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By Divya B
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Advancements in Magnetic Resonance Imaging (MRI) technology has resulted in a growth of its clinical applications at an equal pace. Each subsequent increase in tesla strength has opened up new doors in clinical application possibilities. The MRI market worldwide has grown rapidly over the past few years due to its breadth of clinical applications and proven clinical research track records. However, usage of certain applications beyond the realm of clinical research is being hindered by the lack of reimbursement. Market trends of some of the most promising clinical applications are elaborated below:
* B/ U d2 G$ {: @& k* _Whole Body MRI
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Whole body MR could complement and in some cases, even replace altogether traditional bone scanning techniques, according to studies from across Europe released at the 2006 RSNA meeting. The scanning times for whole body MRI have also dropped with the progress of technology. Whole body MRI can be categorised as MRI for oncologic and non-oncologic purposes, non-oncology includes whole body angiography. For whole body imaging, a 3 Tesla system is generally preferred as parallel imaging can be provided, if required. However, for screening purposes whole body MRI is yet to gain popularity, as it is not cost effective. On the whole, this is a promising clinical application, but still has to improve.
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Functional MRI
$ Y' {! t L' f3 Y7 |MRI is particularly useful in brain and neurological disorders, because it can clearly show different types of nerve tissue. Functional MRI is currently one of the most popular methods for brain imaging, where MRI is combined with Positron Emission Tomography (PET); the structural image provided by MRI is combined with the functional image provided by PET for superior diagnosis. MRI technology's superiority for brain imaging is well established over other modality. It provides clear pictures of the brainstem and posterior brain, which are difficult to view through CT scan.
4 `; z" q& [1 u6 W ^, A [* dThe sales of MRI systems for brain imaging are occurring mostly in university hospitals, where they are used mainly for research purposes. There is a lot of interesting cutting edge research being conducted in university hospitals to study the human brain. These researchers believe higher the Tesla the better it is. At present, they are driving 3 Tesla sales as these produce superior images because of thinner slices. At present, most of the major players including GE Healthcare (GE) and Siemens Medical Solutions (Siemens) are present in this field.
2 B, W2 O7 g5 v$ O sIntraoperative MRI
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Intervention applications for MRI are on the rise. At present, there are a growing number of image-guided minimally invasive procedures, such as biopsies. MRI for image-guided minimally invasive procedures is more popular for the cardiac and breast procedures. MRI can distinguish tumours or other lesions from normal tissues and this has increased its popularity for intraoperative MRI for brain or spine surgeries. The trend for MRI for intraoperative purposes is getting stronger every year.
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There are currently North American and Israeli participants active in the market, namely, Odin and Imris. The most popular one being Odin Medical Technologies, which has now been acquired by Medtronic Navigation, provides an intraoperative system for brain surgeries. Safety is an issue here, as even biopsies require staff, equipment, and supplies in the magnet room that would not otherwise be in a suite used for strictly diagnostic imaging. Intraoperative systems are mainly being used in university hospitals at present, but there is scope for growth by targeting larger hospitals. The major participants could concentrate on bringing out intraoperative systems. There exists a scope for tremendous amounts of innovation in this particular field.
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Breast MRI
7 ]% R! v. U, [7 aThe use of MRI to screen women at high risk for breast cancer was approved recently by the American Cancer Society (ACS). ACS said that breast MRI should be used with conventional mammography as part of an annual screening regimen in certain groups of high risk women, for example, women with a family history of breast cancer. Its ability to detect small abnormal breast lesions has proven that MRI is an effective breast cancer diagnostic tool.
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The above factors are a reason for breast MRI increasingly becoming popular in the United States. Breast MRI for screening purposes will gain popularity in the short term in Europe as well. All the major participants have breast MRI applications or software. Aurora Imaging Technology has a dedicated breast MRI system, which is being distributed in Europe through Paramed Medical Systems. The market for breast MRI is set to boom over other applications. Most imaging centres in the United Kingdom now advertise their breast MRI capabilities to increase referral base. MRI-guided breast biopsy will also most likely gain increasing popularity. However, the cost effectiveness of breast MRI and reimbursement are issues that still need to be addressed. Though at present breast MRI is only a small portion of the MRI procedures in Europe, it is set to become one of the most popular clinical applications in the medium term.
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Cardiac MRI
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Cardiovascular magnetic resonance imaging (CMRI) has had rapid advances over the past few years. Studies have shown that non-contrast MRI is about five times more sensitive than and twice as accurate as immediate non-contrast CT for diagnosing ischaemic stroke. MRI appears to be a more sensitive test in detecting the most common form of stroke as well as for diagnosing haemorrhagic strokes. MRI and CT are both complementary and competing technologies. For example, MRI is preferred for acute stroke, but CT is preferred for coronary artery imaging, and MRI and CT are found to be equally effective in detecting acute intracranial haemorrhage.
* l' s. X. l8 y1 f3 dCT does have an advantage over MR for coronary artery imaging. A 64 slice CT imaging capability, though of lower resolution than a 3 Tesla MRI, is relatively less expensive and hence more popular. Additionally, with the development of 128 slice CT scanners, the image quality is likely to improve drastically and hence increasing its suitability for cardiac applications. On the flip side, however, concerns over the high radiation dose of the multi-slice CT systems might increase the popularity of MRI once again, despite fears of cardiac MRI being sidelined with the advent of 128 slice CT scanners. MR angiography (MRA) is gaining popularity as a clinical application. However, in the short term, breast MRI appears to be more promising application of MRI from a market point of view.
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Conclusion
f# A5 M* a5 G: d- z. d* G% b+ _Of the applications given above, certain clinical applications like MRI for cardiovascular imaging, breast imaging and so on are the most promising ones. At present, musculoskeletal and abdomen imaging are the most popular applications; however, the proportion of procedural volumes for cardiac and breast MRI is set to increase in future.