Low-dose computed tomography is a scientifically grounded method for the reduction of mortality from lung cancer [1, 2]. However, several studies have shown the variability of the lung nodule size, expressed through mean diameter and volume, in computed tomography [3]. Some authors suggested a correlation between volume change, nodule location, and the heart cycle phase [4], while others noted the effect of lung tissue volume, i.e., respiratory cycle phase [5]. Thus, changes in the volume of the lung nodule under the influence of breathing and...

We retrospectively analyzed 63 inspiratory-expiratory ULDCT scans performed as a part of the pulmonary emphysema screening subgroup. Moscow Lung Cancer Screening trial inclusion criteria were as follows: aged from 50 to 75 years asymptomatic (excluding smoking-related cough, sputum, dyspnoea) pack-year index > 20 The exclusion criteria were as follows: younger than 50 years or older than 75 years, pack-year index < 20, smoking cessation > 10 years ago, chest pain, body temperature > 37.5 C, hemoptysis, pink sputum, inexplicable weight loss, hoarse voice, less than...

The mean age of the patient was 58 years. For 30 resultant studies, average nodule volume on inspiration was 0.116 ml, on expiration - 0.145 ml with a delta of 20%. The mean diameter was 5.5 mm and 6.7 mm, respectively.

Our initial observations suggest that lung nodule volumetry in ULDCT may be dependent on the phase of the respiratory cycle. The findings are supported by several studies. A small sample size precludes meaningful statistical analysis. We plan to continue investigating a possible correlation between volumetric nodule change in the inspiratory-expiratory ULDCT and its etiology.

I. Blokhin; Moscow/RU - nothing to disclose V. Chernina; Moscow/RU - nothing to disclose A. Nikolaev; Moscow/RU - nothing to disclose V. Gombolevskiy; Moscow/RU - nothing to disclose A. P. Gonchar; Moscow/RU - nothing to disclose S. Morozov; Moscow/RU - nothing to disclose O. Minkina; Moscow/RU - nothing to disclose

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