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4th Year Revision > Radiology > Flashcards

Flashcards in Radiology Deck (82)
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1
Q

What is the radiographic appearance of progressive peri radicular disease? (2)

A
  • increased bone resorption and increasing size of radiolucency
  • surrounding bone sclerosed
2
Q

What things can be mistaken for pathology? (6)

A
  • maxillary sinus
  • nasal cavity
  • mental foramen
  • submandibular fossa
  • incomplete root development
  • intervertebral space
3
Q

What is the appearance of osteomyelitis? (4)

A
  • ragged moth eaten radiolucency
  • radiopaque sequestra of dead bone
  • sclerosis of surrounding bone
  • periosteal reaction
4
Q

What is the result of osteoradionecrosis? (3)

A
  • reduction in blood supply to bone
  • trauma or infection
  • ragged bone destruction
5
Q

What are the radiological features of sinusitis? (3)

A
  • thickening of the antral mucosa
  • increase in secretions, mucous or pus
  • on CBCT and CT scans air bubbles may be seen within the radiopacity indicating fluid/mucous
6
Q

What are the dental causes of sinusitis? (3)

A
  • periapical pathology
  • oro antral communication
  • possibility of association with implant placement
7
Q

What is a le fort III fracture?

A

Through the orbits and separating the base of skull

8
Q

What does a lateral oblique mandible show?

A

Most of the mandible including the condyle

9
Q

What are the disadvantages of a lateral oblique mandible? (4)

A
  • difficult to interpret
  • require good cooperation if conscious
  • may not show all regions of concern
  • fractures can be missed
10
Q

What does a PA mandible radiograph show?

A

A good view of the posterior body, angle and ramus of mandible

11
Q

What is the superimposition of the PA mandible? (2)

A
  • superimposition of cervical spine may obscure anterior mandible
  • superimposition of mastoid process and zygomatic eminence obscure condyle
12
Q

What does a reverse townes show? (2)

A
  • shows condylar head and neck which are often obscured on a PA mandible
  • demonstrates medial position
13
Q

What does a mandibular true occlusal show?

A

Displacement antero posterior and medio lateral

14
Q

What does an anterior oblique occlusal show? (2)

A
  • can show roots if periapical not possible

- presence of alveolar fracture if unclear on DPT

15
Q

Give an advantage of CT scanning

A

An advantage of CT scanning is that it allows detailed examination in 3 dimensions without superimposition of soft tissue, hard tissue and air spaces

16
Q

What are the TMJ radiographic views? (4)

A
  • trans cranial
  • trans pharyngeal
  • trans orbital
  • tomographic views using DPT
17
Q

What are the advantages of MRI? (3)

A
  • useful if need to see soft tissues
  • can demonstrate the position of the disc
  • no ionising radiation
18
Q

What are the advantages of cone beam CT? (3)

A
  • more readily available than MRI
  • can show disc space and displaced condylar head of patient in occlusion
  • can show fairly early bony changes of both condylar head and glenoid fossa
19
Q

What are the radiological features of sialothiasis?

A

May be superimposed on the maxilla and mandible on DPT

20
Q

How does sialography work? (2)

A
  • radiopaque contrast injected into the salivary duct system

- radiographs taken 2 views at right angles to each other

21
Q

How do you inject into the duct system in sialography? (3)

A
  • use lacrimal dilators to widen duct orifice
  • insert canula
  • inject approx 1-2ml contrast slowly
22
Q

What are the indications for sialography? (3)

A
  • acute intermittent swelling of one salivary gland
  • generalised swelling of one or more glands
  • history of xerostomia
23
Q

What radiographs are used for the submandibular gland? (4)

A
  • pre contrast DPT
  • true occlusal mandible
  • filling lateral and AP view
  • emptying 1/2 DPT side of interest
24
Q

What are the features of a normal parotid? (3)

A
  • main duct even diameter
  • uniform filling
  • branches taper towards the periphery
25
Q

What is chronic sialadenitis?

A

Enlargement of ducts particularly main, first and second branches

26
Q

What is the appearance of chronic sialadenitis? (4)

A
  • dilations can alternate with constrictions like a string of sausages
  • rosary or beading appearance
  • sialoths may be present or mucous plugs
  • truncated ducts give pruned tree appearance
27
Q

What is the appearance of chronic sclerosing sialadenitis?

A

Slight enlargement of main and/or secondary ducts, irregularities of duct walls and loss of terminal duct

28
Q

What are the advantages of an oil based solution? (2)

A
  • densely radiopaque therefore good contrast

- high viscosity therefore slowly excreted from the gland

29
Q

What are the advantages of an aqueous solution? (3)

A
  • low viscosity therefore easily injected
  • easy and rapid removal from gland
  • easily absorbed and excreted if extravasated
30
Q

What is the radiographic appearance of calculi? (4)

A
  • filling defect
  • dilation of duct beyond calculus
  • emptying of CM slowed
  • appears radiolucent compared to the contrast
31
Q

What is the radiographic appearance of stage II sjogrens syndrome?

A

Globular pattern

32
Q

What is the radiographic appearance of stage III sjogrens syndrome?

A

Cavity pattern

33
Q

What is the appearance of a malignant lesion neoplasm?

A

Tumour mass replaces duct pattern

34
Q

What is the appearance of pleomorphic adenoma? (4)

A
  • ball in hand appearance
  • ducts appear to surround tumour
  • filling defect in gland parenchyma
  • pressure of tumour can extend duct
35
Q

What is the appearance of a pleomorphic adenoma on a CT and MRI scan? (2)

A
  • round with distinct boundaries

- smooth margin- inside has a higher density

36
Q

What is the appearance of a pleomorphic adenoma on a ultrasound?

A

Internal echoes are absent or weak

37
Q

What is the appearance of a stafne defect? (3)

A
  • aberrantly positioned salivary gland tissue
  • deep depression or inclusion at angle of mandible during development
  • ovoid radiolucency below ID canal, anterior to angle of mandible
38
Q

What are the effects of cysts on adjacent structures? (4)

A

Teeth- displacement and resorption
Cortices of jaw- expansion and perforation
Inferior dental canal- displacement and compression
Maxillary sinus/nose

39
Q

Why are cysts radiolucent?

A
  • they cause bone to be destroyed
  • bone is now less dense
  • fewer X-ray photons are absorbed
  • more photons hit the film or sensor/plate
  • image is blacker in this region
40
Q

Why do cysts in the antrum look radiopaque?

A

The surrounding air absorbs fewer photons than cyst fluid

41
Q

What is the appearance of an incisive canal/nasopalatine cyst? (6)

A
  • heart shaped
  • smooth well defined
  • corticated
  • usually over 6mm
  • palatal expansion
  • adjacent teeth may be displaced
42
Q

What are the other names for a traumatic bone cyst? (7)

A
  • smooth outline not markedly corticated
  • scalloping of margins
  • cortication more obvious inferiorly
  • periodontal space traceable
  • lamina dura sometimes missing
  • growth along jaw
  • generally above mandibular canal
43
Q

What do malignant neoplasms tend to be? (4)

A
  • fast growing
  • poorly defined
  • invasive and destructive of surrounding tissues
  • destruction of bony cortices
44
Q

What are the presenting features of an oro facial malignancy? (5)

A
  • pain in the jaw
  • loose teeth
  • non healing sockets
  • pathological fracture
  • trismus
45
Q

What are the features to look out for in oro facial malignancies? (4)

A
  • destruction of bone
  • ragged margins
  • no cortical margins
  • spread along inferior dental canal
46
Q

What is multiple myeloma?

A

Multifocal plasma cell proliferation

47
Q

What is the radiographic appearance of a multiple myeloma?

A

Well defined punched out radiolucencies

48
Q

What is the result of multiple myeloma? (6)

A
  • bone pain
  • fractures
  • increased serum calcium
  • anaemia
  • risk of infection
  • kidney damage
49
Q

What is an osteosarcoma?

A

Rare primary malignant tumour of bone. Bone lysis but also neoplastic bone is formed

50
Q

What is the radiographic appearance of osteosarcoma? (4)

A
  • ill defined radiolucency
  • widened PDL space
  • spiking resorption of roots
  • the periosteum is stretched producing new bone which has a characteristic sun ray appearance
51
Q

What are the most common metastatic or secondary tumours? (5)

A
  • breast
  • lung
  • prostate
  • GI
  • kidney
52
Q

How does scintiscan and SPECT work? (2)

A
  • pt injected with a solution containing technetium 99m

- scanned with gamma camera

53
Q

How does PET CT work?

A
  • fluoro deoxyglucose injected IV
  • increased uptake in metabolically active areas such as lytic bone lesions, metastasis etc
  • FDG undergoes radioactive decay with ultimate release of gamma rays
  • pt surrounded by a ring of gamma detectors
  • low resolution CT taken at same time and PET and CT information is merged into 1 image
54
Q

What opacities are closely associated with teeth? (4)

A
  • exostosis or tori
  • dense bone island
  • cement dysplasia
  • complex or compound odontomes
55
Q

What opacities are not necessarily contacting teeth? (4)

A
  • dense bone islands
  • fibrous dysplasia
  • cement dysplasia
  • chronic osteomyelitis
56
Q

What is the location of fibrous dysplasia?

A

Posterior maxilla more common than mandible. May affect adjacent bones

57
Q

What is the radiographic appearance of fibrous dysplasia? (3)

A
  • poorly defined margins
  • initially radiolucent gradually becoming opaque
  • ground glass or orange peel appearance
58
Q

What is the dental result of fibrous dysplasia? (4)

A
  • teeth sometimes displaced
  • rarely resorbed
  • expansion of bone in all directions
  • occlusion affected
59
Q

What is pagets disease also called?

A

Osteitis deformans

60
Q

What happens when the skull is involved with pagets disease of bone?

A

You may develop blindness and deafness

61
Q

What is the radiographic appearance of pagets disease? (5)

A
  • scalloped circumscribed areas of osteoporosis
  • in jaws may develop a ground glass appearance, cotton wool in later stages
  • enlargement of bones, separation of teeth
  • loss of lamina dura, marked hyper cementosis in late stages
  • lytic lesions
62
Q

What are the dental abnormalities of hypophosphatemia? (3)

A
  • poor teeth formation
  • slow or delayed eruption
  • spontaneous abscesses
63
Q

What are the dental abnormalities of cleidocranial dysplasia? (4)

A
  • multiple supernumerary teeth anterior to first permanent molars
  • conical supernumeraries anteriorly
  • retained deciduous dentition
  • unerupted permanent teeth or delayed eruption
64
Q

What is idiopathic osteosclerosis?

A

Localised area of increased radio density of bone of unknown cause and without association to inflammatory, dysplastic or neoplastic processes

65
Q

What are the features of idiopathic osteosclerosis? (2)

A
  • dense bone island

- exostosis

66
Q

What is the radiographic presentation of idiopathic osteosclerosis? (4)

A
  • well defined non expansile radiopacity
  • variable shape
  • usually <2cm
  • normal PDLS of adjacent teeth
67
Q

What is the differential diagnosis of idiopathic osteosclerosis if there is no radiolucent margin? (3)

A
  • sclerosing osteitis
  • exostosis/torus
  • osteoma
68
Q

What is the differential diagnosis of idiopathic osteosclerosis if the radiolucent margin is continuous with the PDLS? (2)

A
  • hypercementosis

- cementoblastoma

69
Q

What are the radiographic features of fibrous dysplasia? (3)

A
  • altered bone pattern
  • bone enlargens but maintains rough anatomical shape
  • margins indistinct and blend into adjacent bone
70
Q

What are the radiographic features of cemento osseous dysplasia? (5)

A
  • well defined radiolucency with sclerotic rim containing varying amounts of well defined radiopaque material
  • lamina dura lost
  • PDLS lost or widened
  • external root resorption rare
  • secondary simple bone cysts may form within lesions
71
Q

Where does an ossifying fibroma occur?

A

Almost exclusively to tooth bearing areas

72
Q

What are the radiographic features of an ossifying fibroma? (4)

A
  • rounded expansile lesion
  • margins usually well defined
  • radio density depends on stage of lesion maturation
  • surrounding bone may be sclerotic
73
Q

What is the management of an ossifying fibroma? (2)

A
  • removal indicated due to progressive growth

- surgical enucleation or resection

74
Q

What is a central giant cell granuloma?

A

A reactive lesion of jaws with benign tumour like behaviour

75
Q

At what age do the majority of central giant cell granulomas occur?

A

Before the age of 20

76
Q

What is the location of a central giant cell granuloma? (2)

A
  • most common anterior to first molars

- mandible>maxilla

77
Q

What are the radiographic features of a central giant cell granuloma? (2)

A
  • often well defined but poorly corticated

- starts unilocular but become multilocular when large

78
Q

What is the management of a central giant cell granuloma? (2)

A
  • enucleation and curettage

- radiographic follow up to check for recurrence

79
Q

What is the differential diagnosis of a central giant cell granuloma? (4)

A
  • simple bone cyst
  • ameloblastoma
  • aneurysmal bone cyst
  • ossifying fibroma
80
Q

What does basal cell naevus syndrome result in? (4)

A
  • multiple odontogenic keratocysts of the jaws
  • multiple basal cell carcinomas of the skin
  • abnormalities of skeleton
  • marked calcification of falx cerebra
81
Q

What is gardeners syndrome a variant of?

A

Familial adenomatous polyposis

82
Q

What are the features of gardner syndrome? (4)

A
  • colorectal polyposis
  • osteomas
  • soft tissue tumours
  • supernumeraries, impacted teeth and multiple areas of idiopathic osteosclerosis