SPECT

Question 1

what does SPECT stand for?

Answer 1

single photon emission computed tomography

Question 2

what planes does SPECT use?

Answer 2

transverse, sagittal, and coronal

Question 3

what is SPECT?

Answer 3

3d image acquisition done by cutting the bone into imaging planes

Question 4

what are the benefits to SPECT?

Answer 4

• provide higher contrast than planar imaging
• no overlap of structures
• improved T:NP
• 3d cinematic representation of the organ

Question 5

what are the benefits to SPECT/CT?

Answer 5

• combination of diagnostic tools to look at anatomy and function
• better lesion localization
• attenuation correction
• more confidence to making diagnosis

Question 6

what is a con of spect/ct?

Answer 6

increased radiation dose to patient

Question 7

for radiochemical purity, what is the desired complex for bone scans?

Answer 7

at least 90% tagged

Question 8

what are the two contaminants that take away from having a ‘perfect’ tag?

Answer 8

• hydrolyzed reduced Tc
• free pertechnetate

Question 9

100% tag means what for our images?

Answer 9

increase T:NT

Question 10

where does free pert localize?

Answer 10

thyroid, breast milk, gastric mucosa, salivary glands

Question 11

what is the difference between “continuous motion” and “step and shoot”?

Answer 11

continuous: acquisition of images with the camera constantly moving around the patient; no stops.

stop and shoot: when acquisition of images only happens when the camera stops at specific intervals around the patient

Question 12

describe an elliptical orbit.

Answer 12

the ability to set two distances to adjust how close one camera will get from one region to another

Question 13

describe a circular orbit.

Answer 13

used when imaging something more circular; allows for some regions to be closer to the camera than others

Question 14

what is the kVp used for CT?

Answer 14

80-130

Question 15

what is the mAs used for CT?

Answer 15

2.5-300

Question 16

what is the matrix used for CTs?

Answer 16

512x512

Question 17

how do you check for motion?

Answer 17

raw cine

Question 18

what measures can you take as a technologist to limit the possibility of motion artifacts?

Answer 18

• communicate with the patient to not move
• adjusting scan time based on what the patient is capable of
• positioning the patient so they’re as comfortable as possible

Question 19

what is CT alignment?

Answer 19

ensures nm images and ct images properly align

Question 20

what are the 5 processing steps?

Answer 20

1. motion correction
2. ct alignment
3. reconstruction
4. reorientation
5. image display

Question 21

what is raw cine?

Answer 21

a short “movie” made of our 2d images

Question 22

what are the two common reconstruction techniques?

Answer 22

1. filtered back projection
2. iterative

Question 23

describe filtered back projection.

Answer 23

it is the simpler method – application of a high pass filter/ramp filter to limit star artifacts

Question 24

describe the iterative method.***MLEM OSEM

Question 25

which reconstruction technique is most often used for bone imaging?

Answer 25

iterative

Question 26

which reconstruction technique produces higher quality images?

Answer 26

iterative

Question 27

what is reorientation?

Answer 27

alignment of the image along the primary axis of the organ

Question 28

do we typically need to do reorientation for bone scans?

Answer 28

no. unless the patient was positioned crooked on the bed

Question 29

what can be displayed?

Answer 29

• reconstructed 3d image (can be cinematically)
• 2d slices

Question 30

how are the the transverse slices displayed?

Answer 30

superior to inferior

Question 31

how are the coronal slices displayed?

Answer 31

anterior to posterior

Question 32

how are the sagittal slices displayed?

Answer 32

right to left

Question 33

what views do we use to describe transverse images?

Answer 33

ANT/POST and R/L

Question 34

what views do we use to describe sagittal images?

Answer 34

SUP/INF and ANT/POST

Question 35

what views do we use to describe coronal images?

Answer 35

SUP/INF and R/L

Question 36

what is an artifact?

Answer 36

structure or feature not normally present

Question 37

what can cause artifacts?

Answer 37

equipment, RP, administration technique, imaging technique/patient prep