POSTER SECTIONS Coverpage Learning objectives Background Findings and procedure details Conclusion Personal information and conflict of interest References

ECR 2023 / C-18281

Vertebral Osteoporotic Fractures on CT imaging and radiological mimics: Practical Diagnostics Guide for Radiologists.

Congress:

ECR 2023

Poster Number:

C-18281

Type:

Educational Exhibit

Keywords:

Bones, Musculoskeletal bone, Musculoskeletal spine, CT, MR, Plain radiographic studies, Education, Demineralisation-Bone, Education and training, Osteoporosis

Authors:

K. Harrison, E. M. Musanhu

DOI:

10.26044/ecr2023/C-18281

DOI-Link:

https://dx.doi.org/10.26044/ecr2023/C-18281

Findings and procedure details

We aim to demonstrate the key features to recognise VFFs. They should not be confused with expected age-related degenerative remodelling, features including sclerotic endplates with the cortices intact and normal bone density.

Vertebral fragility fractures can be characterised by morphometric or morphologic evaluation. This presentation aims to demonstrate morphometric evaluation of VFF on radiographs, CT and MRI, and associated pitfalls.

How to recognise VFFs:

Disruption of the cortices of the endplates and anterior border.
Loss of vertebral body height compared to adjacent vertebrae.
Overall reduction in bone mineral density.
Compare with previous imaging – is there a new vertebral deformity?

Studies have demonstrated the use of average Hounsfield units (HU) on computer tomography (CT) to predict osteoporosis. The suggested threshold for diagnosing osteoporosis is 87-111 HU, with the threshold for ruling out osteoporosis/osteopenia being 99-125 HU³. This method has the potential to do quick opportunistic bone density assessments on readily available imaging thus eliminating the need for extra tests such as dual-energy X-ray Absorptiometry (DEXA) to diagnose osteoporosis.

Manifestations and evaluation of VFF on different imaging modalities utilising:

Different classification systems for assessment of vertebral fragility fractures:

Fig 1

A recent National UK audit with the Royal College of Radiologists used the Genant’s semi-quantitive method to assess for Grade 1, 2 and 3 vertebral fractures. We therefore aim to describe vertebral fractures using X-ray, CT and MRI using the Genant Semi-quantitative method. Using this method, the shape of the fracture has been described as wedge, biconcave and crush fractures (fig.2). The shape has not been shown to have bearing on clinical symptoms or presentation and most fractures demonstrate a combination of deformity shapes⁵.

According to the Genant’s semi-quantitive method, a wedge fracture is defined as a difference in height between the anterior and posterior vertebral borders of >20%. When using this technique, it is important to take into consideration the appearance of adjacent vertebral bodies⁵. Age-related remodelling can also demonstrate a loss of >20% vertebral height without endplate disruption and should not be interpreted as fractures.

Fig 2: “Genant et al. 2009. FIG. 1. Semiquantitative visual grading of vertebral...

Grade 1 20-25% vertebral body height loss with structural evidence of fracture:

Fig 3

$Fig 4: Figure 3/4: 78 year old female with Grade 1, T10 (29%) and T12 (20%) wedge fragility fracture. (a) lumbar spine lateral radiograph. (b) Zoomed in view of T10 and T12 wedge fractures. Disruption of smooth cortex at the superior endplate of both T10 and T12 vertebral bodies is consistent with a fracture (arrow). (c) Diagram demonstrating how to measure anterior and posterior vertebral body heights used to measure % height loss to grade the fracture using Genant’s semi-quantitative classification.$

Fig 4: Figure 3/4: 78 year old female with Grade 1, T10 (29%) and T12 (20%) wedge...

$Fig 5: Grade 1, L1 mixed wedge and biconcave fragility fracture. (a) whole spine computed tomographic sagittal reformat demonstrating multilevel degeneration of the thoracic spine and L1 vertebral fracture. (b) zoomed in view of L1 fracture – there is deformity of the L1 superior endplate with endplate sclerosis (arrow), suggesting this is a long standing fracture.$

Fig 5: Grade 1, L1 mixed wedge and biconcave fragility fracture. (a) whole spine...

$Fig 6: Grade 1, T4 wedge fragility fracture and evidence of progression of fractures 1 year later and new T8 fracture. MRI of C- and upper T-spine sagittal reformat. (a) T2 weighted. Linear high T2 signal fracture line seen through T4 vertebra (b) T1 weighted. Homogenous low T1 bone marrow signal from bone oedema (c) STIR. High signal bone marrow and linear fracture line.$

Fig 6: Grade 1, T4 wedge fragility fracture and evidence of progression of fractures 1...

$Fig 7: Grade 1, T4 and T8 vertebral fragility fracture and evidence of progression of fractures 1 year later. MRI of C- and upper T-spine sagittal reconstruction a, b, c and 1 year apart d, e, f. (d) T2 weighted C- and T-spine MRI 1 year later. Low T2 signal linear fracture line shows chronicity of previously demonstrated T4 fracture and now imaged T8 fracture. (e) T1 weighted. Low T1 signal of fracture line. Normal bone marrow signal shows established fractures. (f) STIR. High signal fracture lines with no evidence of bone marrow oedema.$

Fig 7: Grade 1, T4 and T8 vertebral fragility fracture and evidence of progression of...

Grade 2: 26-40% vertebral body height loss with structural evidence of fracture.

$Fig 8: Lateral lumbar spine radiograph demonstrating grade 2 biconcave L2 fracture. Note the irregularity and deformity of the superior endplate cortex with the most pronounced depression in the middle of the vertebral body.$

Fig 8: Lateral lumbar spine radiograph demonstrating grade 2 biconcave L2 fracture....

$Fig 9: Lateral lumbar spine radiograph demonstrating grade 2 wedge fracture. Again irregularity of the superior endplate with reduction of the anterior VB height compared to the posterior vertebral body height by 30%.$

Fig 9: Lateral lumbar spine radiograph demonstrating grade 2 wedge fracture. Again...

$Fig 10: Grade 2 T11 wedge fracture. (a) Whole spine CT sagittal reconstruction demonstrating multilevel degeneration. This allows us to compare the shape of the T11 vertebra to the adjacent vertebral bodies where we can appreciate the loss of parallel superior and inferior endplates compared to the adjacent vertebrae. (b) zoomed in view of the T11 vertebra to demonstrate disruption of the anterior border cortex (arrow). At the T12 inferior endplate, there is a focal invagination with sclerosis of the adjacent bone, typical features of a Schmorl’s node, not to be mistaken for a fracture.$

Fig 10: Grade 2 T11 wedge fracture. (a) Whole spine CT sagittal reconstruction...

$Fig 11: Grade 2 L4 mixed biconcave and wedge fracture. (a) Lumbar spine CT sagittal reconstruction demonstrating an L4 fracture and an L1 Schmorl’s node (arrow head). Make note of the L4 deformity compared to the adjacent vertebrae and recognise it is an outlier, supporting a diagnosis of a vertebral fracture. (b) zoomed in view of the L4 vertebra to demonstrate the breach in the cortex of the superior endplate (arrow).$

Fig 11: Grade 2 L4 mixed biconcave and wedge fracture. (a) Lumbar spine CT sagittal...

Grade 3: >40% vertebral body height loss with structural evidence of fracture.

$Fig 12: 76 year old female with known osteopenia. Had a fall from standing 3 weeks prior to presentation. Same day lumbar spine radiograph and CT imaging. Grade 3 T12 wedge fracture. (a) Lumbar spine lateral radiograph demonstrates deformity of the T12 superior endplate and significant reduction in the anterior border height compared to the posterior VB height. (b) same CT sagittal reconstruction demonstrating T12 fracture. Sclerosis of the superior T12 endplate shows the fracture is subacute. (c) zoomed in view of T12 grade 3 vertebral wedge fracture.$

Fig 12: 76 year old female with known osteopenia. Had a fall from standing 3 weeks...

Fig 13

$Fig 14: Figure 13/14: 84 year old female with history of previous breast cancer and radiotherapy. CT thorax performed due to ongoing back pain and concerns of breast cancer recurrence causing bony metastases. T8 vertebral wedge fracture with vertebral body sclerosis suspicious of sclerotic metastases. (a) CT sagittal reconstruction demonstrating T8 fracture. Deformity of the anterior border, loss of vertebral body height and sclerosis of the T8 vertebral body. (b) T2 weighted. Low T2 signal fracture line seen through the anteroinferior T8 vertebral body portraying a benign fracture . (c) T1 weighted. No evidence of intermediate bone marrow signal to suggest soft tissue infiltration. (d) STIR. Mild T8 vertebral body oedema consistent with a subacute vertebral fracture. Retropulsion of the vertebral body is seen without impingement of the spinal cord. No adverse features to suggest a pathological malignant fracture.$

Fig 14: Figure 13/14: 84 year old female with history of previous breast cancer and...

When assessing for vertebral fragility fractures it is important to consider fracture mimics. For which we will address below:

Mimics: Schmorl’s nodes and Sheuermann’s disease

Figures 10 and 11 demonstrate typical appearances of Schmorl’s nodes (arrow head). Schmorl’s nodes are caused by invagination or herniation of intervertebral disc material into the vertebral body endplate. Adjacent to the Schmorl’s nodes you often see marginal sclerosis of the bone adjacent to the node due to bone remodelling.

Fig 10: Grade 2 T11 wedge fracture. (a) Whole spine CT sagittal reconstruction...

Fig 11: Grade 2 L4 mixed biconcave and wedge fracture. (a) Lumbar spine CT sagittal...

Scheuermann disease is defined as multiple schmorl’s nodes causing wedging and kyphosis:

Schmorl’s nodes in ≥ 3 contiguous vertebrae
usually in the thoracic spine
at least 5^o of wedging at each level

Fig 15: Scheuermann disease in a 36 year old male. MRI lumbar spine demonstrating...

Mimics: Malignant fractures

Fig 16: Lytic bony metastasis causing wedge deformity of the T10 vertebra in a 49 year...

There are features that can help distinguish between a benign vs. malignant fracture:

Fig 17

Fig 18

$Fig 19: Figure 18/19: Lytic bony metastasis of L1 vertebra causing wedge and loss of the posterior cortex. (a) CT sagittal reconstruction demonstrating lytic lesion at the posterior L1 vertebra. (b) T2 weighted. Isointense signal seen within L1 vertebra with convex bulging of the posterior border suggestive of soft tissue infiltration. Schmorl’s node can been seen in the superior end plate of L4. (c) T1 weighted. Low T1 signal involving almost the entire L1 vertebral body in keeping with an infiltrative process. (d) STIR. Increased signal of the entire L1 vertebra further supporting a pathological fracture.$

Fig 19: Figure 18/19: Lytic bony metastasis of L1 vertebra causing wedge and loss of...

$Fig 20: Sclerotic multilevel spinal metastasis in an 82 year old female. History of inflammatory breast cancer 3 years prior now presenting with sclerotic bone lesions seen on CT sagittal reconstruction. Diffuse sclerosis seen within the vertebral bodies, not conforming to the endplates as would be seen in a fragility fracture.$

Fig 20: Sclerotic multilevel spinal metastasis in an 82 year old female. History of...

Fig 21: 73 year old male with prostate cancer presenting with back pain. Sclerotic...

$Fig 22: 86 year old male with prostate cancer and rising PSA. Presented with new severe back pain. New sclerotic lesion in L4 vertebral body and right superior pubic ramus (image not shown). Vertebral body height is preserved and global sclerosis is seen, which would not be in keeping with a fragility fracture.$

Fig 22: 86 year old male with prostate cancer and rising PSA. Presented with new severe...

Mimics: Multiple Myeloma

Fig 23: 76 year old female with Multiple Myeloma. (a) CT sagittal reconstruction...

$Fig 24: Example of Multiple Myeloma with expansile lytic lesions, an uncommon presentation. Infiltrative mass demonstrated at L1 with thoracic medullary disease progression and compression fractures. (a) T2 weighted. Abnormal isointense bone marrow signal seen in the T6, 7, 8 and 10 vertebral bodies with bulging of the posterior border of T10. (b) T1 weighted. Infiltration of the posterior L1 vertebral body can also be appreciated on this sequence. (c) STIR. High signal particularly demonstrated in posterior L1 and T10 vertebral bodies. The posterior border of T10 can be seen bulging into the spinal canal, without causing impingement of the spinal cord.$

Fig 24: Example of Multiple Myeloma with expansile lytic lesions, an uncommon...