Early detection and more effective treatment — they are medicine’s mantra in 2001.
MRI, the focus of this month’s special section, has long been the staple for non-invasively probing soft tissue for abnormalities, thanks to its high contrast and resolution. In this section, we examine advances in MRI of the breast, heart and joints and the technologies’ ability to detect cancer earlier to facilitate better care.
MRI’s power in seeking out breast cancers, often earlier and better than other technologies, is proving strong in “Breast MRI: An Emerging Adjunct” (page TM-34). While mammography and ultrasound are doing a good and improving job in screening and detecting the vast majority of cancers, breast MRI is stepping up to the plate to detect the most evasive cancers — namely palpable lesions that have been missed or are undistinguishable by mammography or ultrasound, tumors in women most at-risk of breast cancer due to family history, as well as diagnostically difficult breasts, such as patients with dense breast tissue, scar tissue from previous surgery, or implants. Breast MRI also is evaluating chemotherapy and residual tumors following lumpectomy.
Breast MRI still is very much a niche technology. Availability is limited to select sites, most commonly via an add-on breast coil to a conventional MRI system.
The current cancer detection sensitivity level of a mammogram is estimated at 80 percent. Thus, the likelihood that a screening mammogram will reveal malignancy is one in 200 to 250 — which makes adjunct technologies, such as MRI, ultrasound and scintimammography, crucial to overall breast health.
To elevate breast MRI’s standing, research must further prove its clinical utility,
standards must be developed for magnet field strength, what sequences to employ and how much contrast to inject, as well as clinicians becoming educated in all of these areas.
Despite breast cancer’s place in the limelight, we cannot forget the evolving importance of MRI for detecting heart disease (our leading killer) and joint motion ailments that affect and debilitate 11.8 million Americans each year (due to work- and sports-related injuries).
Cardiac MRI is catching on, says Vivian S. Lee, M.D., Ph.D., associate professor of radiology and director of cardiothoracic MR imaging in the Department of Radiology at NYU Medical Center in this month’s Interview (page TM-43). Cardiac MRI is second-to-none in providing high-resolution heart images, measuring cardiac function and blood flow, and imaging vasculature. New state-of-the-art sequences are slicing exam time in half.
Despite the benefits, few hospitals have invested in cardiac MRI systems and coils, and conflicts are arising as to whether cardiac MRI is for radiologists or cardiologists. Truth is, it’s for both — provided the impetus exists to invest in good technology and for clinicians to gain expertise in these specialized applications. Future growth will come in boosting exam speed (from double to eight times current speeds) and advancing coronary MR angiography.
As you’ll see in “MRI Joint Motion Studies: Waging War on Repetitive Strain Injuries” on page TM-38, conditions such as carpal tunnel syndrome, tendonitis and osteolytis, affect a wide cross-section of Americans. MRI’s dominance in joint studies lies in detecting tiny tears in tendon and muscle fibers, detecting rotator cuff injuries, in assessing surgical interventions for carpal tunnel syndrome (CTS) and distinguishing weak nerve signals and median nerve compression in CTS. Ironically, there is a tie to radiology here — with injuries among personnel utilizing filmless radiology (PACS and ultrasound) on the rise.
From the looks of things here, MRI’s best days are yet to come.
Mary C. Tierney, Editor
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