What exactly is a deep lung scan?

What even is a "deep lung scan"? Are we talking about a standard X-ray, or is this some other thing altogether...? thanks.

Honestly, that's just some meaningless slang that doesn't actually convey anything useful. I really don't think medical professionals should be using terms like that when talking to patients because it just creates a ton of confusion.
When it comes to checking out the lungs, you've got a few ways to go about it:
- the standard physical exams—you know, things like auscultation and percussion
- endoscopic stuff, like doing a bronchoscopy, maybe even grabbing a biopsy while they're at it
- X-ray techniques—your basic chest X-rays, or moving up to a CT scan,
- ultrasound, specifically a chest ultrasound
- radioisotopes, which is what they use for lung scintigraphy
- using magnetic fields, so basically an MRI of the chest
- and let's call these the "surgical" approaches—things like a chest puncture or targeting a specific spot in the lungs with X-ray guidance, or maybe a thoracoscopy

...maybe we could also toss in
- using microbiological methods—basically, they take a sputum sample to hunt down any nasty pathogens