The following question has been sent by John Phillips:
Which scanner: Which is the more advanced and best all around scanner….the GE CT750 or the Siemens Flash? If you could only buy one as your only scanner which would you buy? Are there any “must have” options?
Savvas Nicolaou, MD, Vancouver General Hospital, University of British Columbia:
Both are great scanners however overall I would purchase the Siemens Flash scanner because of its great versatility. It allows you many more options on scanning many different types of clinical scenarios.
Cardiac: The Flash scanner allows you to scan with and without b blockers given the 75 msec temporal resolution that can be advantageous in patients that you cannot use b blockers ie asthmatics, COPD, extremely high heart rates.
You have the possibility in scanning prospectively without b blockers thus lowering the dose, you can scan in Flash mode if the heart rate is below 65 beats per minute at doses less than 1 msv
You still can scan spiral for unpredictable heart rates
You also now have the possibility in doing perfusion dynamically or utilizing dual energy for assessing ischemia
You can do a Flash triple rule out around 4 to 5 msv where most scanners require 15 to 20 msv
Thorax: You can dual energy imaging for pulmonary embolism assessing for perfusion defects, or you can sue the flash mode that allows you to also visualize the coronary arteries at the same time and limits motion that is useful for critical ill patients that cannot hold there breaths, this mode is also useful for pediatric patients as you do not need to use sedation to limit motion. By using dual energy you can better see aortic leaks for aortic stent graft assessment given the increased sensitivity at the 80 or 100 kv setting in dual energy mode.
Neuro: You can do whole brain perfusion under 5 msv
You can do dual energy imaging that allows you to quickly subtract the bones from the vessels allowing you to expedite your workflow in CTA’s of the head and neck and also this is very useful for arteries that have lots of calcified plaques as it allows you to subtract the calcium from the vessel wall.
Vascular: you quickly do whole body run offs in a matter of seconds with dual energy that allows you to see distal calcified vessels more clearly due to the pure bone vessel subtraction
Abdomen: You can use dual energy to better assess renal , liver pancreatic lesions and you can save dose from the virtual non contrast scan as you do not need a seperate non contrast scan. You can use dual energy to characterize renal stones separate uric acid from calcium stones.
MSK: You can use dual energy to asses for gout arthropathy also can use the Z sharp ultra high resolution mode to better analyze the bony anatomy at a resolution of 0.24 mm.
Bariatric patients: given the 100 kwatts dual generators and dual tubes you can increase your photon flux to obtain high quality images in these type of patients.
DOSE: Dose is always an issue you have 4D care dose to modulate the tube current adaptive collimation to decrease the dose form spiral scans, but you can also use X care dose to limit the amount of radiation anteriorly particularly to the breast and thyroid tissue. And now you have IRIS that can save dose up to 40 percent.
I think based on all of these advantages that have been tested clinically, the Flash scanner is the most versatile scanner on the market at the present time.
Dr Savvas Nicolaou