Which MRI Magnet is Best? A Market Analysis

By Kim

In the present clinical environment a new wave of advancements is creating a clear divide between MRI providers.

A report, published in August 2012 by IMV Medical Information Division, surveyed MRI/radiology department administrators and MRI lead technologists from 408 hospital-based and non-hospital imaging sites across the U.S from May to June 2012.

This market outlook report analyzed the challenges and opportunities MR providers are facing in the coming years and provided opinions related to future MRI trends.

The report concluded that there is a motivation to stay current with the advances in MRI technology and two clear driving forces were identified: Wide-bore technology (70 cm bore and greater) and high-field magnet strength (greater than 1.0 Tesla).

The IMV study found that high-field, 1.5 Tesla MRI remains the modality’s mainstay platform and that 1.5 Tesla MRI represents 70% of the installed base and 70% of new installations.

Interestingly, the report found that there is minimal demand by providers for 3 Tesla MRI due its limitations arising from the lack of clinical experience with the 3 Tesla platforms.

The report also makes clear that the demand for low-field MRI has virtually disappeared as it represents just 10% of the installed base and less than 1% of planned purchases in 2012.

At CMI, we have stayed current with imaging advancements. This report confirms that CMI’s high-field, wide bore 70cm 1.5 Tesla magnet is the magnet of choice for clinics wishing the latest in MRI technology.

Considerations When Choosing an MRI Centre

By Kim

Not all MRI’s are created equal. Important factors to consider when choosing where to have your MRI include the strength of the facility’s magnet, the protocols which they offer, whether they have invested in dedicated coils specific to the body part being imaged, as well as the overall design of the magnet. Dr. Jason Clement reviews these considerations in the following video.

Respecting a Cautious Approach to MS Treatment – PART II

By Kim

Thank you for your comments relating to the our blog post “Respecting a Cautious Approach to New Research in MS – Part I.  They raise important questions which require a full explanation.  Our response is not an attempt to change your mind or course of action but rather to clearly set out why CMI  does not, at this time, offer CCSVI testing. Our response to the (paraphrased) comments are as follows:

Why the need for controlled studies and proper protocols?
There have been innumerable “cures” and “treatments” for nearly every human disease.  Many of these were accepted by patients and physicians as being unquestionably useful in the treatment of their disease.  However, the (exceedingly) vast majority of these have been proven over time to either be harmful or of no benefit. The idea of “…first do no harm” is based (at least partly) on recognition of this history and the wisdom of this tenet has withstood the test of time.

One of the reasons that ineffective cures and treatments persist is that measuring the effect of an intervention is not as straightforward as one might intuitively imagine.  The only recognized method of proving whether an intervention is effective is in repeated multi-centre placebo controlled randomized studies. In order to be blinded in an interventional procedure, the physicians measuring the effects cannot be the same as the ones doing the procedure. As well the physicians (or other experts) collecting the data or performing the measurements should be experts in that particular field.  When proper confirmatory studies are performed, the results are often surprising and innumerable well accepted treatments (with sometimes thousands of peer reviewed published articles supporting their use) have subsequently been proven to be of no benefit.

Chronic cerebro-spinal venous insufficiency (CCSVI) as a contributing element in multiple sclerosis is a new concept forwarded largely by a single researcher (Dr. Zamboni) only recently  in the Journal of Vascular Surgery –  December 2009.  This pilot study involved a heterogeneous group of 65 patients.  There was no placebo arm.  There was reported improvement in the relapsing-remitting subtype but not in the progressive subtype.  The annualized relapse rate for the entire treated group remained unchanged (which implies that some people had more relapses after intervention.)  Outcomes were not measured and recorded according to standard research guidelines.  It is impossible to derive any conclusions from this report whatsoever.  Most MS neurologists and other experts from multiple disciplines are, in general, exceedingly skeptical of these initial reports.

Notwithstanding these difficulties, the report has gained worldwide attention.  Patients are understandably desperate to see advances in the field and in therapy  and are enthusiastic about this potentially paradigm shifting idea.  However, there are the 3 questions that should be addressed. First, does CCSVI exist. Second, if CCSVI exists then is it associated with MS and further is it causal.  Third, if CCSVI exists and either causes or worsens MS, does balloon angioplasty or venous stenting improve symptoms.  None of these questions can be answered without proper randomized studies.  At this very moment multiple large scientific studies are being preformed to answer these questions.  If validated the procedure would then be enthusiastically offered by practitioners and clinics, including ours, around the world.

Is the test and treatment for CCSVI safe?
Ultrasound and non-contrast MRI for CCSVI are non-invasive tests which are safe to administer. However, the purpose of performing the examination is to obtain a diagnosis and to determine what therapy is available.  To offer imaging (outside of a trial) is to offer implicit support of the diagnosis and its treatment.

In our Medical Director’s teaching hospital based radiology practice about 1/3 of his time is spent performing vascular interventional procedures.  The most common procedure he performs is venous angioplasty for dialysis patients with central venous stenosis.  In dialysis patients, these venous narrowings have occurred most frequently because of previous (dialysis) catheters.  Treatment is required for symptomatic relief of arm (and possible face) swelling or in order to provide blood flow for (life-saving) dialysis.  The natural course of these stenoses is to recur frequently after angioplasty.  Patients are regularly treated several times each year to treat re-stenosis.  Stenting of central venous stenoses can be problematic because of re-stenosis and occlusion of the stent. The experience of treating jugular vein disease is far more limited than other central veins.  Stenting of the jugular veins is of particular concern because of the mobility of the neck and resulting forces/torsion on the stent.  At least one MS patient has already had serious complications from this treatment being performed in the United States.

Clearly physicians everywhere would like to treat patients who have this common and devastating disease.  However it is our view that to ”treat” venous stenoses (outside of a proper clinical trial) without any proper scientific evidence of the effectiveness of this procedure in MS patients would be reckless and unethical.  This opinion is widely held by MS doctors and vascular interventionalists and it is why patients must resort to travelling to Bulgaria or Poland to find a physician who is willing to perform the procedure.

If the patients are prepared to take the risk why don’t we let them decide for the themselves?
Offering imaging of CCSVI at this time (outside of a proper study) is medically questionable (at best) or irresponsible (at worst).  At the moment there is not even a definitive protocol for the test. If the patient is not in a trial then what will be done with the information?  How does the patient (or any of his/her medical caretakers) know how to interpret the meaning of any of the findings?  Performing diagnostic examinations on an ad-hoc basis will not further a patient’s medical care or understanding of any potential link between CCSVI and multiple sclerosis and holds out implied false promise of a diagnosis and therapy. In short, to offer these scans at this time with the current data would violate the core principles on which our clinic was founded and on which it operates.

Is CMI part of a conspiracy to withhold this treatment from MS patients?
We do not believe that there is such a conspiracy, however we can only speak for ourselves. CMI is a privately owned and operated clinic which does not accept money from, nor is it beholding to, any other organization or corporation.

Further, we do not believe we have put “money before people..”.  with our decision not to scan for CCSVI at this time.  In fact we believe the opposite. Though we expect it would be quite profitable for CMI given the desire for this test, we believe it would be unethical and improper for us (outside of clinical trial) to offer and accept money for a service in which there is no definitive protocol, no controlled studies to demonstrate its efficacy and where the treatment risks are unknown and potentially fatal.

We understand that this is cold comfort for those suffering the debilitating effects of this terrible disease. While of little benefit to those who require a cure today, CMI is constantly reviewing the literature and if and when the science determines that there is likely benefit to CCSVI treatment for MS, we will offer the service immediately.

To further support our positioning, please view the latest statement released from Wayne State University, in collaboration with Canadian investigators from the University of Ottawa & McGill.

http://prognosis.med.wayne.edu/article/wsu-neurologists-dispute-italian-researchers-claims-on-risky-ms-treatment

Video: Getting an MRI

By Kim

There are many ways to describe the experience of a getting an MRI. This YouTube video does it well in 5 minutes. What do you think?

Important Questions to Consider When Choosing an MRI Facility

By Kim

When seeking the services of a MRI facility you have choices.  Whether you are considering being imaged at CMI or another clinic, there are important questions to ask to ensure that you are receiving the very best that MRI imaging has to offer.

Within the imaging community, there is considerable variability with respect to technology, the protocols and sequences that are used to obtain your images and perhaps most importantly, the technicians and radiologists who administer, read and report your images.

Other considerations include the quality of the service that you receive and the manner in which your findings are reported to you.

You may find the answers to these questions helpful in searching for an imaging facility that best suits your needs.

What type of technology/equipment does the facility use?

The type of MRI scanner used will directly impact the quality of image being produced and is one of the critical components of image quality.  If you wish the best images available it is imperative that the technology being utilized is “high-field”.  A high-field scanner has the ability to discern anomalies in far greater detail than low-field/extremity magnets and is particularly important when imaging the brain and core of the body.  True high-field MRI machines are those with a magnetic field of 1.5 Tesla or greater.  In addition, as MRI technology changes & advances quickly ask if the machine is more than 5 years old and, if so, ask if it has undergone a major hardware/software upgrade to keep current.

Does the clinic have the right hardware for the scan?

If you need a brain, shoulder, knee, foot, wrist, breast, chest or abdomen scan make sure the clinic has a dedicated coil (a piece of hardware the scanner uses to pick up signal) for that particular area.  Some clinics use an all-purpose coil in place of a coil dedicated to the body part and if so that will negatively impact image quality and therefore the diagnostic accuracy of the examination.

What specific protocols will be utilized in your scan?

A high-field MRI scanner can be programmed with hundreds of commands.  A protocol is the name for the series of commands and sequences a clinic programs into their machine to scan different areas of the body.  These protocols can differ significantly between clinics and can materially affect the information obtained and therefore diagnostic confidence of your scan.  Take for example the MRI evaluation of post traumatic changes in the brain.  In the peer reviewed literature it has been established that particular sequences (2mm Gradient T2* & SWI) are most sensitive for the detection of small hemorrhages that can occur in trauma.  Yet most public and private facilities do not include these sequences limiting the sensitivity of the examination.  The same protocol issues are true for many other parts of the body.

Are the Radiologists who read the scans hospital-based & specialized in the area of the body that they are reading?

The importance of the qualifications and the ability of the radiologist who reads the scans cannot be overstated.  Radiologists who are hospital-based or directly affiliated with a teaching-based hospital have extensive experience garnered through the thousands of scans they have reviewed in their time working at the hospital.  In Canada, radiologists who have not spent a significant time on staff at a hospital reading MRI will not have had the same opportunity to gain the requisite experience.

Another critical consideration is whether the radiologist reading your scan is specialized in reading images in that area of the body.  Due to the broad scope of radiology many radiologists have specialized training or experience in particular body parts.  For example, a radiologist may be primarily focused on the interpretation of neuroimaging examinations but not be involved in the interpretation of chest, abdominal or pelvic imaging.  Increased experience and expertise in a particular area will improve the accuracy of the reporting radiologist in this particular area.

Is the scanner being used an “open or wide- bore” design?

Patients now have the opportunity to seek out the new generation “open or wide-bore” designed scanners that, for example, CMI utilizes.  These scanners provide approximately twice the room in the magnet than traditional high-field scanners and because of their shorter length of tunnel (4ft as opposed to 8ft) more than 60% of exams are performed with the patient’s head outside of the magnet.    Without sacrificing anything in image quality, open bore scanners significantly reduce feelings of anxiety or claustrophobia.  These wide-bore scanners can comfortably accommodate patients up to 550 lbs as opposed to the weight limit of 300 lbs in traditional magnets.

Open-bore scanners should not be confused with “Open” scanners which are typically open on 3 sides and are low field magnets (1.0 Tesla or less) which, though comfortable, provide inferior image quality.

How does the clinic report its findings?

It is important for a MRI facility to work in partnership with your referring physician.  The communication between the referring physician and the radiologist should be open and readily accessible.  Your referring physician has the most familiarity with your personal and medical history, and is the best person to report back to you the results of your imaging.  In this way, you and your physician will have the opportunity to review your findings together, discuss how the results may be related to your medical history and discuss potential treatment options with you.

In the interest of speed of reporting, some clinics offer the radiologist to review your results with you immediately following your scan.  While a radiologist is likely able to review your results (the radiologist on site may not be the one who specializes in the area you had scanned), they lack the critical personal and medical information specific to each patient (such as your relevant history and/or previous images and tests) to be able to properly discuss your results.

A respect for continuity of care and partnership with the referring physician are important factors to consider when choosing a clinic.

Respecting a Cautious Approach to New Research in Multiple Sclerosis

By Kim

The past two months have been an exciting yet turbulent time for those connected with the Multiple Sclerosis community. With the publication and subsequent media attention to Dr. Zamboni’s research into CCSVI (chronic cerebro-spinal venous insufficiency), a world-wide quest has begun to determine the future impact of his potentially ground-breaking research.

Dr. Zamboni’s research has highlighted a potential disruption in blood drainage from the brain and spinal cord, contributing to nervous system damage typical in MS sufferers. In a study by Dr. Zamboni and colleagues published in June 2009, the investigators assessed blood outflow in major veins draining from the brain and spinal cord to the heart in 65 patients with varying types of MS and compared these findings with people who were either healthy or who had unrelated neurological disorders. The outcome showed evidence of slowed and obstructed drainage in the veins in many of the MS patients. Results of subsequent small studies, again led by Dr. Zamboni, suggest that surgery to rectify the narrowed veins may lead to a decrease in the relapse rate of people with relapsing-remitting MS.

The techniques used to evaluate the proposed narrowing of the blood vessels (CCSVI) include ultrasound and MR imaging designed specifically to study the body’s vasculature in a way never performed before.

The MS communities, world-wide, have taken these findings very seriously and as a result, have launched an accelerated & collaborative effort with radiology and physics experts to determine how common the abnormality is and how easily it may be detected. These efforts will move forward in the form of investigator-initiated research, committed to ensuring that the ethics and protocols and the subsequent clinical trial will be well-established and safe for each and every patient.

In Vancouver, the University of British Columbia is leading the way in this collaborated effort, in conjunction with the MS Society of Canada, and we recognize how fortunate we are to have such leaders in the MS community moving forward on such a large scale.

While Dr. Zamboni’s preliminary results offer a very real glimmer of hope, all MS organizations around the world caution both patients and imaging clinics to be patient. It is imperative that the research moves forward collectively, with investigators who are both trained and invested in establishing the highest standards of research. No clinic or hospital in Canada is currently trained on Dr. Zamboni’s imaging or treatment methods, as both the ethics and protocols behind the pending clinical trial have yet to be established.

CMI feels that the most prudent course of action at this time is to follow what the leading organizations and researchers in MS are advising. The MS Society of Canada has advised that “For safety reasons, the MS Society does not recommend that people with MS be examined or treated for CCSVI outside of an established research protocol”. Until such a time as this changes, CMI will not be offering the imaging techniques used by Dr. Zamboni as we support and respect what leaders in the field are advising.

http://www.mssociety.ca/en/research/medmmo_20091021_faq.htm

CCSVI UBC Letter December 10 2009

Navigating the Risks of CT Radiation

By Kim

This past week has seen an unprecedented level of attention over the potential cancer risk posed to patients who undergo CT (Computed Tomography) scans as a result of exposure to ionizing radiation.

Two multicenter studies published in this week’s Archives of Internal Medicine suggest that clinical CT radiation doses are much higher than previously expected, resulting in an increased lifetime potential cancer risk.  The statistics supporting these claims are troubling, although perhaps not unexpected.

Dr. Smith-Bindman & colleagues used clinical data from national databases to evaluate the level of radiation dose associated with several common CT imaging exams in a sample of 1119 patients.  Their results showed a high degree of variability in dose between different types of CT studies, overall doses which were much higher than previously thought, as well as doses which differed significantly within and across institutions, with a mean 13-fold variation between the highest and lowest dose for each study type

In the second study, Dr. Berrington de Gonzalez & colleagues, using risk models based on the 2006 Biological Effects of Ionizing Radiation VII, estimated that approximately 29,000 future cancers could be related to CT scans that were performed in the US in 2007 alone.  Their study suggested that the largest contributors to radiation dose are abdominal and pelvic scans, followed by chest studies.

These two ground-breaking studies have shed light on what many radiologists and physicians have been speaking to for years.  While there is significant utility for CT scans in the acute trauma setting and for identifying solid tumours of the chest & abdomen, it is important to acknowledge the risk-benefit ratio when considering this imaging technique.  According to the Canadian Institute for Health Information, there were 3.4 million CT scans performed in Canada in 2007.  The Canadian Association of Radiologists asserts that up to one-third of CT scans are inappropriate.  In light of the studies published this past week, it is reasonable to consider the value of utilizing alternate imaging techniques that do not expose a patient to ionizing radiation when appropriate.

A sound alternative can be found in Magnetic Resonance Imaging (MRI).  MRI uses non-ionizing radio frequency signals to acquire its images, utilizing a magnetic field, radio waves and computer technology to generate detailed three-dimensional images of body tissue and anatomy.

While CT provides good spatial resolution (the ability to distinguish two structures an arbitrarily small distance from each other as separate), MRI provides comparable resolution with far better contrast resolution (the ability to distinguish the differences between two arbitrarily similar but not identical tissues).  In the case of tumour detection, imaging of the brain, spinal cord & vertebral applications, blockages in the vascular system, and soft tissue injury, MRI, in non-acute circumstances, is documented clinically to be generally superior to CT.

While CT may continue to be relied upon in the hospital setting because of its ease of access, it is important for patients to weigh all the circumstances and consider other perhaps safer and better imaging alternatives.  Both the American College of Radiology and the Canadian Association of Radiologists are encouraging physicians to be more accountable in this regard and to seek out imaging techniques, such as MRI, which provide a greater benefit/harm ratio to the patient.

Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer.  Smith-Bindman et al.

Projected cancer risks from computed tomographic scans performed in the United States in 2007.  Berrington de Gonzalez et al.

Despite the Cuts to MRI’s in British Columbia, Patients Do Have a Choice.

By Kim

In British Columbia, it has just been announced that the B.C. Liberals have ordered Vancouver Coastal Health (VCH) to drastically reduce patient services and specifically, that VCH plans to perform only 18,000 MRIs in the coming year, down from 27,000 in 2008 and 20,500 in 2009. Similar cuts have been announced on Vancouver Island. These cuts are expected to increase wait-times in the public system by approximately 20%. Depending on your location within the province, this could mean wait times in excess of 18 months for a routine MRI.

The impact that this will have on patients is significant. A patient who is on a long-term waiting list may be forced to miss numerous days of work/school and wait for the appropriate treatment because their physician does not yet have the diagnostic answers that they require to treat them. This extended wait contributes to deferment of appropriate treatment, lost wages, and a negative impact a patient’s daily health & well-being.

In British Columbia, unlike some of the other provinces, patients do have options. Within 24-48 hours patients can obtain their MRI scan, with the report sent immediately to their physician. All that is required to start this process is a physician’s referral. Once you have your diagnosis you can also expedite an appointment with a specialist and/or surgeon at one of the private surgical centers in B.C. and see them in a matter of days instead of months.

So instead of waiting for months for the appropriate diagnostic exam, you can have an MRI, specialist consult and (if required) surgery in a matter of days.

There are costs associated with this expedited care but perhaps not as much as you think. What is important to know is that the choice is yours as to whether the costs for expedited care are worth it to you. You do have a choice.

For further information relating to the specific cuts being made province-wide, visit…

http://www2.canada.com/nanaimodailynews/story.html?id=9364fb77-4cca-429e-b91d-33e970da641f&k=27962

The Truth About Whole Body Scans

By Kim

In an age when we as individuals take our health seriously and make an effort to be proactive about our own physical and mental well-being, it is only natural that we want answers with respect to how medical technology & advances can impact us.

In recent months there has been significant attention provided to Whole Body Scans using Ultrasound, Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) as a preventative cancer screening tool. All of these modalities have issues as a screening tool and it is critically important to understand their limitations.

The use of imaging to screen for potentially life threatening disease is neither novel nor new. In recent years CT, due to its quick acquisition time, was utilized as a tool for whole body preventative screening.   However, CT is no longer thought of as a general screening tool for two reasons.  The first is that CT requires ionizing radiation which is a risk factor for cancer.  In particular, if the examination needs to be periodically repeated then this should be considered an unacceptable cost to an asymptomatic patient.  Additionally, CT performed without an intravenous iodine containing agent lacks contrast resolution, therefore the test’s ability to separate a kidney cyst from a solid kidney mass is far more limited than MRI.  Nonetheless, CT remains a useful screening tool for heart scans which use very low amounts of radiation and yield excellent and helpful information.

Ultrasound has been used as a limited screening tool, particularly for the identification of abdominal aortic aneurysms.    However, ultrasound is relatively limited in its scope in comparison to MRI.  For example the spine, brain and bones cannot be assessed at all ultrasonographically.  As well, even in organs that can be addressed ultrasonographically the sensitivity of MRI for the identification of lesions is superior to ultrasound.  Finally, in larger patients ultrasound can be very limited for all but the most superficial structures.

The questions remains, what is different about screening with MRI which makes it superior to these other screening tests? The answer is quite a lot.

Unlike other screening tests, preventative screening with MRI concentrates on those areas which have been well documented to yield the most benefit from early detection. While not every cancer benefits from early detection, many do, such as renal cell carcinoma, liver cancer & certain gynecological cancers. In addition, whole body MRI screening focuses on life-threatening illnesses such as aneurysm, stroke, and vascular disease without exposing the patient to any harmful ionizing radiation.

From a technological standpoint, MRI has the unique ability to clearly define structures and lesions within the body in far greater detail than ever before. The additional detail obtained using MRI makes it possible for a radiologist to classify a lesion that is detected as either benign or as a lesion requiring further investigation with contrast or using other modalities. This significantly reduces the number of false positives requiring invasive follow-up endemic to the other screening modalities.

Individuals now have the opportunity to make a significant investment in their personal health utilizing whole body screening with MRI. You now have the opportunity to be proactive with your health with a safe and comprehensive test. The information obtained will provide valuable information to your physician which can significantly impact your wellbeing today or one day in the future.


Whole Body Scans With MRI – A Wise Investment?

By Kim

Over the last decade, Magnetic Resonance Imaging (MRI) has undergone significant evolution with respect to improvements in scanner strength, enhancements in image quality and clarity, and the ability to capture images in far less time. From a radiologists’ perspective these advances have dramatically impacted their ability to discern abnormalities that may have previously gone undetected.

A further advancement in the world of MRI, now available in British Columbia, is the use of MRI as screening tool for the early detection of a number of potentially life-threatening illnesses and disease.

So – is investing in a preventive MRI screening exam a sound investment? We think so and here’s why.

It provides your physician with exceptionally detailed information about a number of body systems, allowing for the early detection of disease, cancer and other serious illnesses. It allows the opportunity for treatment at an early stage for those cancers/illnesses that are currently undetected and asymptomatic. It offers peace of mind for those patients who have concerns about certain aspects of their health based on their family history and it provides a baseline of perhaps critically important information against which all future scans will be compared.

Does this mean that whole body MRI screening is able to identify every issue within your body? Absolutely not. As with all medical examinations, it has its recognized limitations.

Whole body MRI does not have the capability to effectively diagnose coronary artery disease or evaluate the lungs for cancer (all of which are better done with CT). In addition, as a screening tool it is not optimal for the diagnosis of early colon or prostate cancer. It is also important to recognize that while whole body MRI screening has the potential to uncover a cancerous finding early, this does not guarantee that the cancer found will react successfully to treatment.

Weighing these benefits & limitations, many patients are turning to whole body MRI screening as an investment in their quest for exceptional healthcare. Though it is not, and will never be, all things to all people it is a sound, principled examination, which yields important and perhaps critical information. It is a wise investment.