Test Questions

Front 1

Agatston scores on mdct cardiac exam

Back 1

Minimal. 1-10

Mild. 11-100

Moderate. 101-400

Extensive. >400

Front 2

Type of ct best suited for evaluating of Coranary disease

Back 2

Electron beam scanners are very fast

Front 3

Mtt mean transit time

Back 3

Time for blood to pass through a given region of brain tissue

Front 4

Layers of the uterous

Back 4

Perimetruum

Myometrium

Endometrium

Front 5

Phases of contrast administration

Back 5

Non-enhanced CT (NECT)Helpful in detecting calcifications, fat in tumors, fat-stranding as seen in inflammation like appendicitis, diverticulitis, omental infarction etc.

Early arterial phase - 15-20 sec

Arterial phase 20-30 sec delay

Late arterial phase - 35-40 early venous portal phase", because some enhancement of the portal vein can be seen. All structures that get their bloodsupply from the arteries will show optimal enhancement.

Corticomedulary phase 30-40 sec delay in handed renal cortex (gastric and intestinal wall inhansement) liver spleen pancreas optimization

Portal venous phase 60-70 sec

Hepatic or late portal phase 70-80 sec. In this phase the liver parenchyma enhances through bloodsupply by the portal vein and you should see already some enhancement of the hepatic veins.

Nephrogenic phase - 100 sec This is when all of the renal parenchyma including the medulla enhances. Only in this phase you will be able to detect small renal cell carcinomas.

Delayed phase - 6-10 minutes p.i. or 6-10 minutes after bolustracking. Sometimes called "wash out phase" or "equilibrium phase". There is wash out of contrast in all abdominal structures except for fibrotic tissue, because fibrotic tissue has a poor late wash out and will become relatively dense compared to normal tissue.

Front 6

Voxel dimension

Back 6

Divide dfov by matrix size multiply by length

Front 7

On mdct cardiac exams for Coranary artery calcification areas of calcium are identified when?

Back 7

Greater than 1mm squared in area with hf values of 130 or greater.

Front 8

Slice sensitivity profile is ____

Than the dose profile

Back 8

Narrower

Front 9

Ssp is?

Back 9

Slice sensitivity profile

Or degree of broadening or point spread that occurs along the z axis during volumetric data acquisition.

Front 10

Pixel =

Back 10

Dfov/matrix size

Front 11

Ct xray amount of inherent filtration =

Back 11

3.0 mm aluminum

Front 12

Spatial resolution is affected by

Back 12

Geometric factors such as focal spot size and slice thickness,detector size,reconstruction algorithm, pixel dimention,sampling frequency.

Front 13

Contrast resolution is affected by

Back 13

Slice thickness

Algorithm

And noise

And detector sensitivity

Collomation

Window setting

Front 14

Noise is affected by

Back 14

Dose

Pixel dimention

Front 15

Central volume principal

Back 15

Cerebral blood flow=cbv/mtt

Front 16

A solitary pulmonary nodule

May be defined as

Back 16

Ovoid focal area of increased density less than 3 cm.

Front 17

Infarction core defind

Back 17

Cbv less than 2.5 ml/100 g

Front 18

Angle for butterfly insertion.

Back 18

15 degrees

Front 19

The quantity of absorbed dose based on radiosensitivity of a particular tissue type

Back 19

Effective dose

Front 20

Harmful effects of xrays

Back 20

Stochastic- non threshold but probability increases with increased dose.

Front 21

Enteric precautions

Back 21

Prevents infection through spread of fecal material gloves and gown.

Front 22

R-r interval% at diastole

Back 22

55-75%

Front 23

Gas within a degenerative disk

Back 23

Vacuum effect

Front 24

During a spiral or helical scan how does the scanner acquire data

Back 24

Continuously as the pt moves through the table

And in the form of a volumetric set.

Front 25

Anougther name for fatty liver

Back 25

Steatosis

Front 26

Interstitial disease of the lung

Back 26

Bronchiectasis

Emphysema

Asbestosis

Sarcoidosis

Front 27

Leiomyoma

Back 27

Benign mass of smooth muscle found commonly on the uterus

Front 28

Perotoneal organs

Back 28

Stomach, liver, gallbladder, spleen, ovaries, transverse colon, and most of the small bowel.

Front 29

Minimum intensity projection techniques used for

Back 29

Demonstrating air trapped within the trachea and bronchial tree

Front 30

Used in pet ct as contrast

Back 30

Fludeoxyglucose f 18 (fdg)

Front 31

Average photon energy of a ct scanner at 120 kvp

Back 31

70 kev

Front 32

Photon flux

Back 32

Rate xrays pass through a unit area over a unit of time.

Front 33

Linearity

Back 33

Relationship between ct number and actual linear attenuation coefficents

Front 34

adding a math filter to remove blurring

Back 34

Convolution

Front 35

Orthogonal

Back 35

Reformatted image that lie perpendicular to original plane of acquisition

Front 36

Ray sum

Back 36

Measurement of transmitted radiation made by a single detector

Front 37

Information included in a 3d recon is controlled by the

Back 37

Threshold setting

Front 38

Normal cvb in 100 g of brain tissue

Back 38

4-5 ml

Front 39

Quanta time computerized tomography used for

Back 39

Diagnosis of osteoporosis

Front 40

Range of ct hu numbers on a modern ct system

Back 40

-1024 to + 3071

4096 different values on a 12 bit system

Front 41

The Compton efect

Back 41

Xray photon ejects an outer shell electron producing scatter radiation

Front 42

Bremstralong

Back 42

Xrays produced by acceleration or expecially deceleration of an electron while passing close by a nucleus.

Front 43

Characteristic

Back 43

Ejection of a inner core electron being replaced by an outer shell electron drop in energy given off in xrays.

Front 44

Pt dose Is directly effected by filtration . Detector efficiency and source to detector distance .

Back 44

But not filament size

Front 45

First type of reconstruction used in prototype ct scanners

Back 45

Iterative technique.

Front 46

Common areas of calcification in the brain

Back 46

Chord plexus and pineal gland

Front 47

Dermoid tumor of the ovary

Aka

Back 47

Cystic teratoma

Front 48

Stores majority or sperm

Back 48

Vas deferens

Front 49

Crystal material used in scintillating crystal detectors

Back 49

Cesium iodide, cadmium tungstate, bismuth germinate, gadolinium oxysulfide, and gemstone material.,

Front 50

Mathematical process by whereby data from tube rotations just above and just below a given slice position are used for image reconstruction ,which also clears up pt motion Artifacts.

Back 50

Interpolation

Front 51

After back projection math marital filters and kernels used to remove the unwanted blurring effect

Back 51

Convolution

Front 52

Reconstruction of ray sums onto a matrix

Back 52

Back projection.