What is Radiology?

Radiology is the study of images of the human body. A Radiologist is a physician who has become a specialist in Radiology – a doctor who has taken additional training in the interpretation of medical images. Although Radiology initially starts with X–ray images later it extends to Ultrasound, CT, MRI, Angiograms, Radio nuclide images studies etc.

In general, “Radiology” refers to medical imaging techniques, employing advanced computers and other complex equipment, that allows doctors to see inside a patient’s body without bloodshed and pain. Although the word “Radiology” implies radiation, not all of the techniques actually use radiation. And although radiology is most commonly used for diagnosis, sometimes it's used therapeutically.

How is Radiology useful for patients?

Radiology plays a key role in the management of disease by giving information about the nature, site and extent of the disease in addition to cause and complications of the disease. By this information it is possible to decide what treatment (medical or surgical) is necessary for the disease. If surgery is involved, it helps to determine whether the patient is fit for surgery or not and also helps to determine the time for surgery and plan for surgical approach. Radiology is also useful in interventions like FNAC (Fine Needle Aspiration Cytology), Abscess Drainage, Tumor Ablation and in treating vascular lesions like Aneurysm and Arterio–Venous Malformations.

Radiology is also useful in therapeutic follow up of the disease, especially to know the possible recurrence of the tumor. It is useful to detect complications following a surgery. More importantly, it helps in early and accurate diagnosis.

What are the various methods in Radiology?

There are different methods through which a radiologist can diagnose the disease.
These are as follows.

• X–rays.
• Image Intensifier.
• Ultrasound and Color Doppler.
• CT Scan.
• MRI.
• Angiography.
• Radio–nuclide study.

Certain diseases need only one diagnostic method for establishing diseases. The majority of diseases need more than one investigation. Usually the Radiologist and clinician will decide what methods are essential to bring out the disease information.

Let us study about all these methods in detail.

What is an X–ray?

X–rays are part of the high frequency electromagnetic radiation. Because of special properties like penetration through soft parts of the body and reactions with photographic emulsion, X–rays are useful in diagnosis of various diseases.

How X –rays are useful in diagnosis?

X–rays are useful in the diagnosis of diseases involving bones, lungs, gut, kidneys and gall bladder. They are used in CT–scan, Image intensifier and Mammography. They are useful in detecting the congenital, inflammatory, traumatic, degenerative and neo–plastic diseases with variable sensitivity and specificity depending on the region affected.

Plain
Here, X–rays are used by themselves. For example, as diagnostic tools for bone, lungs, intestines, kidneys and gall bladder stones diseases. However, when X–rays are used alone their diagnostic capacity is limited. Certain diseases need only plain X–rays for diagnosis.

Contrast
Contrast (barium / iodine) solution and X–rays are used to get disease information. In this procedure, first contrast is given through various routes depending upon the region of investigation. Then X–rays are used/applied. Addition of contrast (barium / iodine solution) has widened the applicability of X–rays. Contrast is given either orally, intravenously or through other routes depending upon the region (part) under investigation.

Contrasts studies
‘Barium swallow’ is used to evaluate esophagus disorder. ‘Barium meal’ is used to evaluate stomach diseases. ‘Barium enema’ is used to evaluate colon disease. ‘Barium follow through’ to evaluate small bowel diseases. Intravenous contrast is used for functional and structural assessment of kidneys. Myelogram is used for spinal canal pathology. Hysterosalpingogram is used in the studies of the uterus and tubes of infertile women. An Angiogram is used in the study of lumen of blood vessels.

Why should I hold my breath while taking X–ray?

Patients are often asked to hold their breath, depending on the part being examined, this may be on inspiration or expiration. This is to ensure that the chest and abdominal organs will not be moving and ‘Blurred’ on the films.

What are the dangers or side affects of X–rays?

X–ray radiation is dangerous if a person receives excessive exposure.

How to over come the side effects of X–rays?

Strictly follow the safety precautions in the X–ray room. An image intensifier is an X–ray based device with very low radiation to the patient and to operator. It is useful for real time, dynamic study of an organ or system.

Has any patient had an allergic reaction or side effects with Barium?

Yes, but it is extremely rare. Only a small percentage of the population has experienced an allergic reaction to barium or to the flavoring materials.

What is Ultrasound?

High frequency (20 to 20,000 MHZ) sound waves are called Ultrasound.

What are the advantages of Ultrasound Scan?

• No radiation risk.
• Noninvasive.
• No special preparation.
• Immediate report.
• Reproducible results.
• Painless.
• Sedation is not required.
• Inexpensive.

For what diseases is an Ultrasound Scan useful?

It is useful for the liver, gall bladder, spleen, kidneys, urinary bladder, uterus, ovarian and pancreatic diseases. It is used to evaluate structures and functions of heart. High frequency probes are useful to investigate the eyeball, thyroid, breast, scrotum, infant's brain and joint diseases. In pregnancy – ultrasound scan provides maximum information regarding fetus and its environment.

How is an Ultrasound Scan useful in Pregnancy?

In the first three months (1st Trimester)

• Confirmation of pregnancy.
• Viability of pregnancy.
• To know the single / twin pregnancy.
• Type of abortion.
• To know the short cervix.
• Congenital anomaly like the absence of head (anencephaly).
• Maternal uterine and ovarian abnormalities.
• Ectopic pregnancy.

4th,5th,6th months (2nd Trimester)

Congenital anomalies

• Growth pattern.
• Liquor quantity.
• Placental position.

7th, 8th, 9th months (3rd Trimester)

• Congenital anomalies.
• Growth pattern.
• Liquor quantity.
• Placental position.
• Position of foetus.
• Foetal movements.

Are there any side effects or radiation dangers to the mother or to baby with an Ultrasound Scan?

There are no known dangers or side effects.

How much time is required to complete the Ultrasound Scan?

The exam length varies depending on the region and the disease. Most ultrasound exams are completed within an hour.

How is sex determination possible with an Ultrasound Scan?

It is possible after fourteen weeks when the baby is in position. This enables the lower body to be seen and the gender of the baby can be identified.

Is fasting necessary for Ultrasound Scan?

Yes. You may be asked not to eat before certain ultrasound exams so that the images of the abdomen will be clearer. The gallbladder is also required to be seen as a part of the abdominal exam.

What is a CT Scan?

CT scan is short for Computed Tomography. It is an X–ray based equipment. The ‘CT scan’ is a technique that uses X–rays to take many multiple “Cross–section” images of the body, which are then assembled into a three–dimensional image by a computer. It is a painless non–invasive radiological investigation.

Which diseases/ conditions is a CT scan is used for?

• Headache.
• Head injury.
• Vertigo.
• Epilepsy.
• Paralysis.
• Stroke.
• Unconsciousness.
• Head size is inappropriate for age.
• Psychiatric problems.
• Few lung diseases.
• Pancreatic problems.
• Any fixed swelling over scalp.

What is MRI?

‘MRI’, is a technique that uses a magnetic field and radio waves to take multiple ‘Cross–section’ images of the body, which are then assembled into a three–dimensional image by a computer.

What are advantages of MRI Scan over CT Scan?

• No radiation.
• No bony or air artifact.
• Multi–section imaging.
• High intrinsic contrast.
• Specificity and extension of disease is more accurate.
• Few diseases can be diagnosed early.

Is it safe if pregnant women undergo an MRI?

There is no known reason not to have an MRI during pregnancy. However, doctors generally try to avoid offering this exam if you're in the first twelve weeks of pregnancy. The doctor might speak with one of the MRI radiologists (the doctors who specialize in MRI) to discuss whether this is the best exam to help diagnose your medical symptoms.

What is a Radionucleid Scan?

These are techniques for creating images that show the function of internal organs. Nuclear medicine does this by using a ‘Gamma camera’ to take pictures of small amounts of radioactive materials that have been introduced into the body. The total radiation dose is small.

What is an Angiography?

Vascular / interventional techniques, Angiography allows doctors to see inside the body’s blood vessels by introducing a very thin tube (catheter), injecting a contrast into the tube, and then taking X–rays. This is useful for finding various irregularities or blockages which can affect the heart and other organs.