normal chest radiograph question

[darrylportelli]

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So, this is gonna be a very dumb rookie question....

why does the heart in a normal PA radiograph appear on the right not the left

ex http://4photos.net/photosv2/262068_chest_xray.jpg

the heart in the image is pointing to the right......

do you have to imagine that you are facing the patient from the front??

also when the x rays shoot to the cassette, which side do you view from the film ( ill try to explain with a diagram)

xrays---------->|<------back of cassette

do you read the film from the side where the xrays shoot rom or from the back??

the lecturers just told us the theory we didnt get to see this in practice!!!
thanks

 

[NickNaylor]

I have yet to see any xray or CT/MRI imaging where left and right aren't flipped.

 

[DrBowtie]

You view it as if you are facing the patient.
Cross sectional imaging is viewed as if you are standing at the foot of the bed.

 

[dragon529]

You always view AP or PA radiograph with the patient's left on your right and patient's right on your left. This is standard practice. Just by the radiograph, you would not be able to tell if the radiograph is PA or AP. However, keep in mind that whatever object of interest should be placed closest against the film or 'cassette'. So, if you want to see the lung and chest.. you do PA. If you want to do a spine review for scoliosis or the like, you do AP.

Hope that helps.

 

[Rendar5]

You always view AP or PA radiograph with the patient's left on your right and patient's right on your left. This is standard practice. Just by the radiograph, you would not be able to tell if the radiograph is PA or AP. However, keep in mind that whatever object of interest should be placed closest against the film or 'cassette'. So, if you want to see the lung and chest.. you do PA. If you want to do a spine review for scoliosis or the like, you do AP.

Hope that helps.

Good answer. But I will point out that you can tell the difference between a PA and an AP view based on such things as clavicle position and scapula position.

 

[darrylportelli]

so If I understand correctly, you view the film from ''behind the cassette''

xrays---------> o |<-------view from here
|=cassette o= patient, so you view the film from behind the cassette as if you were facing the patient, that is why its flipped right??
thanks

 

[loveoforganic]

Good answer. But I will point out that you can tell the difference between a PA and an AP view based on such things as clavicle position and scapula position.

How so? Unless you mean by judging their size on the film? Other than magnification of the more distal structure, there isn't going to be any visible difference (other than a slight resolution difference it takes however many thousand films to get good at seeing for most), right?

 

[Rendar5]

How so? Unless you mean by judging their size on the film? Other than magnification of the more distal structure, there isn't going to be any visible difference (other than a slight resolution difference it takes however many thousand films to get good at seeing for most), right?

A PA film requires the patient to push both shoulders anteriorly, clearing the scapula from the lung fields. The posture adjusts scapula and clavicle position.

 

[loveoforganic]

Ah, right, thanks 🙂

 

[Law2Doc]

so If I understand correctly, you view the film from ''behind the cassette''

xrays---------> o |<-------view from here
|=cassette o= patient, so you view the film from behind the cassette as if you were facing the patient, that is why its flipped right??
thanks

Conceptually i think you are okay. But I don't think there's really any " flipping" involved. It's just convention of how they look at it. I'd bet it dates back to when they first invented the technology they didn't initially use film, they looked at it live, and so if you were standing in front of a patient with your fluoroscope his heart would be on your right.

 

[colbgw02]

Conceptually i think you are okay. But I don't think there's really any " flipping" involved. It's just convention of how they look at it. I'd bet it dates back to when they first invented the technology they didn't initially use film, they looked at it live, and so if you were standing in front of a patient with your fluoroscope his heart would be on your right.

Link? I really don't think this is accurate. Film has been used since the first radiograph, dating to December 1895.

 

[Law2Doc]

Link? I really don't think this is accurate. Film has been used since the first radiograph, dating to December 1895.

Thomas Alva Edison invented an early version of the fluoroscope, an improvement on a fluoroscope developed by roentgen himself, which was mostly cardboard with a calcium tungsten viewer, which was held in front of a patient and didn't involve film. There was competition between this live modality and the static film radiograph, and the radiograph ultimately won, but not before the convention if looking at a patient from the front became commonplace.

 

[colbgw02]

Thomas Alva Edison invented an early version of the fluoroscope, an improvement on a fluoroscope developed by roentgen himself, which was mostly cardboard with a calcium tungsten viewer, which was held in front of a patient and didn't involve film. There was competition between this live modality and the static film radiograph, and the radiograph ultimately won, but not before the convention if looking at a patient from the front became commonplace.

I see what you were getting at. I got from your original post that you were indicating that film radiography grew out of fluoroscopy, since you indicated that "they didn't initally use film", which is not true. I think it's more accurate to characterize fluoroscopy and film (and later screen-film) radiography as complimentary modalities that were developed concurrently

 

[PSurg530]

so If I understand correctly, you view the film from ''behind the cassette''

xrays---------> o |<-------view from here
|=cassette o= patient, so you view the film from behind the cassette as if you were facing the patient, that is why its flipped right??
thanks

I don't think this is a good way to think about it because the sidedness will be the same for a PA and AP film even though the patient is facing the other way (the heart will always be shown on the right). Regardless of how the film is taken or where the patient is, it will always be shown as if you are looking at the patient's front. And CTs/MRIs will always be shown as if you are standing at the patient's feet looking up toward the head. So in practice, it will always be backwards (left side of the patient on the right of the film, and vice versa).