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X-ray of the sacroiliac joints
Last reviewed: 23.04.2024
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X-ray of the ilio-sacral (ileosacral) joints visualizes the most important anatomical structures of the musculoskeletal system: paired sacroiliac joints that connect the articular surfaces of the sacrum (os sacrum) and the iliac bones (os ilium) entering the pelvic ring.
Indications for the procedure
Visualization of these joints using X-ray is carried out:
- with injuries of the sacroiliac joint (one or both) and pelvic bones - cracks and / or fractures; [1]
- To find out the causes of frequent or persistent pain in the sacroiliac joint , felt as pain in the lower back (lumbosacral spine) or in the pelvis;
- in cases of problems with movement due to a violation of their stability (these joints belong to partially movable joints - amphiarthrosis);
- in order to diagnose local inflammatory processes, for example, with suspected sacroiliitis.
Preparation
Before this study, preparation is needed, which consists in temporarily (within three days of the procedure) limiting the intake of food rich in fiber (fiber), as well as increasing gas production in the intestine. And in the presence of such a problem as constipation, laxatives should be used on the same three days.
In addition, in the evening on the eve of the X-ray, you should not eat after 19 hours, and in the morning you should do a cleansing enema.
Technique of the x-ray of the sacroiliac joints
Common X-ray techniques include shielding body parts adjacent to the X-ray area: when examining the ileosacral joints, lead plates are required to protect the upper abdomen according to the International Commission on Radiological Protection (ICRP) radiation protection protocol.
The specificity of the location of the structures of the sacroiliac joint - the parts of the ilium and the sacrum that form it are located at an angle to the sagittal (median) plane of the body, overlapping each other in the frontal (straight) plane - requires targeted radiography in several projections.
The patient is placed on the X-ray table on his back, but the part of the body below the waist should be at a slight angle to the horizontal surface of the table, for which rollers are used. A cassette with an X-ray film is placed where the upper posterior protrusions (awns) are projected on the crest of the iliac spine, and the X-ray machine beam is focused from a meter distance to the abdominal cavity - slightly to the side of its midline, at the level of the upper anterior os ilium awns. [2]
The position of the patient in a half-sitting position and tilting the body forward or leaning back (with the cassette placed under the buttocks) may be necessary in cases of fractures of the ileosacral joints. [3]
Complications after the procedure
A short-term negative consequence of this examination may be a feeling of discomfort and increased pain in an inflamed or injured joint. To avoid this, it is possible to administer a local anesthetic (novocaine blockade) before starting the procedure.
There were no cases of complications after this procedure, since the radiation doses are very low, and when its total dose is less than 1000 mSv (millisieverts), there are no health risks.
For comparison: in an X-ray of the pelvic ring bones (including the sacrum) in frontal projection, the radiation dose does not exceed 2.23 mSv, in the lateral projection - 1.57 mSv.
Reviews
Numerous reviews of specialists testify to the rather limited diagnostic capabilities of the X-ray of the sacroiliac joint to identify the causes of the so-called sacroiliac pain syndrome: according to estimates, the accuracy of this method does not exceed 40.5%, and the sensitivity does not reach 30%.
Also, radiography is not suitable for the early detection of sacroiliitis and other lesions of the sacroiliac joints, therefore, other methods of instrumental diagnostics are used, in particular, osteoscintigraphy, computed or magnetic resonance imaging.