Adrian Reagan MD, Presenter: Nothing to Disclose

Niv Khorrami, Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

Luck Jan-Luck Louis MD, Abstract Co-Author: Nothing to Disclose

Ana-Maria Bilawich MD, Abstract Co-Author: Nothing to Disclose

Sharon Gershony MD, Abstract Co-Author: Nothing to Disclose

To determine whether DECT head generated monoenergetic data sets reduces petrous apex beam hardening artifact and improves assessment of gray- white differentiation in the ED.

A total of 20 consecutive DECT head studies were scanned on the 128-slice dual source scanner in the ED. Protocol included the following parameters, 64 by 0.6mm collimation reconstructed to, 3mm, axial slices at 100 kv and 140kv Sn. The 3 mm 20 D34 axial DECT scans were uploaded in the monoenergetic dual energy class on the multimodality workplace and ME energy levels from 40 to 190 keV in 4 keV increments were analyzed through the cerebrum.  Noise was calculated by using the standard deviation of 4 regions of interest measuring 10mm(sq) within the pons, external capsule, head of the caudate, and gray white interface. The weighted mixed data DECT 3 mm axial images simulating a 120 kvp exam were analyzed on the MMWP as well using identical ROI size and anatomic distribution from the same patients.  Signal to noise ratio was compared between the monoenergetic and weighted polychromatic data sets.  Subjective image quality and diagnostic confidence using a 5-point Likert scale was performed between the two data sets by two ER radiologists one with 12 and one with 5 years of experience.  

A Mann-Whitney U test was used to compare the SNR between the monoenergetic and polychromatic DECT weighted data sets and maximal optimal values were appreciated at 68keV and at the 108 keV monoenergetic levels resulting in a U value of 1 (p < 0.01). Similar statistical analysis of the supratentorial brain yielded a U value of 0 (p < 0.01).  The two radiologists reported superior grey –white matter differentiation and a greater reduction of beam hardening artifacts on the monoenergetic images as compared to routine weighted 120 kvp axial scans.  

Monoenergetic generated scans from DECT heads at 68 keV and 108 keV improved the assessment of the posterior fossa and grey -white matter differentiation.

Acute Stroke evaluation with Monoenergetic images obtained from DECT heads has the potential in improving the detection of acute brain infarcts.

Reagan, A, Khorrami, N, Nicolaou, S, Louis, L, Bilawich, A, Gershony, S, Monoenergetic Reconstruction of Acute NC DECT Head at 68 keV and 108 keV Results in Superior Image Quality in Comparison to Polychromatic CT in Improvement of Grey-white Matter Differentiation and Reduction in Posterior Fossa Artifact.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13028611.html