In a paragraph-long section in the latest prospectus titled "Multi-spectral imaging capacity using one X-ray source" (pages 83-84), Nanox states that it has (only) one "working prototype" and that prototype "uses 60 KvP / mA."
The elaborate and nonsensical explanation of this novel metric, KvP / mA, may simply be a roundabout admission that the prototype's tube (almost certainly an "analog" dental/industrial one, with a hot-cathode and of low quality) can handle no more than 60 kV tube voltage. Such a low tube voltage would render it ineffective for general diagnostic imaging (but could be ok in special cases, such as extremities, depending on its remaining tech characteristics).
Nanox mentions the "KvP / mA" metric five times in that section with the exact same spelling, and refers to it interchangeably as "a ratio" or "a combination" that demonstrates the superiority of the "novel" x-ray source, and that reflects "complete independence and separation between the strength of X-ray penetration and the amount of photons for illumination." Elsewhere in the prospectus, Nanox claims that a slightly different spelling, "kVp/mA," represents energy with its acceptable range of values specified in industry standards:
The Nanox.ARC, using our X-ray source, is being designed ... to have a full kVp/mA energy throughout range as per industry standards (page 85)
According to Nanox, the first component of the metric, KvP, "represents the speed of electrons that gives the X-ray its penetrating power," rather than misspelled tube voltage. The second component, mA, "represents the amount of photons or brightness levels of the X-ray image," rather than tube current.
Ok so far?
Nanox then proceeds to make various assertions about modern x-ray sources:
For legacy X-ray sources, KvP / mA ratios were codependent in a linear relationship and each X-ray source could only produce one set of KvP / mA combinations dedicated for a particular use (for example, either tissue images or bone images, but not both simultaneously). We believe our X-ray source technology can produce multi-spectral imaging from one X-ray source, which allows for variable energy levels to be controlled during one scan. With multi-spectral imaging, one source chip can be used for multiple types of scans, such as head-scans, abdomen, mammography and angiograms, involving both soft and hard tissues at variable densities, simultaneously.
Those claims translate into the following false statements:
- modern diagnostic x-ray systems cannot image human tissues
- a bone is not made of tissues
- a particular intended use requires only one specific tube voltage/tube current combination
- tube voltage cannot be controlled independently of tube current in modern systems
- modern systems cannot vary photon energy levels (for example, by varying tube voltage) while scanning
- the relationship between tube voltage and tube current in modern x-ray sources is only linear
- it is impossible to use the same modern x-ray source for imaging tissues of different densities or for different radiological scans/examinations
Nanox then illustrates the "functionality and capability of multi-spectral (separation) imaging" of its proposed novel x-ray source, apparently not to be confused with modern spectral or energy-resolved imaging.
According to the diagram, a Nanox device can image six separate sets of body parts by using six different tube voltages and a fixed tube current, that is, six different ratios of tube voltage and tube current, which appears to contradict the single "60 KvP / mA" ratio that Nanox claims to be using. The diagram also implies that imaging blood vessels with the proposed novel source requires much higher tube voltage than imaging lungs, and that the difference in tube voltages between imaging blood vessels and lungs is 5x the difference in tube voltages between imaging bones and lungs (worse, if the chart uses a log scale).
If all this was too long or too technical to read, here is the summary: there is no such thing as KvP / mA or multi-spectral imaging. That is Nanox for you.
Update: Nope, not an April Fool's Day joke.
Update: Nanox predecessor called all this "Independant [sic] KVP [sic] /MA [sic] control." It also called it "5D X-Ray Multi-spectral imaging"
We call it the 5th dimension of X-Ray, the ability to create an MRI like multi-energy derived image, which provides a novel separation between bones, hard tissue, soft tissue, lesions, cardiovascular system and more.
Quite exciting, given that MRI has nothing to do with x-rays (it is a completely different technology) and that the old-style legacy 4D energy-resolved x-rays operate only in the four dimensions of space-time. But then something happened, and Nanox never mentioned 5D ever again, to my knowledge.
Update: Of course, kVp and mA are independently controlled in virtually all x-ray devices using legacy x-ray tubes, going back to year 1913 (some portable x-ray medical devices have fixed kVp and/or mA, for simplicity).
