Basic principles and clinical potential of photon-counting detector CT

Flohr, Thomas; Ulzheimer, Stefan; Petersilka, Martin; Schmidt, Bernhard

doi:10.1007/s42058-020-00029-z

Cited by 39 publications

(50 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Energy-integrating detector computed tomography (EID-CT) is used for detection of atherosclerotic disease [1][2][3]. Photon counting detector CT (PCD-CT) technology has recently been introduced [4,5], with expectation for improved clinical applications [6][7][8][9]. While EID-CTs convert incoming photons into electric currents using scintillator and photodiode layers indirectly, PCD-CTs directly convert X-ray photons into proportional electric signals using semiconductor materials.…”

Section: Introductionmentioning

confidence: 99%

“…This new technology, along with techniques for rendering energy-resolved data, reduces electronic noise resulting in higher dose efficiency, especially in low dose examinations. The reduced level of electronic noise not only results in less image noise but also to fewer streak artifacts and more stable Hounsfield units (HU) numbers [4,5,10,11]. More energy thresholds can be applied, making advanced material decomposition possible [4].…”

Section: Introductionmentioning

confidence: 99%

“…The reduced level of electronic noise not only results in less image noise but also to fewer streak artifacts and more stable Hounsfield units (HU) numbers [4,5,10,11]. More energy thresholds can be applied, making advanced material decomposition possible [4]. This is a feature expected to have large clinical benefits in coronary CT angiography imaging and characterization of atherosclerotic plaques [12,13].…”

Section: Introductionmentioning

confidence: 99%

“…AS has shown a high negative predictive value, as an AS of 0 strongly correlates with a lack of cardiovascular events over the following 5 years [12,17]. A disadvantage of the AS is the standardized 3 mm slice thickness, leading to partial volume averaging and calcium blooming artifacts (CBA) [4,18] which may make calcifications appear larger than their true size [16]. Also, partial volume averaging may lead to an underestimation or complete neglect of smaller and less dense calcifications.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Skoog

Henriksson

Gustafsson

et al. 2022

Int J Cardiovasc Imaging

View full text Add to dashboard Cite

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. 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.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Skoog

Henriksson

Gustafsson

et al. 2022

Int J Cardiovasc Imaging

View full text Add to dashboard Cite

show abstract

“…AS has shown a high negative predictive value, as an AS of 0 strongly correlates with a lack of cardiovascular events over the following 5 years [15,16]. A disadvantage of the AS is the standardized 3 mm slice thickness, leading to partial volume averaging and calcium blooming artifacts (CBA) [4,17] which may make calci cations appear larger than their true size [14]. Also, partial volume averaging may lead to an underestimation or complete neglect of smaller and less dense calci cations.…”

Section: Introductionmentioning

confidence: 99%

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

Skoog

Henriksson

Gustafsson³

et al. 2021

Preprint

View full text Add to dashboard Cite

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.

show abstract

Technical note: Exploring the detectability of coronary calcification using ultra‐high‐resolution photon‐counting‐detector CT

Chang,

Ren,

Tang

et al. 2023

Medical Physics

View full text Add to dashboard Cite

BackgroundCoronary calcification is a strong indicator of coronary artery disease, and patients with a “zero” coronary calcification score have a much lower risk of future cardiac events than those with even small amounts of calcium. However, false‐negative (incorrect zero scores) may occur if small calcifications are missed at CT due to limited spatial resolution.PurposeTo demonstrate lower limits of detection for coronary calcification using an ultra‐high‐resolution (UHR) mode on a clinical photon‐counting‐detector CT (PCD‐CT), compared to a conventional energy‐integrating‐detector CT (EID‐CT).MethodsChicken eggshell fragments (0.4–0.8 mm) mimicking coronary calcifications were scanned on a clinical PCD‐CT (NAEOTOM Alpha) in UHR mode and a conventional EID‐CT (SOMATOM Force) with matched tube potential and radiation dose levels to the PCD‐CT. PCD‐CT images were reconstructed with a sharp kernel (Qr68) and a quantum iterative algorithm (QIR‐3). Two sets of EID‐CT images were reconstructed: routine clinical kernel (Qr36, ADMIRE‐3) and a sharper kernel (Qr54) with similar noise to PCD‐CT images. With institutional review board approval, in vivo exams performed with the PCD‐CT in UHR mode were compared against patients’ clinical EID‐CT exams. The visibility of calcifications on PCD‐CT and EID‐CT images was assessed and compared qualitatively.ResultsPCD‐CT images visualized all calcified fragments, while EID‐CT failed to detect those below 0.6 mm using a routine protocol. EID‐CT with Qr54 improved visibility but distorted boundaries. Calcifications were less visible on EID‐CT than PCD‐CT as phantom sizes increased. 0.6‐ and 0.7‐mm calcified fragments were barely visible on 35‐ and 40‐cm phantom EID‐CT images. Patient cases showed small calcifications missed on EID‐CT but detected on PCD‐CT.ConclusionAt matched radiation dose, PCD‐CT in UHR mode provided higher spatial resolution and improved the detectability of small calcified fragments for different phantom/patient sizes in comparison to EID‐CT.

show abstract

Basic principles and clinical potential of photon-counting detector CT

Cited by 39 publications

References 70 publications

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

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

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

Technical note: Exploring the detectability of coronary calcification using ultra‐high‐resolution photon‐counting‐detector CT

Contact Info

Product

Resources

About