RESUMO
PURPOSE: We aimed to identify the optimal reconstruction settings based on qualitative and quantitative image quality parameters on standard and ultra-high resolution (UHR) images using photon-counting CT (PCCT). METHOD: We analysed 45 patients, 29 with standard and 16 with UHR acquisition, applying both smoother and sharper kernel settings. Coronary CT angiography images were performed on a dual-source PCCT system using standard (0.4/0.6 mm slice thickness, Bv40/Bv44 kernels, QIR levels 0-4) or UHR acquisition (0.2/0.4 mm slice thickness, Bv44/Bv56 kernels, QIR levels 0-4). Qualitative image quality was assessed using a 4-point Likert scale. Image noise (SD), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated in both the proximal and distal segments. RESULTS: On standard resolution, larger slice thickness resulted in an average increase of 12.5 % in CNR, whereas sharper kernel led to an average 8.7 % decrease in CNR. Highest CNR was measured on 0.6 mm, Bv40, QIR4 images and lowest on 0.4 mm, Bv44, QIR0 images: 25.8 ± 4.1vs.8.3 ± 1.6 (p < 0.001). On UHR images, highest CNR was observed on 0.4 mm, Bv40, QIR4 and lowest on 0.2 mm, Bv56 and QIR0 images: 21.5 ± 3.9vs.3.6 ± 0.8 (p < 0.001). Highest qualitative image quality was found on images with Bv44 kernel and QIR level 3/4 with both slice thicknesses on standard reconstruction. Additionally, Bv56 with QIR4 on 0.2 mm slice thickness images showed highest subjective image quality. Preserved distal vessel visualization was detected using QIR 2-4, Bv56 and 0.2 mm slice thickness. CONCLUSIONS: Photon-counting CT demonstrated high qualitative and quantitative image quality for the assessment of coronaries and stents.
Assuntos
Angiografia por Tomografia Computadorizada , Angiografia Coronária , Fótons , Humanos , Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Razão Sinal-Ruído , Doença da Artéria Coronariana/diagnóstico por imagem , Reprodutibilidade dos Testes , AdultoRESUMO
BACKGROUND: We sought to compare the degree of maximal stenosis and the rate of invasive coronary angiography (ICA) recommendations in patients who underwent coronary CT angiography (CCTA) with photon-counting detector CT (PCD-CT) versus those who underwent CCTA with whole heart coverage energy-integrating detector CT (EID-CT). METHODS: In our retrospective single-center study, we included consecutive patients with suspected CAD who underwent CCTA performed with either PCD-CT or a 280-slice EID-CT. The degree of coronary stenosis was classified as no CAD, minimal (1-24 â%), mild (25-49 â%), moderate (50-69 â%), severe stenosis (70-99 â%), or occlusion. RESULTS: A total of 812 consecutive patients were included in the analysis, 401 patients scanned with EID-CT and 411 patients with PCD-CT (mean age: 58.4 â± â12.4 years, 45.4 â% female). Despite the higher total coronary artery calcium score (CACS) in the PCD-CT group (10 [interquartile range (IQR) â= â0-152.8] vs 1 [IQR â= â0-94], p â< â0.001), obstructive CAD was more frequently reported in the EID-CT vs PCD-CT group (no CAD: 28.7 â% vs 26.0 â%, minimal: 23.2 â% vs 30.9 â%, mild: 19.7 â% vs 23.4 â%, moderate: 14.5 â% vs 9.7 â%, severe: 11.5 â% vs 8.5 â% and occlusion: 2.5 â% vs 1.5 â%, respectively, p â= â0.025). EID-CT was independently associated with downstream ICA (OR â= â2.76 [95%CI â= â1.58-4.97] p â< â0.001) in the overall patient population, in patients with CACS<400 (OR â= â2.18 [95%CI â= â1.13-4.39] p â= â0.024) and in patients with CACS≥400 (OR â= â3.83 [95%CI â= â1.42-11.05] p â= â0.010). CONCLUSION: In patients who underwent CCTA with PCD-CT the number of subsequent ICAs was lower as compared to patients who were scanned with EID-CT. This difference was greater in patients with extensive coronary calcification.