Ingenuity ct

All non-enhanced CT images were obtained on the multidetector CT scanners (Ingenuity CT, Philips; Brilliance iCT, Philips; Somatom Force, Siemens Healthcare; Somatom Definition Flash, Siemens Healthcare; Somatom Definition AS, Siemens; Optima CT660, GE Healthcare; Discovery 750, GE Healthcare). The chest CT scanning parameters were the following: tube voltage of 120 kVp, pitch of 0.8–1.0, 250–400 mA (using automatic tube current modulation technique) tube current, a matrix of 512 × 512, reconstructed slice thickness of 1 mm, reconstructed slice interval of 1 mm, rotation time of 500–600 ms. Non-enhanced CT scanning was performed with coverage from the thoracic inlet to the lung base in the supine position.

A 64-slice spiral CT (Philips, Ingenuity CT, Israel) is used to obtain the image data of the PB-LMA model. The scanning process is detailed as follows. Firstly, topical anaesthesia is carried out adequately on the patient’s throat. Next, intravenous anaesthesia is carried out for the patient with the monitor of vital signs. CT scans are carried out to obtain data of PB with the inserted LMA loaded with different CP values, measured by a manometer at the LMA inflation valve.Figure 2

CT image displayed in the GUI of 3D modelling software from different views.

The scanning parameters are detailed as follows: 120 kV, 30 mAs, 1 mm scanning thickness, 0.75 mm $\times$ 0.75 mm in-plane resolution, $512\times 512$ matrix. Firstly, CT images in DICOM format obtained for each scan, as displayed in Fig. 2, are used as references to establish 3D models of PB-LMA interactions. After threshold segmentation, dynamic region growth, 3D calculation and smoothing, we constructed 3D models for each part of the PB-LMA interactions are, as shown in Fig. 3.Figure 3

3D reconstruction model of PB and LMA (A: 3D image of PBs, including cricoid cartilage (I), thyroid cartilage (II), hyoid bone (III), mandible (IV), spine (V), B: LMA50; C: 3D image of PB-LMA50; D: LMA100; E: 3D image of PB-LMA100. The position indicated by the elliptical dotted line is the closed hypopharynx).

CT examinations were conducted on 128-slice (Siemens SOMATOM Definition CT) and 64-channel (GE Discovery CT750, Philips Ingenuity CT) scanners with patients in the supine position following a 6-h fasting period. Patients were trained to control their breathing before the scan to minimize any breathing-related artifacts. The CT scans encompassed the region extending from the diaphragm to the bony pelvic floor. Prior to undergoing the contrast-enhanced CT examination, patients were administered contrast agents (5.300 mL/kg, iohexol 40 mg I/mL) via the anterior elbow vein at a rate of 5.1 mL/s. The following parameters were used for the CT scan: tube current ranging from 150 to 350 mA, tube voltage of 120 kVp, field of view spanning 30–45 cm, matrix size of 512 × 512, and reconstructed slice thickness between 1 and 5 mm.

Pulmonary CT images were obtained using scanners from GE (LightSpeed VCT, LightSpeed 16, and HiSpeed CT/i), Siemens (Definition AS+, Emotion 16, and Sensation 64), and Philips (iCT 256 and Ingenuity CT) Healthcare systems. The CT image parameters were as follows: 100–130 kVp; 47–351 mA; slice thickness, 0.6–1.25 mm; pixel spacing, 0.38–0.89 mm; reconstruction interval, 0.39–6 mm; and matrix, 512 mm × 512 mm.

Image acquisition was performed in supine position using multi-detector CT scanners (Brilliance 64, Ingenuity CT, Philips Healthcare, Best, The Netherlands; Somatom Definition AS+, Somatom Sensation Cardiac 64, Siemens Healthineers, Erlangen, Germany). An initial scout scan was used for planning of the field of view, and subsequent helical scanning was acquired with a peak tube voltage of 120 kVp or 130 kVp and adaptive tube load, without previous application of any intravenous or oral contrast agents. Sagittal reformations of the spine with a slice thickness ≤3 mm were reconstructed with a bone kernel and used for further analysis in this study. The sagittal reformations of the spine were used for VF detection by a board-certified radiologist with 11 years of experience, who used the classification proposed by Genant et al. (43 (link)). CT imaging was performed for various indications not related to bone densitometry.

This cross-sectional study examined a convenience sample and was designed to evaluate the LV’s location during CPR based on LDCT images from health screenings. All participants provided informed consent for the data collection and the publication of their images, and the study’s protocol was approved by our institutional review board (B-1507/306-308).
Because the end of the xiphoid process was not identifiable in the scout images, a radio-opaque marker was attached to the skin over the xiphoid process to monitor changes in sternal location according to the positional changes. The xiphoid process marker was attached by a trained nurse, who performed palpation of the sternum’s distal end. Two scout images of the chest were obtained in the different positions before the LDCT for all participants. The first scout image was obtained in the EAD position to simulate real CPR positioning, and the second scout image was obtained in the IAR position, which is the standard position for LDCT. All LDCT procedures were performed in the IAR position only using a 128-slice multi-detector row CT unit (Ingenuity CT; Philips Medical Systems, Best, The Netherlands). The institutional picture archiving and communication system (G3 PACS; Infinite Inc., Seoul, Korea) was used to analyse the images for this study. All images were evaluated and interpreted by two board-certified chest radiologists.