Diagnostic Imaging Modalities

Question 1

What organization is the regulator of all imaging modalities in Ontario?

Answer 1

CMRITO
college of medical radiation and imaging technologists of ontario

Question 2

What modalities does the CMRITO regulate?

Answer 2

-radiography
-nuclear medicine
-radiation therapy
-MRI
-diagnostic medical sonography

Question 3

-national voice for MRT professionals
-works with provincial organization to represent and protect the MRT
(OAMRS, PLI, continuing education)

Answer 3

CAMRT
Canadian association of medical radiation technologists

Question 4

-national voice for DMS in Canada
(PLI, continuing education)

Answer 4

Sonography Canada

Question 5

T/F
Radiation therapy is considered a treatment modality and not imaging modality

Answer 5

True

Question 6

Treatment modality that employs ionizing radiation to treat cancers and various diseases

Answer 6

Radiation therapy

Question 7

-based on the acoustic properties of the tissue it is passing through
-sound waves are produced by electrical stimulation of a specialized crystal in the transducer
-sound waves are reflected at differing tissue interfaces
*the greater the difference, the greater the echo

Answer 7

Ultrasound

Question 8

What is the average cost of an ultrasound machine?

Answer 8

$50,000

Question 9

What is the average exam time of an ultrasound?

Answer 9

30 minutes

Question 10

T/F
Ultrasound machines are very common, found everywhere

Answer 10

True

Question 11

What are the 2 contributors to image creation in ultrasound?

Answer 11

-transducer
-image receptor

Question 12

Production of multi frequency sound waves
US

Answer 12

Transducer

Question 13

Transducer receiving echoed signal
US

Answer 13

Image receptor

Question 14

What are the 4 imaging descriptors in ultrasound?

Answer 14

-anechoic
-hyperechoic
-hypoechoic
-isoechoic

Question 15

US
a structure/region that does not produce any echos (black)

Answer 15

Anechoic

Question 16

US
highly reflective (echogenic) structures as compared with surrounding structures (white)

Answer 16

Hyperechoic

Question 17

US
a structure/region that produces fewer echos than normal (dark)

Answer 17

Hypoechoic

Question 18

US
a structure/region that produces a similar number of echoes as are produced by surrounding tissue

Answer 18

Isoechoic

Question 19

What are some advantages to ultrasound?

Answer 19

-non ionizing
-relatively fast, inexpensive and available
-ability to differentiate between cystic, solid and complex
-may be used for image guidance of biopsies
-excellent for dynamic evaluations of joints

Question 20

What modality is the gold standard for pancreas, liver, gallbladder, and uterus?

Answer 20

Ultrasound

Question 21

What are some disadvantages of ultrasound?

Answer 21

-Limited resolution and demonstration of structures
-operator dependent
-presence of acoustic barriers (air, bone)

Question 22

T/F
Acoustic barriers will reflect all of the sound back to the transducer and nothing beyond them will be imaged

Answer 22

True

Question 23

-little or no difference in tissue density
-little or no difference in contrast on the image
-can be transmitted, scattered or absorbed
-interaction between energy and matter is of concern

Answer 23

Xray

Question 24

What is the average cost of an xray machine?

Answer 24

$500,000

Question 25

What is the average exam time of X-rays

Answer 25

5 minutes

Question 26

Considered the workhorse of medical imaging

Answer 26

Xray

Question 27

What are some advantages of xray?

Answer 27

-relatively inexpensive -very fast -workhorse of MI -numerous trained staff -usually non invasive

Question 28

What are some disadvantages of xray?

Answer 28

-ionizing radiation -limited soft tissue differentiation -oral contrast needed to demonstrate GI system -can be invasive with IV contrast

Question 29

What is the gold standard in early detection of breast cancer?

Answer 29

Mammography screening

Question 30

What 2 images are tone for mammo screening?

Answer 30

2 of each breast Cc- cranial caudal MLO- media lateral oblique

Question 31

What is done if suspicious areas are identified on a screening mammogram?

Answer 31

Additional images ( coned down or mag. Projections)

Question 32

When is a diagnostic mammogram done?

Answer 32

When palpable nodule is present

Question 33

What is the average cost of a mammography machine?

Answer 33

$500,000

Question 34

What is the average time of a mammo exam?

Answer 34

10 minutes

Question 35

-produces cross sectional image by scanning a slice of tissue from multiple angles as it goes around in an arc with a narrow xray beam -calculated the linear coefficient -allows for image manipulation with windowing/leveling and image reconstruction into Sagittal, coronal or 3D images

Answer 35

CT

Question 36

What is the average cost of a CT scanner?

Answer 36

1 million

Question 37

What is the average exam time for CT?

Answer 37

15 minutes

Question 38

Gold standard for trauma

Answer 38

CT

Question 39

Air -1000 Water 0 Bone 1000

Answer 39

Hounsfield units for CT

Question 40

What factors contribute to image creation in CT?

Answer 40

-collimated xray beam attenuation detection -detectors receive the attenuated signal

Question 41

What are the image descriptors of CT?

Answer 41

-CT number (HU) reflects the attenuation of a tissue to water -window width - greyscale, contrast scale -window level - midpoint of densities, brightness

Question 42

-provides imaging based on structural/anatomical properties and functional/physiological properties -uses magnetic fields and radio waves to produce an image -the rate at which the nuclei recover produces the image -uses large magnetic, radio transmitter, powerful computer to produce images

Answer 42

MRI

Question 43

T/F MRI uses non-ionizing, which is good. But could potentially be harmful due to magnets

Answer 43

True

Question 44

How are MRI images produced?

Answer 44

-magnet is turned on and causes the proton in the hydrogen nucleus to spin (precession) -radio waves are sent in pulses (resonance) with magnet -radio frequency pulses are off the nuclei begin to slow down spinning, this is the rate of relaxation (T1 and T2) -this gives info on normal tissue or pathological tissue

Question 45

What is the average cost of an MRI machine?

Answer 45

2.5 million

Question 46

What is the average exam time for MRI?

Answer 46

30-45 minutes

Question 47

What are the advantages of MRI?

Answer 47

-structural and functional capabilities -soft tissue differentiation -complimentary to other modalities -does not use ionizing radiatoon

Question 48

What is the modality of choice for imaging CNS and spine

Answer 48

MRI

Question 49

What are the disadvantages of MRI?

Answer 49

-expensive -complex to operate/interpret -long scan times -claustrophobia -metal in body -MRI compatible equipment in rooms increase cost

Question 50

-patient ingests or receives (IV) radio pharmaceuticals that emit radiation from the patient to create an image -a gamma camera detects that radiation emitted from the patient -creates a scintigraphic image

Answer 50

Nuclear medicine

Question 51

-provides physiological information (functional maps) based on metabolic uptake of radionuclides in tissues and organs -very poor resolution -critical contribution to assessing spread of disease

Answer 51

Nuclear medicine

Question 52

What is the most common used include in nuclear medicine?

Answer 52

Technetium 99m

Question 53

T/F Nuclear medicine emits 140kev gamma radiation (gamma camera)

Answer 53

True

Question 54

What is a gamma camera used for?

Answer 54

Fractures, infections, tumors, Mets Cost = $500,000 Time = 45 minutes exams

Question 55

What is the PET/MRI hybrid used for?

Answer 55

Revolution in oncology, surgical planning, radiation therapy Cost = $2 million

Question 56

-same as radiopharmaceuticals as conventional NM -gamma camera with ability to rotate around patient (like CT) -poor resolution and sensitivity

Answer 56

SPECT

Question 57

-uses different radiopharmaceuticals that decay by positron emission -produces a metabolic image -uses multiple gamma detectors, can reformat into 3D images -higher quality images than SPECT -especially useful in oncology -technologist receives larger doses

Answer 57

PET

Question 58

Gamma camera that detects gamma radiation emitted from patient

Answer 58

Image creation of NM

Question 59

Rotating gamma camera for multiplanar gamma radiation collection

Answer 59

SPECT image creation

Question 60

Increased uptake directly proportional to the emission of gamma radiation

Answer 60

Hot spot

Question 61

Reflection of decreased uptake directly proportional to the emission of gamma radiation

Answer 61

Cold spot

Question 62

-radiopharmaceuticals that emits a positron - through the collection following annihilation, two gamma rays are created -two opposite gamma cameras detect gamma radiation simultaneously emitted from patient

Answer 62

PET image creation

Question 63

What are the advantages of NM?

Answer 63

-images physiological/metabolic function of tissue -safer for patients with iodine allergies -earlier diagnosis and better prognosis (very sensitive)

Question 64

What are the disadvantages of NM?

Answer 64

-uses ionizing radiation -not cheap, funding model complex -radioactive nuclide supply issues -lacks anatomical information