Learning objectives
To understand the technical differences between digital tomosynthesis,
fan beam CT and cone beam CT image acquisition
To understand the challenges of imaging osteosynthesis material in 3D at high spatial resolution
To illustrate the value of iterative reconstruction in metal artifact reduction
We illustrate the objectives and performance of these techniquesin a comparative experimental study on a cadaveric forearm.
Background
Imaging techniques of the wrist
Trauma to the wrist affects all population groups and constitutes a significant public health issue because of the likelihood of fractures and ligament ruptures [1].
Radiography remains the standard imaging tool but lacks sensitivity and specificity,
and can leadto unnecessary wrist immobilization,
particularly in patients with suspectedscaphoid fracture.
CT is more efficient butsometimes less available and can miss trabecular fractures [1].
New imaging techniques have emerged that might be useful in the diagnosis of wrist injuries: digital tomosynthesis and cone...
Findings and procedure details
Experimental setup and imaging sessions
In this experimental study (Fig.
3),
we performed image acquisition on a cadaveric forearm with four techniques: digital tomosynthesis (Definium 8000,
GE Healthcare),
high resolution CT,
CT with iterative reconstruction (both Discovery 750HD,
GE Healthcare) and cone beam CT with a supine scanner (Newtom 5G,
QR,
Verona).
Prior to the first imaging session,
an orthopaedic surgeon induced a controlled transverse osteotomy of the scaphoid.
A second imaging session was performed after reduction of the osteotomy with placement of a Herbert...
Conclusion
Owing to its higher intrinsic resolution and lower susceptability for metal artefacts,
Cone beam CT technique clearly resulted in improved image quality compared to high resolution CT and CT with iterative reconstruction.
References
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Evaluation of the diagnostic performance of tomosynthesis in fractures of the wrist.
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Bandos AI,
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Comparison of digital mammography alone and digital mammography plus tomosynthesis in a population-based screening program.
Radiology 2013; 267(1):47-56.
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Cone Beam CT for dental and maxillofacial radiology: evidence-based guidelines.
Radiation Protection report 172.
2012
De Cock J,
Mermuys K,
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Cone-beam computed tomography: a new low dose,
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