Radiology

Radiology is the medical specialty that deals with generating images of the interior of the body using different physical agents (X-rays, ultrasound, magnetic fields, among others) and using these images for the diagnosis and, to a lesser extent, for the prognosis and treatment of diseases. It is also generically called radiodiagnosis or diagnostic imaging. Radiology must be distinguished from radiotherapy, which does not use images, but directly uses ionizing radiation (x-rays of higher energy than those used for diagnosis, and also radiation of other types) for the treatment of diseases (for example, to stop or slow the growth of tumors that are sensitive to radiation).

Classification

Depending on the organ, system, or part of the body being studied

• neurological radiology or neuroradiology
• Head and neck radiology
• Dental radiology
• chest radiology
• Heart radiology
• Abdominal radiology
• Gastrointestinal radiology
• Genitourinary radiology
• radiology of the breast
• Gynecological radiology
• vascular radiology
• Musculoskeletal radiology
• Pediatric radiology
• podological radiology
• Geriatric radiology

According to your main activity

• Nuclear medicine: generates images by using radioactive tracers that are fixed with different affinity to the different types of tissues. It is an exclusively diagnostic branch and in some countries it is constituted in a separate medical specialty.
• Diagnostic or radiodiagnostic radiology: it focuses primarily on diagnosing diseases through the image.
• Interventional radiology: focuses primarily on the treatment of diseases, using minimally invasive surgical procedures guided by imaging techniques.

The borderline between diagnostic and interventional radiology is not well defined: diagnosticians often also perform interventional procedures in their respective area, and treatment specialists (interventional radiologists) often diagnose diseases of the peripheral circulatory system. Currently, in many countries, the subspecialty of vascular and interventional radiology is integrated with the rest of radiology into a single specialty, although there is controversy as to whether they should be separated as official specialties.

Classically, X-rays were used. X-rays (or Röntgen rays) were discovered over a hundred years ago by Wilhelm Conrad Röntgen, a German scientist who studied the effects of Crookes tubes on certain photographic plates when subjected to passage of an electric current.

Modalities

Conventional radiology: Ionizing radiation is used to capture images of any part of the body with a greater emphasis on bones and joints.

Sonography: ultrasound or ultrasonography, through the use of ultrasound, images of the interior of the body are obtained, specifically soft organs that are not visible by conventional radiology. Bone and gas are barriers that prevent the effective passage of ultrasound and limit its use. It is the ideal method to evaluate pregnant patients since ultrasound waves do not affect the fetus.

Computerized tomography: computerized tomography (CAT), allows three-dimensional examinations of all the organs of the body, incorporating a powerful computer into a rotating X-ray tube that is capable of reconstructing the images. Positron emission tomography (PET or PET) is recently being incorporated into radiology techniques. It is a technology that uses radioactive isotopes that are introduced into organic molecules or radiopharmaceuticals that are injected into the patient and later the radioactive emission of the different tissues is analyzed according to the uptake of the radiopharmaceutical they present. Glucose labeled with fluorine-18 is generally used, so there is a greater affinity for tumor or inflammatory lesions. Combined CT and PET studies can be performed, allowing for higher spatial resolution along with functional imaging.

MRI: The kits contain powerful devices capable of generating magnetic fields of up to more than 3 tesla. The fields thus generated are capable of orderly aligning the nuclear magnetic moment of atoms with an odd number of nucleons of the organism under study. Using radio frequency antennas, the moments of certain atoms in the organism are misaligned, each one oriented in a different direction, at random; when these electromagnetic radiations stop emitting, the moments align again and emit that previously received radiofrequency energy. These radiations, collected and processed by computer, are used to reconstruct images of the interior of the body in any direction in space. The greater or lesser intensity of the resulting image corresponds to the facility to release that energy from each tissue. Thus, each fabric will be seen in a different and particular way.

Mammography: Uses a low dose of radiation and in turn compresses the breast, in obtaining diagnostic images of the breasts or mammary glands and armpit tissue. Essential in the diagnosis of breast cancer.

Angiography: the blood vessels of the body are studied through images obtained using the use of radiation and a catheter through which a radiopaque contrast is introduced that allows visualization of the blood vessels for study and diagnosis of a condition.

The medical professional in charge of supervising the radiological examination and interpreting the medical image is the radiologist or the nuclear medicine doctor, in the case of nuclear medicine. The professional in charge of obtaining medical images is the radiology technician.

Radiology in dentistry

In the dental area, a distinction is made between intraoral and extraoral radiographic techniques.

Intraoral techniques

Intraoral techniques can be:

• Periapical techniques: in them it is possible to observe both the crown and the periapical bone tissue;
• coronal techniques: allow to observe the crown of the tooth;
• occlusal techniques: occlusion.

Extraoral techniques

They allow observing lesions outside the oral cavity, at the level of the paranasal sinuses, TMJ, fractures in the maxillary bones, among others.