Jian Jiang, Presenter: Research Grant, General Electric Company

To compare in dual-energy CT (DECT) conventionally reconstructed polyenergetic images (PEIs) at 120 kVp to virtual monoenergetic images (MEIs) at different kiloelectron volt (keV) levels for evaluation of renal parenchymal masses in regard to objective image quality and subjective image quality.

We perspectively evaluated 128 row dual-source DECT studies. Twenty patients who had renal parenchymal masses underwent abdominal DECT. On the basis of the Data of the 80 and 140 kVp tube using dual-source CT technology, PEIs and MEIs in 10-keV intervals from 40 to 120 keV were reconstructed. Renal parenchymal masses and soft tissue attenuation and image noise were measured in various regions of interest and the Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were subsequently calculated. MEI reconstructions with the highest CNR, SNR and the subjective image quality by two experienced readers were compared to PEI for those.

Good inter-reader agreement of the subjective score was noted (k = 0.782, p = 0.000). The mean score of subjective image quality of 70 keV was the highest in the MEIs, which was significantly higher than that of PEI (P=0.020). MEI at 60 keV had the highest CNR compared to PEI. There was no significant difference in CNR between 60 keV and 70 keV (P=0.693). The SNR of 70keV was higher compared to PEI. The image noise of 70 keV was lower than that of the other MEIs, which was no significantly higher than PEI. 

These results highlighted that MEI at 70 keV provided a better image quality in diagnostic levels comparing with PEI, which improve their diagnostic confidence in the assessment of renal parenchymal masses by evaluating MEI reconstructions at 70 keV.

 The aim is to improve radiologists' diagnostic confidence in the assessment of renal parenchymal masses by evaluating MEI reconstructions at 70 keV.

Jiang, J, Objective and Subjective Image Quality of Renal Parenchymal Masses with Virtual Monoenergetic Dual-energy CT Reconstructions.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011913.html