patient surface

[milan2003_07]

Hello,

"[FONT=&quot]Tissue density heterogeneities are tied to the calculation region and may be either included or excluded in dose calculation. When the heterogeneities are not considered in the dose calculation, the entire volume inside the patient surface is calculated as homogeneous water."

[/FONT]What does "the patient surface" mean here? Is it merely a person's skin?

Thanks

 

[SoothingDave]

You're obviously reading something about some sort of medical scanner.

The surface of anything is the thing that separates the inside from the outside.

 

[milan2003_07]

You're obviously reading something about some sort of medical scanner.

The surface of anything is the thing that separates the inside from the outside.

Your explanation is clear to me, but I suspect there is a misprint in the original text. "Patient surface" - do we really say so? I suppose "patient" means here a person who has come to see a doctor and "surface" is his skin. So if we were speaking about one's skin we should have written "patient's surface". Or something else is meant here by "patient surface"?

Thanks

 

[Raymott]

Your explanation is clear to me, but I suspect there is a misprint in the original text. "Patient surface" - do we really say so? I suppose "patient" means here a person who has come to see a doctor and "surface" is his skin. So if we were speaking about one's skin we should have written "patient's surface". Or something else is meant here by "patient sureface"?

Thanks

This does seem to be an odd phrase, but articles about this also refer to "patient volume", "patient heterogeneity" etc. if you read some of the articles that are listed if you Google search for:
"Tissue density heterogeneities are tied to the calculation region"

You don't need a possessive here:
- the top of the desk - the desk top, not the desk's top
- the cover of the book - the book cover.
- the surface of a patient - the patient surface

 

[milan2003_07]

Thanks for the reply. I'd like to find out if the meaning of "surface" in "patient surface" is "a patient's skin" or "surface" has some specific meaning here?

Thanks!!!

 

[SoothingDave]

It's some sort of scanner, no?

This sounds like engineer talk for how they analyze the data. To the guy writing the software, the body of the patient is just an object. It has a surface, it has a volume, it has surface area, it even has cross-sections. It's got no relation to the actual skin or bones of the patient, it's how the data is looked at once it is scanned.

That's my take on it. This seems to be discussing the data, not the patient.

 

[azcl]

***Not a teacher***

"[FONT=&quot]Tissue density heterogeneities are tied to the calculation region and may be either included or excluded in dose calculation. When the heterogeneities are not considered in the dose calculation, the entire volume inside the patient surface is calculated as homogeneous water."
[/FONT]

What I understand this to be saying is that when a calculation is made for the amount of a drug or treatment that is to be administered to a patient, different assumptions can be made. Generally speaking, a larger dose will be given to a patient with a greater body mass (or volume).

So what this quote appears to be saying is that sometimes, the different densities of different types of tissue (fat, muscle, bone etc) are included in the calculation of dosage - this is what is meant by heterogeneities. Other times, a more simple assumption is made - i.e. that the total volume of the patient (as you say, the volume inside his skin) is just made up of a single uniform substance - namely water.

Ade