Diagnostic Radiology/Chest Anatomy

Chest anatomy refers to the structures and components located in the thoracic region of the body, commonly known as the chest. The chest houses vital organs and structures, including the heart, lungs, major blood vessels, and the thoracic cage (ribcage). Here is an overview of the key components of chest anatomy:

• Thoracic Cage (Ribcage):
  • Ribs: The ribcage consists of 12 pairs of ribs, each attached to the thoracic vertebrae in the spine. Ribs provide protection to the organs within the chest, particularly the heart and lungs.
  • Sternum: The sternum, or breastbone, is a flat, elongated bone located in the center of the chest. It consists of three parts: the manubrium, body, and xiphoid process. The sternum serves as an attachment point for several ribs and supports the chest's structure.

• Lungs:
  • Lungs: The lungs are a pair of respiratory organs situated on either side of the chest. They are responsible for the exchange of oxygen and carbon dioxide during breathing. The right lung has three lobes, while the left lung has two lobes, allowing space for the heart.
  • Bronchi and Bronchioles: The trachea (windpipe) divides into the right and left main bronchi, which further branch into smaller bronchi and bronchioles within the lungs. These airways transport air to and from the alveoli (air sacs) for gas exchange.

• Heart and Great Vessels:
  • Heart: The heart is a muscular organ located in the chest, slightly to the left of the midline. It pumps blood throughout the body, supplying oxygen and nutrients to tissues. The heart consists of four chambers: two atria (left and right) and two ventricles (left and right).
  • Aorta: The aorta is the body's largest artery and originates from the left ventricle of the heart. It carries oxygenated blood from the heart to the systemic circulation, delivering it to the body's tissues.
  • Superior and Inferior Vena Cava: These large veins return deoxygenated blood from the upper (superior) and lower (inferior) parts of the body to the right atrium of the heart.

• Mediastinum:
  • Mediastinum: The mediastinum is the central compartment of the chest that houses the heart, major blood vessels, esophagus, and other structures. It extends from the sternum to the vertebral column.

• Esophagus:
  • Esophagus: The esophagus is a muscular tube that carries food and liquids from the mouth to the stomach through a process called peristalsis. It passes through the chest as it travels to the abdominal cavity.

• Diaphragm:
  • Diaphragm: The diaphragm is a dome-shaped muscle that separates the chest (thoracic) cavity from the abdominal cavity. It plays a crucial role in the breathing process, contracting and relaxing to change the volume of the thoracic cavity and facilitate breathing.

• Major Blood Vessels:
  • Pulmonary Arteries and Veins: Pulmonary arteries carry deoxygenated blood from the right side of the heart to the lungs for oxygenation, while pulmonary veins return oxygenated blood from the lungs to the left side of the heart.
  • Coronary Arteries: Coronary arteries supply the heart muscle with oxygenated blood, ensuring its proper function.

Understanding chest anatomy is essential for healthcare professionals, especially those in cardiology, pulmonology, thoracic surgery, and emergency medicine. It enables the diagnosis and treatment of conditions related to the heart, lungs, and other thoracic organs.

Normal Chest Anatomy

Name and define the three zones of the airways

Define a secondary pulmonary lobule

Define an acinus

List the lobar and segmental bronchi of both lungs

• Identify the following structures on the posteroanterior (PA) chest radiograph:
• Lungs -- right, left, right upper, middle and lower lobes, left upper and lower lobes, lingula
• Fissures -- minor, superior accessory, inferior accessory, azygous
• Airway - trachea, carina, main bronchi
• Heart - right atrium, left atrial appendage, left ventricle, location of the four cardiac valves
• Pulmonary arteries -- main, right, left, interlobar
• Aorta -- ascending, arch, descending
• Veins -- superior vena cava, azygous, left superior intercostal ("aortic nipple")
• Bones -- spine, ribs, clavicles, scapulae, humerus
• Right paratracheal stripe
• Junction lines -- anterior, posterior
• Aortopulmonary window
• Azygoesophageal recess
• Paraspinal lines
• Left subclavian artery

Identify the following structures on the lateral chest radiograph:

• Lungs -- right, left, right upper, middle and lower lobes, left upper and lower lobes, lingula
• Fissures n-- major, minor, superior accessory
• Airway -- trachea, upper lobe bronchi, posterior wall of bronchus intermedius
• Heart -- right ventricle, right ventricular outflow stripe, left atrium, left ventricle, the location of the four cardiac valves
• Pulmonary arteries -- right, left
• Aorta --ascending, arch, descending
• Veins -- SVC, IVC, left brachiocephalic (innominate), pulmonary vein confluence
• Bones -- spine, ribs, scapulae, humerus
• Retrosternal line
• Posterior tracheal stripe
• Right and left hemidiaphragms
• Raiderís triangle
• Brachiocephalic (innominate) artery