The Grand Showdown: Computed Tomography vs. Magnetic Resonance Imaging. Who Will Go The Distance?

Things are heating up in the heavyweight division of the medical imaging modalities. In an elaboration of a theme from the forthcoming Frost & Sullivan research service "The European Market for the Key Medical Imaging Modalities” Medical Imaging Research Analyst Martin Bryant steps into the ring to try and arrive at a points decision between the MRI and CT modalities.

Depending on whom you ask in the industry, you are likely to receive varying opinions upon whether CT or MRI will have the upper hand in the medical imaging market come 2010. Whilst it is well established that each modality has certain advantages over the other for certain clinical applications - one need only look at CT's much vaunted capability in imaging the lungs - there are areas where the boundaries can be seen to be blurring. Product managers on both sides of the MRI/ CT divide are now wont to talk up the capabilities and benefits of their modalities, whilst increasingly neglecting to mention the fact that MRI and CT can in fact be complementary procedures in certain applications. The gloves would indeed seem to be off.

Short Term Reimbursement Worries

The current macro-economic outlook for both modalities would suggest something of a false start. At first glance, MRI would seem to be suffering most directly from low reimbursement being generally prevalent in Europe at present, given its greater capital investment and attendant procedural and maintenance costs when compared to CT. This problem is further heightened given the EBM Plus 2000 reform in the German market, the largest for both CT and MRI. There is currently debate raging as to the extent of cuts in MRI procedure reimbursement. Nearly all MRI applications will be effected by this, and possibly by a reduction totalling as much as 30 per cent. This of course will impact negatively on MRI.

But will CT benefit. To some extent yes. Private imaging centres looking for a high end technology that nevertheless brings a reasonably fast return on investment may well be tempted to choose CT ahead of MRI, for example. Yet there are deeper forces at play: MRI is younger than CT, and is only just becoming a financially viable modality in many hospitals. CT, on the other hand, has all but reached the end of its recent government investment lead boom in countries such as Britain and France; countries that are still playing catch up in Europe in terms of MRI installed base, as are Spain and Italy. This means that CT is becoming a replacement market destined to market stability in the coming years, whereas MRI can expect modest growth.

Added to this, CT itself faces reimbursement issues, notably in Spain, where there is no differentiation in reimbursement for procedures, whether they be performed on either the latest multi-slice CT technology, or decade-old single slice scanners. This will only increase hesitation in investing in the latest 64 slice scanners as the industry recovers from the recent 16 slice boom.

Hope Lies With The Cardiologists

Round One to MRI, then. However, CT is currently staging a counter attack with the arrival of 64 slice CT, despite health care payor misgivings about a reimbursement rate that reflects the clinical capabilities of this technology. 16 slice CT is seen as being the bare minimum requirement to enable the modality to be used in cardiac applications, an area in which MRI has long been seen to be superior. With the advent of 64 slice CT, however, cardiac CT is now seen as a very viable means of examining the heart. The major industry players are currently competing at the very high end of CT, with one vendor offering a system that can capture the heart in 5 beats. This capability has seen the very same scanner become the world's first CT scanner to be installed purely for cardiac applications in the Round Rock Cardiology Centre in Texas, its image acquisition speed set to make the imaging of sick patients who have difficulty holding their breath for longer periods more feasible than the slower MRI procedure. If the reimbursement climate in Europe is to ever prove welcoming, new installed base will be created by the cardiology community as they begin to choose multi-slice CT ahead of high-field MRI, for its superior speed and, crucially, the fact that it requires less capital than MRI. This will again lift CT growth and give it the impetus to leave the replacement phase behind.

MRI is a long way from throwing in the towel, however. When this analyst has quizzed MRI product managers on this, he has on occasion been greeted with scoffing and the response that MRI will soon categorically trump CT with improved image quality and ever faster scan times.

Volume of Images, Radiation, and The Long Term Outlook

One can debate the varying speeds of MRI and CT. Indisputable, however, is the fact that both modalities are creating ever increasing volumes of images per procedure. This creates opportunities as well as problems. Whichever modality can best meld Computer Aided Reading software to its hardware offering, and thus manage the workflow problems of this upsurge in images more effectively, will gain advantage over the other. One element of the increased speed and image acquisition of ever higher sliced permutations of CT that gives it a natural disadvantage, however, is the fact that this will lead to higher doses in radiation. This is again an issue in Spain, where the government now insists that levels of radiation dose be stipulated in all CT tenders. Among the radiologist community voices are being raised too, with online discussion forums welcoming the increasing attention being afforded this problem. Many US radiologists in fact demanding that physicians desist from automatically referring patients for a CT scan for diagnosis, instead using the modality only to confirm their own diagnosis.

This can only bode well for MRI, which, as the name suggests, relies on magnetic resonance to image rather than radiation. Indeed, safety concerns coupled with better clinical benefits have also seen MRI come out on top in recent studies to assess both modalities' capability in whole body imaging.

And this is where MRI wins on a points decision. It is simply higher up the imaging value chain, and can image almost anything effectively and with a sharpness of image quality that is generally unsurpassed by CT. CT may offer more attraction in the short term, but the broad industry consensus remains that MRI is the future. Once health care policy catches up with the technological innovations of MRI, improved reimbursement will see this modality become the long term undisputed champion.

For further information please contact:

Katja Feick
Corporate Communications
+44 (0) 207 915 7856