Pictures of fractures, perhaps

XRAYS

["Think of the medical imaging technique that uses electromagnetic waves to reveal what’s hidden beneath the skin, often showing broken bones in black and white."]

"Pictures of fractures" hints at medical images showing broken bones, which are commonly captured using X-rays. The word "perhaps" signals that "fractures" might not be the only thing X-rays show, but it’s the most direct link. The answer is simply the plural form of the imaging technique—XRAYS—since crossword answers are often in that format.