Visualization Of Pulmonary Nodules Research Articles

Expert consensus on indocyanine green fluorescence imaging for thoracoscopic lung resection (The Version 2022)

The use of the white-light thoracoscopy is hampered by the low contrast between oncologic margins and surrounding normal parenchyma. As a result, many patients with in situ or micro-infiltrating adenocarcinoma have to undergo lobectomy due to a lack of tactile and visual feedback in the resection of solitary pulmonary nodules. Near-infrared (NIR) guided indocyanine green (ICG) fluorescence imaging technique has been widely investigated due to its unique capability in addressing the current challenges; however, there is no special consensus on the evidence and recommendations for its preoperative and intraoperative applications. This manuscript will describe the development process of a consensus on ICG fluorescence-guided thoracoscopic resection of pulmonary lesions and make recommendations that can be applied in a greater number of centers. Specifically, an expert panel of thoracic surgeons and radiographers was formed. Based on the quality of evidence and strength of recommendations, the consensus was developed in conjunction with the Chinese Guidelines on Video-assisted Thoracoscopy, and the National Comprehensive Cancer Network (NCCN) guidelines on the management of pulmonary lesions. Each of the statements was discussed and agreed upon with a unanimous consensus amongst the panel. A total of 6 consensus statements were developed. Fluorescence-guided thoracoscopy has unique advantages in the visualization of pulmonary nodules, and recognition and resection of the anterior plane of the pulmonary segment. The expert panel agrees that fluorescence-guided thoracoscopic surgery has the potential to become a routine operation for the treatment of pulmonary lesions.

The influence of model iterative reconstruction on the image quality in standard and low-dose computer tomography of the chest. Experimental study

Background. One of the ways to reduce the radiation dose in CT is to the image reconstruction algorithms. The latest offer from CT scanner manufacturers is Model Iterative Reconstruction (MIR). Aims: to compare the quality of visualization of the structures of the chest organs and to prove the effectiveness of the low-dose protocol with iterative model reconstruction. Methods. A calibration phantom with a spatial resolution module and an anthropomorphic phantom of the upper body of an adult with nodules in the lungs were scanned using two CT scanners of different manufacturers. Two protocols were applied: the standard dose protocol (SDCT) with the algorithms of hybrid iterative reconstruction (HIR) of images and MIR and a low-dose protocol (LDCT) with the MIRalgorithm. The quality of the obtained images was evaluated by the following parameters: noise (SD), the contrast-to-noise ratio (CNR), spatial resolution and visualization of pulmonary nodules. The radiation dose was calculated according to the scanner data, the data of individual dosimeters placed on the anthropomorphic phantom, and using a dosimetric phantom. Results. The average SD was 11.5; 24.4 and 21.6; CNR 85.47; 40.6 and 45.6; spatial resolution 2 mm; 2 mm and 3 mm for SDCT with MIR, SDCT with HIR and LDCT with MIR respectively. Visualization of the pulmonary lesions remained excellent in all cases. The radiation dose in case of SDCT was 2.7, and in case of LDCT 0.67 mSv. The dose reduction was confirmed by the dosimeter data. Similar results were obtained by repeating the experiment with a second scanner. Conclusions. The model iterative reconstruction application will allow reducing the irradiatin dose during CT scanning of the chest organs without deterioration of the visualization quality.

MRT-Analyse der Bewegungen von Lungenrundherden

Visualization of pulmonary nodules using magnetic resonance imaging (MRI) plays a minor role compared with computed tomography (CT). Technical developments made it possible to apply MRI more and more frequently in functional imaging. Imaging of the motion of pulmonary nodules during respiration, e.g., to optimize high precision therapy techniques, is a new field of research. This paper describes developments in analysis and visualization of pulmonary nodules during respiration using MRI. Besides actual 2D techniques new 3D techniques to quantify motion of pulmonary nodules during respiration are presented.

Endobronchial Ultrasound-Guided Transbronchial Lung Biopsy in Fluoroscopically Invisible Solitary Pulmonary Nodules: A Prospective Trial

Transbronchial biopsy (TBBX) for solitary pulmonary nodules (SPNs) is usually performed under fluoroscopic guidance, but the diagnostic yield depends on lesion size and varies widely. Nodules < 3 cm frequently cannot be visualized fluoroscopically. An alternative guidance technique, endobronchial ultrasound (EBUS), also allows visualization of pulmonary nodules. This study assessed the diagnostic yield of EBUS-guided TBBX in fluoroscopically invisible SPNs. The study was a prospective trial using a crossover design. All patients with SPNs and indications for bronchoscopy were included in the study. An EBUS-guided examination was performed in patients with fluoroscopically invisible nodules. The EBUS probe was introduced through a guide catheter into the presumed segment. If a typical ultrasonic picture of solid tissue could be seen, the probe was removed and the catheter left in place. The biopsy forceps were introduced and specimens taken. One hundred thirty-eight consecutive patients with SPNs were examined. Of those, 54 patients presented with SPNs that could not be visualized with fluoroscopy. The mean diameter of the nodules was 2.2 cm. In 48 patients (89%), the lesion was localized with EBUS, and in 38 patients (70%) the biopsy established the diagnosis. The 16 patients with undiagnosed SPNs were referred for surgical biopsy; 10 of those lesions were malignant and 6 were benign. The diagnosis in nine patients (17%) saved the patients from having to undergo a surgical procedure. The only complication was a pneumothorax in one patient. EBUS-guided TBBX is a safe and very effective method for SPNs that cannot be visualized by fluoroscopy. The procedure may increase the yield of endoscopic biopsy in patients with these nodules and avert the need for surgical procedures.

Computer aided diagnosis in chest radiology - current topics and techniques

The proliferation of digital data sets and the increasing amount of images, e. g. through the use of multislice spiral CT or multiple follow-up examinations in the context of new therapies, are ideal prerequisites for computer-aided diagnosis (CAD) in chest radiology. Multiple studies have described the applications and advantages of computer assistance in performing different diagnostic tasks. More powerful computers will enable the introduction of these systems into the clinical routine and could provide an enormous increase in morphological and functional information. The commercial introduction of tools for detection and visualization of pulmonary nodules has already begun. This is one of the most widely-reported applications in view of the ongoing studies on lung cancer screening. The next generation of tools will improve the diagnosis of emphysema through detection, quantification and classification. Many more uses are being developed, for instance the detection and classification of infiltrates, volume measurements or functional pulmonary imaging (e. g. dynamic ventilation CT or (3)Helium-MRI). Grossly simplified, most systems use a three level structure consisting of segmentation/feature extraction, classification of extracted features and an output unit. The output can be mere visualization through color-coding, volume measurements or calculated probabilities. The output supports the radiologist in establishing his findings and preparing differential and final diagnoses as well as providing quantitative data for follow-up studies. Different techniques are used for segmentation of lung areas as the basis for a variety of applications. Some commonly-used techniques for this and other tasks are density masks and threshold-based algorithms. Data processing is predominantly carried out with Bayesian classifiers or neural networks. This article describes the current status of research and provides insight into the common schemes and capabilities of the systems. It focuses particularly on common topics such as segmentation, volume measurement, detection of pulmonary nodules, quantification of emphysema and analysis of ground glass opacities.

Clinical application of single dual-energy subtraction technique with digital storage-phosphor radiography

We used a single-exposure dual-energy subtraction technique with a storage-phosphor computed radiography (CR) system to evaluate various pulmonary diseases. Clinical applications of this method have been studies at our institution. In our experience, the dual-energy subtraction technique provided better visualization of pulmonary nodules, tracheobronchial abnormalities, pulmonary vascular diseases, calcification in a nodule, and rib lesions than conventional CR images did. Single-exposure dual-energy subtraction images were obtained with a sandwich technique using two storage-phosphor imaging plates with a 1-mm-thick copper filter interleaved between the two. The front plate obtains a lower kilovoltage image, whereas the back plate obtains a higher kilovoltage image. We can visualize soft tissue and bone images as well as unsubtracted digital images by the subtraction process.