Magnetic Resonance Imaging and Diabetes
Since the creation of magnetic resonance imaging scanner in 1977 by Dr. Raymond Damadian (Wakefield, 2000), this breakthrough technology has made tremendous impact in the field of diagnostic medical imaging. With the advancements in technology, scans are getting faster and images being clearer, it has contributed in diagnosing virtually any medical conditions. Although the use of MRI to study diabetes by scanning brain has been conducted in the past, there has not been many researches done to study the effect of diabetes using MRI and yet to be utilized routinely with patients with diabetes.
Diabetes is prevalent in today’s society. With over 30 million people with diabetes in United States, this accounts for 9.4% of the entire U.S. population. (National Diabetes Statistics Report, 2017). Although type 1 diabetes only accounts for 5%-10% of diabetic populations (Damjanov, 2012), this is significant due to potentially severe complications associated with this disease. With so many individuals suffering from this disease, there had to be a way to monitor and diagnose diabetes early. Through the breakthrough usage of Magnetic Resonance Imaging and specific contrast agents, we are now close to being able to monitor and treat diabetes early.
Prior to discussing the research, discussion of effect of diabetes in human physiology should be done. Islet of Langerhans in pancreas contains beta cells, which produce insulin. Insulin is a hormone that helps to control the blood glucose levels. After a meal, blood glucose level increases and insulin is produced from pancreas to absorb glucose into cells for energy. Insulin also assists in storing glucose in liver for an event where blood glucose level is too low. Thus, insulin production is vital for a normal physiological function. However, diabetes attacks islet of Langerhans and beta cells are destroyed. This leads to increased blood flow to the islet capillaries, thus resulting in islet cell death and no production of insulin. This finding was observed postmortem in test rats (Medarova, 2007).
There was a necessity to be able to monitor effect of type 1 diabetes in order to determine the effectiveness of treatments and progression of the disease. Thus, researchers have developed a method to monitor type 1 diabetes in a noninvasive manner by utilizing MRI and contrast agents. According to the research, test rats were injected with streptozotocin (STZ) to induce type 1 diabetes. Then, they were injected with Gadolinium-diethylenetriaminepentaacetic acid residues with fluorescein isotiocyanate (PGC-GdDTAPA-F) (Medarova, 2007). This is also known as long-circulating T1 contrast agent. Use of contrast agent decreases spin-lattice relaxation time and produces stronger and brighter signal on T1 weighted images (Westbrook, 2011). This paramagnetic contrast agent was specifically designed to target areas of increased blood flow and accumulate extensively in blood pools. Thus, this contrast agent was appropriate for this research. Scan was conducted in MRI on T1 weighted. The results showed increased permeability and blood pooling in pancreas. This was noted in 1 hour post injection and peak contrast agent collection in pancreas at 17th hour. Researchers also noted washout of contrast agent at 40 hours (Medarova, 2007). The scan showed abnormal morphology of islet cells and blood pool was noted.
From the results of the MRI scans, the researchers noted T1 time was decreased when contrast agent was used compared to control animals and this represented increased accumulation of contrast agent to the specific area scanned by MRI. T1 weighting was preferred in order to better visualize pancreas and brighter signal from the contrast agent. In order to obtain high quality quantitative images, inversion recovery was used, because it can produce high signal-to-noise ratio and heavy T1 weighted images that provides large contrast differences with the additional use of contrast agent. High resolution 3D MR angiography also further supported this finding by showing increased blood volume in pancreas as opposed to control animals. Also, it is important to state that these findings also applied to type 2 diabetes (Medarova, 2007)
This is a groundbreaking research for studying diabetes can contribute by early diagnosis of diabetes and monitoring of progression of treatments to determine effectiveness in treating diabetes. The fact that MRI can be utilized in this situation is highly advantageous due to no radiation delivered to patients and the fact that this method can be conducted in a noninvasive manner. Although more research is needed prior to conducting human trials, this is a step in right direction and further benefits patients with diabetes.