0:00

Two other things which I want to discuss, which is now grouped under advanced CT

0:05

technologies. So what I see generally here in the field is

0:09

majority of the CTs used in the US are right now

0:13

has migrated from four-slice to 16-slice to

0:17

64-slice scanner.

0:19

We can consider 64-slice scanner was some of the

0:23

basic CT scanners these days. However, we are

0:27

also seeing other CT scanners, which is more advanced CT

0:31

technology. The advanced CT technology can be looked at two ways.

0:35

One is the wide detector CT scanner,

0:40

which is 320-slice scanner or

0:43

250-slice CT scanner, which enables to

0:47

cover the entire heart in one rotation

0:51

rather than multiple rotation. I will discuss later on

0:55

the advantage of this when I talk about cardiac CT physics.

0:59

But this is where the current technology, we can acquire

1:02

320 slices at one time, means you can cover a

1:06

larger anatomy with one rotation or even half a

1:10

rotation. So there is a lot of advantage.

1:13

The advantage of minimizing the use of contrast for pediatric

1:18

patient, minimizing the motion artifact, and so forth,

1:22

has been possible with these particular advances.

1:26

Similarly, one of the other manufacturer has used what is called a

1:29

dual-source CT scanner. Instead of one X-ray tube,

1:33

they have two X-ray tube inside the gantry with two different

1:37

detectors set. Therefore, you can cover the area

1:41

with a much more higher temporal resolution.

1:44

I'm going to talk about the temporal resolution aspect later in the image

1:48

quality, but that's what this principle advances of this

1:51

one. Both of these advanced technology race

1:55

happened because there was a race to image the heart

1:59

as fast as possible because of the rapid motion of the

2:03

heart. And these two methodology is the principle

2:07

behind covering an entire heart in either one

2:10

rotation or in one heartbeat.

2:14

But the current excitement in CT is the photon counting

2:18

CT technology. We are now looking this as a next

2:22

evolutionary phase in CT, and the photon

2:25

counting CT, we are already seeing a major

2:29

advantage in terms of metal artifact reduction,

2:33

lower radiation dose, higher resolution, and so forth.

2:37

But the principle behind this, this is a fundamental difference

2:41

in the way the detector technology works.

2:44

And I want to go into more detail later, but

2:48

until now, all the other CT scanners we have uses what is

2:52

called as energy integrating detector,

2:56

which means, I'm going to go in to explain later about the principle behind it,

3:00

but in photon counting detector, X-rays are directly captured

3:04

in the detector instead of converting into light photon and that

3:08

light photon creating an X-ray image.

3:12

Here it's directly converted, and we're going to discuss more detail, but

3:16

that's where the current technology.

3:18

So what I want to give here is like this is one of the example to show you

3:22

what's possible now with the photon counting CT.

3:25

With the energy integrating detector,

3:28

if the patient has any metal, it would create lot of these

3:32

streak artifact, which makes it almost impossible to

3:36

diagnose anything around that area.

3:38

There are a number of softwares available to reduce some of it,

3:42

but the photon counting CT further

3:46

enhances the capability of this metal artifact

3:49

reduction, which and among the many advantage, this is one of the

3:53

advantage I see.

3:55

The introduction of multi-detector CT open up the field of CT even

3:59

further.

4:01

All these things which I have listed here, cardiac CT, dual

4:05

energy CT, perfusion CT, or hybrid

4:08

CT and CT fluoroscopy, was not possible

4:12

prior to multi-detector CT.

4:15

And all these new area were developed with the introduction of

4:19

multi-detector CT.

4:21

I had the opportunity to be on the front line to see how each of these

4:25

technology developed because we were getting the first or second

4:29

generation multi-detector CT, and we saw the development

4:33

all these new fields in the field. Now cardiac CT is now the

4:37

mainstay among the cardiologist.

4:39

And with the nuclear medicine or in cancer treatment, hybrid

4:43

CT is the mainstay. Manufacturers are not even making

4:46

PET/CT by themself or the SPECT scanner by themself.

4:50

Every scanner they develop now in the nuclear medicine is a hybrid CT

4:54

scanner, hybrid technology, PET/CT or SPECT/CT, and so

4:57

forth. So I just want to share this technology

5:01

overview to give an excitement. The principle behind

5:05

it we're going to discuss as we go along.