0:00

The first subject we're really going to dive into is the notion that M R I

0:06

is the safe modality. Now,

0:09

there are lots of ways that we could define safety.

0:13

I think the minimum that we should be able to agree on is

0:17

that if we're describing safety,

0:20

we're talking about the prevention of injury.

0:24

If we look at the trajectory of M R I accidents in the

0:28

United States over time,

0:31

we have to acknowledge that we haven't lived up to the expectation.

0:35

If you look at the blue line,

0:38

the blue line represents change in MRI procedure volume

0:43

growth over time, using the year 2000 as a baseline.

0:49

And up until the COVID years,

0:52

we had fairly co consistent growth in M R I procedure

0:56

volume. The red line by contrast,

1:00

represents MRI classified adverse event reports to the US fda.

1:06

Now,

1:07

the number of adverse event reports is significantly smaller than the

1:12

number of imaging procedures,

1:15

so that tends to be more noisy data.

1:18

We see spikes and valleys a little bit more pronounced in the

1:23

accident data than we do in the procedure volume data.

1:28

But if we were to do linear regressions trends,

1:31

trends for each of these two lines,

1:34

linear regression for the procedure volume data,

1:38

and a linear regression of the MRI accident data,

1:45

the slopes of those two lines,

1:47

the accident line is increasing at almost three times

1:52

the rate that procedure volume line is increasing.

1:57

Said very simply,

1:59

A greater proportion and a greater total number of MRI

2:05

studies produce adverse events today as

2:09

compared to two decades ago. This may seem counterintuitive.

2:14

The natural assumption is as we have more experience

2:19

with the modality,

2:21

we have a better understanding of what causes harm and

2:26

more importantly, how to stop that harm from occurring.

2:31

So as I say, this is completely counterintuitive,

2:35

the idea that with more experience,

2:39

we are seeing greater numbers in total numbers and in proportion

2:43

of r i adverse events,

2:46

many of which result in harm to either patients or caregivers.

2:52

So why would it be that accidents are growing faster

2:57

than procedure volume? Well,

3:00

the only reason we would expect it to be the same is if things remained the

3:05

same. But if we look at just MRI hardware to begin with,

3:10

over that 20 year timeframe,

3:12

we are seeing stronger and stronger magnets. We've,

3:16

in that timeframe,

3:17

gone from 1.5 to 3.0 to a couple of years ago.

3:22

The US FDA has approved up to 70 for human use,

3:27

so stronger and stronger MRI magnets.

3:30

Better active shielding means a steeper spatial field

3:35

gradient, and that's the primary driver of attractive force.

3:40

We have imaging gradients time,

3:42

varying gradients that are faster and stronger for more rapid acquisitions and

3:47

more high RF pulse sequences.

3:50

The more RF we put in, the more potential signal we get out.

3:56

So both for clearer images and for faster acquisitions,

4:02

we have faster imaging gradients and higher RF pulse

4:06

sequences as compared to 20 years ago.

4:09

So the notion that we are standing still and simply seeing these

4:14

risks increase is a bit of a misnomer.

4:18

If we just look at the hardware alone, each one of these stronger magnets,

4:23

better active shielding, faster imaging gradients,

4:26

and more RF in our pulse sequences,

4:29

each one of those adds incrementally a slight bit of risk.

4:35

There are very few technological advances in the MRI

4:40

hardware that don't also come with

4:44

small but real risk factors that get added into the exam.

4:49

But not only are we adding risk in the form of technological

4:54

improvements in the MRI hardware,

4:57

we are also seeing increases in risk coming from the way

5:01

we use MRI clinically. Some of this has to do with patient cohorts,

5:06

patients with complications or contraindications.

5:10

It was not that long ago in the timeframe that we were looking at in that chart

5:15

when every MRI system manufacturer had legal disclaimers

5:21

in the operator's manual disclaimers that essentially said,

5:25

under no circumstances are you to image any patient who has an implant,

5:30

a device, a foreign body. Now, if we look today,

5:34

depending on the facility,

5:35

that's somewhere between 25 and 40% of your patients who have

5:40

implants, devices or foreign bodies.

5:43

So patients with complications and contraindications as a proportion of

5:48

the total patient cohort has skyrocketed.

5:52

It is still not very frequent,

5:55

but we now use MR as an imaging platform for emergent

6:00

and trauma patient imaging. Even if it's not emergent or trauma,

6:04

we still do high acuity patients, patients from the icu.

6:09

We are doing MR guided procedures.

6:11

We are doing increasing numbers of anesthesia and

6:16

sedation cases,

6:17

whether that's simply because of anxiety and claustrophobia

6:22

or in relation to MR guided procedures or high acuities.

6:28

So we see increasing risk factors from the scanners

6:33

themselves.

6:33

We see increasing risk factors from the way we use them clinically

6:39

and from an operational standpoint, really,

6:43

if you look at the bottom one first, reduced reimbursement per study,

6:48

I think that this is really the engine that drives.

6:51

The other ones reduce staffing,

6:54

greater throughput pressures. You could change throughput to revenue.

6:59

They're really one and the same,

7:01

and patients requiring greater time,

7:05

non compensated time for research, lookup of implants,

7:09

devices, and contraindications.

7:13

Each of these things also add incrementally to the risk

7:17

profile. Now, it's important to note that in the data,

7:21

the graph that I shared with you,

7:23

that there are a couple of missing elements from the adverse event data.

7:29

First off,

7:30

the data presented is only that from the MOD

7:35

database, the FDA's public facing interface with their medical device

7:40

reporting data,

7:42

and only the data that is classified as mri.

7:48

If an MRI interacts with an implanted medical device such as a

7:52

pacemaker and causes the pacemaker to malfunction and causes harm to that

7:57

patient,

7:58

that adverse event 99 times out of a hundred gets classified

8:03

exclusively as a pacemaker event.

8:06

Even though the MRI had an essential contributing factor

8:11

to the adverse event,

8:13

it is only classified under the device that experienced the malfunction,

8:18

which means any adverse events caused by an MRI

8:22

acting on an implant or device tend not to be covered in that data.

8:28

So the red line data is underrepresented because of adverse

8:32

events related to MRI interaction with implants and devices.

8:38

Similarly,

8:39

contrast related reactions are classified separately under contrast.

8:45

So if we look at the data,

8:47

we need to recognize not only the mathematical trending

8:52

of increased adverse events

8:55

Over time,

8:56

but we also need to recognize that that data is incomplete and there is data

9:01

missing from that cohort that probably makes the red line

9:06

grow even taller than it is in that data.