Non Invasive Analysis Of Skeletal Structures Flashcards
What are clinical investigations?
Diagnosis of pathologies
Identification of fractures
Pre-surgical visualisation
What are forensic purposes?
Assessment of microscopic trauma
Skeletal observation without defleshing/destroying
What are imaging techniques?
2D and 3D
What are 2D techniques?
Plane plate radiography
Modified plane plate radiography
Ultrasonography
What are 3D techniques?
Computed tomography (CT) MRI
What are 3D imaging systems based on?
2D image capture
What is each slice comprised of?
Pixels
What is 3D data comprised of?
Voxels
Resolution =
Pixel/voxel
Why is radiography useful clinically?
Cheap, fast and low radiation dosage
What is difficult about radiography?
Difficult to make accurate measurements
What is good about modern digital plates?
Reusable and can be processed instantly using a specialised reader and computer software
What is macro-radiography useful for?
Observing fine details
What do modern digital detectors allow?
Very high resolution images
What is based on x-ray radiography and digital detectors?
Computed Tomography
What does a CT do?
Measure the transmission of a thin beam of x-rays through a full scan of the body
What is the attenuation coefficient?
Is a quantity that characterises how easily a material or medium can be penetrated by a beam of light, sound, particles or other energy or matter
How is X-ray attenuation represented?
Hounsfield units
What are the 4 radio densities of the hounsfield scale?
Air, fat, water and compact bone
What has no supraimposition?
CT
What are the pros of CT?
Availability, large gantry size and relatively quick scan and reconstruction
What are the cons of CT?
Poor spatial resolution, streak artefacts associated with bone, higher radiation dose than radiography and relatively high running costs
What is specifically designed for high-resolution imaging bone?
Micro CT
What are the pros of micro CT?
Great quantification of structural indices which aid in explaining bone form
High spatial resolution
Good contrast in dry bone
What are the cons of micro CT?
Gantry size does not allow for imaging of whole bones
Larger specimens result in lower resolution and loss of detail
Long scan and reconstruction time
What is based on the excitation of hydrogen nuclei in water
Magnetic resonance imaging
Micro MRI can be used on what?
Much smaller scale
What can micro MRI be applied to?
Visualisation of trabecular bone
What do bone minerals lack?
Free protons
What are the pros of Micro MRI?
Good contrast between tissue types
Non ionising
What are the cons of the Micro MRI?
Good but limited resolution for trabecular analysis
Limited resonator size
Lengthy scan time
What is virtopsy?
Implementation of modern imaging techniques to augment current examination techniques or offer alternative means of analysis
What are the two reasons for imaging bone?
Clinical Investigations and Research Purposes
What are the research purposes?
Investigation bone structure
Cortical and Trabecular bone
