Cardiac visceral fat volume estimation from low-dose chest computed tomography: a study with a designed beating heart phantom

Background: Since 2017, a pilot project for lung cancer screening by chest low dose computed tomography (LDCT) has been implemented in Moscow. Patients to be included into the screening have risk factors for ischemic heart disease (IHD). The association between epicardial adipose tissue (EAT) volume and coronary artery atherosclerosis, IHD, and atrial fibrillation has been demonstrated previously.Aim: To demonstrate the feasibility of LDCTbased EAT volumetry using a dynamic (contracting) heart phantom.Materials and methods: The study was performed with the designed dynamic heart phantom and chest phantom in two stages. At stage I, two adipose tissue pieces were scanned inside and outside the chest phantom using CT and LDCT. At stage II, the dynamic heart phantom was scanned outside and inside the chest phantom. In addition, we scanned the heart phantom with a coronary calcium phantom. The contracting heart phantom was developed within three months. All scans of the phantom were performed within one day. We determined the adipose tissue thresholds in LDCT and the EAT volumetric error with both chest CT and LDCT. Measurements of the adipose tissue volumes were performed by the radiologist twice with semi-automatic software.Results: The results of stage I helped to identify optimal density thresholds for LDCT-based adipose tissue volumetry in lung cancer screening, ranging from -250 HU to -30 HU. The stage II results showed that for all heart phantom scanning variants, the average EAT volumetry error did not exceed 5%, except for the case of contracting heart phantom with added coronary calcium in a chest phantom with body mass index (BMI) 29 (-5.92%). Adding the coronary calcium phantom to the heart phantom in LDCT increased the error by an average of 4% in BMI 23 and BMI 29 chest phantoms.Conclusion: LDCT-based EAT volumetry with fat density threshold from -250 HU to -30 HU is feasible in lung cancer screening, including patients with coronary calcium. However, considering the phantom design, further patient studies, and correlation of EAT volumes between LDCT for lung cancer screening and сoronary CT angiography are required.

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LOW-DOSE COMPUTED TOMOGRAPHY IN MOSCOW FOR LUNG CANCER SCREENING (LDCT-MLCS): BASELINE RESULTS

Problems in oncology ◽

10.37469/0507-3758-2019-65-2-224-233 ◽

2019 ◽

Vol 65 (2) ◽

pp. 224-233

Author(s):

Sergey Morozov ◽

Viktor Gombolevskiy ◽

Anton Vladzimirskiy ◽

Albina Laypan ◽

Pavel Kononets ◽

...

Keyword(s):

Computed Tomography ◽

Lung Cancer ◽

Cancer Screening ◽

Low Dose ◽

Early Stage ◽

Lung Cancer Screening ◽

Stage I ◽

Malignant Neoplasms ◽

Number Needed To Screen ◽

Low Dose Computed Tomography

Study aim. To justify selective lung cancer screening via low-dose computed tomography and evaluate its effectiveness. Materials and methods. In 2017 we have concluded the baseline stage of “Lowdose computed tomography in Moscow for lung cancer screening (LDCT-MLCS)” trial. The trial included 10 outpatient clinics with 64-detector CT units (Toshiba Aquilion 64 and Toshiba CLX). Special low-dose protocols have been developed for each unit with maximum effective dose of 1 mSv (in accordance with the requirements of paragraph 2.2.1, Sanitary Regulations 2.6.1.1192-03). The study involved 5,310 patients (53% men, 47% women) aged 18-92 years (mean age 62 years). Diagnosis verification was carried out in the specialized medical organizations via consultations, additional instrumental, laboratory as well as pathohistological studies. The results were then entered into the “National Cancer Registry”. Results. 5310 patients (53% men, 47% women) aged 18 to 92 years (an average of 62 years) participated in the LDCT-MLCS. The final cohort was comprised of 4762 (89.6%) patients. We have detected 291 (6.1%) Lung-RADS 3 lesions, 228 (4.8%) Lung- RADS 4A lesions and 196 (4.1%) Lung-RADS 4B/4X lesions. All 4B and 4X lesions were routed in accordance with the project's methodology and legislative documents. Malignant neoplasms were verified in 84 cases (1.76% of the cohort). Stage I-II lung cancer was actively detected in 40.3% of these individuals. For the first time in the Russian Federation we have calculated the number needed to screen (NNS) to identify one lung cancer (NNS=57) and to detect one Stage I lung cancer (NNS=207). Conclusions. Based on the global experience and our own practices, we argue that selective LDCT is the most systematic solution to the problem of early-stage lung cancer screening.

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Ability of Evaluation Coronary Calcium Index Based on Ultra-Low-Dose Computed Tomography Used in Moscow Lung Cancer Screening Project

Rational Pharmacotherapy in Cardiology ◽

10.20996/1819-6446-2021-06-18 ◽

2021 ◽

Vol 17 (3) ◽

pp. 414-422

Author(s):

A. E. Nikolaev ◽

A. N. Shapiev ◽

O. A. Korkunova ◽

G. Z. Mukhutdinova ◽

P. V. Tkacheva ◽

...

Keyword(s):

Computed Tomography ◽

Lung Cancer ◽

Coronary Artery ◽

Cancer Screening ◽

Low Dose ◽

Lung Cancer Screening ◽

Coronary Calcium ◽

Slice Thickness ◽

Diagnostic Significance ◽

Low Dose Computed Tomography

Aim. Determination of the possibility of reliable quantitative assessment of the coronary calcium index based on ultra-low-dose computed tomography (ultra-LDCT) which used in Moscow Lung Cancer Screening project.Material and methods. The study included the results of 254 ultra-LDCT studies conducted as part of the Moscow lung cancer screening project. For compare the parameters of coronary calcium on different images used 16 pairs of ultra-LDCT images with a slice thickness of 1 mm and CT images with a slice thickness of 3 mm, performed without ECG synchronization, performed with an interval of less than 10 days, as well as 18 pairs of ultra-LDCT with a slice thickness of 1 mm and CT with ECG synchronization with a slice thickness of 3 mm, performed on the same day after execution. Analysis of DICOM 3.0 standard images was performed. Quantitative indicators of coronary calcium in patients from lung cancer screening were analyzed, a comparative analysis of the calcium index for Agatstone, Volume, Mass, and using the CAC-DRS scale (assessment of the degree of calcification by scores from 0 to 3 and the number of affected arteries from 0 to 4 points) was performed.Results. Evaluation ultra-LDCT with a slice thickness in 1 mm and with a CT scan with slice thickness in 3 mm with and without ECG-synchronization for the presence of coronary calcium, and subsequent rating according to the index Agatston, Volume, Mass, as the total coronary calcium and for each coronary artery (right, left, left descending, left circumflex) received the complete data correlation (Pearson's - 1), with full correlation (Spearman's >0.9), with good rank correlations (>0,9). Compare qualitative (CAC-DRS V) and quantitative (CAC-DRS A) estimates on ultra-LDCT with CT with ECG synchronization in the same patients show a complete correlation of data was obtained (Pearson's formula - 1), with a complete correlation (Spearman's formula - 1).Conclusion. Coronary calcium which detected in lung cancer screening subjects should be included in the overall decision-making process for further routing of patients (cardiologist, interventional surgeon, pulmonologist, therapist). Ultra-LDCT is a method that has high diagnostic accuracy in detecting and evaluating the prevalence of coronary calcium in comparison with standard CT with and without ECG synchronization, as demonstrated in our study. Evaluation of coronary calcium according to ultra-LDCT without ECG synchronization used in screening, preferably with a 1 mm slice thickness. Despite the fact that the gold standard is CT with ECG synchronization with a 3 mm slice thickness, the diagnostic significance of ultra-LDCT which used in lung cancer screening is high in relation to detecting coronary artery calcification.

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