What causes an azygos fissure?
Discussion. The azygos fissure forms when the embryologic azygos vein (posterior cardinal vein) migrates through the apical portion of the right lung instead of medial to it. As the vein invaginates the lung, it creates a fissure (mesoazygos) with 4 pleural layers (2 parietal and 2 visceral).
What does azygos lobe mean?
In human anatomy, an azygos lobe is a normal anatomical variation of the upper lobe of the right lung.
Where is the azygos fissure located?
right lung
It is typically located in the apicomedial portion of the right lung, separated from the rest of the right upper lobe by a visible fissure, termed an azygous fissure. The fissure can be identified as a fine, convex line on a chest radiograph in the para mediastinal portion of the right lung.
What is the lobe of azygos vein?
azygos lobe (lobe of azygos vein) a small anomalous lobe situated at the apex of the right lung, produced when the azygos vein arches over the upper part of the lung instead of at the hilus and presses deeply into the lung tissue to form a fissure that isolates a medial part of the lung.
Is Azygos fissure normal?
The azygos vein, located at the bottom of the fissure, is visible as a teardrop-shaped opacity [2]. The incidence of this normal variant is estimated between 0.4% and 1.2% [2; 4]. Accessory pulmonary fissures, including the azygos fissure, are known to affect up to 50% of the population.
How common is an azygos lobe?
An azygos lobe is a rare, anatomical variant of the upper lobe of the right lung found in approximately 1% of anatomic specimens and 0.4% of chest radiographs [1].
What are fissures in lungs?
A pulmonary fissure is a boundary between the lobes in the lungs. Its segmentation is of clinical interest as it facilitates the assessment of lung disease on a lobar level.
Is azygos lobe rare?
Azygos lobe is a very rare but normal anatomic variant of right upper lobe seen in only 0.4% of population radiologically and in 1% specimen during anatomical dissection [1,2].
What is accessory azygos fissure?
Accessory fissures of the lung usually occur at the borders of bronchopulmonary segments. They are common normal variants but are less commonly seen on imaging. Some of the more common accessory fissure include 1: azygos fissure: most commonly seen accessory fissure.
Can you see lung fissures on xray?
The right lung has two fissures, oblique fissure and horizontal fissure, which separate the lung into three lobes – upper, middle, and lower. Each lobe has its own visceral pleural covering. Only the horizontal fissure is commonly seen on a frontal chest X-ray.
What do alveoli do?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
What is a lung fissure?
A pulmonary fissure is a boundary between the lobes in the lungs. Its segmentation is of clinical interest as it facilitates the assessment of lung disease on a lobar level. This paper describes a new approach for segmenting the major fissures in both lungs on thin-section computed tomography (CT).