Hemorrhagic complications during pleural interventions—such as thoracentesis and chest tube insertion—remain a significant clinical concern, primarily due to inadvertent injury of the intercostal artery (ICA). The highly variable ICA anatomy is frequently not visualized on conventional imaging, limiting the reliability of landmark-based techniques. Color Doppler thoracic ultrasound (CDUS) has emerged as a non-invasive, real-time modality capable of identifying ICAs and their anatomical variants prior to pleural access. This narrative review synthesizes current evidence on CDUS-guided ICA screening, focusing on its technical principles, diagnostic performance, and clinical applicability. While feasibility and utility are supported by multiple observational studies, robust evidence demonstrating a reduction in bleeding complications is still lacking. Barriers to widespread implementation include heterogeneous scanning protocols, operator dependency, and the absence of standardized training. We discuss the anatomical rationale for pre-procedural vascular mapping and highlight emerging protocols aimed at standardizing ICA visualization. Although not yet incorporated into major clinical guidelines, CDUS represents a promising tool to enhance procedural safety. Emerging AI applications may further improve vessel detection by reducing operator dependency and enhancing reproducibility. High-quality prospective studies are essential to validate potential clinical benefits, optimize implementation strategies, and support integration into routine pleural practice.

Background: Coronavirus Disease 19 (COVID-19)-associated pneumonia is characterized by a broad spectrum of severity. Endothelial injury is a prominent component of the disease, but the relative contribution of vessels of different sizes to this condition has not been extensively investigated. Quantitative computed tomography (CT) represents a potential tool to evaluate pulmonary vascular involvement. Objectives: To investigate the relative contribution of vessels of different sizes in COVID-19-associated pneumonia of different severity using the Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) software. Methods: We conducted a single-center retrospective study, including patients admitted to the Pisa University Hospital between March and April 2020 with COVID-19-associated pneumonia. We excluded patients with severe motion artifacts, inadequate CALIPER segmentation, or inconclusive etiologic confirmation. All CT scans were analyzed using CALIPER, which automatically segmented lung parenchyma and vascular-related structures (VRSs). VRS volumes were stratified by vessel cross-sectional area (20 mm²). Results: We analyzed 258 patients. We observed that an increase in the percentages of VRSs with cross-sectional areas up to 20 mm² was associated with the need for lower intensity of care and with better gas exchange. The opposite trend was observed for the percentages of >20 mm². Conclusions: Our data provide novel information on the involvement of blood vessels of different sizes in the gas exchange impairment of COVID-19 patients. CALIPER represents a promising application for the study of vascular structures of the lung.