Dr. Korey Jay BSc DC
Diagnostic imaging has improved by leaps and bounds since the development of the first radiographs over one hundred years ago. In 1896 Wilhelm Roentgen discovered and pioneered the study of radiology, and in certain parts of the world radiographs (x-rays) are still referred to as “Roentgenographs” in his honour. Prior to the discovery of radiographs, health care practitioners had to rely solely on clinical findings to establish a diagnosis. Now there are a wealth of imaging tests to aid in the diagnosis of a variety of conditions or anomalies, this post will attempt to differentiate some of the types of imaging available and what types of conditions they are best used for.
The basis of radiography is that certain forms of radiation will penetrate different materials at different strengths. For instances, x-rays will easily penetrate soft tissues such as skin and muscle, but will not be able to penetrate bone or metal as easily. Armed with this knowledge, one can use the differences in the penetrative power of the x-ray to create an image of the body. Radiographs are of particular use as a scanning tool, as they are quick and easy to obtain. However, there are some drawbacks to radiographs. As radiographs produce a two dimensional image, it is necessary to take at least two radiographs at perpendicular angles to one another in order to get a sense of the three dimensional structure “One View is No View!”. Radiographs are also relatively non-specific or sensitive. Cancerous processes of bone, for instance, often require nearly 60% progression of damage until they show up on a regular plain film radiograph. Also, radiography utilizes ionizing radiation which can cause cell death or other damage and thus must be employed judiciously.
In order to compensate for the lack of sensitivity or specificity of the regular plain film radiograph, the CT Scan was developed. A CT, or “Cat Scan”, is essentially a three-dimensional radiograph. Employing a circular or tube-shaped apparatus, the CT Scanner basically takes a series of 360 degree radiographs to obtain a “slice” of the body being examined. This technology was a great leap forward, and has advantages of being quick and quite specific. The disadvantage of ionizing radiation still exists, however.
As any expectant mother will tell you, ultrasound is a powerful and amazing tool. In place of ionizing radiation, ultrasound utilizes ultrasonic frequency sound waves, which have the ability to penetrate tissues to produce an image. Ultrasound is useful as it is not damaging to the individual, it produces an image in which one can also view the soft tissues (muscle, joint, ligament etc. which are not easily read on a radiograph) and the images may be obtained quickly. This allows ultrasound to be employed to assess the abdominal contents such as the organs of the body in an efficient manner. As with radiographs however, ultrasound technology does not produce a clear image, which results in a lack of sensitivity.
Magnetic Resonance Imaging (MRI):
MRI is the gold standard of imaging, and the only way to produce a more clear, sensitive and specific image is to actually biopsy a tissue (Biopsy=cutting out a section of tissue to look at under a microscope). The basic concept of MRI is that the cells and tissues of our body create a net magnetic “spin” or “direction” due to the inherent polarity of the nuclei of the atoms they are composed of (confusing? Tell me about it!). Without getting in to nuclear physics too much, MRI works by applying a hugely powerful magnet to knock the body’s magnetic polarity off-kilter. When the magnet is turned off, a scanner in the machine registers the “Resonance” of the body’s tissues as they return to their resting state. While confusing, this triumph of physics results in a crystal clear image that may be viewed three dimensionally and is safe to the patient. Drawbacks to MRI are long waiting times, you may not have MRI if you have any metal in your body (it is a giant magnet, think about it!) and it can be a long, noisy and somewhat claustrophobic environment.
Chiropractors are trained extensively in utilizing every type of diagnostic imaging to reach a working diagnosis for our patients. We at Queen Street Chiropractic Centre believe that imaging is to be employed only when there is some uncertainty or suspicion of underlying factors, or if there has been trauma to the area of concern. A proper and thorough medical history and physical examination is still the preferred method of diagnosing the patient’s complaint. However, if necessary the Doctors at Queen Street Chiropractic Centre will refer for diagnostic imaging, and will be more than happy to sit down with a patient to assess the images and discuss the findings and what options are available to the patient.
Feel free to book an appointment at Queen Street Chiropractic Centre today!