CT vs Tomo vs Fluoro

I have been having some interesting discussion with Nuno Lemos aka StockZombie @ Twitter, who has compiled his due diligence on Nanox at "Nanox Vision – a fools gold?"  

Here is some feedback on some of his points. 

Can you replicate CT with Tomo?

Nanox has been misleading the public, investors, and medical professionals for quite some time that it can do CT (including the "noise-free simulation" slide shown on the TV screen near the end of the RSNA 2020 presentation, 24:04).

That simulation was supposedly done with an imaginary device with 11 sources and detectors that don't exist.

But Nanox admits in its Prospectus that it intends to do only tomosynthesis - no usable axial slices can be produced.  CT or CAT is a short-cut for Computed Axial Tomography.  See also below.

Does the proposed Nanox.Arc 2.0 have 5 or 6 x-ray sources?

The information about the 5 x-ray sources comes from a video showing the making of Nanox.Arc 2.0.  If one pays close attention at 0:19-0:20, one can see the holes of the 5 sources.  I tweeted about it and so did Nanox promoter, but he did not count the holes.  

counted by me

not counted by promoter

The CEO was lying throughout the RSNA 2020 presentation that the device had 6 x-ray sources.  If the sources were so precious and novel, he would have gotten a least the number correct, as this was the first public demo of the source.

Here is how Nanox advertised its presentation on its exhibitor page at RSNA 2020:

Nano-X Imaging Ltd Nanox is a developer of MEMs based electrons field emitter cold-cathode, enabling the manufacturing of digitally controlled, low-cost x-ray tubes. Nanox's technology is under third party review, pending 510k clearance. Please join the Virtual Meeting Room button below at 10:30 am CST on Thursday, December 3 for a Featured Demonstration as Nanox unveils a proprietary digital X-ray source based on a silicon MEMs electrons field-emission technology. The presentation debuts a novel X-ray tube that emits digitally controlled X-ray pulses and can be used across multiple medical imaging use cases. https://www.nanox.vision 

So, what is the main proposed modality of Nanox.Arc 2.0?

Page 1 of the Prospectus explains that the main use of the Nanox.Arc that Nanox supposedly plans to commercialize is tomosynthesis:

Subject to receiving regulatory clearance, the first version of the Nanox.ARC that we expect to introduce to the market will be a three-dimensional (“3D”) tomosynthesis imaging system. Tomosynthesis is an imaging technique widely used for early detection, that is designed to produce a high-resolution, 3D X-ray image reconstruction of the scanned human body part for review by a professional diagnostics expert

Slide 8 from the March 17, 2021 Oppenheimer presentation states: 

The Nanox.ARC 3D computerized tomosynthesis:  New breed of medical imaging.  

Also, if one looks carefully during the RSNA 2020 presentation video (for example, at 12:55), what Nanox appears to be doing for any "scan" is collecting 45 images (5 sources x 9 tilted positions) and creating synthetic slices from them in a plane parallel to the flat detector placed in the "box" below the arc.

Can the proposed Nanox.Arc, either single-source or 2.0, do fluoro?

According to Nanox, Nanox.Arc can do fluoroscopy (even though it is not its main use case), but Nanox can also license its proposed x-ray source to traditional device manufacturers to incorporate in their own fluoroscopy systems (the white paper addresses that second case).  Today's fluoroscopy systems are very simple - a single source (pulsed, for two reasons - to prevent source overheating, and to reduce radiation exposure) and a fast detector (10+ fps) - clearly a single-source Nanox.Arc can do it (for say, $200,000/unit) ,assuming a powerful enough hot-cathode dental source with a stationary anode (but the best price quote for a new system I have gotten is $28,500/unit FOB Shanghai, and it is not cleared yet in the USA, so it cannot be used as a predicate).  

Slide 20 of the January 2020 presentation at JP Morgan shows the multi-source Nanox.Arc device doing "3D fluoroscopy" (I guess you need a Hololens or Oculus headset for it) using 3 of the 5 sources. 

Yes, fluoroscopy has its own product code(s) for 510K clearance purposes (for example, JAA), but a system can have more than one product code for clearance purposes.

Update:  Here is the completely-misleading slide from the January 2021 JP Morgan presentation that shows that the proposed Nanox.Arc 2.0 can replace the Chinese fluoroscopy system, among others.  See also my previous post, focusing on cost.