If one were to develop cancer from radiation, like that from a nuclear reactor, and the cancer propogated on the lungs, would an x-ray scan pick that up?
Well just as Loru has stated, X-Ray (and CT scans) can only distinguish tissues based on the underlying molecular density. Watery tissues will be shown as darker patches, a hematome (blood leaking into a space) will be shown as very dark, while bones will have a very light presentation. Cancers, especially those of advanced grades, would have created so much damage to the surrounding tissues that they undergo a process called calcification. A denser area in an organ that is supposed to be watery, for example, will be a very strong indication for cancer, even though some kind of chronic infection is also likely.
PET scan and fMRI would be much more definitive in early-stage neoplasm, they can detect the rate of metabolism in an area, which is pretty much the tell-tale sign of cancer because it uses so much energy in multiplying. The usual case scenario is when people feels that they are having a lump in certain area, or complaining of significant weight-loss and paleness, and this can be used to consult the patients to go to a hospital if they live in a remote area.
For the lungs part, it pretty much shows up darkish in the X-Ray and CT, as well as in MRI (since it is mostly air). If there is a neoplasm metastases there it can be shown as lighter patches among the darker area. Darker than usual will be noticed as fluid as is in the case of Pleural Effusion or Pneumonia.
OK, microgravity is fun, but there's even less known about body functioning in a low gravity. How will, let's say, martian environment affect the development of a human body starting from the moment of fetation? It may be not only low gravity, but also all kinds of solar radiation since Mars has no magnetic field. (Let's put aside the breathing problem because of obvious reasons).
well low gravity should have less problems than no gravity at all. Although a child grown in Mars would have trouble visiting Earth as an adult, he will have lesser bone density, and perhaps significantly taller if having similar nutritional regiment to his counterparts on Earth. The lack of Magnetic Field will create many problems since we evolved in a low-radiation environment. But then again, in all probability, when people started to breed on Mars it would have been terraformed and an artificial magnetic shield perhaps has been in function.
This can create an interesting scenario in the interplanetary humanity. Perhaps businessmen from Earth and Mars would have conference only either on Mars or in LEO, but then again, the advancements in Life Support technology and exoskeleton might eliminate this problems for the hypothetical Martians, since even the Terra-Forming part is still technologically centuries away.
