TY - JOUR
T1 - Optimized energy of spectral CT for infarct imaging
T2 - Experimental validation with human validation
AU - Sandfort, Veit
AU - Palanisamy, Srikanth
AU - Symons, Rolf
AU - Pourmorteza, Amir
AU - Ahlman, Mark A.
AU - Rice, Kelly
AU - Thomas, Tom
AU - Davies-Venn, Cynthia
AU - Krauss, Bernhard
AU - Kwan, Alan
AU - Pandey, Ankur
AU - Zimmerman, Stefan L.
AU - Bluemke, David A.
N1 - Publisher Copyright:
© 2017
PY - 2017/5
Y1 - 2017/5
N2 - 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%.
AB - 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%.
KW - Delayed iodine CT
KW - Dual energy CT
KW - Infarct
KW - Virtual monoenergetic
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U2 - 10.1016/j.jcct.2017.02.003
DO - 10.1016/j.jcct.2017.02.003
M3 - Article
C2 - 28229910
AN - SCOPUS:85013042383
SN - 1934-5925
VL - 11
SP - 171
EP - 178
JO - Journal of cardiovascular computed tomography
JF - Journal of cardiovascular computed tomography
IS - 3
ER -