Reference: Rinck PA: Rinckside - Thirty years take
MRI from the cutting edge to sustainability. Diagnostic Imaging Europe. 2010;
26,2: 7,8,14.
Reprinted as Rinck PA: Three decades take MRI from cutting edge to sustainability.
Diagnostic Imaging (US edition). 2010; 32,4: 17-19,23.
Key Words: Medical imaging; magnetic
resonance imaging; history; development of medical imaging; magnetic field strength;
equipment prices; market forces; aging population; low technology.
January 1990
March 1991
April 1991
August 1991
June 1992
January 1993
August 2005
 Check
also
Contrast
Agents
March 1995
November 2006
July 2008
|  hirty
years ago, I counted 12 MRI machines worldwide. Once the total had passed 25,000,
I gave up counting. Yet I wonder how many MRI systems will be in operation in
30 years time? The highest field strength for human MRI applications 30 years
ago was 0.15T. Today it is 7T. And 30 years from now? We will see (or perhaps
not).
The
development of MRI has been accompanied by paradigm shifts, changes in basic assumptions
regarding conventional wisdom. Back in the 1980s, physicists declared that it
would be impossible for MRI to compete with the rapid imaging times of CT because
of physical and chemical restrictions imposed by T1 and T2 relaxation times. They
also claimed that it would be impossible to image the human body with a field
strength higher than 0.3T. As we know today, both scientific statements were wrong.
"Clinical
MRI is based on subjective perceptions, as are all diagnostic imaging techniques."
For
most of my scientific and medical life, from the very beginning of MRI, I subscribed
to the view that MRI should be promoted. I always believed MRI to be a clean and
clear science, but it is not. Clinical MRI is based on subjective perceptions,
as are all diagnostic imaging techniques. Medicine
can be found in the middle ground between art and science. Diagnostic imaging
is one of the pillars of modern medicine, but in spite of all the numbers and
equations, the clinical part is as much an art as it is a science. Although
accomplished radiologists check numbers and curves, they also trust their eyes
and rely on their visual perception, their memory, and their cognitive processes.
Medical imaging, and thus MRI, is not just about what is in the pictures, and
neither is it simply pattern recognition. A good medical image reader has an excellent
training plus a certain innate, intuitive ability to spot minute inconsistencies
on an image and understand the medicine behind them. Scientists
involved in MRI, mostly chemists and physicists, always looked down on the physicians,
the radiologists. I could understand this attitude. They had developed a technology
that the average radiologist would never grasp, let alone develop. Thirty years
ago, I was the only physician at Paul Lauterbur's laboratory for the duration
of my stay; one young radiologist among chemists and computer scientists. Chemists
and physicists in Europe and the U.S. conducted the science part of the MRI business
(until companies' marketing and financial people took over) and made decisions
on how the technology would develop. This ultimately, though unintentionally,
had a negative impact on the technology. The enduser with sole responsibility
for patient outcome is, of course, the radiologist. MRI
is a stable technology; 6% of all imaging studies performed in developed countries
involve MRI and 10% involve CT. The most popular systems operate at 1.5T, and
in the U.S., these units account for approximately 75% of all clinical MRI installations.
Few significant technical changes are expected in the near future. Price pressure
has resulted in the cost of MRI equipment remaining static or falling, and the
introduction of 1.5T systems with fewer bells and whistles. A brand new, state-of-the-art
1.5T MRI machine can be bought for €600,000 or less. Profit
margins on imaging equipment sales are typically low. Manufacturers aim instead
to increase revenues through service and maintenance, though this is more difficult
in developing markets. The more basic the equipment, the more feasible it becomes
for the hospital's medical physics groups or technical staff to service the machines
locally. The
highest field strength available for routine clinical imaging is 3T. Sales of
high-field systems have, however, been slow, and U.S. hospitals appear to be retreating
from 3T in favor of cheaper 1.5T equipment. Some issues relating to 3T MRI, such
as energy deposition and dielectric uniformity, have been improved, but other
problems remain. The systems are noisy, expensive to service, and can exacerbate
imaging artifacts. In addition, there is no proof that imaging at 3T is diagnostically
superior to imaging at 1.5T (or lower field strengths). I have yet to find a single
scientific paper of substance proving that the diagnostic outcome of patient examinations
at 3T is better than at 1.5T. Three-T
was announced as the solution to clinical MRI, but it is not. Instead, it has
added another problem to the healthcare system. The “feel good” factor,
where one has done everything technically and financially possible, is higher,
but this is still not sufficient. What will happen with the recently introduced
7T machines remains to be seen. |
| Market
Forces A
considerable amount of money has been pumped into diagnostic imaging during the
past 25 to 30 years, tax money, insurance money, investors' money. The U.S. Government
Accountability Office reported in 2008 that high-tech imaging had grown rapidly
from 2000 onwards. The office blamed referring physicians' use of MRI, CT, and
PET for a doubling of Medicare's imaging-related costs to $14 billion from 2000
to 2006. The availability of MRI more than tripled between 2000 and 2005, with
the number of machines per million people growing from 7.6 to 26.6. The
growth in MRI hardware sales has stagnated over the past few years in countries
where the modality has become an established part of medical diagnostics. MRI
sales have decreased by 30% to 40%, as have sales of CT systems and nuclear medicine
equipment. The oversaturated North American market has been worst hit. Sales of
MRI units are still on the increase in some emerging markets, including Eastern
Europe, Latin America, and Asia. New
players, such as China and India, are expected to drive demand for diagnostic
imaging solutions and, to some extent, the direction of technological development.
Both countries offer huge internal sales territories, particularly China. Most
parts of China and India are extremely poor and have inadequately developed healthcare
systems, making low-cost, high-volume imaging solutions essential. These cheaper
machines will rapidly spill over into the Western markets. Mainstream
modality manufacturers increasingly have to decide whether new ideas have any
clinical and commercial relevance. R&D work will focus more on clinical relevance,
in terms of both applications and patient outcomes, than on new pulse sequences,
new coils, and new technical functions. A
huge number of imaging examinations are nonessential and it is futile for patients
to have these scans. In the U.S., the number of pointless procedures is, fortunately,
falling now. From 2010, MRI reimbursement is lower, which could further affect
the number of MRI examinations performed. The price for an MRI examination has
already fallen in some European countries, too. Japanese
health authorities pay several times less for MRI than U.S. insurers do. MRI is,
nonetheless, widespread in Japan owing to the availability of low-cost MR equipment
specifically geared for that market. Cheaper technology operating at lower field
strengths could be introduced in the U.S. if healthcare reforms force vendors
to make that decision. If this happens, the European market will doubtless follow
suit. Manufacturers
are, first and foremost, interested in money. This is their raison d'être,
the purpose that justifies their existence. There is nothing wrong with this goal,
though the motivation to make money has shaped radiologists' arsenal. It was not
in manufacturers' interest to develop a handful of general-purpose systems. Competition
between different company departments has brought us the clinical 3T MRI equipment
and 128-slice CT scanners. We now have a plethora of diagnostic imaging equipment
for rich nerds. MRI
is an extremely sophisticated technology, and as such, it is perfect for extracting
even subtle diagnoses. CT is cruder, but mentally a lot easier to comprehend.
Both modalities will be challenged and overtaken by different technologies from
unexpected directions: digital radiography, ultrasound, and in vitro laboratory
tests. Aging
Population Healthcare
resources are being stretched by the growing proportion of elderly inhabitants
in many countries, and no government can afford to support everything. Social
security funding is being reduced, owing to reductions in the workforce, and services
are facing cutbacks. Governments and/or reimbursement agencies will be unable
to fund existing standards of care in the future. Rationing already exists and
will increase. Diagnostic imaging services will continue to undergo major changes
as we address the rapidly increasing healthcare demands of these aging societies.
The escalating chronic disease burden will have to be managed more efficiently.
Efficiency and cost-effectiveness will become the key drivers of change, where
as reimbursement will increasingly be linked to patient outcomes. The
number of CT, MRI, and nuclear medicine procedures performed will plateau or perhaps
even decline. Patients will be managed at home, avoiding hospital admissions,
using ultrasound and portable digital radiography. Diagnosis and follow-up will
increasingly rely on in vitro diagnostics, building on advances in metabonomics. Low-Technology
Future? Further
technological development is not the be-all and end-all of MRI. Circumstances,
politics, manufacturers' decisions, and financial considerations can all change
– and will change – MRI, radiology, and medicine.
"Further
technological development is not the be-all and end-all of MRI. Technically doable
is not necessarily feasible."
There
are not enough well-trained radiologists and radiographers to operate our increasingly
sophisticated MRI systems. Why should we waste time considering the future of
MRI if there is no one to run the machines and no one who understands the technology?
Without an increase in training, all bright new ideas are useless. A country's
health system cannot afford medical disciplines and techniques that are not based
on solid human foundations. Teleradiology and computer-assisted diagnosis are
merely stopgap solutions. To put it another way, if there are no doctors left
who know their craft, then the craft will die. Without the human factor you will
have too many mistakes. Technically doable is not necessarily feasible.At
the RSNA 2009 meeting, congress president Dr. Gary J. Becker openly, and quite
distinctly, called for an end to a culture of preventable medical error and waste,
and demanded an improvement in the quality of medical imaging. My
prediction is that 10 years from now we will have a mass market of simplified
MRI systems. I have always wanted a low- or medium-field MRI machine, something
that is small and attractive, reasonably priced, easy to service and maintain,
and simple to use. In other words, a diagnostic imaging machine that any trained
physician could operate safely and reliably. |
April 2010
_
_