Opportunistic diagnosis of osteoporotic vertebral fractures on standard imaging performed for alternative indications

Abstract

Osteoporotic vertebral fractures (VFs) are the most common type of osteoporotic fracture. Patients with VF are at increased risk of hip fractures or additional VFs, both of which contribute to patient morbidity and mortality. Early diagnosis of VFs is essential so patients can be prescribed appropriate medical therapy. Most patients with clinical suspicion for VF have an X-ray of the spine. Many VFs are invisible on X-ray and require further imaging. CT can provide excellent bony detail but uses high doses of ionising radiation. MRI provides excellent soft tissue detail and can distinguish old from new fractures in addition to differentiating osteoporotic VFs from other causes of back pain. Bone scans have a limited role due to poor specificity. The literature suggests that radiologists frequently miss or do not report VFs when imaging is requested for an alternative clinical indication and when there is no clinical suspicion of VF. Common examples include failure to identify VFs on lateral chest X-rays, sagittal reformats of CT thorax and abdomen, lateral localizers on MRI and scout views on CT. Failure to diagnose a VF is a missed opportunity to improve management of osteoporosis and reduce risk of further fractures. This article discusses the role of radiographs, CT, MRI and bone scintigraphy in the assessment and recognition of osteoporotic fractures. This article focuses on opportunistic diagnosis of VFs on imaging studies that are performed for other clinical indications. It does not discuss use of dual energy X-ray absorptiometry which is a specific imaging modality for osteoporosis.

Figure 1.

Lateral lumbar spine radiograph of an 80-year-old female with multiple insufficiency compression fractures; severe anterior wedge fracture at T12, mild compression fracture of L1 and L4 superior endplates and moderate compression fracture at L2.

Figure 2.

Lateral thoracic spine radiograph with multiple mild vertebral insufficiency compression fractures of T4, T5, T6,T9, T11 and moderate compression fracture of T12.

Figure 3.

Sagittal STIR image of an acute mild compression osteoporotic fracture of T10 in a 67-year-old female patient. STIR, short tau inversion recovery.

Figure 4.

Sagittal reformatted CT of the lumbar spine in an 83-year-old female demonstrating severe osteoporotic compression fracture of L1, moderate compression fracture of T11 and mild compression fracture of L2

Figure 5.

There are foci of increased radioisotope uptake in the mid-thoracic spine on bone scan.

Figure 6.

Sclerotic pathological wedge compression fractures of T6 and T7 secondary to metastatic disease on sagittal reconstruction of staging CT thorax in patient with primary non-small cell lung cancer correlating with uptake in bone scan in Figure 5.