Why Upper Cervical X-Rays Are Taken at Angles Built Around Your Skull

Where your skull meets your spine there are two small joint surfaces, one on each side, carrying the entire weight of your head. Those surfaces are curved and angled rather than flat, the angle is different from person to person, and in most people the left one and the right one are not the same as each other. That last part surprises patients more than anything else in this explanation.

A standard cervical X-ray series takes its images from fixed positions, because it is designed to answer general questions like whether a bone is fractured or how much degeneration is present. For those questions it works well. For the question an upper cervical practitioner is asking, which is whether one specific joint has shifted and in which direction, a fixed angle means the beam usually crosses the joint surface rather than running along it.

Looking at a joint from an angle it was not designed to be viewed from produces a shadow, not a measurement. A shadow can suggest a misalignment that is not really there. It can also flatten out one that is.

Blair imaging inverts the order. Before any image is taken, your skull and upper neck are measured, and those measurements set the angle for each individual view. The beam is aimed to travel parallel to your joint surface, not the average joint surface.

What comes back is a picture of that joint seen squarely. From it, Dr. Porter can determine whether the joint has actually misaligned, in which direction, and to what degree, and those three answers together produce the vector for the correction.

This is also why the adjustment can be so light. Force is what you use when you are not certain where to go. When the direction has already been established on film, the correction becomes a matter of accuracy rather than effort, and there is no reason to twist or crank a neck to deliver it.

There is a practical payoff that patients care about more than the anatomy. A correction placed along the right vector tends to hold longer than one placed approximately, and upper cervical care is built entirely around holding.

At each visit you are checked before anything else happens, and if the correction is holding you are not adjusted. Over a course of care that usually means fewer adjustments rather than more, which is the opposite of what most people expect when they hear that imaging is involved.

X-rays use ionizing radiation. That is true, it is reasonable to ask about, and the answer should not be a brush-off.

Two things reduce the exposure in practice. Digital imaging requires substantially less radiation than the film systems most people are picturing, and a targeted series of the upper neck covers a small area rather than a broad one. The judgment that matters more than either is whether the images are worth taking at all. We image when it will direct the correction. If it will not, it is not done, and you will be told why either way.

Children are handled differently. Pediatric visits generally skip imaging unless a specific injury calls for it, and pregnant patients are worked with under the Webster Technique with imaging only where there is a clear clinical reason.

You do not get handed a folder and a summary. Your images go up on the screen at the second visit and Dr. Porter walks you through them: this is the joint, this is the angle we built for you, this is what it should look like, this is what yours looks like.

Patients tend to find this the most useful appointment of the whole process, because it converts a vague sense that something is wrong in your neck into something you can see. It also makes it much easier to have an honest conversation about whether this approach is the right one for you.

Imaging answers a structural question and nothing else. It does not tell you whether your headaches are coming from your neck, whether your dizziness is cervicogenic or vestibular, or whether the thing bothering you is mechanical at all. Those answers come from history and examination, and the film is one input among several.

It also does not settle every case in our favor. Sometimes the images and the exam together say that upper cervical care is not what you need. When that happens you will hear it plainly at your report of findings, and Dr. Porter will point you toward what does fit.