Combined modalities and targeted contrast media are on the clinical horizon, but they will become a reality for specialist referral centers in the coming years.
MRI imaging has become the preferred diagnostic imaging method for imaging the central nervous system, particularly for detecting brain tumors, spine lesions, imaging blood vessels, and stroke-affected areas of the brain. Generating radio waves from water molecules in the body using a very powerful magnetic field, this technology has gained impetus from the keen interest shown by technology developers and manufacturers that wish to make it more patient friendly.
A 1.5T system continues to remain as the preferred choice for many of the diagnostic centers and smaller hospital setups to cover most of their clinical needs. Widespread use of 3T scanners is already becoming a reality and future developments in coil technology and new image contrasts will continue to provide new tools for clinical diagnosis.
The future holds good for MRI with ultra-high-field systems with 7T and 9.4T systems currently being evaluated. Combined modalities and targeted contrast media are further on the clinical horizon, but will become a reality for specialist referral centers in the coming years.
A substitute for serial biopsies in active prostate cancer surveillance. MRI may help monitor men with prostate cancer who are under active surveillance, according to a study published in the American Journal of Roentgenology. Researchers from Winthrop University Hospital, Mineola, N.Y., performed a study to report the multi-parametric MRI characteristics of prostate cancer patients who discontinued active surveillance after repeat imaging revealed possible evidence of tumor upgrading.
Two hundred patients with prostate cancer were being monitored with active surveillance; 114 patients had undergone an initial multi-parametric MRI study before active surveillance started and at least one follow-up multi-parametric MRI study performed after active surveillance began. The MRI findings were evaluated and correlated with pathology results, if available.
The results showed that 14 patients discontinued active surveillance because changes on follow-up MRI suggested progression of cancer. Seven of the 14 (50 percent) patients had a biopsy after follow-up multi-parametric MRI, and biopsy results led to tumor upgrading in six of the 14 (43 percent) patients. The duration of active surveillance ranged from 4 to 110 months. All patients received definitive treatment.
The researchers concluded the small number of patients with follow-up multi-parametric MRI findings showing worsening disease supports the role of MRI in patients with early stage prostate cancer. Multi-parametric MRI is useful in monitoring patients on active surveillance and may identify patients with clinically significant cancer amenable to definitive treatment.
Safe even for patients with non-MRI-conditional pacemakers or ICDs. Non-MRI-conditional pacemaker or ICD may not be a contraindication for MRI, according to a study published in The New England Journal of Medicine. Researchers from several states sought to determine the risks associated with MRI at a magnetic field strength of 1.5T for patients who had a pacemaker or ICD that was not approved by the Food and Drug Administration for MRI scanning, thereby considered to be non-MRI-conditional.
One thousand patients with pacemakers and 500 with ICDs were included in the study. The results showed that no deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI.
The researchers concluded that in their study, device or lead failure did not occur in any patient with a non-MRI-conditional pacemaker or ICD who underwent clinically indicated nonthoracic MRI at 1.5T, was appropriately screened, and had the device reprogrammed in accordance with the pre-specified protocol.
MRI detects breast cancer sooner than mammography. MRI screening improves early diagnosis of breast cancer among women who are at average risk for developing breast cancer, according to a study published in Radiology. Researchers from Germany performed a prospective observational study to investigate the utility and accuracy of breast MR imaging as a supplemental screening tool in women at average risk for breast cancer, as well as the types of cancer detected with MR imaging screening. The study included 2120 women who underwent 3861 screening MR imaging studies. The women, aged 40 to 70, had no breast cancer-associated risk factors. The study covered an observation period of 7007 women-years.
According to researchers, the results suggest that MRI can serve as a useful supplemental screening tool for women at average risk, especially those with dense mammographic tissue, and MRI is superior to supplemental ultrasound for this purpose. The results also highlight the ability of MRI in the detection of more aggressive types of cancer.
"The faster a cancer grows and the better it is in seeding metastases, the better will it be picked up early by MRI," lead author Christiane Kuhl, MD, chair of the Department of Radiology at RWTH Aachen University in Aachen, Germany, said in a release, "In our cohort, cancers found by MRI alone exhibited features of rapid growth at pathology."
Brain MRI may help diagnose cognitive disorder. Diffusion tensor imaging suggests subcortical disconnection within large-scale cognitive neural networks is a key mechanism of vascular cognitive disorder, according to a study in Radiology. Researchers from the United Kingdom investigated associations between neuroimaging markers of cerebrovascular disease, including lesion topography and extent and severity of strategic and global cerebral tissue injury, and cognition in carotid artery disease.
A total of 108 patients with symptomatic CAD participated in the study – 53 were cognitively impaired. All underwent MRI and the Addenbrooke's Cognitive Examination–Revised. The results showed that the 53 cognitively impaired patients, classified as having probable vascular cognitive disorder, were older than nonimpaired patients. Lesion volumes did not correlate with global cognitive performance (lacunar infarctions, acute lesions, and chronic subcortical ischemic lesions). In contrast, cognitive performance correlated with presence of chronic ischemic lesions within the interhemispheric tracts and thalamic radiation. Skeleton mean diffusivity showed the closest correlation with cognition and promising diagnostic accuracy for vascular cognitive disorder. Findings were confirmed in subjects with a low risk of preclinical Alzheimer disease indexed by the absence of MTA (n=85).
The researchers concluded that subcortical white matter ischemic lesion locations and severity of ultrastructural tract damage contribute to cognitive impairment in symptomatic CAD, which suggests that subcortical disconnection within large-scale cognitive neural networks is a key mechanism of vascular cognitive disorder.
MRI systems have developed into the workhorse of high-quality diagnostic imaging and the applications of MRI have widened significantly toward functional imaging, real-time treatment monitoring for minimal invasive procedures using the unique contrast features of the method. As the use of MRI grows, physicians can expect to see an increase in the type of scans done with MRI. This phenomenon is also being driven by decreasing budgets. As radiology budgets get smaller, many healthcare providers are looking for equipment that gives them a variety of use cases for the price. MRI is expanding to different areas of medicine and the advantages of the technology continue to be realized, manufacturers and physicians can expect the market to grow around the world. New challenges are arising with significant changes and productivity pressure in healthcare delivery in the developed markets while the need for simplicity and ease of use is growing in the emerging markets.