David Zopfs1, Simon Lennartz2, Kai Laukamp3, Nils Große Hokamp4, Anastasios Mpotsaris5, David Maintz6, Jan Borggrefe7, Victor Neuhaus8. 1. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: david.zopfs@uk-koeln.de. 2. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: simon.lennartz@uk-koeln.de. 3. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: kai.laukamp@uk-koeln.de. 4. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: nils.grosse-hokamp@uk-koeln.de. 5. Department of Diagnostic Radiology, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074 Aachen, Germany. Electronic address: ampotsaris@ukaachen.de. 6. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: david.maintz@uk-koeln.de. 7. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: jan.borggrefe@uk-koeln.de. 8. Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. Electronic address: victor-frederic.neuhaus@uk-koeln.de.
Abstract
OBJECTIVES: To compare virtual monoenergetic images (VMI) reconstructed from venous phase Dual-Layer CT (DLCT) with polyenergetic images (PI) of DLCT-Angiography (DLCT-A) regarding vessel contrast and image quality especially in sight to atherosclerotic carotid artery stenosis. METHODS & MATERIALS: 25 DLCT-A and 55 venous phase DLCT were analyzed in this retrospective study. For objective analysis PI and VMI (40-120 keV) were assessed comparing attenuation, standard deviation, signal-/contrast- to noise ratios (SNR, CNR) in the common carotid artery (CCA), vertebral artery, sternocleidomastoid muscle and air. For subjective analysis, vessel contrast, delineation of the superficial temporal artery, depiction of calcified plaque as well as vessel patency within the atherosclerotic stenosis of the internal carotid artery were rated and the extent of the calcified plaque and remaining vessel lumen were measured in venous phase DLCT. RESULTS: In venous phase DLCT, attenuation, SNR and CNR in the CCA increased with lower keV. Attenuation, SNR and CNR at 40 keV in the CCA were comparable to PI of DLCT-A (all: p > 0.05). Subjective image contrast, assessment of vessel patency within a stenosis as well as delineation of the superficial temporal artery were rated superior at 40-60 keV in comparison to PI of venous phase DLCT (all: p ≤ 0.05). Slightly more blooming of the atherosclerotic plaque was found in VMI at 40-60 keV. There was no difference of NASCET-criteria of carotid stenosis between VMI at different keV-levels and PI (p = 1.0). CONCLUSION: VMI at 40 keV reconstructed from venous phase DLCT yield an image quality equal to CT-Angiography, especially regarding vessel contrast. Perception and assessment of the carotid artery within an atherosclerotic stenosis are not impaired at low keV.
OBJECTIVES: To compare virtual monoenergetic images (VMI) reconstructed from venous phase Dual-Layer CT (DLCT) with polyenergetic images (PI) of DLCT-Angiography (DLCT-A) regarding vessel contrast and image quality especially in sight to atherosclerotic carotid artery stenosis. METHODS & MATERIALS: 25 DLCT-A and 55 venous phase DLCT were analyzed in this retrospective study. For objective analysis PI and VMI (40-120 keV) were assessed comparing attenuation, standard deviation, signal-/contrast- to noise ratios (SNR, CNR) in the common carotid artery (CCA), vertebral artery, sternocleidomastoid muscle and air. For subjective analysis, vessel contrast, delineation of the superficial temporal artery, depiction of calcified plaque as well as vessel patency within the atherosclerotic stenosis of the internal carotid artery were rated and the extent of the calcified plaque and remaining vessel lumen were measured in venous phase DLCT. RESULTS: In venous phase DLCT, attenuation, SNR and CNR in the CCA increased with lower keV. Attenuation, SNR and CNR at 40 keV in the CCA were comparable to PI of DLCT-A (all: p > 0.05). Subjective image contrast, assessment of vessel patency within a stenosis as well as delineation of the superficial temporal artery were rated superior at 40-60 keV in comparison to PI of venous phase DLCT (all: p ≤ 0.05). Slightly more blooming of the atherosclerotic plaque was found in VMI at 40-60 keV. There was no difference of NASCET-criteria of carotid stenosis between VMI at different keV-levels and PI (p = 1.0). CONCLUSION: VMI at 40 keV reconstructed from venous phase DLCT yield an image quality equal to CT-Angiography, especially regarding vessel contrast. Perception and assessment of the carotid artery within an atherosclerotic stenosis are not impaired at low keV.
Authors: David Zopfs; Simon Lennartz; Nuran Abdullayev; Thorsten Lichtenstein; Kai Roman Laukamp; Robert Peter Reimer; Christoph Kabbasch; Jan Borggrefe; Marc Schlamann; Victor Neuhaus; Nils Große Hokamp Journal: Quant Imaging Med Surg Date: 2021-08