One of the most recent big advances in MRI technology have been on the software side, enabling faster contrast scans and greatly simplified cardiac imaging workflows.

Medical technology is progressing at a rapid pace, and the advancements play an ever-increasing role in health and wellness treatments. Magnetic resonance imaging (MRI) is one of the most common and valuable medical imaging modalities used in hospitals today and the MRI systems have evolved dramatically over recent years. These advances include higher field strengths, new techniques, faster gradients, improved coil technology, and more robust sequence protocols.

The standard MRI technique that has been implemented from the last 30 years comprises a single contrast agent that is injected into a patient's veins to help illuminate the problem components. Contrary to the conventional method, the new multicolored MRIs will enable the simultaneous detection of two contrast agents, thereby allowing medical professionals the opportunity to chart multiple characteristics of a patient's internal organs in a single device.

One of the most recent big advances in MRI technology have been on the software side, enabling faster contrast scans, greatly simplified cardiac imaging workflows, and allowing MR scans of the lungs. In addition, new MRI scanners have entered the market recently with higher strength of magnetic field (1.5–3T field strength) yielding better resolution of images, newer sequences of images, and the advent of open MRI for patients who are claustrophobic or overweight.

Indian Market Dynamics

The Indian MRI equipment market is estimated at Rs. 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. The 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 5-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 5-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 5-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 United States 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 the 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

The 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.

While MRI for neurology and brain disorders dominates the current market (about 35–41 percent), 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.

Improvements 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 on 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.

Despite this innovation, NYU Langone magnetic resonance (MR) physicist Martijn Cloos, 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 MRF (PnP-MRF), which embodied their decision to throw out the ideal scanner.

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.

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.

Way Forward

One of the most important factors in any kind of imaging is the signal-to-noise ratio (SNR). This is essentially a measure of how strong the actual signal is as compared to the background. Improving this parameter in a technique such as MRI is the goal of a biomedical engineering researcher. An augmented SNR has more than just technical implications. Practically, it can mean cutting down on imaging time and amplitude of radio waves, which can translate into a more comfortable patient experience and a lower energetic burden on the instrument. Recently, 7T and 9.4T field strength MRIs have been introduced with higher SNR and contrast-to-noise ratio (CNR) compared to lower field strengths. However, limitations such as inhomogeneous transmit fields and extensive contraindications for patient scanning restricts their clinical application in acute stroke.

MRI has become an essential technology in modern medicine. Today, a majority of the people undergo MRI scans – thanks to the improved life expectancy and the easy availability of these specialized equipment. Thus, in light of the mounting demand for MRIs and other disease detection tools, the market is pegged to achieve a bright future for revolutionary medical technologies. Another positive factor is the increasing portfolio of MRI technology. Constantly evolving, MRI will continue to be an indispensable part of the standard medical setup, yet its full range of applicability will only continue to grow. As technology gets versatile and complex, the detection of ailments gets quicker and completely reliable, and the demand for new-age MRI machines will only surge.

Second Opinion

 When Technology Befriends Outreach: MRI for all by 2020

Today radiology has evolved into an exponentially growing, high demand, result oriented field, delivering large volumes of qualitative and quantitative data of high quality, tailored to ensure highest value and outcome-based patient care. The changing approach involves a multidisciplinary, multimodality data analysis with growing machine learning and artificial intelligence.

MRI today trumps all other modalities in diagnostic capability and tissue characterization. It enjoys the undisputed position in a range of conditions from being the first screening modality to the pinnacle of super specialty imaging. However, complexity of scans, long exam duration, and high cost continue to be challenges.

Time in radiology being critical for both man and machine, innovations in MRI technology have focused not only on superior hardware but also improved sequences and softwares, enabling simplified imaging workflow, faster acquisitions, improved patient experience all of which have further encouraged expansions in the field of MRI.

Some of the important advances include multicontrast MR techniques, which deliver more data in a single acquisition, and in a fraction of the time used for conventional imaging. Shorter scans, fewer rescans, save time, cost and improve efficiency with better patient tolerability and lower sedation times. Enhanced patient experience innovations such as silent MRI sequences and ambient imagery, sound, and light, have been exceptional.

Given the rising number of patients using devices requiring MRI scanning and most implants such as knee and hip replacements, spine implants, pacemakers, and implantable cardioverter defibrillators (ICDs) now being MR-conditional, automated sequences for MR-conditional implant scans have increased the number of patients who benefit from MR scanning. Newer advances such as dedicated pulmonary software and weight-bearing MRIs are also contributing to enhanced growth.

One of the potentially game changing fields is cardiac MRI. Complexity of the examination with long scan times and high cost had made it rather prohibitive despite the diagnostic capability and indications. Simplification of advanced cardiac MR with automated image acquisition, visualization, free breathing exams, artificial intelligence, and machine learning speed cardiac MRI exam reviews and automatically identifies the anatomy and creates standard views including cardiac function, 4-D flow, 2-D phase contrast with identification ofregurgitation jets, vortices, and sheer wall stresses.

Last but not the least, while at the high end of the spectrum, FDA has cleared the first 7T MRI system in October 2017, demand is not restricted to A and B towns. Increased awareness and improved affordability with increasing numbers of older populations, are inherent drivers propelling the fast growth in the MR sector. However, researchers need to focus on low-cost, inexpensive, readily available, simplified and automated technology/equipment platforms.

Dr Mona Bhatia
Head of Radiology and Imaging,
Fortis Escorts Heart Institute


10 Diagnostic Imaging Trends for 2018

Best of 2017 Medical

 

Digital version