Dr Viana sent this, which I find very helpful
The first thing is that this is an incidental finding in a male patient over 45; it’s very unlikely that an axial spondyloarthritis would have such extensive changes on radiographs without a compatible history. Furthermore, the lack of involvement of the interapophyseal and sacroiliac joints also doesn’t make me think of ankylosing spondylitis, and the osteophytes of the cervical and thoracic spine don’t remind me of enthesophytes (which are very delicate and vertical, usually at the periphery of the disc). Additionally, ankylosing spondylitis classically shows ascending involvement, from the sacroiliac joints to the lumbar spine and so on. The most appropriate description I have read – I don’t remember if it was by Resnick himself – says that DISH is an "ossifying diathesis", so the focus of the changes is on new bone formation, and findings related to inflammation are notably absent; I think that’s the catch.
The most characteristic element of DISH is the presence of continuous, thick, and coarse paravertebral osteophytes that result from the ossification of soft tissue structures around the vertebra. Such "bridging" osteophytes are most commonly anterior and symmetrical in the cervical and anterolateral segments and asymmetrical in the thoracic segment, where they predominate from T7 to T11 and to the right of the midline, and a linear radiolucency separating the vertebral body from the ligamentous ossification is common. In the cervical spine, coarse ossification of the prevertebral soft tissues is typical, notably along the lower half of the anterior contour of the vertebral body, with a "candle flame" or "parrot’s beak" appearance. The lumbar spine is the most rarely affected segment, with abnormalities along the anterior contour of the vertebral bodies (similar to those of the cervical segment) or anterolaterally (similar to those of the thoracic spine), with no predominance of laterality; ossification of the interspinous and supraspinous ligaments may also be present. New bone formation and enthesophytes/spurs of the pelvic entheses and appendicular skeleton (notably at sites such as the patella, anterior tibial tuberosity, calcaneus, and olecranon) characterize extravertebral enthesopathy in DISH syndrome. (I’ve translated this last paragraph from my book).
From Dr Robinson:
Is the take home message that it is DISH if the SI joints are normal?
Unfortunately no.
23% of DISH cases have intra articular ankylosis when assessed by CT.
2 papers attached (just skim through and look at the figures, they aren’t otherwise very riveting papers imo).
The mature entheseal spurring along the iliac crests on your XR is extremely good for DISH.
On Wed, Mar 5, 2025 at 9:51 AM hilary wrote:
Apologies in advance for a very basic question.These images are from a skeletal survey in a 78M done for "high globulin levels".I have no other medical history and there are no previous imaging studies in our facilities.
The spine changes look like ankylosing spondylitis.
His SI joints, shoulder, hip, and peripheral joins look mostly normal.
This is not the concern of the referrer, but I am confused by this.
Do I report this as spine changes of AS without SI joint fusion or sacroiliitis?Please clarify.
Hilary
ct sacroiliac joints DISH.pdf
DISH sacroiliac joints and spine CT.pdf
