Related Experiment Video
Updated: Jul 25, 2026
09:17
Point-of-Care Lung Ultrasound in Adults: Image Acquisition
Published on: March 3, 2023
Right hilar pseudomass due to partial right lower lobe atelectasis
1Radiology Service, Lexington VA Medical Center, KY 40511, USA. johnwoodring@aol.com
Journal of Thoracic Imaging
|June 29, 2001
Summary
Right lower lobe atelectasis can mimic a hilar mass on frontal radiographs due to hilum rotation. Recognizing this "pseudomass" variant prevents unnecessary lung cancer investigations.
Area of Science:
- Radiology
- Thoracic Imaging
Background:
- Right lower lobe atelectasis can present with atypical radiographic findings.
- Misinterpretation of these findings can lead to misdiagnosis and unnecessary procedures.
Observation:
- Rotation of the right hilum into an anteroposterior plane during frontal radiography.
- Partial aeration of the right lower lobe in the presence of atelectasis.
Findings:
- A "pseudomass" may appear in the right hilar region on frontal chest radiographs.
- This appearance is a variant of right lower lobe atelectasis, not a true hilar mass.
Implications:
- Accurate identification of this "pseudomass" prevents misdiagnosis of a hilar mass.
- Comparison with prior normal chest radiographs is crucial for correct diagnosis.
- Thoracic computed tomography (CT) can confirm the absence of a hilar mass when prior imaging is unavailable.
Related Concept Videos
01:23Assessment of Respiration
The respiratory system's basic structures and primary functions lay the foundation for nurses' comprehensive respiratory assessments. This assessment includes subjective and objective data to gauge the patient's respiratory health.
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like asthma or COPD,...
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like asthma or COPD,...
01:17Pulmonary Cycle: Exhalation
In terms of human respiration, the act of expelling air, known as exhalation (or expiration), operates on the principle of pressure gradients. During expiration, the pressure within the lungs exceeds that of the surrounding atmosphere. Under normal conditions, quiet breathing involves passive exhalation and is free of muscular contractions. This is because the exhalation process is driven by the natural elastic recoil of the lungs and chest wall, both of which have an inherent tendency to...
01:31Anatomy of Respiratory System II: Lower Respiratory Tract
The lower respiratory tract is anatomically composed of several vital structures, including the larynx, trachea, bronchial tree, alveoli, lungs, and pleurae. Each component has a specific function, and all are intricately connected to ensure efficient respiration.
The Larynx
It is located between the pharynx and the trachea, acts as a passageway for air, and hosts several critical structures, such as the epiglottis, vocal cords, and glottis. The epiglottis acts as a gateway, guiding food to the...
The Larynx
It is located between the pharynx and the trachea, acts as a passageway for air, and hosts several critical structures, such as the epiglottis, vocal cords, and glottis. The epiglottis acts as a gateway, guiding food to the...
01:08Pneumothorax II: Pathophysiology
Pneumothorax means the presence of air in the pleural space — the thin potential gap between the visceral and parietal pleura. This condition disrupts the normal pressure balance that keeps the lungs inflated, leading to partial or complete collapse of the affected lung.Normal physiologyUnder normal conditions, the pleural space maintains a slightly negative intrapleural pressure, which keeps the lungs expanded against the chest wall. This negative pressure creates a delicate balance between...
01:10Atelectasis II: Pathophysiology
Atelectasis develops when alveoli lose their air and collapse inward. Because lung tissue is naturally elastic, these air sacs shrink rather than remaining open. Collapsed alveoli are no longer ventilated, reducing their role in gas exchange. Blood flow may continue in these regions, creating a ventilation–perfusion mismatch. Clinical findings include decreased breath sounds, dullness to percussion, reduced chest expansion, and decreased tactile fremitus as sound transmission through collapsed...
01:29Pneumonia I: Introduction
Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...