Alternative Imaging Modalities Flashcards
What does MRI stand for?
Magnetic resonance imaging
What are the disadvantage of plain radiographs?
Only 2d image
Limited to soft tissue
Ionising radiation.
Static picture requires demineralising
Advantages of plain radiography
Cheap
Readily available
Relatively low dose
What are the advantages of CT scans?
Images bone and soft tissue
Differentiate between different tissues
Fast
Multiplaner- can manipulate and reconstruct images
What are the disadvantages of CT scan?
High dose- 2msv
Often requires iv dyes to distinguish tissues
Artefact
Expensive compared to radiography
What are the uses of CT scan?
Generally head and neck Intracranial bleed, infarct, tumour Trauma Implant planning Orthognathic planning
What are cone beam ct scanners characterised by?
Field of view
Volume element- pixel with depth
What does smaller voxels produce?m
Higher resolution image
What do smaller voxels mean re. Time and dose
The smaller the longer time exposure and higher dose
What are the advantages of cbct?
3D
Multiplaner
Dose compared to conventional CT
What are the disadvantages of cbct?
Artefact from high attenuation objects
Scan times are longer than pa rads
Dose is high compared with regular radiographs
Where is cbct useful?
Implantology
Localisation of impacted teeth
Endo
Trauma
What planes is the cbct data reconstructed into?
Axial Sagital Sagital Panoramic Cross section
What does mri stand for?
Magnetic resonance imaging
What does CT stand for?
Computed tomography
