Advanced Imaging Modalities

Question 1

________ developed patent for the first “whole body” CT

scanner for larger patient openings in 1976.

Answer 1

Dr. Ledley (DDS)

Question 2

Greater hard tissue object sensitivity than conventional
x-ray imaging systems
Demonstrates soft tissues

Answer 2

Multi-detector Computed Tomography

Question 3

The greater the # 
basis images, the 
\_\_\_\_\_\_ the 
reconstruction 
algorithm

Answer 3

better

Question 4

Does CBCT or MDCT have better imaging of soft tissue?

Answer 4

MDCT

Question 5

_____ is the feature of a MDCT where the operator can narrow the densities to be able to differentiate all the soft tissues or hard tissues or other entities separately from the other entities in the image

Answer 5

Windowing

Question 6

Disadvantages of \_\_\_\_
1) High dose of ionizing radiation
2) Expensive and not as readily available as     
conventional imaging
3) Sensitive to artifacts from metallic 
restorations and patient movement

Answer 6

C.T.

Question 7

• One of the most important advantages MR
has is the ability to separate tissues with
extracellular water from cellular tissues
with intracellular water.

Answer 7

Magnetic resonance imaging (MRI)

Question 8

What are the 3 components of Magnetic Resonance Imaging (MRI)?

Answer 8

Magnets
Resonant energy
Imaging

Question 9

Advantages of the _____

1) No ionizing radiation
2) Best soft tissue imaging

Answer 9

Magnetic Resonance Imaging

M.R.I.

Question 10

Disadvantages of \_\_\_\_\_
• 1) Sensitive to motion artifacts
• 2) Expensive financial and temporal 
demands
• 3) Claustrophobia

Answer 10

Disadvantages of MRI

Question 11

ABSOLUTE CONTRAINDICATIONS of \_\_\_\_\_\_\_\_
General
• Imbedded ferrous metals
Specific
• Cardiac pacemakers
• Cerebral aneurysm clips
• Cochlear implants
• Intra-ocular metallic foreign bodies

Answer 11

MRI

Question 12

Infusion of a radiopaque dye into a salivary gland’s ductal
pattern and evaluating the fill pattern with radiographic
imaging

Answer 12

Sialogram

Question 13

● Technique is used for evaluation of the parotid and
submandibular glands as these glands have a primary duct
amenable for gland infusion
●Sublingual gland lacks a primary duct; it has multiple ducts
excreting into the floor of the mouth therefore it is not suitable
for sialographic examination

Answer 13

Sialogram

Question 14

• Imaging technique where bone binds a
radioisotope Tc99
• Gamma camera takes images of where the
radioisotope has collected
• Metabolic activity determines degree of
radioisotope binding

Answer 14

Nuclear medicine bone scan

Question 15

Advantages
1) Radioactive isotope concentrates in areas
of rapid bone turnover and gives positive
response with 10% increase of osteoblastic
activity
Disadvantages
1) Expensive and invasive
2) Morphologic changes not imaged
3) Findings not specific to any disease process

Answer 15

Nuclear medicine bone scan

Question 16

• Combination of PET 
and CT is referred to 
as hybrid or fusion 
imaging 
• Superior to plain 
nuclear medicine 
alone
Useful for:
• location of a tumor
• followup of chemotherapy 
or surgery
• staging dementia, evaluate 
stroke

Answer 16

PET CT scan

Question 17

Advantages• Allows functional study of a metabolic 
process
• Provides a visual image that 
corresponds with patient anatomy
Disadvantages• Higher dosimetry
• High finances 
• Slow imaging; not capable for time 
sequences > 30 seconds

Answer 17

PET SCAN

Question 18

• ultrasound uses non-ionizing sound waves and has
not been associated with carcinogenesis
• ultrasound examination is less expensive to conduct
than CT or MRI
• ultrasound imaging is useful for the evaluation of
physiology as well as anatomy (e.g. vascular lesions
in jaws).

Answer 18

Ultrasonography