classified by severity (mild, moderate or severe) and type such as wedge, biconcave and crush fractures47-50 Varying degrees of accuracy are reported46 and the semi quantitative scale (figure 2) is the currently preferred method for grading vertebral fractures from VFA47,51 fracture are identified as having osteoporosis by DXA52
. Since not all patients who have a vertebral , VFA can provide a useful addition to the DXA
series and using VFA in practice increases the number of patients requiring therapeutic intervention for osteoporosis52,53
.
Vertebral fracture assessment within a DXA service DXA-based VFA provides an attractive, low dose method for detecting vertebral fractures in the typical populations seen in bone densitometry services and provides a high level of accuracy, particularly in moderate and severe fractures. While it is likely to be cost effective and appropriate to undertake a VFA on all Caucasian women over the age of 70 with a low BMD, as recommended by Schousboe et al39
vertebral fracture in the younger population is significantly less and therefore time and resources are not best targeted at low risk patient groups54
.
, the risk of . Furthermore, there are training and financial implications if a DXA
service wishes to offer VFA as part of their pathway. While VFA is frequently not commissioned in the UK, some services are developing their patient pathways to include this additional measurement where indicated and this appears to be an increasing trend. Training is required to ensure that all staff are suitably qualified and experienced to undertake the extended remit of VFA scanning55
. Each scan adds extra time and financial
costs to the overall examination and for reporting of the VFA scans. In addition to the financial burden, it is important to consider the added radiation dose associated with VFA. On the spectrum of radiation doses used in clinical imaging, DXA and VFA result in very small doses in the microsievert range and by definition are considered to be 'trivial'46,56
all radiation exposures in patients for medical reasons must be justified57
. However, under the ionising radiation (medical exposure) regulations (IR(ME)R), . Therefore, undertaking VFA in a
population who are at a low risk of vertebral fracture and without a level of clinical suspicion of a fracture is inappropriate and in breach of IR(ME)R. Robust protocols for patient selection are therefore essential for the use of VFA.
The use of vertebral fracture assessment is growing in the UK but is still limited
In patients who undergo VFA, where a vertebral fracture is identified on the scan, projection radiographs K
Figure 2: GE Lunar Prodigy dual energy lateral vertebral assessment scan, utilising morphometric software to indicate fracture presence and grade.
sh det O
are recommended to characterise the fracture and exclude any other underlying pathologies. Osteoporosis and other reasons for pathological fracture are not mutually exclusive and therefore other pathologies should be excluded in patients where a fracture is identified25,58 detecting mild vertebral fractures46,48
. Furthermore, VFA has poor accuracy for and further imaging may be required to confirm an equivocal fracture.
Other congenital and developmental pathologies can mimic fractures, particularly with the poorer resolution on VFA compared to projection radiography59
. Further imaging may be required to differentiate between
non-fracture deformities such as Scheuermanns’ disease, degenerative changes, or to examine for another fracture-causing pathology, such as malignancy or Paget’s disease of bone25
. This follow-up imaging may
include projection radiography, magnetic resonance imaging, computed tomography, nuclear medicine or PET
The International Society for Clinical Densitometry recommends undertaking VFA in patients with a T-score of ≤-1.0 when at least one or more of the following is present: women aged ≥ 70 or men ≥ 80 years;
ET-CT depending on the pathology suspected58. The
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