Grapefruit USA Inc (GPFT)

[goldcoastoh]

hi sonoma...there are a lot of similarities between photograph and radiography...

here's some points on your question...generally speaking first.

there are geometric properties...meaning that if the object to image receptor distance (OID) is great (subjective), then the object will be magnified. it's like how a shadow works on the wall with a flashlight. meaning the closer your hand gets to the flashlight the bigger your hand's shadow looks on the wall.

in fluoroscopy (dynamic: conventional c-arm) we have another option, not available in radiography (static), and that's electronic magnification...

when x-rays leave the tube and go through the body and then strike the image receptor - they turn into light photons, the light photons then turn into electrons (and because only electrons have a charge compared to the x-ray and the light photons), the electronics are then focused to the output screen (and intensified with focusing) --- this is called flux gain --- i always thing of Doc Brown. however, if the focal point (or criss cross) is further away from the output screen, say in mag 1 or mag 2...done by increasing the negativity inside the eye to repel the electrons (like charges repel) and cause them to travel more grouped-together through the I.I., then the image is magnified... the whole process is similar to how the eye works and is why in traditional c-arm fluoro - the image intensifier (receptor) is called (I.I.) or simply the "I," i.e., the eye.

in addition, today's digital processes, in static radiography for example, permit zoom on the monitor by simply clicking and dragging your mouse around the area you want to zoom in on... let's say a radiologist wants to look more closely at something on a chest x-ray...well, on some software packages, they can just zoom in on it without loosing detail.

this would be similar in CT and MRI "screen shots."

as far as the detector size that the DViS uses, by looking at the videos which i'm sure you've watched where dean is near the prototype gantry and the tube/detector plate are revolving...you can sorta get an idea...but i memory serves i think it's always spinning to fast if you don't know what you're looking for/at.

here's a youtube vid...

at the end of the vid - the tube - is the thing on the very top center in the gantry...and the detector plate opposite (it's the long gray/metallic thing).

my thought is that for the DViS zooming, it may be similar to the digital process i spoke of...i dunno. but i think static images on today's 9900 can be zoomed in on digitally, thinking back to the last tradeshow i was at...but, dont quote me...

in fluoro, a dose saving concept is called "last image hold," which means that the last image you saw, remains...this is the one which could be zoomed in on if memory serves...ours while not a 9900 doesn't have this feature. moreover for 2 monitor systems (typical industry "standard") you can usually flip them back and forth between monitors...save one image and recall later, and compare to new image, etc. i spoke of this earlier.

by reading early posts on IHUB, it is my understanding that the DViS (in fluoro mode) also has replay of its dynamic imaging, called cine.

and also can have digital subtraction capabilities...the idea is you "subtract" the background in order to only concentrate on what you want to look at...say a contrast enhanced vessel or such similar flow of a contrast media. the contrast media being radio-opaque...an iodinated product...for vessels.

these last two things aren't really that big of deal, just a software thing... even old c-arms can have a digital subtraction upgrade.

at time point 6:50 you can watch digital subtraction imaging...

what get's me excited is to think of these things in 3d realtime.