The chest is the region of the body between the neck and the abdomen, along with its internal organs and other contents. Contents of the chest include the organs (heart, lungs), muscles, internal structures, arteries and veins, bones and external structures (nipples, mammary glands).

The portion of the chest protected by the ribcage is also called the thorax. The words chest and thorax are often mistakenly used interchangeably. 

Chest Radiology, Thoracic Radiology (or Imaging)
The subspecialty concerned with the diagnostic radiology of diseases of the thorax, especially the heart or lungs.

Breast Imaging
The subspecialty within diagnostic radiology devoted to the diagnosis and treatment of breast diseases and conditions unique to women.

Cardiac Radiology
The subspecialty of radiology concerned with diagnosis and treatment of diseases of the heart.