by Robert Braile, D.C.

 Part 1 - Chiropractic and Full Spine Radiography

Full spine x-rays are a unique part of chiropractic’s history. From the initial introduction of x-ray into chiropractic, full spine x-rays have been a tool used almost exclusively by chiropractors. Unfortunately, over the years fewer chiropractors are incorporating this procedure into their practice. Today most students aren’t even taught the technique, analysis or advantages of full spine x-ray.

Historically, one of the largest proponents of full spine x-rays was Dr. Clarence Gonstead. His work was based on the use of full spine x-rays. Indeed today, many of the followers of Gonstead’s work, and the derivatives such as Dr. Barge’s technique, still promote the use of full spine x-ray.

Over the years there have been those within chiropractic who have chastised the taking of full spine x-rays. Their reasons were not without merit. Claims of over-radiation and poor pathological diagnostic quality were not entirely accurate but not completely unfounded. The average practitioner stayed away from full spine x-rays because of the cumbersome film used in these 14"x36" full spine studies. In fact, it was probably the expense of the film and the storage problems created by 14"x36" film that kept most chiropractors who may have been interested in full spine work away from the procedure.

As a new practitioner nearly 20 years ago, I myself was interested in full spine pictures but not thrilled with the concept of 14"x36" film. I quickly realized that the options in full spine work were very limited, and I would have to solve some key problems myself, if I wanted to get into this type of work.

In years past, single exposure full spine x-rays were taken by exposing the patient to the same level of radiation at all areas of the body within the x-ray field. The only exception to this was a slight decrease in radiation from variations due to the "Heel Effect". Obviously, smaller parts of the body such as the head, neck and upper torso need less x-ray to make a proper exposure than would the lower spine and pelvis. This difference in body part thickness meant that if the same level of radiation was used on the same speed screen, the image would appear with the upper body being blackened and the lower body being white. To prevent this, some form of compensation would be needed.

Initially compensation was made by utilizing variable speed screens. This meant that the 14"x36" screen would have different speeds in different areas. The thinner parts would have slower speeds, while the thicker parts would have faster speeds. This old system did allow for proper imaging, but did nothing to protect the patient from higher levels of radiation where such higher levels were not needed.

With the consciousness of today’s consumer being focused on the most safety in imaging through the lowest possible exposure, a method other than split screens was needed. This is where filtration came in. Years ago, I purchased a filter that was suppose to solve the problem of over-radiation, and eliminate the need for split screens. These full spine filters or wedges decreased the amount of radiation to the patient’s body parts that didn’t need as much. This was accomplished by using aluminum to filter down the x-ray beam over the thinner areas of the patient. This allowed me to use the same speed screens for my full spine pictures while decreasing the amount of radiation that was directed to my patient in the thinner less dense areas. This meant that no part of the spine received more radiation than was needed to produce the image. It also meant that there was no need for expensive split, or multi-speed screens.

With the elimination of the split screens, I could also solve the other problem of the cumbersome 14"x36" film. This was done by using two 14"x17" pieces of film in one 14"x36" cassette, and by placing blockers in the proper place to allow for proper identification marking of the two 14x17 films. This yielded a 14"x34" picture using two pieces of film that I could later store in a standard x-ray envelope. These innovations for me represented a breakthrough. This meant I could take full spine films with standard high speed screens, standard 14x17 film, and not over-expose any portion of the patient.

Today, the quality and ease of use of full spine films is comparable to most other films. I have recommended these type of x-rays to doctors and students for years. I have found these types of films give me much additional information that is unavailable in standard sectional images. Aside from their clinical value, these films are a great patient educational x-ray tool for explaining the chiropractic approach to care. Patients better relate to films that show complete images of spinal and postural situations.

Recently, there has been a resurgence of interest in full spine x-ray. For years I made my own x-ray wedges based on my own experience and needs. Now I have new doctors and x-ray companies asking me to make wedges for them. So what started as an interest in keeping full spine x-rays in my practice, has grown into a small full spine x-ray wedge production business.

With full spine filtration wedges, and the using two pieces of 14x17 film, the problems of full spine x-rays of the past have been overcome. Most full spine x-rays are taken at either 72 or 84 inches. Because of this distance the angular distortion is about the same as a 14x17 inch study taken at 40 inches. Today, with the new more accurate and efficient x-ray machines, full spine x-rays are easier and of better quality than ever before. All that is needed is for more of our practitioners to embrace this unique chiropractic technology and learn how to become the experts at it.

 Part 2 - How to Take Full Spine Studies

Please remember that no filtration system works for all patients full spine x-rays can be taken on a large majority of patients. The technique and skill of the x-ray operator will determine the ultimate quality of the films. Each x-ray machine is also different. Accurate logs of your x-rays should be kept until you determine the perfect technique and factors for your system.

 Needed Equipment

The following equipment is essential to be able to take full spine x-rays using wedges.

1. X-ray equipment capable of shooting upright films at 72 or 84 inches. Check with your dealer to fully explain if your system has such capabilities.
2. Light projecting collimator with appropriate slide rails or other mounting accommodations.
3. Cassette holder with bucky capable of holding both 14"x36" as well as 14"x17" and any other size films you wish to take.
4. Full spine cassettes with either 14"x36" screens or two 14"x17" screens mounted end to end.
5. Appropriate film and developing capabilities.
6. A set of full spine x-ray wedges.
7. All other needed equipment for x-ray imaging.
8. Two 14"x36", or one 28"x36" view boxes.

Principle Behind Full Spine Wedges

In order to properly take a full spine x-ray, the patient must be exposed to one exposure of x-ray taken at 72 to 84 inches away from the x-ray tube. Using full spine wedges allows you to take a full spine x-ray while reducing the level of radiation to the parts of the spine that do not require as nearly as much x-ray.. This accomplishes a few things:

1. No part of the spine receives more radiation than is needed to produce the image.
2. Reduction of x-ray radiation up to seven times over split screen systems.
3. No need for expensive multi-speed screens.
4. No screen speed lines on films, images appear as one continuos picture.
5. Can allow the doctor to use either one 14"x36" or two 14"x17" films.
6. If the doctor chooses to use 14"x17" films, they can be stored in standard x-ray envelopes.

 Which patients should not receive full spine x-rays.

Obviously not all patients are the same. Therefore, just as obviously not all patients can receive full spine films. Below is a list of possible criteria you may need to remember when determining who can not be adequately imaged using full spine films.

1. Extra large patients where the difference between the cervical thickness and the lumbar thickness is far too great for the wedge to compensate. These individuals will also present a basic problem of x-ray generation at 72" and may best be imaged using at 14"x17" film at a 40" distance.
2. Very tall patients where their spinal structure will not fit in a single exposure. These individuals may require a full spine picture of the thoracic and lumbo-pelvis, followed by a separate cervical x-ray, or a full spine x-ray of the cervicals, thoracic and lumbars, followed by a separate pelvis shot.
3. Many patients who can easily be imaged with a full spine A-P view can not be imaged with a full spine lateral view. Due to the increased thickness difference in body parts viewed laterally, it is recommended that only small and medium patients be imaged using lateral full spine films. Most doctors prefer to only use full spine x-rays for the A-P views.
4. Any particular patient that will present difficulty in taking films at 72" is not a candidate for full spine x-rays. Size, ability to stand still, posture and positioning must all be considered.

Aside from the considerations above, quality full spine films can be taken on the majority of your patients. Please use your own good judgment when determining what are the capabilities of your x-ray system and equipment. Since each x-ray installation behaves slightly differently, the criteria for who can have these full spine x-rays will vary.

 Proper Training

Taking full spine x-rays does require some expertise. This article will give you some helpful pointers on taking these films. However, these instructions in no way should replace formal training on these procedures. Anyone not familiar with the taking of full spine x-rays should seek proper training.

 The Procedure

1. The decision is made as to whether only an A-P full spine is taken, or if a lateral will also be taken. Remember that many people who can have an A-P study cannot be imaged properly in the lateral full spine.
2. Patient is appropriately dressed or gowned.
3. Full spine cassette is placed in bucky.
4. X-ray tube is set at either 72 or 84 inches from film. The further away the distance, the stronger the x-ray machine will need to be. It may be advisable for tube life to remain at 72 inches for most full spine studies.
5. The full spine wedge is NOT in place at this time.
6. The patient is placed with their back to the film in the center of the bucky. (for A-P) Arms at side looking straight ahead. If a lateral is to be taken patent is positioned at 90 degrees to film with arms folded in front of them to keep arms out of image.
7. Instruct patient to stand comfortably straight but not falsely at attention. The patients head does not have to contact bucky in an A-P study. Patient should feel comfortable with the feeling to them that their weight is evenly distributed between their two feet.
8. Set the collimator light beam to the size of the film (either 14"x34" or 14"x36") then close in light slightly to show calumniation on film. (Many states require this, check you state law.)
9. Use collimator light to align x-ray beam. Unlike other studies, you are more concerned about the top and bottom of these films than the central ray. You do not want to cut off the cervicals or lose the lower lumbars. If the patient is too tall, you will have to decide what portion of the patient you do not need in the full spine image.
10. It is recommended that you place the top of the light from the calumniator at just the correct height to include the atlas and occiput in your study. Then see if the bottom of the light includes the lumbar and pelvic structures you desire to see.
11. If the patient is too tall, you may want to take a separate study of the pelvis later or, lower your beam to include the lower structures and take separate cervical films later.
12. Line up your film and bucky with the light beam from your collimator. Remember, if you are taking a 14"x34" study, you are still using a 14"x36" cassette. There are no 14"x34" cassettes in production at present. Because of this either the top or the bottom 2 inches of the cassette has no film. You must remember which side your 2 inch gap is on and position the cassette and bucky accordingly. It is advisable to always load your film the same way with the 2 inch gap in the same place so as to be consistent and avoid errors.
13. Set x-ray factors based upon a 72 or 84 inch exposure of the largest body part in the study. This is usually the lumbar or pelvic regions. Remember, you are taking the study at 72 inches and not 40 inches. This increased distance will require a large increase in x-ray production in order to have the same exposure to the patient. Consult your x-ray factor chart or an x-ray expert if you are unfamiliar with what factors to use. Since each machine is different, you may not get perfect films at first until you can regulate the proper technique. The new x-ray units with automatic exposure control are the best answer to factor determination.
14. In an A-P full spine study, you may want the patient to open their mouth in order to image the atlas - axis region. You therefore would get overlap of the jaw in the mid cervicals. You need to decide which structures are most important to you.
15. Select the proper size x-ray filtration wedge you are going to need. (most wedge packages sell two sizes, small and large) Larger differences between the patient’s cervical and lumbar thickness will require a larger wedge. A good rule of thumb to use is that medium to large men require a large wedge, while medium and smaller women will require a smaller wedge.
16. When the patient is finally properly positioned and the factors are set, place the full spine wedge into the collimator slide mount. You may have some other mounting system depending on your collimator. Older collimators can always be fitted with Velcro strips which can accordingly be secured to the Full Spine Wedge plates. The thicker part of the wedge should be upward covering the cervical spine.
17. With the collimator light still on you should see that the wedge blocks the light on the patient’s upper half of their body. No light should be seen above the blocked out area or the wedge many be malpositioned.
18. You should now be ready for the exposure.
19. After the exposure remove the wedge immediately so as not to allow you to improperly collimate for the next x-ray.
20. Keep an accurate and complete record of your exposure factors and which wedge you used on each study in order to improve your technique. This procedure will yield you the best long term films possible.

 Points to Remember

• The heavier or larger the patient, the less likely they are a candidate for full spine films.
• Many more people can be x-rayed using a full spine A-P study than a lateral study.
• If you are using two 14’x17" films in a 14"x36" cassette, two inches of your cassette contain no film. Align your studies accordingly.
• Make sure your x-ray setup is installed properly with the Heel Effect causing the stronger beam of x-ray to be produced to the bottom of your exposure. You may have to check with your x-ray installer to assure this. Most proper installations are already set this way. If it is reversed, it may create some problems in any full spine imaging.
• Full spine studies can be shot at 84 inches. However, this will require more x-ray generation from your machine, and may be beyond the limits of your equipment. The harder you work your x-ray machine the shorter the overall life span.
• Be sure your exposures are not beyond the capacity limit of your x-ray tube and equipment. Automatic safety protection circuitry is the best way to ensure that you can not inadvertently damage your equipment.
• Due to distance and angular distortion, full spine studies may be less pathologically diagnostic. Additional pathology films may need to be taken if clinically indicated.
• Full spine x-rays are more posturally and structurally demonstrative. These films better show spinal distortion than do sectional shots.
• Full spine x-rays are gravitational and should not be taken with patient recumbent.

It is my hope that those that decide to utilize full spine x-rays will have a good clinical experience. Full spine x-rays were developed in chiropractic especially for the structural nature of the work we do. Aside from the clinical benefits, you will also be able to more easily relate spinal findings to your patients with these films. The more the patient understands, the more cooperative they ultimately are in their care.