I really like new technology, especially when it offers a very obvious advantage for patients. I recently heard about a new CT scanner that is so fast, it dramatically reduces radiation exposure for patients and can take crisp images of moving organs (like the heart). I asked to speak with Siemens’ VP of Sales and Marketing, Dr. André Hartung, to find out about the new Somatom Definition Flash Dual Source CT Scanner (it takes longer to say the machine’s name than to scan your entire body). Of course, I invited my Medgadget friend, Gene Ostrovsky, to join the call. I’ve included a “bonus track” for more advanced readers at the end of this blog post. Enjoy!
Listen to the podcast here:
Dr. Val: Just to set the stage for our listeners – can you explain what a CT scanner is, and how it differs from an MRI?
Hartung: Both CT scanners and MRI machines allow healthcare professionals to look inside the human body for diagnostic purposes. While CT scanners use x-rays to produce images, MRI machines use magnets. CT Scanners are very fast and widely available – almost every hospital has one.
Dr. Val: When would a doctor want to use a CT scanner instead of an MRI machine?
Hartung: CT images are especially good at detecting cancer. Also, because CT scans can be done so quickly, they are also useful diagnostic tools for stroke, heart attack, or when a patient is in critical condition – when every second counts.
Dr. Val: You said that CT scans are based on x-ray technology. How much radiation exposure does the average CT scan cause?
Hartung: That depends on the part of the body that is being studied, or the kind of scan involved. For example, a heart image may expose the patient to between 5 and 15 milliseverts of radiation. Of course, the newest CT technology can perform the same scan with only 1 millisevert of radiation. Just for a point of reference, the average person receives 2-4 milliseverts of radiation every year from the environment.
Dr. Val: Siemens has developed a new CT scanner (the Somatom Definition Flash Dual Source CT scanner) that is a vast improvement over previous models. How exactly is it better?
The Somatom has 2 tubes and 2 detectors, whereas older CT scanners only have one tube and one detector. This makes the dual source CT the fastest scanner on the market. We can scan the entire body in less than 5 seconds – an image of the chest takes 0.6 seconds. The benefit of speed is that it dramatically reduces radiation exposure for patients.
Dr. Val: Tell me about the “light bulb moment” when the engineers realized that two detectors would allow the whole CT image acquisition process to go much faster.
Hartung: The best analogy I can think of is a camera. If you’re going to take photos of moving objects, you need to have a certain shutter speed or else the photos will be blurry. The “shutter speed” of this CT is so fast that it can capture the heart as it’s beating – without any blur.
Dr. Val: Can this new technology be adapted for use in a trauma bay in an emergency department?
Hartung: Yes, speed is critically important in trauma situations, so this dual source technology is ideal for Emergency Departments. The rapid diagnostic information can be life-saving when every second counts.
Dr. Val: What is it like for a patient to undergo a scan in the Somatom Definition Flash Dual Source CT scanner?
Hartung: The patient barely knows its happening, it’s so fast. The scanner can capture an image of the entire body in 5 seconds, so you don’t even have to hold your breath. The patient lies on his/her back, and the table moves at a speed of 43 centimeters per second over the body’s section of interest. The linear acceleration is very smooth, and the table has to accelerate through a distance of 30 centimeters before it reaches maximum speed.
Dr. Val: How many hospitals in the US have (or will have) one of these new scanners?
Hartung: These super fast scanners will be of most value to trauma centers. We anticipate that most academic centers in the US will want to invest in one.
Dr. Val: How much more does one of these cost than a regular CT scanner?
Hartung: The cost is similar to other high-end CT scanners on the market today.
Dr. Val: What’s the most important thing for patients to know about the Somatom Definition Flash Dual Source CT scanner?
Hartung: It’s dual source, and delivers a dual benefit: the fastest speed and lowest radiation dose of any CT scanner on the market today.
“Bonus Track” for the technically inclined – Gene Ostrovsky asks Dr. André Hartung:
1. What does the CT technician need to know about operating this new type of dual source CT?
2. How large are the computers that process this imaging data?
3. Is bore size an issue?
4. Do MRI and CT engineers ever cross-pollinate?