"Spiral CT"=CTPA?

[strongboy2005]

I have come across 2 questions now that have used the terminology "Spiral CT of the chest" as an answer choice in a patient with symptoms of pulmonary embolism. In both cases, "pulmonary angiogram" was an answer choice, but never CT pulmonary angiogram (CTPA). Is "Spiral CT" the same thing as a CTPA in this context? Why do the boards prefer the "Spiral CT" terminology? It seems like outdated terminology...

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[shan564]

I have come across 2 questions now that have used the terminology "Spiral CT of the chest" as an answer choice in a patient with symptoms of pulmonary embolism. In both cases, "pulmonary angiogram" was an answer choice, but never CT pulmonary angiogram (CTPA). Is "Spiral CT" the same thing as a CTPA in this context? Why do the boards prefer the "Spiral CT" terminology? It seems like outdated terminology...

Yes, a spiral CT is a CTPA.

I think some people use the term "spiral CT" because it's not really an angiogram... it's a CT that looks specifically at the vessels. I'm not sure if it's an outdated term or if/why different people use different terms, but I've always heard it referred to as a spiral CT on the wards and as a CTPA in the textbooks.

 

[deleted103644]

The previous poster is wrong. Pretty much every CT is now a spiral CT.

Historically the distinction was necessary, particularly for PE protocols.

It is not equivalent to a CTPA, as you can have a spiral CT without administering any contrast (it just refers to the gantry moving in a helical motion relative to the body).

The only place where you will actually need to specify a spiral CT will be for PE protocols on the exam.

 

[strongboy2005]

So if a question just says "spiral ct of the chest", do I assume this is with contrast? Or do PE protocols sometimes do spiral CT without contrast?

 

[YouAreAwesome]

So if a question just says "spiral ct of the chest", do I assume this is with contrast? Or do PE protocols sometimes do spiral CT without contrast?

Sprial CT almost always means spiral CT PE protocol. A CT without contrast is worthless for detecting PEs. It might be a good idea to do a google image search to see what a PE looks like on imaging to drive that home.

I guess you can't always assume spiral CT means spiral CT PE protocol, although that's kind of splitting hairs. The one case I could see this mattering is if angiogram is listed in one place and spiral CT in another. Technically, angiogram is the gold standard but it's not generally used in practice unless suspcioun is high and spiral CT is negative. But, if you see "spiral CT" and angiogram, and the spiral CT doesn't specifically mention "with contrast" or "PE protocol" (technically these are 2 different things, but again probably splitting hairs for Step 2 purposes), then go with angiogram.

 

[YouAreAwesome]

To put that another way, I don't think angiogram can ever be wrong. "Spiral CT" can technically be wrong if it doesn't explicitly state "PE protocol" or "CTA."

 

[deleted103644]

Almost all CTs are now spiral CTs unless you are working in a bankrupt hospital.

The questions need to be updated.

 

[OveractiveBrain]

I have come across 2 questions now that have used the terminology "Spiral CT of the chest" as an answer choice in a patient with symptoms of pulmonary embolism. In both cases, "pulmonary angiogram" was an answer choice, but never CT pulmonary angiogram (CTPA). Is "Spiral CT" the same thing as a CTPA in this context? Why do the boards prefer the "Spiral CT" terminology? It seems like outdated terminology...

You will not be tested CT with Contrast vs CT Angiogram vs Spiral Ct vs Spiral CT with PE protocol.

Your choices will be:
1. V/Q Scan,
2. CT Scan (of whatever particular variety they happen to give you)
3. Pulmonary Angiogram,
4. Just Start Heparin,
5. Ultrasound of the Legs

 

[shan564]

But, if you see "spiral CT" and angiogram, and the spiral CT doesn't specifically mention "with contrast" or "PE protocol" (technically these are 2 different things, but again probably splitting hairs for Step 2 purposes), then go with angiogram.

According to MTB 2CK, you don't do angiograms anymore because they're associated with unacceptably high morbidity. If it says "spiral CT" as an answer choice vs. "pulmonary angiogram", I think it's still fair to pick "spiral CT" because a CTPA is still a type of spiral CT.

 

[deleted103644]

According to MTB 2CK, you don't do angiograms anymore because they're associated with unacceptably high morbidity. If it says "spiral CT" as an answer choice vs. "pulmonary angiogram", I think it's still fair to pick "spiral CT" because a CTPA is still a type of spiral CT.

Be careful.

Pulmonary angiogram will always be the gold standard for detection of a pulmonary embolism.

There will still be some rare cases where a CTPA is inconclusive and you need to do an old school PA for both diagnostic and possible therapeutic intervention.

 

[shan564]

Be careful.

Pulmonary angiogram will always be the gold standard for detection of a pulmonary embolism.

There will still be some rare cases where a CTPA is inconclusive and you need to do an old school PA for both diagnostic and possible therapeutic intervention.

Sure, but I don't think you'd ever do a pulmonary angiogram before doing a CTPA unless there was a clear contraindication...

 

[deleted103644]

Sure, but I don't think you'd ever do a pulmonary angiogram before doing a CTPA unless there was a clear contraindication...

If you were sure you needed to intervene, you still might.

 

[OveractiveBrain]

Be careful.

Pulmonary angiogram will always be the gold standard for detection of a pulmonary embolism.

And some Step 2 questions do ask you what is the BEST TEST, not the BEST NEXT STEP to test your knowledge of gold standards.

Sure, but I don't think you'd ever do a pulmonary angiogram before doing a CTPA unless there was a clear contraindication...

NOT STEP 2 MATERIAL:

In a massive pulmonary embolism, PE with hypotension, prior to giving intraarterial tPA the recommendation is to do an angiogram. If your pretest probability is so high that you know there is a PE, and if you don't give tPA they will die, then you do not do the CT, you just do the angiogram. Although, if its that emergent, you might just give the tPA.

There are two indications for Pulmonary Angiogram:
1. Clinical suspicion for PE is high and CT is negative AND U/S extremity is negative
2. Administration of tPA to ensure clot is present

 

[GatorSkin21]

Another thing you may want to understand is Contrast Spiral CT / CTPA is done by injecting contrast and visualizing via CT, whereas Pulmonary Angiogram has contrasted injected but is visualized directly via X-Ray.