Modeling Respiratory Signals by Deformable Image Registration on 4DCT Lung Images

The lung organ of human anatomy captured by a medical device reveals inhalation and exhalation information for treatment and monitoring. Given a large number of slices covering an area of the lung, we have a set of three-dimensional lung data. And then, by combining additionally with breath-hold measurements, we have a dataset of multigroup CT images (called 4DCT image set) that could show the lung motion and deformation over time. Up to now, it has still been a challenging problem to model a respiratory signal representing patients’ breathing motion as well as simulating inhalation and exhalation process from 4DCT lung images because of its complexity. In this paper, we propose a promising hybrid approach incorporating the local binary pattern (LBP) histogram with entropy comparison to register the lung images. The segmentation process of the left and right lung is completely overcome by the minimum variance quantization and within class variance techniques which help the registration stage. The experiments are conducted on the 4DCT deformable image registration (DIR) public database giving us the overall evaluation on each stage: segmentation, registration, and modeling, to validate the effectiveness of the approach.

Superimposed High Frequency Jet Ventilation Minimises Diaphragm, Bronchus, and Mediastinum Motion during One-Lung Flooding

Background: One-Lung Flooding (OLF) represents an ideal acoustic pathway for focused ultrasound ablation of lung tumours. Despite stabilization of the adjacent hemidiaphragm by OLF, standard Pressure-Controlled Ventilation (PCV) of the contralateral lung causes an unacceptable movement of the flooded lung. We examined whether Superimposed High Frequency Jet Ventilation (SHFJV) reduces lung motion compared to PCV during OLF. Methods: The study included 15 pigs: 10 underwent OLF; 5 controls underwent two-lung ventilation without OLF. Using ultrasound, diaphragm displacement on the flooded lung side was measured during PCV and SHFJV in the left lateral (LLP), Supine (SP), and Right Lateral Positions (RLP). Bronchus and mediastinum displacements were measured in the right lateral position. Results: Diaphragm displacement on the flooded lung side was significantly reduced during SHFJV, compared with PCV, in all animal positions (LLP: 7mm [4.75-8.0] vs. 17mm [14.75-19.0], P=0.0039; SP: 4mm [3.75-4.25] vs. 17mm [16.0–18.5], P=0.0039; RLP: 8mm [5.75-9.0] vs. 20mm [14.0-23.25], P=0.0078). Displacement of both the bronchus and mediastinum were significantly reduced during SHFJV, compared with PCV, in RLP (bronchus: 2.0mm [1.75-2.25] vs. 3.0mm [2.75-3.0], P=0.027; mediastinum: 4.5mm [4.0-5.0] vs. 10mm [7.0-10.0], P=0.0078. Conclusion: Thus, SHFJV minimises diaphragm, bronchus, and mediastinum motion during OLF, which is a prerequisite for effective lung tumour ablation.

Superimposed high-frequency jet ventilation minimises diaphragm, bronchus, and mediastinum motion during one-lung flooding

Background: One-lung flooding (OLF) represents an ideal acoustic pathway for focused ultrasound ablation of lung tumours. Despite stabilization of the adjacent hemidiaphragm by OLF, standard pressure-controlled ventilation (PCV) of the contralateral lung causes an unacceptable movement of the flooded lung. We examined whether superimposed high-frequency jet ventilation (SHFJV) reduces lung motion compared to PCV during OLF.Methods: The study included 15 pigs: 10 underwent OLF; 5 controls underwent two-lung ventilation without OLF. Using ultrasound, diaphragm displacement on the flooded lung side was measured during PCV and SHFJV in the left lateral (LLP), supine (SP), and right lateral positions (RLP). Bronchus and mediastinum displacements were measured in the right lateral position. Results: Diaphragm displacement on the flooded lung side was significantly reduced during SHFJV, compared with PCV, in all animal positions (LLP: 7 mm [4.75–8.0] vs. 17 mm [14.75–19.0], P = 0.0039; SP: 4 mm [3.75–4.25] vs. 17 mm [16.0–18.5], P = 0.0039; RLP: 8 mm [5.75–9.0] vs. 20 mm [14.0–23.25], P = 0.0078). Displacement of both the bronchus and mediastinum were significantly reduced during SHFJV, compared with PCV, in RLP (bronchus: 2.0 mm [1.75–2.25] vs. 3.0 mm [2.75–3.0], P = 0.027; mediastinum: 4.5 mm [4.0–5.0] vs. 10 mm [7.0–10.0], P = 0.0078; Figs. 5, 6). Conclusion: Thus, SHFJV minimises diaphragm, bronchus, and mediastinum motion during OLF, which is a prerequisite for effective lung tumour ablation.