scholarly journals Comparison of the Agatston score acquired with photon-counting detector CT and energy-integrating detector CT: ex vivo study of cadaveric hearts

2022 ◽  
Author(s):  
Susann Skoog ◽  
Lilian Henriksson ◽  
Håkan Gustafsson ◽  
Mårten Sandstedt ◽  
Sebastian Elvelind ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Energy Levels ◽  
Photon Counting ◽  
Rank Correlation ◽  
Calcium Score ◽  
Agatston Score ◽  
Photon Counting Detector ◽  
Ex Vivo Study ◽  
Calcified Coronary Lesions ◽  
Excellent Reproducibility

AbstractThe purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50–150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-processing multimodality workplace. The best match with Sa36 was PCD-CT Qr36 images, at a monoenergetic level of 72 keV. Statistical analyses showed excellent correlation and agreement. The correlation and agreement with regards to the Agatston score (AS) between the two methods, for each position as well as between the two positions for each method, were assessed with the Spearman´s rank correlation. The correlation coefficient, rho, was 0.98 and 0.97 respectively 0.99 and 0.98. The corresponding agreements were investigated by means of Bland–Altman plots. High correlation and agreement was observed between the AS derived from the EID-CT and a PCD-CT. Both methods also demonstrated excellent reproducibility.

scholarly journals Comparison of the Agatston score acquired with photon-counting detector CT and energy-integrating detector CT: Ex vivo study of cadaveric hearts

2021 ◽  
Author(s):  
Susann Skoog ◽  
Lilian Henriksson ◽  
Håkan Gustafsson ◽  
Mårten Sandstedt ◽  
Sebastian Elvelind ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Energy Levels ◽  
Photon Counting ◽  
Rank Correlation ◽  
Calcium Score ◽  
Agatston Score ◽  
Photon Counting Detector ◽  
Ex Vivo Study ◽  
Calcified Coronary Lesions ◽  
Excellent Reproducibility

Abstract The purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. Method In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50-150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-processing multimodality workplace. Results The best match with Sa36 was PCD-CT Qr36 images, at a monoenergetic level of 72 keV. Statistical analyses showed excellent correlation and agreement. The correlation and agreement with regards to the Agatston score (AS) between the two methods, for each position as well as between the two positions for each method, were assessed with the Spearman´s rank correlation. The correlation coefficient, rho, was 0.98 and 0.97 respectively 0.99 and 0.98. The corresponding agreements were investigated by means of Bland-Altman plots. Conclusion High correlation and agreement was observed between the AS derived from the EID-CT and a PCD-CT. Both methods also demonstrated excellent reproducibility.

scholarly journals Improved coronary calcification quantification using photon-counting-detector CT: an ex vivo study in cadaveric specimens

2021 ◽  
Author(s):  
Mårten Sandstedt ◽  
Jeffrey Marsh ◽  
Kishore Rajendran ◽  
Hao Gong ◽  
Shengzhen Tao ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Photon Counting ◽  
Coronary Calcification ◽  
Photon Counting Detector ◽  
Ex Vivo Study

scholarly journals Effect of Deep-Level Defects on the Performance of CdZnTe Photon Counting Detectors

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2032
Author(s):  
Yingrui Li ◽  
Gangqiang Zha ◽  
Dengke Wei ◽  
Fan Yang ◽  
Jiangpeng Dong ◽  
...  
Keyword(s):  
Deep Level ◽  
Energy Levels ◽  
Photon Counting ◽  
Optical Microscope ◽  
Deep Level Defect ◽  
X Ray ◽  
Photon Counting Detector ◽  
Related Defect ◽  
The Difference ◽  
Cdznte Detectors

The effect of deep-level defects is a key issue for the applications of CdZnTe high-flux photon counting devices of X-ray irradiations. However, the major trap energy levels and their quantitive relationship with the device’s performance are not yet clearly understood. In this study, a 16-pixel CdZnTe X-ray photon counting detector with a non-uniform counting performance is investigated. The deep-level defect characteristics of each pixel region are analyzed by the current–voltage curves (I–V), infrared (IR) optical microscope photography, photoluminescence (PL) and thermally stimulated current (TSC) measurements, which indicate that the difference in counting performance is caused by the non-uniformly distributed deep-level defects in the CdZnTe crystals. Based on these results, we conclude that the CdZnTe detectors with a good photon counting performance should have a larger Te cd 2 + and Cd vacancy-related defect concentration and a lower A-center and Tei concentration. We consider the deep hole trap Tei, with the activation energy of 0.638–0.642 eV, to be the key deep-level trap affecting the photon counting performance. In addition, a theoretical model of the native defect reaction is proposed to understand the underlying relationships of resistivity, deep-level defect characteristics and photon counting performance.

Direct Visualization of A2, A3, and A4 Finger Flexor Pulley Injuries at 3-T and 7-T MRI: An Ex Vivo Study

2020 ◽  
Author(s):  
Rafael Heiss ◽  
Frank W. Roemer ◽  
Christoph Lutter ◽  
Rolf Janka ◽  
Volker Schöffl ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Direct Visualization ◽  
Ex Vivo Study

Impact of metal artefacts in QCT of the hip caused by a contralateral Gamma type nail: an ex vivo study

2014 ◽  
Author(s):  
Klaus Engelke ◽  
Nicolas Bouler ◽  
Oleg Museyko Fuerst ◽  
Sebastien Parratte ◽  
Thomas Fuerst ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Metal Artefacts ◽  
Ex Vivo Study

Interactions between programmable shunt valves and magnetically controlled growing rods for scoliosis

2020 ◽  
Vol 26 (6) ◽  
pp. 667-670
Author(s):  
Thomas Larrew ◽  
Mohammed Alshareef ◽  
Robert F. Murphy ◽  
Ramin Eskandari ◽  
Libby Kosnik Infinger
Keyword(s):  
Remote Control ◽  
Ex Vivo ◽  
Shunt Valve ◽  
Growing Rods ◽  
Growing Rod ◽  
Before And After ◽  
Magnetically Controlled Growing Rods ◽  
Ex Vivo Study

OBJECTIVEAlthough the advent of magnetic growing rod technology for scoliosis has provided a means to bypass multiple hardware lengthening operations, it is important to be aware that many of these same patients have a codiagnosis of hydrocephalus with magnet-sensitive programmable ventricular shunts. As the magnetic distraction of scoliosis rods has not previously been described to affect the shunt valve setting, the authors conducted an investigation to characterize the interaction between the two devices.METHODSIn this ex vivo study, the authors carried out 360 encounters between four different shunt valve types at varying distances from the magnetic external remote control (ERC) used to distract the growing rods. Valve settings were examined before and after every interaction with the remote control to determine if there was a change in the setting.RESULTSThe Medtronic Strata and Codman Hakim valves were found to have setting changes at distances of 3 and 6 inches but not at 12 inches. The Aesculap proGAV and Codman Certas valves, typically described as MRI-resistant, did not have any setting changes due to the magnetic ERC regardless of distance.CONCLUSIONSAlthough it is not necessary to check a shunt valve after every magnetic distraction of scoliosis growing rods, if there is concern that the magnetic ERC may have been within 12 inches (30 cm) of a programmable ventricular shunt valve, the valve should be checked at the bedside with a programmer or with a skull radiograph along with postdistraction scoliosis radiographs.

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