Radiology Services – CT Scan – Computed Tomography Scan
A large number of X-rays taken from different angles are processed and combined using computer technology to generate cross-sectional or tomography images. This non-invasive diagnostic procedure is known as a CT scan or X-ray CT or CAT scan. Doctors use CT scans to accurately analyse the various internal organs and diagnose diseases, disorders, trauma, and injuries.
Computed Tomography (CT) has revolutionised diagnostic radiology and medical engineering in 1970s. In the medical profession, CT applications are diverse and the last 20 years have seen many rapid developments. The evolution of different types of CT scanners in combination with various applications such as preventive medicine and disease screening has made clinical procedures more innovative and automatic.
In India, CT technology has played an indispensable role in the development of clinical and medical practice. It has become an integral component in radio-diagnosis to detect and treat cancers, lung infections, benign tumours, cardiac diseases, muscle and skeletal deformities, etc., CT technology is very useful in colonography, cardiac studies, radiotherapy planning, cancer detection and staging, guided surgical treatments, etc.,
Why is CT Scan Necessary?
Faster Acquisition At Optimised Dose
CT scans not only apply optimum dose of radiation, but they also ensure faster acquisition of precise and large-size images taken at various angles. Clinicians make use of high-quality scans acquired at a faster pace to diagnose and treat diseases in young and old patients of smaller or larger build.
CT technologies are successfully employed by clinicians across a wide spectrum of procedures such as –
- Cardiac or Heart-related studies.
- Peripheral angiography.
- Brain and neurosurgical procedures.
- Detection of diseases in organs of chest and abdomen.
- Orthopaedic diagnosis for muscle and bone deformities and injuries.
- Oncology department for cancer and tumour detection, etc.
The advanced CT machines provide the clinicians with accurate information for efficient and definitive diagnoses at low-dose of radiation exposure. The patients will also be able to stay calm and comfortable during the scanning procedure. CT technology builds patient’s confidence and increases the trust in the doctor. The technicians and radiologists can take scans of young and old-aged people in a more comfortable manner.
High Image Quality
Tomography comprises of the following two sequences of steps –
- Taking pictures of slices of organ or regions of the body from different angles.
- Processing them using a computer to generate high quality pictures that assist the clinicians in visualization.
Radiologists take 3- D images of high image quality along the X, Y, and Z axes. The Z-axis visualisation is very important and modern CT scanners enables the acquisition of 128 slices per rotation in axial scanning modes. This procedure delivers improved Z-axis visualisation relative to non-overlapped picture reconstruction.
Researchers and clinicians conduct critical studies using the CT technology as it ensures better image clarity and optimised imaging power. Most modern CT scanners are highly efficient in examining the coronaries or blood flow. In addition, they eliminate the use of Doppler studies for diagnosing gangrenes and thrombosis assessment. A large number of diagnostic functions and studies can be combined and performed in an effective manner using CT scanners.
Revolutionary Technology For CT Systems
The modern CT Scanners have the potential to revolutionise CT technology. The following advantages can be gained by radiologists and clinicians –
- Manage heavy patient workflow to improve healthcare efficiency.
- Older patients and young children can be treated in a friendlier manner.
- Patients have fear of radiation, and these technologies guarantee lower doses of radiation. The patient-doctor trust and relationship improves as a result.
- The scanners are environmentally friendly with easily replaceable parts and end-of-life recycling option.
- They help the clinic and healthcare industry save electricity bills, as power consumption can be reduced by 60 percent using the energy saving mode.
- Patient safety is paramount in healthcare and CT scanners ensure image accuracy and low radiation exposure without time delays in treatment.
- What are the dangers of CT scanning?
CT scans make use of X-Ray radiations and patients have fear of allergies and swelling. However, modern CT scanners use only very low radiation and there are no dangers in practical terms. Pregnant women should take precautions and make an informed choice to protect the foetus from radiation exposure. Some CT scans require injection of contrast material which can cause allergic reactions or mild medical problems.
- What is a ‘contrast’ medium?
A contrast is an iodinated compound injected intravenously to make the blood vessels transparent. This enhances the ability of CT scans to pick up abnormalities. We recommend only the safest contrast (non-ionic) material for all the patients at our centre. Patients co-operate and comply better when they know that cheaper ionic contrast has more adverse reactions.
- What are the dangers of contrast medium?
The contrast medium or dye involved in a CT scan can cause allergic reactions of a mild nature. The patient may develop hives, itchiness, and mild rashes. On very rare occasions, the patient undergoing the CT scan may have swelling in the throat or other parts of the body. Asthmatics may become allergic to the contrast medium and have an asthma attack.
- What should the patient do after taking a scan with contrast medium?
The patients are advised to wait for some time after the scan to ensure that they do not have any side effects. The radiologist or technician or support staffs have to be informed of any allergic reaction immediately, so that he or she can apply the antidote for treatment. We keep the necessary antidotes and anti-allergic medicines ready all the time at our centre.
- Who is at ‘high-risk’ for contrast injection?
Contrast injection can be risky for the following patients –
- Those who have a past history of reaction to contrast/any other drugs.
- Patients with bronchial asthma.
- Those who have cardiac or kidney disease.
- Those who have chronic diabetes.
- What other indications make the doctor recommend a CT scan?
Doctors conduct a physical examination and go through the patient’s past medical history. They may recommend CT scan for following cases –
- Diagnosis of muscle and bone disorders, such as bone tumours and fractures.
- Pinpoint the location of a tumour, infection or blood clot.
- To determine the need for guide procedures such as surgery, biopsy and radiation treatment.
- Detect and monitor diseases of heart, lungs, brain, kidneys, liver, etc.,
- Detect cancers, internal injuries and internal bleeding.
- What can a patient expect during the CT scan?
The CT scan is performed using a large device, called the gantry, which is connected to a computer in the next room. You take off your clothes as directed by the technician and lie on a narrow table that slides into the gantry. This table can be raised, lowered or tilted. You may be strapped and asked to rest your head in a special cradle or on a pillow. This helps you stay in position and makes the head stay still for brain scans.
The X-Ray tube rotates around your body as you lie still on the table inside the gantry. You have to hold your breath so that the images do not get blurred. Clicking and whirring noises are generated and each rotation yields several images of different slices or parts of the organ or body from different angles.
The radiologist stays in a shielded room which has a computer connected to the gantry. He or she advises you during this whole procedure via the intercom. The computer is observed to study the pictures sent by the CT scanner.
Infants or small children can undergo the CT scan in the presence of an adult or parent. If you are permitted into the room, then you may have to wear a lead apron to shield yourself from X-ray exposure.
CT scans are painless but you may have to relax for some time after the exam. Exams that use the intravenous contrast medium may make the patient experience a brief heat sensation or metallic taste in the mouth. Sometimes the contrast medium is inserted through the anus using an enema kit. This procedure can make you experience a sense of fullness or cramping for some time.
Post CT Scan Instructions
Normal activities can be started immediately after the exam. The radiologist or doctor may give special instructions if you have been injected with the contrast medium. You will have to drink a large quantity of fluids such as water or juices as they help you urinate and expel the contrast medium from the body.