Search results for "volume measurement"
showing 10 items of 23 documents
Erythrocytes labeled with [18F]SFB as an alternative to radioactive CO for quantification of blood volume with PET
2013
Inhaled radioactive CO is currently the tracer of choice for blood volume quantification by positron emission tomography (PET). This measurement is of great interest for several clinical and research applications. However, owing to the short half-life of the radiolabeled CO, it can only be used in centers equipped with a cyclotron. In the present work, we propose an alternative method to label the red blood cells with [(18) F] in order to obtain blood volume measurements by PET. The use of the radioactive synthon [(18) F] N-succinimidyl 4-[(18) F]fluorobenzoate ([(18) F]SFB) was evaluated for erythrocyte labeling and PET blood volume imaging. The images provided by [(18) F]SFB labeled eryth…
Is periapical surgery follow-up with only two-dimensional radiographs reliable? A retrospective cohort type sensitivity study
2021
Background Two-dimensional (2D) radiographic techniques are commonly used for assessing lesion prognosis after endodontic surgery. The present retrospective cohort study analyzes the sensitivity and ability of different radiographic techniques in obtaining area and volume measurements of periapical lesions. Material and Methods Preoperative and follow-up (6-48 months) periapical and panoramic radiographs (index test) and cone-beam computed tomography (CBCT) images (reference standard) were selected from an endodontic microsurgery database. Sensitivity was analyzed independently by two examiners. The areas of the 2D radiographic images and CBCT volumes were studied using Itk-Snap software an…
Focal liver lesions: interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound-assisted volume measurements
2021
Purpose: This study was conducted to assess the interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound (3D-CEUS) volume calculations of focal liver lesions (FLLs).Methods: Thirty-nine patients (15 men and 24 women; mean age, 55.4 years) with 39 Flis (mean size, 3.1 +/- 1.8 cm; size range, 1 to 8 cm) prospectively underwent 3D-CEUS. Four readers calculated the volume of each lesion in an independent and blinded fashion in two separate sessions by means of a semi-automatic, commercially available proprietary software. The differences in lesion volumes (cm(3)) among sessions and readers were assessed using the Mann-Whitney U test and the Kruskal-Wallis test…
Workflow-centred open-source fully automated lung volumetry in chest CT
2019
Aim To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. Materials and methods Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. Results A total of 28…
Bronchodilatory Effect of Deep Inspiration Is Absent in Subjects With Mild COPD
2004
Study objectives To investigate whether the bronchodilatory effect of deep inspiration is impaired in subjects with COPD. Methods We measured deep inspiration-induced bronchodilation in 19 patients with COPD and 17 healthy subjects (mean age, 67.8 ± 7.1 years vs 62.5 ± 9.3 years, respectively [± SEM]). Each subject underwent a series of single-dose methacholine provocations to induce at least a 15% reduction in inspiratory vital capacity (IVC). When this was achieved, subjects were asked to perform four consecutive deep inspirations, after which the IVC measurement was repeated and the percentage of bronchodilation by deep inspiration was calculated. Results The percentage of reduction in I…
Mapping cyclic stretch in the postpneumonectomy murine lung
2013
In many mammalian species, the removal of one lung [pneumonectomy (PNX)] is associated with the compensatory growth of the remaining lung. To investigate the hypothesis that parenchymal deformation may trigger lung regeneration, we used respiratory-gated micro-computed tomography scanning to create three-dimensional finite-element geometric models of the murine cardiac lobe with cyclic breathing. Models were constructed of respiratory-gated micro-computed tomography scans pre-PNX and 24 h post-PNX. The computational models demonstrated that the maximum stretch ratio map was patchy and heterogeneous, particularly in subpleural, juxta-diaphragmatic, and cephalad regions of the lobe. In these…
Airway distensibility by HRCT in asthmatics and COPD with comparable airway obstruction.
2013
Introduction: Decreased airway distensibility (AD) in response to deep inspirations, as assessed by HRCT, has been associated with the severity of asthma and COPD. Aims: The current study was designed to compare the magnitude of AD by HRCT in individuals with asthma and COPD with comparable degrees of bronchial obstruction, and to explore factors that may influence it. Results: We enrolled a total of 12 asthmatics (M/F:7/5) and 8 COPD (7/1) with comparable degree of bronchial obstruction (FEV1% predicted mean±SEM: 69.1 ± 5.2% and 61.2 ± 5.0%, respectively; p = 0.31). Each subject underwent chest HRCT at FRC and at TLC. A total of 701 airways (range 20 to 38 airway per subject; 2.0 to 23.1 m…
Effect of unilateral diaphragmatic paralysis on postpneumonectomy lung growth.
2013
Respiratory muscle-associated stretch has been implicated in normal lung development (fetal breathing movements) and postpneumonectomy lung growth. To test the hypothesis that mechanical stretch from diaphragmatic contraction contributes to lung growth, we performed left phrenic nerve transections (PNT) in mice with and without ipsilateral pneumonectomy. PNT was demonstrated by asymmetric costal margin excursion and confirmed at autopsy. In mice with two lungs, PNT was associated with a decrease in ipsilateral lung volume ( P < 0.05) and lung weight ( P < 0.05). After pneumonectomy, PNT was not associated with a change in activity level, measureable hypoxemia, or altered minute venti…
Mechanostructural adaptations preceding postpneumonectomy lung growth
2012
In many species, pneumonectomy results in compensatory growth in the remaining lung. Although the late mechanical consequences of murine pneumonectomy are known, little is known about the anatomic adaptations and respiratory mechanics during compensatory lung growth. To investigate the structural and mechanical changes during compensatory growth, mice were studied for 21 days after left pneumonectomy using microCT and respiratory system impedance (FlexiVent). Anatomic changes after left pneumonectomy included minimal mediastinal shift or chestwall remodeling, but significant displacement of the heart and cardiac lobe. Mean displacement of the cardiac lobe centroid was 5.2 ± 0.8 mm. Lung imp…
Dynamic determination of oxygenation and lung compliance in murine pneumonectomy.
2011
Thoracic surgical procedures in mice have been applied to a wide range of investigations, but little is known about the murine physiologic response to pulmonary surgery. Using continuous arterial oximetry monitoring and the FlexiVent murine ventilator, the authors investigated the effect of anesthesia and pneumonectomy on mouse oxygen saturation and lung mechanics. Sedation resulted in a dose-dependent decline of oxygen saturation that ranged from 55% to 82%. Oxygen saturation was restored by mechanical ventilation with increased rate and tidal volumes. In the mouse strain studied, optimal ventilatory rates were a rate of 200/minute and a tidal volume of 10 mL/kg. Sustained inflation pressu…