (commonly called C7) is between the shoulders, a person with big shoulders will often need a forth view to see all seven bones in the neck from the side. Then there are the holes in the neck bones, called foramina, where various nerves leave the spinal cord in the neck to travel down to the shoulders and parts of the arms. Since these holes are at an angle, at least two more views must be obtained if there is reason to believe that these holes, or foramina, may be deformed. Thus neck x-rays often involve six or seven pictures just to see everything.

Another question I often get is "If you can see the problem on the first picture, why are you taking more?" The reason is that we will almost always need a second picture 90 degrees from the first to see if what we are looking at has moved in more than one direction. For instance, if your arm is broken, it does you little good in the long run if the doctor just straightens it from side to side if it also needs straightening up or down. Yet if the doctor only has one picture, he or she will not know if it needs that additional straightening. Or say the doctor is trying to get a piece of broken glass out of your foot. Just knowing where it is from side to side will not help the doctor much if he or she does not know how deep inside the foot it is as well. This is why you do not receive just one picture when the doctor sends you for "an x-ray".

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