Virtual Phantoms has just published an update to its flagship module VirtualDoseCT to modernize and simplify the data entry for calculating patient dose from a CT exam, and clarify that the results are applicable to any CT scan.
The key change is the option to directly input the value of CTDIvol for the scan, rather than relying on a combination of the normalized CTDIw, the mAs per rotation, and the pitch.
When VirtualDose was first published, there were still CT machines in common use that did not display or store a value of CTDIvol, but may only show the mAs for the scan. The tools available at the time for estimating CT dose would rely on a standardized value of CTDIw per 100 mAs that was known for the different machines, so that was the approach that Virtual Phantoms took as well.
In today’s environment, it is rare that CTDIvol would not be available to enter directly. Also, as modern machines use of tube current modulation has become standard practice, CTDI values have become more patient specific, and it has become harder to obtain standardized constant current CTDI values.
Now when opening the VirtualDoseCT page, the default screen has a field for CTDIvol (in addition to the ones for kVp and beam collimation, plus the other factors necessary to describe the patient and the scan). From these, the patient dose can be displayed on the screen or downloaded in a PDF report.
The original mode based on scanner model selection is maintained for compatibility and for instances where it still might be necessary to rely on standardized machine output values. Scanner-specific values will be added for new models as they become available, but they are not necessary for the calculation.
Besides all that, the interface has been updated using an Angular programming infrastructure, which should make everything run faster and more smoothly across all web platforms!
