[Unknown Member]

Agree that in this day and age every scan is an HRCT but with lack of big components (as you mentioned). Air trapping is very important in making the diagnosis of ILD (esp UIP) and also prone position can be critical for early stages of NSIP.

So the answer to your question is no. If they suspect ILD, do the full HRCT protocol.

[ckjj]

All our Chest are HR . We add expiratory or procubitus if needed !

[Unknown Member]

Habits die hard. Many thing we do today are just carry overs from the olden days. Thick slice HRCT were done before because the CTs were inferior. Unfortunately the clinicians don’t know that. They read in their textbooks and see that HRCT is the diagnostic tool for ILD. They don’t realize all CTs are high res now. Same thing with “spiral CT.” The books tell them to get spiral CT for renal stones. So they order spiral CT, nevermind it’s all been spiral for 15 years.

[Dr_Cocciolillo]

The benefit of hrct is prône imaging and to lesser extent expiration

[aldoctc]

Funny that I just had this discussion with one of the pulmonologists….
 
And also interesting (to me at least) that I mentioned that, with the advancements in CT technology, the added value of HRCT is more with the protocol (e.g. prone and expiratory images) than the image quality itself.  Seems like a lot of us are on the same page.  
 
Another point I’ll make is that while every rad knows (or should know) what UIP is, unless you’re used to doing HRCT and interacting with pulmonologists, a report on a standard (i.e. non-HRCT) chest CT is unlikely to specifically state if a UIP pattern is or isn’t present.  I don’t think this is necessarily bad and I’m not bashing those that don’t do a lot of HRCT but I think (or at least I’d like to think) that I add some value when reporting HRCT by addressing if UIP is present or not.  
 
And to end my little rant, I’ll vent my frustration with non-pulmonolgists that order HRCT for something like a nodule followup because “High resolution is better, isn’t it?”  Every time I hear an ordering clinician say something like that I want to get a blank stare and say “Yes it is.  It goes to 11!” (for those of you familiar with “This is Spinal Tap”)
 
 

[Unknown Member]

I try to categorize too.

Going on a tangent. I was reading my post above. Funny but “it’s been all spiral for 15 years” don’t sound so old. But if someone told me “15 years ago” in the 90s, I would have thought stone ages.

Goes to show, we really need to give up old habits.

[ruszja]

I still get the occasional request for a HRCT to look for ‘nodules’ (usually from primary care noctors). Because you know, its ‘high resolution’ so it must be better right…..
 
Thanks for bringing this up. I may look into changing it to have a ‘chest wo’ and a ‘chest wo + HR’ and add the respective provider education in the order system. the ‘+’ gets them prone and expiratory images. 

[doctorhassankhaldi_408]

Is there any difference between say 1mm axial images acquired on a ct chest vs 1mm axial images acquired on a HRCT? Is the resolution/dose the same on those axial 1mm images?

I realize the protoco is different with insp/exp and possibly prone images of the hrct protocol.

[Unknown Member]

Maybe the difference is that a CT Chest with formatted with lung windows and thin slices gets them a “rule out PNA” read whereas the same set of images under HRCT gets them the chest radiologist alphabet soup read.

[doctorhassankhaldi_408]

Gotcha, but in terms of the actual resolution of the images obtained, no difference?

[Unknown Member]

No difference on acquisition but in some centers the reconstructions are different.

[doctorhassankhaldi_408]

Thanks!

[cpmolnar]

Make sure you like the filters used for the reconstructions, some are suboptimal, despite what the vendors tell you.

[leann2001nl]

Still havent seen a case where I have thought differently on the nodule/mass based on the kernel. Still waiting.

[leann2001nl]

Cant wait to read about the person who decided the 3 mm nodule was growing or had slightly irregular margins bc they used sharper kernel.

[Unknown Member]

Spiral has been around closer to 30 than 15 years.

If acquisition is at .625 mm, resolution is exactly the same, provided your recons are the same as your HR protocol, and/or you include the source images in your PACS display protocol.
Then the only addition for true HR is prone/expiratory second acquisition.

If on a standard chest CT, you are not acquiring AND viewing .625, or at most 1mm source images, its not equivalent to HR. If you acquire at .625, but recon at 3 or 5 mm, and dont view the source images, its not the same.

We display source Ax .625 , 3 plane 5x4mm, and Cor 12×2 MIP for all Chest.

Slab MIP great for nodule detection and sizing, and useful for detecting subtle nodule ca++, source images best for nodule characterization, and also sometimes useful to allow declaration of ca++.

[doctorhassankhaldi_408]

Thanks Uncle Duke!

[CTscans]

We changed the name of the exam to Chest CT – ILD Pulmonary protocol

This way the high res confusion was addressed.

[ruszja]

Quote from T1 or T2

We changed the name of the exam to Chest CT – ILD Pulmonary protocol

This way the high res confusion was addressed.

 
That’s the way to do it.
 
We need to eliminate the ‘high res’ nomenclature in the ordering system, just like we stopped calling a renal stone study a ‘spiral CT’ 20 years ago (well, we did, Dr X the crusty urologist still insists on calling the tech to make sure they do it right).

[poymd25]

Turfwar to Nestor Muller in [i][b]2002 [/b][/i]- “do you sitll do HRCT anymore? We don’t”
NM “No, of course not. Its all helical”