Balaji Superspeciality Hospital

Ultrasound And Doppler

Ultrasound is a high-frequency sound that you cannot hear but it can be emitted and detected by special machines. It travels freely through fluid and soft tissues and is a safe and painless scan. Our procedures conform to world-class standards and PNDT guidelines.

Understanding the Ultrasound:

An Ultrasound is a Test procedure in which high-frequency sound waves (sonar and radio technology) are used to create ‘pictures’ of the inside of the body. Sonography refers to a medical test that is conducted with the help of an Ultrasound Device. Apart from being safe, an Ultrasound is also a painless and generally affordable process – making it popular with both patients and the medical fraternity. Ultrasound images are engineered in ‘real-time’, and let us see both the structure of our internal organs as well as the function (that is, the movement) of our blood vessels. While it has various kinds of medical uses and health applications, an Ultrasound is perhaps the most popular and preferred Test used to monitor the development of the fetus in pregnant women. An individual doesn’t normally have to go through any special preparation to taken an Ultrasound Test. For smokers who are above the age of 65, an abdominal Ultrasound Test may be a wise course of action even if there are no other overt symptoms of illness or discomfort.

What is the Procedure of an Ultrasound?

An Ultrasound Test is carried out by a doctor or an Ultrasonologist who has been specially trained for the purpose. An Ultrasound Test usually takes between 20 minutes to an hour, and normally doesn’t require any special preparation.

For an Ultrasound of the gall bladder or liver (also called Ultrasound Upper Abdomen or Ultrasound Whole Abdomen), the individual needs to fast or abstain from any kind of eating for several hours before the Ultrasound begins. Some individuals may feel more comfortable in loose-fitting clothes for the duration of the Test.

A bladder that is full of water is able to generate better pictures or images of the uterus and other organs (since air is a bad conductor of ultrasound and makes the scan a failure). Therefore, in the case of an Ultrasound for a woman who is pregnant and individuals for lower abdomen ultrasound, plenty of water must be drunk – and the individual must be careful not to urinate for some time before the Test.

In the case of an External Ultrasound, the Transducer (a wand-like instrument) is placed over the part of the body (for example, the heart or the abdomen) that needs to be studied and has been administered a lubricating gel before-hand for this purpose. This process is usually free of any kind of pain or discomfort.

In the case of an Internal Ultrasound where the ovaries or urinary organs need to be studied in greater detail, the Transducer is inserted into the rectum (the process is called Endorectal Transducer, in the case of males) or the vagina (the process is called Endovaginal Transducer, in the case of females). These studies can be routinely performed in approved outpatient clinics.

A specialized and new approach advocates the use of a Transesophageal Transducer in cases where the esophagus or thorax (chest cavity) is being studied. The Transesophageal Transducer is ‘inserted’ into the body by passing it down the patient’s throat. This is known as TEE (Trans-esophageal Ultrasound) and is generally conducted in specialist settings.

In cases where the digestive system is ‘under the scanner’, so to speak, an endoscope – known as Endoscopy Ultrasound (EUS) – may be employed. There are also some kinds of Transducers – known as Intravascular Ultrasound or Endovascular Ultrasound – that can be placed onto the end of a catheter and inserted into blood vessels. They are used in cases when the walls of blood vessels need to be evaluated. Internal Ultrasounds may involve a slight degree of discomfort or pain, and sometimes cause minor internal bleeding. The patient may be administered appropriate medication to alleviate the pain and this is usually conducted in specialist settings.


Understanding the Science Behind Ultrasound Tests

The term ‘Ultrasound’ literally means sounds belonging to a ‘frequency’ that humans are not able to ‘detect’ or hear. For most diagnostic applications, this frequency range lies between  2 and 18 megahertz (MHz). Higher frequencies can generate better Ultrasound image quality but are susceptible to getting absorbed (and therefore, ‘diminished in power’) by the skin and other soft tissues. Lower frequencies can penetrate deeper past the layers of skin & tissues but produce images of a relatively lower resolution and quality.

During the process, the Ultrasound professional (referred to as the ultrasonolgist) will hold a wand-like device called the Transducer in his or her hand. The transducer is placed on the patient’s body externally. In some cases, insertion may be done via the rectum (for males) and vagina (for females) and the Transducer in such situations is ‘placed internally’.

Be it external or internal, sound waves are emitted by the machine which travels through the skin and tissue till it reaches a surface that is too dense for it to penetrate further. The sound waves are then reflected back (similar to the act of light reflecting off a mirror or, say, an echo of our own voice) – resulting in an image. This image or picture is also sometimes referred to as a Sonogram. Different shades of gray indicate different densities of the reflecting surface inside the body, which can be an organ or an internal structure. Despite being different technically, the terms Ultrasound and sonogram are sometimes used interchangeably.