Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone - Publication

Publication

Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone

Journal Paper/Review - May 10, 2014

Frellesen Claudia, Vogl Thomas J, Ackermann Hanns, Bodelle Boris, Schulz Boris, Beeres Martin, Wutzler Sebastian, Geiger Emanuel, Nau Christoph, Wichmann Julian L, Lehnert Thomas, Kerl J Matthias, Stock Wenzel, Bauer Ralf

Citation

Frellesen C, Vogl T, Ackermann H, Bodelle B, Schulz B, Beeres M, Wutzler S, Geiger E, Nau C, Wichmann J, Lehnert T, Kerl J, Stock W, Bauer R. Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone. Eur Radiol 2014; 24:1725-34.

Type

Journal Paper/Review (English)

Journal

Eur Radiol 2014; 24

Publication Date

May 10, 2014

Issn Electronic

1432-1084

Pages

1725-34

Brief description/objective

OBJECTIVE
To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT.

METHODS
One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDI(vol)), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared.

RESULTS
In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDI(vol) (8.3 vs. 12.4 mGy; -33%) and DLP (594 vs. 909 mGy cm; -35%) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level.

CONCLUSION
Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level.

KEY POINTS
• Automated kV selection in thoraco-abdominal trauma CT results in significant dose savings • Most patients benefit from a 100-kV protocol with relevant DLP reduction • Constantly good image quality is ensured • Image quality benefits from higher kV when arms are positioned downward.