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7 Articles in Volume 6, Issue #8
Hyoid Bone Syndrome
Minimally Invasive Interventional Spine Treatment – Part 1
Mobile MRI—Imaging on Wheels
On the Role of Primary Care Within a System of Integrative Multi-disciplinary Pain Management
Pediatric Headaches
Practical Applications of Low Level Laser Therapy
Strength Testing in Pain Assessment

Mobile MRI—Imaging on Wheels

The seminal discovery—that atomic nuclei in a strong magnetic field rotate with a frequency that is dependent on the strength of the magnetic field and that their energy increase when radio waves with the same frequency or resonance are absorbed—was made early in the 20th century. This discovery was later followed with another in which the possibility would exist to create a two dimensional picture by introducing gradients in the magnetic field. There were several key scientists, including Paul Lauterbur, Peter Mansfield, and Raymond Damadian, that were instrumental in MRI as we know it today.

All seem to have played an important and controversial role in the development of what we recognize today as being MR imaging. Physicists had already been using nuclear magnetic resonance (NMR), first reported in 1938, to study various materials, but it was Damadian who postulated that hydrogen in water could prove responsive within the cells of living tissue. Moreover, he thought that abnormal cells such as cancer cells, might respond differently than normal healthy cells. Subsequent research has shown that relaxation times cannot reliably differentiate between cancer and normal tissue. He eventually built his prototype scanner in 1977 called “Indomitable,” and which now is located and preserved in the Smithsonian Institute.1 His scanner would flood the body with intense, but seemingly harmless magnetic fields combined with radio waves to cause hydrogen nuclei within the body’s molecules to vibrate and emit radio-frequency (RF) energy. The MRI scanner detects the RF energy emissions and transforms them into a viewable image. Even minor changes in tissue resonance, perhaps caused by pathology, can affect the rate at which energy is emitted and, consequently, will affect the final image produced. MR imaging is now considered to be safe; emitting no ionizing radiation and, in many cases, is the gold standard diagnostic imaging test of choice for many applications.

“MR imaging is now considered to be safe; emitting no ionizing radiation and, in many cases, is the gold standard diagnostic imaging test of choice for many applications.”

Mobile MRI-A Function of Efficiencies

In 2001 (the most recent year for which data were available), the average number of MRI procedures in hospitals with fixed MRI units was 3,300. Facilities with more than one MRI unit were performing an even greater number of procedures — approximately 5,390 per unit. Based on 2001 data, there were approximately 5,550 sites in the U.S. performing MRI procedures, including 4,000 sites with a fixed MRI scanner onsite, and 1,685 sites utilizing mobile technology. At that time, the majority of mobile MRI users were small (less than 200 beds) hospitals (81%), while 9% of the mobile users were 200-399 bed hospitals. The remainder were non-hospital (private, corporate owned) sites. Although the total number of facilities (hospitals, private clinics, etc) that now own MRI scanners has increased considerably since 2001, there is growing evidence that the mobile MRI sector is growing at an even faster pace due primarily to two reasons: the high cost of owning a fixed MRI scanner combined with a growing demand for MRI scans across the board. Utilization data derived from Medicare seems to support an approximate 8% total radiology workload increase per year, with CT and MRI procedures being ordered at the highest rate.2 With the added demand for MRI services, fixed unit providers are under pressure to be able to service the growing demand, but they do so with aging technology.

MRI scanners can cost millions of dollars, with hospitals and health care systems in general, being reluctant to swap out the older generation MRI scanners for new ones due to obvious economic reasons. Rapidly evolving software advances and upgrades can only compensate for hardware obsolescence to a certain degree. MRI technology is rapidly advancing and MRI provider competition in many regions is tight, partly due to state restrictions on MRI ownership expansions. Some states require a certificate of need (CON) to be issued prior to opening an MRI center, often a formidable task for prospective investors. Other trends such as shrinking payor reimbursement, an aging baby boomer population demanding more diagnostic precision, and greater workload demands on existing radiologists are some of the factors that have helped to drive the need for faster (more efficient), more accurate, and more accessible MRI services.3 Mobile MRI is evolving at a rapid pace for all these reasons and it can make good sense in the current cost-constrained health care environment.

While MRI systems are among the most expensive imaging devices in terms of unit and operating costs even though, like most technology, relative costs have decreased over time. Some have predicted that there are three powerful trends that will shape the future of MRI, those being;

  • the requisite of improved image quality or resolution,
  • the need for faster patient processing, and
  • a significantly increased demand for MRI examinations, but at a lower reimbursement rate across the payor mix.

Not everyone agrees, but this may lead one to speculate that the higher field 3T units would be those devices in line to replace the older, low and mid field units currently being used in hospitals and outpatient clinics.4 Even if this is true, however, replacing existing high field units might not be enough to maintain sales projections for new MRI units, according to some industry leaders. Some observers are suggesting that users of high field units such as research centers, large hospitals and teaching hospitals already have high field units. These facilities are more likely to purchase or rent a mobile MRI unit than to incur the cost of building expansion and/or purchase another MRI system.

Cost-effectiveness: When Does Mobile MRI Make Sense?

The DMS Interim Solutions Group out of Fargo, ND is a mobile imaging company that services a variety of clients for different reasons. Their mobile MRI trucks are really self contained imaging suites that are delivered directly to a site. They can even provide their client hospitals with choices of floor plans in their mobile truck of choice. Standard features include an exam room, computer room, patient waiting area, control room with operator console, heating and air conditioned mobile suites, and an exterior facade designed to match and blend into the existing facility landscape. The DMS Group is often called by health care providers such as hospitals to supply a mobile MRI unit when that facility is under construction, or they are having a patient gridlock that is straining their existing MR imaging capacity. Other potential scenarios where mobile MRI services would be considered include periods when hospitals are installing new or upgrading existing equipment or recovering from natural disaster. Like many mobile MRI vendors in the marketplace today, the DMS Group’s Interim Solutions provide an array of services including operations and support personnel to help optimize the provider client’s diagnostic imaging services to their referring physicians and community in general. Since reimbursement is such a critical part of this whole process, the DMS imaging group also provides billing and compliance specialists who make sure that correct billing and coding procedures are followed

With over 7,000 hospitals in the country, there are still many rural areas that have only small hospital facilities which service proportionately small communities. These smaller facilities cannot afford to have their own MRI units and must weigh the disadvantages of referring their patient outside their network for MRI services versus collaborating with other small hospitals and entering into a joint radiology venture to contract for mobile services. This shared service scenario is becoming more common every day as facilities look for cost efficiencies without having to compromise their service lines and face the prospect of losing patients. Adding mobile MRI to a hospital facility that does not have MRI can benefit all stakeholders including patients, physicians, hospitals, and vendors. It is recommended that facilities opting to enter into a collaborative agreement seek legal counsel to avoid any antitrust pitfalls. Mobile equipment, including PET, CT and MRI are all gaining prominence primarily due to the inability of many small to medium size hospitals to purchase these modalities outright and who, instead, look to mobile vendors to fill that service void.

“Mobile equipment, including PET, CT and MRI are all gaining prominence primarily due to the inability of many small to medium size hospitals to purchase these modalities outright and who, instead, look to mobile vendors to fill that service void.”

In addition to the mobility aspect, hospitals have a preference for imaging equipment with innovative features that incorporate the most recent technology, take advantage of increased resolution, and leads to enhanced diagnostic accuracy. As well, more technologically advanced equipment can provide greater efficiencies in terms of patient throughput or volume, thus allowing a greater number of cases to be processed in a given timeframe. Since prospective hospital clients will inevitably calculate a break-even point; balancing the costs incurred for contracting with a mobile MRI vendor versus expected return (direct and indirect) on investment, the number of possible MRI exams per day will be a critical component of this equation. In this regard, mobile MRI vendors can take advantage of newer technology that employs faster scan capabilities which can facilitate hospital productivity and radiology workflow in general.

In Southeastern Michigan, MRI Consultants operate eight mobile (truck) units that serve at least three very large healthcare conglomerates that all have their own research/teaching and large hospital(s) centers. These larger hospital clients have their own in-house large field (1.5-3T) MRI units but the patient demand simply outstrips their space availability and/or financial resources to regularly replace or add to these capital intensive and costly-to-operate units. Their solution, like many other hospitals across the country, is to contract with a local mobile MRI vendor that will bring in a mobile unit and park it in a convenient location close to the hospital. Dr Ram Gunabalan is the physician owner of MRI Consultants and is a board-certified physician (nuclear medicine/radiology). He is also the owner of a freestanding facility, Biomagnetics, that operates as a fixed MRI and multi-modality radiology facility in Madison Heights, MI. His mobile service includes a full mobile radiology suite built into the truck trailer, complete with MR-certified radiology technicians. He feels strongly about the certification aspect of his service and states that his mobile units have all met the most stringent of regulatory standards set out by agencies such as JCAHO, which includes proper personnel credentialing. Dr Gunabalan encourages potential hospital clients to expect that his mobile services will meet or exceed any regulatory agency requirements, which in turn, will help ensure compliance with the client hospitals internal radiology quality assurance program criteria. MRI Consultants work closely with physicists from Wayne State University in Detroit, MI on some peripheral aspects of MR imaging such as software advancements which ultimately drive the hardware outputs. Due to advancing hardware developments over the last few years, radiologists receive more information per test (more images per exam) from applications such as 3D imaging methods, diffusion and perfusion imaging, and cardiac MRI, along with integrating information from different pulse sequences and 3D imaging, that it is all becoming extremely challenging. To properly handle increasing amounts of MRI information, an increasing number of software tools are also becoming available.

It is imperative the mobile MRI vendors like MRI Consultants continue to invest in both hardware and software developments, both of which can lead to greater economic efficiencies and, ultimately, more clinically valuable testing. For those hospital centers that have transitioned into picture archiving and communication systems or PACS throughout their facility, it important to know that some mobile MRI vendors can seamlessly integrate their services with the facility’s existing digital imaging network. All in all, mobile MRI makes sense for many facilities looking to expand their existing MRI capability without incurring the costs of installing and operating a fixed system. Industry analysts have stated that demand for expensive fixed high field systems appears to be on the decline and, furthermore, the market may already be saturated. There appears to be a growing demand for less powerful but more efficient low to mid field systems instead. This will help insure that mobile MRI will continue to thrive in our cost managed and competitive health care environment.

Last updated on: December 13, 2011
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