By: Dr. Philip Chao

3T MRI is simply the best MRI available today it has the highest quality, clearest images, and is the fastest.  The “T” stands for Tesla and is used to talk about magnet strength—a bit like Megapixels with digital cameras.  The more “T”, the better the detail of the pictures. MRI scanners come in different sizes, shapes and—most importantly—strengths.  Old fashioned “Opens” are typically 0.3T but can be as strong as 1T (always ASK; it’s important).  “Closed” MRI’s range from 1T to 3T, with 1.5T being industry standard for high field MRI.

3T MRI is more detailed than any MRI done at lower field strengths and because the magnet is stronger, it is also 4 times faster!  Imaging times at 3T can be as short as 1 minute per scan!  The same scan in a weaker, 0.3T Open MRI would    take 9 minutes.

The increased power of 3T scanner improves the quality of all MRI scans.  Last night, we scanned a young gymnast whose big toe was painful. He had already had three 1.5T MRI scans elsewhere and all three failed to show any abnormality that might explain the pain!  Our 3T scan was positive—in the first 2 minutes of the scan!  Remember, three different facilities failed to show the abnormality … because their MRI scanners just weren’t strong enough.  It matters where you have your MRI performed.

There is a new kind of “Open” MRI scanner called the “Open Bore” MRI.  It is a full-strength 1.5T MRI scanner with two important differences.  It has the widest opening of any MRI made today—30 inches (70 cm).  It is also the shortest MRI made today.  At a mere 3 ft in length, your entire body is NEVER in the scanner.  It is the strongest OPEN MRI magnet in the world, and it is the fastest.

When considering where to go for an Open MRI, keep in mind that the less powerful “traditional” 0.3T scanner has an opening that is only 19 inches high.  The “Standup” MRI scanner has an opening of only 18 inches wide.  Instead of the 30 inches of the Open Bore scanner.  Also, our 30-inch wide OPEN MRI (the most spacious in the world) has a weight limit of 550 pounds.  This is ideal for patients who are claustrophobic.  You have not had a comfortable MRI scan until you have tried our Siemens 18-channel Espree.

One of the advantages of newer 3T MRI and 1.5T MRI scanners is advanced software.  BLADE is special motion-correction software that literally changes the image from night to day if the patient is unable to hold still.  Older scanners do not have BLADE (also called PROPELLER) to freeze motion.  Patients who have had an MRI  scan and gotten sub-optimal results should search for a 1.5T Spree scanner and ask if they have BLADE, REVEAL, NATIVE and BEAT.

Ionizing radiation causes cancer.  MR doesn’t use any.  CT uses massive doses of it.  In fact, in some cases the dosages are greater than that received by witnesses to the atomic bomb in Hiroshima!  In most cases, 3T MRI scans are so clear and detailed that they can be used instead of a CT—without the radiation.

MRI and CT have different capabilities with regard to image-contrast techniques.  Different ways to “highlight” abnormalities—making them “light up like light bulbs.”  The techniques for CT are fairly limited: Basically one can either modify slice thickness or radiation dose.  Beyond that, they have only iodine-based contrast injections to improve image quality.  Injectable contrasts for CT are more dangerous than those used for MRI’s—20% of patients who receive iodinated contrast will have a temporary fall in their renal function.  About 1 in 100 will have a permanent decrease in renal function from the test and 1 in 500 will have a severe crippling loss of kidney function.

MRI, on the other hand has many more image-contrast techniques designed to make abnormalities “light up” on the screen.  In addition to injectable contrast, there are a great number of other image-contrast techniques that do not involve any injection at all.  One such image-contrast is called diffusion weighted imaging (“DWI”).  In the brain, this shows early strokes; in the body it shows tumors of the GI tract and of the kidneys.  We found two pancreatic cancers last year and liver mets in several patients using this technique.  In the past year, we diagnosed two kidney tumors based on their appearance on DWI.  No other MRI facility in Delaware does DWI and, consequently, might have missed these tumors.  Siemens calls this technology REVEAL because it shows cancers as bright white lesions.  CT and ultrasound do not have a similar technology.  Another remarkable image-contrast is diffusion tensor imaging (“DTI”), which can detect microscopic damage to your brain (ideal for patients with traumatic brain injury).  CT scans or regular MRI scans cannot detect this damage.  Susceptibility weighted imaging (“SWI”) is another image-contrast technique.  Among other things, SWI allows us to see microscopic bleeding in your brain that can cause headaches, memory loss and other symptoms and might be invisible on an ordinary MRI scanner—and will not be seen using CT.

In the event injectable contrast is required, you should know that some MR contrasts are safer than others.  Since 2008, we have used only the safest MR contrasts (despite the minor price difference).  Our MR contrasts do not hurt your kidneys and have never caused a single case of nephrogenic systemic sclerosis.  There are 6 different MR contrasts marketed in the U.S., but only one can be safest at each field strength.  We use Prohance at 3T and Multihance at 1.5T.  Ask your MRI provider what kind of contrast they use.

Knowledge is power.  Ask questions.  Make informed decisions.  Choose your MRI facility carefully.  A weak MRI produces blurry images and can miss lesions that might be causing your symptoms.  Insurance companies reimburse exactly the same amount for both the very best MRI scan and the very worst.

Dr. Philip Chao graduated Phi Beta Kappa from Yale University and was Scholar of the House. He continued his studies at the University of Rochester School of Medicine and Dentistry, receiving his medical degree in 1983. After a transitional internship year at the Mary Imogene Bassett Hospital in Cooperstown NY, Dr. Chao did his residency in Radiology at Brooklyn’s SUNY Health Science Center (1984-1987), where he became Chief Resident. He stayed on to complete a fellowship in Neuroradiology (1987-1988). Dr. Chao has been interested in MRI technology since its very beginning – the first MRI scan took place in 1981 while he was pursuing his medical studies. The University of Pennsylvania, where Dr. Chao was both a Body MRI Fellow (1988-1990) and a Neuroradiology Fellow (1989-1990), was at the heart of the development of this technology and Dr. Chao was able to work with pioneers in MRI on the first GE Signa 1.5T (tesla) scanner. His advanced research and specializations complete, Dr. Chao left the University of Pennsylvania for a position as Director of MRI in Wilmington DE – a position he held for 14 years. Dr. Chao eventually left that position to create the best MRI center in Delaware, using the very latest technology: 3T MRI. While 3T (tesla) scanners have been used for scanning research patients since 2002, these advanced, more powerful MRI scanners only became available for clinical use in 2004. Dr. Chao worked hard to bring 3T technology to Delaware and in February 2007, MRI Consultants, LLC began operating the first 3T scanner in the State.
3T is the newest horizon for MRI.