Single Detector VS Multidetector CT Scans

Question 1

Milestone of multidetector row CT

Answer 1

increased scan speed
improved z-axis spatial resolution,
better utilization of the available x-ray power

Question 2

The single-row design was used in

Answer 2

both third- and-fourth generation systems

Question 3

How many elements that were arranged in an arc in third generation systems

Answer 3

approximately 700 detector elements were arranged in an arc.

Question 4

Fourth-generation systems used ____ in a single row arranged in a complete ring.

Answer 4

as many as 4,800 detectors

Question 5

Each detector element is quite wide in the z direction

Answer 5

approximately 15 mm

Question 6

Slice thickness in single detector ct scans is controlled by

Answer 6

opening or closing of the collimator.

Question 7

The width of the detector limits

Answer 7

Slice thickness

Question 8

The largest allowable slice thickness

Answer 8

less than the detector width, typically 10 mm.

Question 9

The radiation emitted from the collimated x-ray source in these systems is commonly referred to as

Answer 9

fan beam

Question 10

Each gantry rotation produces data for

Answer 10

a single slice

Question 11

calculating the area of patient anatomy to be covered

Answer 11

multiply the slice increment selected by the number of slices acquired.

Question 12

If slices are contiguous the slice increment will be equal to

Answer 12

slice thickness

Question 13

MULTIDETECTOR ROW SYSTEMS also known as

Answer 13

• Multi-slice CT or MSCT
• Multi-detector CT or MDCT
• Multi-channel CT or MCCT
• Multi-row CT or (MRCT less common as abbreviation)

Question 14

How many parallel rows of detectors do multidetector row systems have?

Answer 14

4 to 64 parallel rows

Question 15

MDCT provides

Answer 15

longer and faster z axis coverage per gantry rotation.

Question 16

What is the scanning slices per year?

Answer 16

1991 - 2
1998 - 4
2002 - 16
2003 - 32
Now - 64 with 0.4s rotation

Question 17

Slice thickness in multidetector ct scans is determined by

Answer 17

combination of x-ray beam width and the detector configuration

Question 18

The radiation emitted from the collimated x-ray source in these systems is commonly referred to as

Answer 18

cone beam

Question 19

Multiple detector channels can be used for

Answer 19

either axial or helical data acquisitions

Question 20

Depending on the scanner manufacturer and the number of detector rows, the parallel rows may be:

Answer 20

• Uniform array with equal size

- Variable, with thinner rows centrally and wider rows peripherally.

Question 21

variable-width detector rows are also called

Answer 21

adaptive arrays,
non-uniform arrays, or
hybrid arrays.

Question 22

used determine the slice thickness and number of slices that can be acquired simultaneously.

Answer 22

size and number of segments

Question 23

Compared with SDCT, for a given slice thickness

Answer 23

MDCT results in a fourfold increase in the volume of data acquired in a single rotation

Question 24

the slice thickness of an MDCT scanner is determined by the

Answer 24

degree of physical collimation of the x-ray beam and the width of the detectors in the slice thickness (z axis) dimension.

Question 25

The width of the slice is changed by

Answer 25

combining different numbers of individual detector elements together.

Question 26

When combined, the electronic signals generated by adjacent detectors are

Answer 26

summed

Question 27

currently being used in clinical setting

Answer 27

256-row detectors

Question 28

256-row scanners have the ability to

Answer 28

image the heart, brain, and many other organs in a single rotation

Question 29

were responsible for the demise of fourth-generation scanning systems

Answer 29

MDCT designs

Question 30

To form a complete ring

Answer 30

many separate detector elements were required

Question 31

In MDCT, how many detectors will be used?

Answer 31

307,200 detectors