What is PET CT Scan?
A positron emission tomography scan commonly known as PET scan is an imaging test that
allows the doctor to check for diseases in the body. This type of test may be used in cancer
treatment. It can be done along with a CT (Computed Tomography) scan.
A PET/CT Scan is advanced nuclear medicine imaging technique which detects abnormalities and changes in the body at the cellular and molecular level.
Why is a PET Scan Performed?
A PET scan helps to inspect the blood flow, the oxygen intake, or the metabolism of the organs and tissues. PET scans show problems at the cellular level, thus giving the best view
of complex systemic diseases.
It plays a critical role in oncology, neurology, various cardiac disorders, and detection of hidden bacteria in patients with fever of unknown origin, thus allowing early diagnosis and appropriate treatment.
For some types of cancer, a PET-CT scan is a way to help find cancer and its stage. Stage describes where and how much the cancer has spread. Depending on the stage of the
cancer and how it is affecting the body’s functions, doctors choose the best treatment and also predict the chance of recovery.
Cancer cells have a higher metabolic rate than noncancerous cells. Because of this high level of chemical activity, cancer cells show up as bright spots on PET scans. For this reason, PET scans are useful both for detecting cancer and for seeing if the cancer has spread, if the cancer treatment is working, if there is a cancer recurrence, etc.
How is a PET CT Scan Performed?
The scan uses a special dye containing radioactive tracers.
These tracers are either swallowed, inhaled, or injected into a vein in the arm depending on what part of the body is being examined. Certain organs and tissues then absorb the tracer.The body needs time to absorb the tracers, so one may have to wait for about an hour before the scan begins. How long it takes for your body to fully absorb the tracer will depend on the area of the body being scanned.
When detected by a PET scanner, the tracers help the doctor to see how well the organs and tissues are working.
The tracer will collect in areas of higher chemical activity, which is helpful because certain tissues of the body, and certain diseases, have a higher level of chemical activity. These areas of disease will show up as bright spots on the PET scan.
Preparation before PET scan
Benefits of PET/CT Scan
What is an MRI (Magnetic Resonance Imaging) Scan?
MRI is widely used in hospitals and clinics for medical diagnosis, staging and treatment monitoring without exposing the body to radiation.
An MRI scan uses a large magnet, radio waves, and a computer to create a detailed, cross-sectional image of internal organs and structures. It is a non-invasive and painless procedure.
The MRI scanner typically resembles a large tube with a table in the middle, allowing the patient to slide in.
MRI scans vary from 20 to 60 minutes, depending on what part of the body is being analyzed and how many images are required.
What is MRI used for?
MRI scanners are particularly well suited to image the non-bony parts or soft tissues of the body. The brain, spinal cord, and nerves, as well as muscles, ligaments, and tendons, are seen much more clearly with MRI rather than with regular x-rays and CT.
An MRI scan can be used as an extremely accurate method of disease detection throughout the body and is most often used after other testing fails to provide sufficient information to confirm a patient’s diagnosis.
Neurosurgeons use an MRI scan not only in defining brain anatomy but also in evaluating the integrity of the spinal cord after trauma. It is also used when considering problems associated with the vertebrae or intervertebral discs of the spine. An MRI scan can evaluate the structure of the heart and aorta, where it can detect aneurysms or tears. MRI scans are not the first line of imaging test for these issues or in cases of trauma.
It provides valuable information on glands and organs within the abdomen, and accurate information about the structure of the joints, soft tissues, and bones of the body. Often, surgery can be deferred or more accurately directed after knowing the results of an MRI scan.
Functional Magnetic Resonance Imaging (fMRI)
One kind of specialized MRI is functional Magnetic Resonance Imaging (fMRI) which uses MRI technology to measure cognitive activity by monitoring blood flow to certain areas of the brain.
The blood flow increases in areas where neurons are active. This technique has revolutionized brain mapping by allowing researchers to assess the brain and spinal cord without the need for invasive procedures or drug injections. This is used to observe brain structures and determine which areas of the brain “activate” (consume more oxygen) during various cognitive tasks. It is used to advance the understanding of brain organization and offers a potential new standard for assessing the neurological status and neurosurgical risk. A functional MRI scan can help detect anomalies inactivity.
As such, doctors use fMRI to assess the risks of brain surgery by identifying the regions of the brain involved in critical functions, such as speaking, movement, sensing, or planning.
Functional MRI can also be used to determine the effects of tumors, stroke, head and brain injuries, or neurodegenerative diseases, such as Alzheimer’s.
In short, fMRI tests what tissues do rather than how they look.
What is Genetic Testing?
Genetic testing involves examining your DNA, the chemical database that carries instructions for your body's functions. It looks for changes, sometimes called mutations or variants, in your DNA. Genetic testing can reveal changes (mutations) in your genes that may cause illness or disease.
Although genetic testing can provide important information for diagnosing, treating and preventing illness, there are limitations.
BRCA Gene Test
The BRCA gene test is a blood test that uses DNA analysis to identify harmful changes (mutations) in either one of the two breast cancer susceptibility genes — BRCA1 (BReastCAncer gene 1) and BRCA2 (BReastCAncer gene 2).
BRCA1 and BRCA2 are tumor suppressor genes. Normally, these genes help prevent cancer by producing proteins that suppress abnormal cell growth. Certain changes (mutations, pathogenic genetic variants) in these genes affect their normal function, thereby potentially allowing cells to grow unchecked. BRCA1 and BRCA2 gene tests detect mutations in these genes that are linked mainly with hereditary breast and ovarian cancers.
A harmful variant in BRCA1 or BRCA2 can be inherited from either parent. Each child of a parent who carries any mutation in one of these genes has a 50% chance of inheriting the mutation. People who inherit harmful variants in one of these genes have increased risks of several cancers—most notably breast and ovarian cancer and also tend to develop cancer at younger ages.
The BRCA gene test is offered to those who are likely to have an inherited mutation based on personal or family history of breast cancer or ovarian cancer.
How is Genetic Testing performed?
Genetic testing involves analyzing an individual’s blood, skin, hair, or other body tissues to look at his orher DNA, chromosomes, or proteins for a change, or mutation, that is associated with a genetic condition. When a mutation occurs, it may affect all or part of a gene and can result in an abnormal function leading to disease.
Three major types of genetic testing are available in laboratories: cytogenetic (to examine whole chromosomes), biochemical (to measure protein produced by genes), and molecular (to look for small DNA mutations).