Finding the right tests…
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Finding the right tests…
CT Scan
The craniovertebral junction is the small, complex joint where your skull meets the top of your spine, held together mostly by ligaments rather than a disc, which is why instability here can be hard to catch on a scan taken in one fixed position. This test images that junction twice - once with your neck bent forward and once tilted back - then reconstructs both into 3D, so a radiologist can compare how the bones move between the two positions rather than judging alignment from a single snapshot. It's a specific study ordered when instability is suspected but doesn't show up clearly on a standard neck CT, including after certain injuries or in congenital conditions affecting this joint.
This scan images the base of the skull, the atlas and axis vertebrae, and the ligaments holding them together, in both flexed and extended neck positions. It's built to detect abnormal movement between the two positions, not just a single alignment. Your doctor interprets the movement pattern together with your symptoms.
This is the joint where your skull sits on the first two neck vertebrae, the atlas and axis. Unlike most of your spine, there's no disc here - the joint depends on ligaments for stability, which is part of why it can loosen in ways a still image doesn't always catch.
A standard neck CT captures one position. This test takes images with your neck flexed forward and again extended back, then builds 3D reconstructions of each, so the radiologist can directly compare bone position and spacing between the two. Research on this technique has shown it can pick up abnormal facet joint movement in patients whose standard scans looked stable.
- Suspected instability at the craniovertebral junction after injury - Congenital abnormalities of this region with unclear stability on standard imaging - Follow-up after surgery in this area, to check for new instability - Symptoms suggesting spinal cord involvement without a clear cause on regular imaging
This is a more specialized study than a routine cervical spine CT - ask your doctor why it's specifically being requested for you.
CVJ stands for craniovertebral junction, the joint where your skull meets the top two vertebrae of your neck.
It means the scan is taken in two different neck positions - flexed forward and extended back - so the radiologist can compare bone movement between them, rather than judging stability from one fixed position.
A standard cervical CT images the neck in one position. This scan is specifically built to catch instability that only shows up when the neck moves, using two positions and 3D reconstruction.
Yes, you'll be positioned with your neck bent forward for one set of images and tilted back for another. Ask the centre how this is managed if you have limited neck movement or pain.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Since it involves two full sets of images instead of one, it does involve more radiation than a single-position scan. Your doctor weighs this against how specific a question the scan is answering.
It's ordered when instability at the craniovertebral junction is suspected but hasn't been clearly confirmed on standard imaging - the two-position comparison can reveal movement a single scan would miss.
The scan itself isn't painful, though holding a flexed or extended neck position briefly may be uncomfortable if you already have neck pain. Tell the technologist if a position is difficult for you.