Optimized energy of spectral CT for infarct imaging: Experimental validation with human validation

Veit Sandfort, Srikanth Palanisamy, Rolf Symons, Amir Pourmorteza, Mark A. Ahlman, Kelly Rice, Tom Thomas, Cynthia Davies-Venn, Bernhard Krauss, Alan Kwan, Ankur Pandey, Stefan Zimmerman, David A. Bluemke

Research output: Contribution to journalArticle

Abstract

Objectives: Late contrast enhancement visualizes myocardial infarction, but the contrast to noise ratio (CNR) is low using conventional CT. The aim of this study was to determine if spectral CT can improve imaging of myocardial infarction. Materials and Methods: A canine model of myocardial infarction was produced in 8 animals (90-min occlusion, reperfusion). Later, imaging was performed after contrast injection using CT at 90 kVp/150 kVpSn. The following reconstructions were evaluated: Single energy 90 kVp, mixed, iodine map, multiple monoenergetic conventional and monoenergetic noise optimized reconstructions. Regions of interest were measured in infarct and remote regions to calculate contrast to noise ratio (CNR) and Bhattacharya distance (a metric of the differentiation between regions). Blinded assessment of image quality was performed. The same reconstruction methods were applied to CT scans of four patients with known infarcts. Results: For animal studies, the highest CNR for infarct vs. myocardium was achieved in the lowest keV (40 keV) VMo images (CNR 4.42, IQR 3.64-5.53), which was superior to 90 kVp, mixed and iodine map (p = 0.008, p = 0.002, p < 0.001, respectively). Compared to 90 kVp and iodine map, the 40 keV VMo reconstructions showed significantly higher histogram separation (p = 0.042 and p < 0.0001, respectively). The VMo reconstructions showed the highest rate of excellent quality scores.A similar pattern was seen in human studies, with CNRs for infarct maximized at the lowest keV optimized reconstruction (CNR 4.44, IQR 2.86-5.94). Conclusions: Dual energy in conjunction with noise-optimized monoenergetic post-processing improves CNR of myocardial infarct delineation by approximately 20-25%.

Original languageEnglish (US)
JournalJournal of Cardiovascular Computed Tomography
DOIs
StateAccepted/In press - Jan 23 2017

    Fingerprint

Keywords

  • Delayed iodine CT
  • Dual energy CT
  • Infarct
  • Virtual monoenergetic

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

Cite this

Sandfort, V., Palanisamy, S., Symons, R., Pourmorteza, A., Ahlman, M. A., Rice, K., Thomas, T., Davies-Venn, C., Krauss, B., Kwan, A., Pandey, A., Zimmerman, S., & Bluemke, D. A. (Accepted/In press). Optimized energy of spectral CT for infarct imaging: Experimental validation with human validation. Journal of Cardiovascular Computed Tomography. https://doi.org/10.1016/j.jcct.2017.02.003