Radiographic Interpretation and CBCT Flashcards
What details are useful to include when reporting on periradicular changes?
Location
Size
Margins
What these changes signify
If appropriate suggest further investigation or treatment
What are the steps in the system of examination for EO radiographic images?
symmetry
margins
bone consistency
dentition
supporting bone
any other features
-> summary/proposals
What are the stages in visual analysis of EO radiographic images?
If you can see right and left- compare and look for differences
Start at the top and go down
Look for unusual opacities and radiolucencies
Look for site (how is it related to other structures- does it affect/relate to aetiology), size (can be misleading), shape
What does a straight horizontal upper margin slightly curved at the sides suggest?
Presence of a liquid/fluid (meniscus)
What does a curved upper margin suggest radiographically?
Something expanding
What does radiolucency suggest? In which cases would it be seen?
Loss of hard tissue
-> Seen in bone and teeth OR Cysts
What causes structures to appear radiopaque?
Increased attenuation
What are the causes of increased attenuation?
Increased density e.g. cortical bone
Increased thickness e.g. overlaps
Changes/Alteration of tissues e.g. soft tissue calcification
Soft tissue within an air space
Amalgam and gold restorations
What are the different descriptors for shape when interpreting radiographs?
Circular- expanding evenly
Unilocular- one obvious lesion, simple
Multilocular- scalloped margin, internal divisions
Irregular- difficult to describe (more worrisome- esp. if irregular borders)
What may size of a radiographic lesion indicate?
Length of time it has been present (not always)
What are the different descriptors for margins of radiographic lesions?
Well defined:
Corticated (white line)
Non-corticated
Ill-defined (require investigation)
Why are corticated lesions preferred?
Slow progressing as bone remodelling required
What are the different effects a lesion seen on a radiograph can have on other structures?
no effect
displacement
expansion
resorption (aggressive)
What are the options in the radiological sieve used in making provisional diagnosis?
normal
developmental
traumatic
inflammatory
cystic
neoplastic
osteodystrophy
metabolic/systemic
idiopathic
iatrogenic- caused by tx
foreign body
artefact- broken digital receptor
What are unerupted teeth surrounded by?
Reduced enamel epithelium
-> Can undergo pathological change
What happens if you remove a tooth that has a cyst but not the cyst itself?
It can remain and grow
-> if assymptomatic monitor radiographically every 6-12 months
What can happen to corticated lesions due to infection?
Loss of corticated margin
What is the issue with the antral septum
Can create illusion of pathological lesion from some views
What are the features of conventional CT?
Thin fan shaped beam directed at patient on table
Detectors pick up the beam as it goes around patient many times
Creates axial slices- modern machines can look at sagittal and coronal
Very high x-ray dose
Shows hard and soft tissues
What are the features of CBCT?
Beam is cone shaped, requires bigger detector to pick up beam
Will typically go around patient once (single rotation)
Less radiation
Better for hard tissues
What are the indications for using CBCT?
Implant planning
Impacted teeth (normal and supernumeraries)
Location
Relations, e.g. inferior alveolar canal, root resorption
Pathology – cystic lesions, infections,
Indications for CBCT continued:
Benign tumours
Orthognathic surgery
Hypodontia
Cleft palate – bone defects
Dental abnormalities – dilaceration, double teeth
Endodontic problems
Autotransplantation
In what situations in CBCT not used?
Cancer patients
What are some of the most important principles when using CBCT?
Use only when question cannot be answered adequately with lower dose method
If evaluation of soft tissues required- consider Medical CT or MRI
Use smallest volume compatible with clinical situation
Choose lowest resolution compatible with equipment (lowers dose)
