Ultra-high-end MRI systems will create a new MRI market segment, bringing a paradigm shift in imaging across existing as well as new clinical areas.

For decades now, magnetic resonance imaging (MRI) has been noted for its excellent soft-tissue imaging capability with zero radiation dose. It has been called the imaging modality of the future over and over, but due to its complexity, long exam times, and high cost, its growth has been severely limited. The global market is currently experiencing steady growth (mid-single-digit growth rate). Although economic uncertainty and budgetary constraints have slowed down the market in certain countries, technological innovation and extended/new clinical applications of MRI due to their high importance in the imaging space have enabled it to overcome the restraints.

Over the years, Indian medical imaging equipment market has been growing at a robust pace on account of rising demand from hospitals, increasing incidence of chronic diseases, and introduction of hybrid imaging systems. Indian medical imaging equipment market is projected to cross
USD 1.6 billion by 2021. Rising number of global players foraying into the country, coupled with escalating number of applications of diagnostic imaging systems and rising healthcare expenditure, has also been fueling demand for medical imaging equipment in the country. Moreover, growing awareness regarding early diagnosis of diseases among people and increasing technological advancements is expected to drive the medical imaging equipment market in India in the coming years.

Recent national initiatives provide robust growth opportunities for the Indian medical devices industry, including medical imaging equipment. With 100 percent FDI allowed in medical devices industry, India is emerging as an attractive hub for foreign companies to set up their research and manufacturing facilities. Backed by all these factors, Indian medical imaging equipment market is anticipated to grow at a robust pace over the next five years.

Indian Market Dynamics

MRIMRI

The Indian MRI equipment market is estimated at 1632 crore, at 380 units in 2016. The 1.5T systems continue to be popular with a 63 percent value share, and a 68 percent volume share in this segment. 3T systems, which are seeing fast growth have a 25 percent value share and an 11.3 percent volume share. The 0.2T–0.5T systems, although gradually perceived as exiting this segment, continue to maintain presence with a 2 percent share in the Indian market. The refurbished segment constitutes the balance share. Indian market has not yet procured any 7T system.

GE, Philips, and Siemens have a combined share of 95 percent in the Indian market; the balance is shared by Hitachi and Toshiba.

The digital MRI systems with advanced clinical outcomes and new imaging protocol workflows are gaining preference. The discerning customer appreciates the flexibility of adjusting and retrospectively correcting the scan. A higher-speed system takes almost one-third the time of the conventional scan. The only noise a patient hears in a silent MRI is the room level noise. Awareness that MRI imaging capacity can be expanded through data-driven workflow optimization is removing major operational bottlenecks at the facilities.

Global Market Dynamics

Developing nations focused on investing in their healthcare infrastructure should spur growth in the global market for medical MRI. BCC Research reveals that countries, such as China, India, Brazil, and the Middle- East, represent opportunities for growth in the MRI market. The market should reach nearly USD 6.1 billion and USD 8 billion in 2016 and 2021, respectively, growing at a five-year compound annual growth rate (CAGR) of 5.7 percent.

The North American market for MRI systems should reach USD 3.1 billion in 2021 and USD 2.4 billion in 2016, growing at a five-year CAGR of 5.4 percent. The MRI systems market in the Asia-Pacific region is expected to reach USD 2.1 billion in 2021, up from USD 1.5 billion in 2016, growing at a five-year CAGR of 7.3 percent.

Wide-bore magnetic resonance imaging systems comprise over 85 percent of the US medical imaging market. The US market for MRI systems includes low-, mid- and high-field MRI systems as well as wide-bore and closed-bore MRIs for all field strengths. Growth in this market is driven by a shift toward mid- and high-field strength systems as they become more and more accessible to various consumers due to declines in average selling prices.

Mid-field MRI systems represent the largest medical imaging market in the US and will continue to experience steady growth. Mid-field systems are projected to lose some market share as purchasers shift to improved high-field systems, but mid-field systems will still maintain stable market growth until 2022. However, low-field MRI systems are rapidly declining as these systems are becoming obsolete due to both their low image quality compared to mid-field and high-field systems, and the accelerating growth in the refurbished market for mid-field systems. Similar to mid-field systems, closed-bore systems will lose market share to wide-bore systems as their popularity continues to grow. The ASP of these systems will continue to fall due to competition from higher-field systems.

Improving socioeconomic conditions in emerging regions and substantial investments by their governments in building and enhancing their healthcare infrastructure have increased demand for medical imaging systems.

Three Big Predictions

  • lThe commercial launch of ultra-high-end MRI systems (for example, 7T and 9T – currently used for research purpose) during 2016–2020 will create a new MRI market segment, bringing a paradigm shift in imaging across existing as well as new clinical areas.
  • lWhile MRI for neurology and brain disorders dominates the current market (about 35–41%), the use of MRI in cardiac, abdominal, lung, and breast imaging is expected to triple over the next four years extending the use of MRI in new clinical applications.
  • lImprovements in MRI systems such as high-performance gradients, surface coils, reduction techniques in terms of noise, artifacts and dosage, coupled with parallel imaging techniques and imaging informatics have substantially increased the level of quality and speed of image acquisition, thereby boosting the clinical performances.

Technology Update – Throwing out the Ideal Scanner

Despite decades of massive investment, traditional MRI still yields only qualitative images that are not resolved enough to guide database-driven diagnoses and research in the age of big data.

A new effort to overcome these challenges began with work led by Mark Griswold at Case Western Reserve University and published in Nature, which described magnetic resonance fingerprinting (MRF). Prior to that, MRI scanners had to wait for the magnetic spins to return to their normal equilibrium between each sequential radio wave pulse, a profound hindrance to imaging speed. MRF instead built images from the complex interplay of overlapping signals, a distinctive fingerprint matched to tissue qualities.

With advances in computation, MRF images were built on a small fraction of the scanner data matched to databases of known tissue patterns. The method replaced slower approaches required to process all the data to build an image from scratch. Despite this innovation, the first author of the current paper, NYU Langone magnetic resonance (MR) physicist Martijn Cloos, PhD, who is also an assistant professor in the Department of Radiology, saw that MRF was held back by its attempt match the real spins it captured to patterns from a simulated scanner calibrated to offer perfectly uniform exposure.

Unable to force uniformity, MRF images did not always reflect reality. To correct this, Cloos and colleagues designed Plug-and-Play MR Fingerprinting (PnP-MRF), which embodied their decision to throw out the ideal scanner.

Described in the newly published study, PnP-MRF matches its measurements to a simulated database of every possible magnetic field interaction or distortion as it builds images, and so requires zero calibration. Along with capturing spin characteristics, the new method was shown to effectively map the distortions that occur as MR radio waves interact with tissue, which radiologists had previously sought to erase via calibration. The study authors argue that these same field distortions also serve as a new set of tissue parameters that can aid in diagnoses.

Where MRF used a single source of radio wave pulses to generate signals, PnP-MRF is a circling strobe light of many broadcast magnetic fields, hitting the atoms from different directions separated by milliseconds to create a new kind of fingerprint. An artifact introduced by any one radio wave pulse may show a dark spot in one version of an image, but not in the same place in all data sets, enabling the dismissal of errors.

Taken together, these innovations enable PnP-MRF to correct for each scanner's peculiarities and magnetic field-tissue interactions, conclusions confirmed by a series of numerical and tissue experiments.

"In our design, the complexity in creating MRI images has moved from the machinery to the computation," says Cloos, "Rather than building chambers to house extensive magnet coils that fight non-uniformities, near-future scanners, by embracing heterogeneous fields, will consist of simple tabletop magnets, or possibly even hand-held MRI wands."

Way Ahead

MRI has continued to rapidly develop since its introduction as a clinical tool in the early 1980s. Technological advancements have helped it to emerge as a standard diagnostic technique in the global healthcare system. The technology has a clear edge over other modalities such as CT due to its non-ionizing nature, enabling its use in high-risk as well as pediatric patients. The technique also allows anatomic as well as functional imaging that allows its application in perfusion and diffusion imaging as well as navigation and planning in surgery. Widespread use of 3T scanners is already becoming a reality and future developments in coil technology and new image contrasts will continue to provide new tools for clinical diagnosis. The future holds good for MRI with ultras high-field systems with 7T and 9.4T systems currently being evaluated. Combined modalities and targeted contrast media are further on the clinical horizon, but will become a reality for specialist referral centers in the coming years.

Dr Seema Sud,Senior Consultant Radiologist, Sir Ganga Ram Hospital, New Delhi
Second Opinion
Technological Trends

Magnetic resonance imaging (MRI) is already the most flexible diagnostic imaging modality, allowing us to characterize many aspects of the living patient from metabolism and physiology to tissue microstructure. The recent advances in MRI have been more on the software side and are mainly directed toward decreasing scan time, reducing different types of artifacts, and enhancing the resolution of images obtained.

Newer software delivers eight contrasts in a single acquisition that too in fraction of time compared to conventional MRI. So we can generate multiple image contrasts in a single MR scan – including T1, T2, STIR, T1 FLAIR, T2 FLAIR, dual IR, phase sensitive IR, and proton density weighted images of the brain in a single acquisition, which will lead to significant time savings, fewer rescans, and therefore cost saving and helping clinicians in decision making.

MRI for lung has always been considered inferior to CT scan. But that now is expected to change with ultrashort echo time sequence for dedicated pulmonary MRI. It allows viewing tissue with very short relaxation times and high susceptibility regions, where signals generally disappear too quickly for accurate MR imaging.

Simultaneous acquisition of images as opposed to sequential acquisition in conventional MRI is expected to cut down the time of imaging by a factor of eight.

Cardiac MRI is now being more simplified with 7-D cardiac MRI exam, which gives information about the full motion of the myocardium during the cardiac cycle, blood flow, and time. It also cuts down the imaging time to about 10 minutes using a single, free breathing exam. The whole data would be processed by a cloud-based computing system.

Weight-bearing MRI scans are now possible. Some clinical pathologies, particularly in the musculoskeletal environment, are not really apparent in the supine position. The body coil is placed on the patient in the supine position, and then positioning adjustments are made directly on the scanner. A full exam can be completed in 6 to 8 minutes.

Dr Seema Sud,
Senior Consultant Radiologist,
Sir Ganga Ram Hospital, New Delhi

Second Opinion
Points to Look for When Buying

MRI has become the imaging choice for not only the brain and spine but also for the rest of the body. Amongst its many advantages, non-ionizing radiation foundation, superior contrast resolution, imaging in any plane and tremendous potential for newer ways to image are the main reasons behind the upsurge in MRI usage. MRI scanners of different magnet strengths are commercially available in India, ranging from 0.2T to 3T. Lower-field scanners (less than 1T) have the advantages of easier installations and lower costs, and are used in specific situations, but these systems suffer in broader clinical applications due to lower signal strengths and longer scan time. So for routine clinical use, 1.5T or 3.0 T MRI scanners are preferred. Needless to say that as the magnet field strength increases, the signal increases and the costs go high as well.

A 1.5T system continues to remain as the preferred choice for many of the diagnostic centers and smaller hospital setups to cover most of their clinical needs. The principal advantage of 3T (high-field) MRI system is the increase in signal-to-noise ratio, which plays a major role in improvement in spatial and temporal resolution and reduction in scan time. 3T machines have great utility in functional imaging, MR spectroscopy, non-contrast angiography, and diffusion tensor imaging. Higher contrast provided in 3T system may permit reduction of gadolinium (MR contrast agent) doses. Advantages for 3.0T MRI are also seen in imaging of the nerves, estimation of body fat, perfusion, or dynamic imaging. Hence these systems are the obvious choice for research and teaching institutes and are slowly gaining popularity among private diagnostic centers and hospitals.

Apart from field strength, another factor to consider is the bore diameter of the magnet gantry. The usual choice is between the traditional 60 cm, which is associated with better homogeneity versus 70 cm, which is associated with better acceptability by claustrophobic patients.

Coils are an essential part of MRI and these are designed for specific areas though some systems offer larger coil coverage that helps scanning without having to reposition the patient. These may be available as 8-channel to 32-channel coils for various regions, designed to obtain maximum signal in the shortest of time.

Apart from magnet strength, i.e., 1.5 T and 3.0 T, a high-performance gradient system is also vital for high-quality imaging. Hence depending on 1.5T or 3.0T, the gradient strength of at least 33 mT/s (milli Tesla/sec) to 50 mT/s or more and a slew rate of at least 120 T/m/s (Tesla/meter/sec) to 200 T/m/s with 100 percent duty cycle for full FOV is preferred.

For imaging of various body parts, all the vendors provide appropriate software including sequences, post-processing packages with image display, and archive facility. As MRI scan times are still higher, a better patient cooperation is always desired; hence a good motion-correction capability is probably the most important and underlining feature that any MRI system should have. This feature can avoid repeating the scan and also allow a faster patient turnaround while offering good image quality for accurate diagnosis, regardless of the patient movements during the scan.

Today some vendors have also started offering MRI sequences, which are lower on noise. High noise during certain types of scans is a big deterrent to patient comfort and results in their poor cooperation during the scans.

Other ancillary items are MR-compatible patient trolley, and MR-compatible monitoring systems with monitoring of ECG, pulse oximeter, respiratory, and external triggering. These are necessary for studies under sedation, e.g., imaging of children and uncooperative adults. Additional necessary accessories for patient comfort include paddings, high-quality noise-reduction headphones, MR-compatible IV stand, patient-operated audio alarm, and close circuit color TV and camera for patient monitoring. Usually a dry laser camera for film printing is bought together with the MRI system.

High-field MRI systems need uninterrupted power supply with supporting UPS with batteries, and proper air conditioning with humidity control. Lower power consuming systems are highly beneficial to reduce the overall running cost too. Equally important is the backup by the vendor for machine maintenance.


A New Cancer Treatment

10 Unbelievable Innovation in Medicine

 

Digital version