Low kV (Quantum) vs Spectral (QuantumPlus) - how would you scan (cardiac) infants?

Daniel Stromer

I just came over the publication by Dang et al on Cardiac infants, where they compared 70 and 120 kV protocols.

→ Access publication

Furthermore, there is a commentary article by Horst and Yu:

→ Commentary pdf

The commentary basically outlines, that dose reduction shouldn't take priority when compromising ultimately diagnostic confidence - a discussion we are experiencing over many clinical domains.

Using Quantum (70 kV) mode limits spectral capabilities, 120 kV QuantumPlus comes with higher dose.

The publication poster based on the work of Habib Geryes et al proposes also Quantum mode for Cardiac scans:

→ Publication poster

So the question to you all is:

What are your experiences, maybe not even limited to cardiac imaging?

Marcel Dijkshoorn

Hi Daniel,

Here my perspective, agree with the comment.

''dose reduction shouldn't take priority when compromising ultimately diagnostic confidence''

Diagnostic outcome should always outweigh ''under-dosing''. However we also know that spectral imaging often does not add any additional information over low keV data. So is you know upfront based on the clinical indication or prior experience that spectral is not helpful we also should not overdose and there is no good justification for 120-140kV in every protocol.

Staying in the cardiac domain, pediatrics are not small adults and severe coronary calcification's are not to be expected outside donor hearts and coronary stents are generally rare and already know from patient history. So I think there is a good case for scanning at 70kV by default and switching to 120-140kV on indication or when in doubt that spectral will or will not contribute.

For dual source protocols at 0.2mm UHR mode spectral is already of the table (at this time) so there is no reason to stay at 120kV in pediatric contrast media studies. (96*0.2 is generally less desirable in pediatrics)

To get to your question whats your experience:

In pediatrics we general but with exceptions use 70kV for standalone CTA, Sn100 for non-contrast lung and some bone studies. Spectral 120 is mostly default in oncology and combinations of vascular and soft-tissue and/or metal presence like trauma and post-surgery follow-up.