Chest CT Scan – Diagnostic Imaging

00:01 A chest CT, quite important.

00:04 And I'll give you when it's important for you to perhaps dissect an x-ray versus dissecting a CT and why it's important.

00:12 This is a perfectly normal CT of your chest. Here, you will notice that the areas of the parenchyma which represents the huge black areas that is completely clear, lucent and that's done on purpose and that's relatively normal.

00:29 Now the thing that you wanna keep in mind CT is I do want you to pay attention to the vertebrae at the bottom of the picture.

00:36 And that vertebrae then represents the back or the transverse process.

00:40 Now, in order for you as a clinician to then properly interpret your CT, you must know that your individual is sleeping on their back, think of it that way.

00:49 And the way that you're looking at them is you're at the bottom of their feet looking at their feet and they're laying on their back.

00:56 So their right side will be the opposite of what you can expect.

01:02 We'll talk more about positioning and orientation.

01:04 But at this point, you're at the bottom of the feet looking at your patient who is laying on his or her back.

01:11 That's a normal positioning of your CT. Now why might you wanna use your CT? Well, the mediastinal view becomes quite important for us with identifying the pleura as you see here.

01:21 The pulmonary vessels and the lymph nodes.

01:24 Now lymph nodes to you then represent – well, as you get closer into a lung and you're thinking about the hilum – we'll talk about that all-important description called bilateral hilar lymphadenopathy.

01:38 And when it comes to your pleura, well, there are number of issues with the pleura that you wanna keep in mind including things like pneumothorax, including cancers such as mesotheliomas.

01:50 In order for you to truly identify your PE evaluation, to see the nodes well, then you're thinking about using IV contrast.

02:01 So for pulmonary embolus type of evaluation and to see nodes well, you must be thinking about using contrast.

02:07 But the point is this.

02:08 If your patient has renal failure then you wanna be careful by using the contrast and just because it's the best image. Is it the best thing for your patient? Alright. So those are things that you wanna keep in mind when dealing with the question about contrast and such. Continue.

02:24 Now, on this chest CT which you end up finding.

02:28 So once again let's set up the position here.

02:30 You're at the bottom of the feet of your patient looking up or looking at the patient laying on his or her back.

02:36 There is the vertebrae that you see at the bottom and so therefore as you can imagine, the right side would be the left side of the hemisphere of the lung and then what you expect to find as being the left side would then be the right side of the hemisphere.

02:51 So make sure that you're quite familiar as to how to position your patient with CT.

02:56 The anterior portion of this patient would be on the top of the CT. Okay.

03:02 Now once you've oriented yourself as such, well here, CT is often times used.

03:07 And as far as you're concerned as to what kind of issues are taking place in the parenchyma.

03:12 So what you're seeing here in the parenchyma at some point, let's say that I'm going to add in interstitial lung disease.

03:19 And by interstitial lung disease, maybe its infections such as atypical pneumonia, mycoplasma pneumonia or maybe perhaps fibrosis of whatever type, you know, maybe it's drug-induced or maybe it's your fibrosis step that we'll talk about later as being idiopathic.