Synapse vincent software

Airway segmentation and airway luminal area measurements were obtained using SYNAPSE VINCENT software (FUJIFILM Medical, Tokyo, Japan)⁵. The segmental bronchus was defined as the 3rd generation airway. Following automatic luminal segmentation of the airway tree, all branches of the 3rd to 6th generation airways in all segments were manually identified by tracking from the 3rd to the 6th generation [5 (link), 21 (link)]. For each branch, cross-sectional images perpendicular to the longitudinal center line of the lumen were generated, and the lumen areas and internal diameters in the middle third portion were automatically measured and averaged. The mean lumen area for each generation airway was calculated in all segments.

Thoracic CT was performed for the evaluation of muscle mass^{11 (link)}. CT was performed with 1 mm to 5 mm-thick samples at slice intervals of 1 mm to 5 mm. We analyzed single-slice axial CT images captured at the sum of the cross-sectional areas of the major and minor pectoralis muscles at the top of the aortic arch as the pectoralis muscles areas. By contrast, muscle areas at the 12th thoracic vertebra were measured as the erector spinae to assess the muscle mass. Muscle areas at the aortic arch and Th12 level were semi-automatically defined using SYNAPSE VINCENT™ software (Fujifilm Medical Co., Ltd., Tokyo, Japan), and the muscle area was quantified based on the CT hounsfield unit (HU) range, i.e., − 29 HU to + 150 HU. W assessed the change in muscle mass following 6 months and 1 year from the first evaluation. The measurements were performed five times to confirm the accuracy of CT measurement; the average value of five measurements was recorded.

All patients underwent abdominal/pelvic computed tomography (CT) at least twice: at the time of cancer diagnosis and just before surgery. The cross‐sectional areas of the right and left psoas muscles (psoas muscle area: PMA) at the middle level of the third lumbar vertebra were measured using SYNAPSE VINCENT software (Fujifilm Co., Tokyo, Japan). The border of the psoas muscle was manually outlined and quantified using a Hounsfield unit threshold from −29 to +150.¹⁸ The PMA value just before surgery was divided by that at the time of cancer diagnosis, and the resulting value was defined as the rate of change in PMA (CPMA) (Figure 2). According to the median CPMA, patients were divided into the preoperative skeletal muscle wasting and no‐change groups. The clinicopathological factors, as well as the short‐ and long‐term outcomes of the two groups, were compared. The measured PMA was normalized according to height using the following equation: normalized PMA, defined as the psoas muscle mass index (PMI, cm²/m²) = measured PMA (cm²)/height (m²). The cutoff level of sarcopenia in PMI value was 6.36 cm²/m² for males and 3.92 cm²/m² for females.¹⁹ Obesity was defined as body mass index (BMI) ≥ 25 kg²/m².²⁰ Sarcopenic obesity was defined as patients with both sarcopenia and obesity.

Computed tomography (CT) scans of the abdomen were performed during each patient’s periodic check-up. Each patient was imaged in the supine position and the thickness of each slice was 1.0mm. Axial CT images were used for muscle and fat mass evaluations at the level of the third lumber spine [14 (link)]. The abdominal muscle area (AMA), abdominal subcutaneous fat area (ASFA), and abdominal visceral fat area (AVFA) were automatically measured using SYNAPSE VINCENT software (version 3.0, Fujifilm Medical, Tokyo, Japan), which enables the tissue segmentation using Hounsfield unit thresholds [15 (link)]. To avoid the potentially confounding influence of body size, we also adjusted AMA, ASFA, and AVFA by dividing by the height of each patient (AMA/height, ASFA/height, and AVFA/height, respectively) [16 (link)].