GI Radiology
Answers to questions, I was afraid to ask
What is Ultrasound
Ultrasound imaging is a medical diagnostic technique where sound waves are being used to image various parts of the body. Other terms for ultrasound imaging are sonograms, US and sonography.Ultrasound is widely used these days as it is painless and safe for adults, children and foetuses. There are no side effects such as the ones associated with radiation.
During the ultrasound scan, the sonographer rests a small probe over the skin. This probe produces sound waves i.e pulsations that travel through the tissues. Some of the sound waves are being reflected back to the transducer and the computer analyses the returning echoes and produces the image on the screen.
What is best seen on Ultrasound?
Ultrasound is being used to image mostly solid organs such as liver, kidneys, uterus and ovaries, muscles and blood vessels and babies in the womb.
It has, however, limited value in organs such as lungs, bone, stomach and bowel/colon.
Ultrasound images are black and white but the colour Doppler is being used to evaluate organ and blood vessel blood flow and this is what the red and blue colours on the screen are.
What should I expect during an ultrasound?
Before the abdominal ultrasound scan, the sonographer will explain the examination procedure. You will be asked to lie on the examination couch exposed part of your abdomen.
Clothes: wear clothes so that you could easily expose the whole abdomen including the lower abdomen, without needing to undress fully. Often, the sinologist may need to see the lower chest; so tight upper garments could become awkward.
The gel: We will put a little bit of ultrasonic gel on your skin and a small ultrasound probe will be used to obtain images of your internal organs. This gel does not leave a stain on your clothes. It is easily wiped away with a tissue.
How much fasting is needed for an ultrasound?
The gall bladder: The main reason for fasting for the abdominal scan preparation is to give time for the gallbladder to fill up with bile and expand so it is visible during the ultrasound scan examination. The gallbladder is like a balloon and stores the bile. When you eat something fatty the gallbladder excretes the bile into the bowel to break down the fat so it collapses and therefore is difficult to be visualized on ultrasound. Thus, you need to fast for 4 to 6 hours before an ultrasound exam to allow your gall bladder to fill sufficiently. Longer fasting times are cruel and unnecessary.
Which liquids to drink?: On the other hand, you may drink as much water as you like before an ultrasound exam. (No ultrasound exam will be cancelled because you drank water prior to the test). So, if you are a diabetic, feel free to have a sugary drink if you need it. If you wish to have coffee, have it black (milk residue in the stomach may give echoes). Any fizzy drink will create bubbles in the stomach and intestine and affect the quality of the examination.
Liver: A liver ultrasound does not need to be done fasting. However, if the blood supply of the liver is to be assessed (portal Doppler) food may hamper the quality.
A liver fibroscan will need you to be fasting as fat reaching the liver will change the reflectivity and may give a false high reading.
Pelvis and lower abdomen: Examination of the pelvis, and scans for the urinary system need you to have a full bladder, thus you should drink about a litre of liquids/water to make urine. Schedule your appointment early on a hot day, as sweating could make you lose much of the water you drink.
For the transabdominal pelvic scan (gynec & early pregnancy), you are required to have your bladder full. The reason for this is that as your bladder is anterior to your uterus and ovaries are being used as an acoustic window (a window to see through). When your bladder is full will push out of the way the bowel that can obscure your uterus and ovaries. For a transvaginal ultrasound, the sonographer will ask you to empty the bladder. A special lubricated probe will be inserted into the vagina and will be moved to different directions to obtain the best images. The scan could also be done during menstrual bleeding, but the preference is pure of the patient if she chooses not to.
The Abdominal Scan
Abdominal ultrasound scans are the most common ultrasound examinations as there are many organs within the abdominal viscera. The main organs visualized with ultrasound in the upper abdomen are the liver, the gallbladder, the pancreas, the kidneys and the spleen. Upper abdominal or RUQ pain could be related to these organs and sometimes the stomach.
The liver is the second largest organ in the body. The role of the liver is to process nutrients absorbed by the bowel, fight infections, remove toxins from the body such as alcohol, control cholesterol and release bile to name a few. The gallbladder which is a pear shape sack that stores the bile produced from the liver and releases it via the biliary tract when we need to break down the fat. Stones within the gallbladder called gallstones can cause pain and indigestion.
The pancreas is responsible for producing insulin and regulate the blood sugar in the bloodstream.
The kidneys are responsible for filtering the toxins from the blood and also regulate the blood pressure. Kidney stones are very common and can cause pain and sometimes obstruction that can be manifested by blood in the urine.
The spleen is part of the immune system and clears the blood of proliferating blood cells.
The main reason for abdominal scans is abdominal pain or RUQ pain that sometimes can be associated with food and in most cases is related to gallstones.
The Pelvic Ultrasound Scan
Gynaecological problems such as heavy bleeding, painful periods or sex and generalized pelvic pain are very common and affect all age groups. Pelvic ultrasound scans are regularly deployed to identify any causes of these symptoms such as uterine polyps, fibroids, ovarian cysts. Thus, this scan sees your uterus, endometrium and ovaries, with the related organs.
There are two kinds of pelvic ultrasound scans the transabdominal or supra-pubic (through the bladder) and the transvaginal. (through the vagina).
There is a bit of conflict of opinions as to which scan is the best. Both ultrasound approaches are used to image the uterus and the ovaries for any abnormality. They both give useful information that can be combined for the best diagnostic outcome. Sometimes the transabdominal image quality is so good that there is absolutely no need to invade your privacy. However, both tests are complementary to each other to build a diagnosis.
The pelvic ultrasound scan may be performed in the investigation of a number of problems including:
- gynaecological symptoms such as pelvic pain, irregular, frequent or absent periods or other menstrual problems
- to investigate the existence of endometrial polyps, fibroids or ovarian cysts
- as a follow-up scan to monitor known conditions such as fibroids, ovarian cysts or polycystic ovary syndrome (PCOS)
- to assess for any abnormality that might be affecting your fertility
- Ovarian screening
The Urinary Tract Ultrasound Scan
Urinary tract or waterworks problems are very common affecting both sexes. Kidney stones can cause immense pain and blood in the urine. Kidney stones can cause pain and also stop the kidneys from draining in the bladder by blocking the ureters resulting in what is called hydronephrosis. If renal hydronephrosis is left untreated, it can result in scarring and other significant problems with your kidneys. Bladder problems are also very common. In men, bladder problems can be associated with an enlarged prostate. In women can be amongst other causes, a result of uterine fibroids that press on the bladder.
How it works
A CT machine sends X-ray beams through the body, taking many 2D pictures from various angles, which a computer later joins together to form a 3D image.
What is Radiation?
Ionizing Radiation is the emission of high-energy electromagnetic waves that move subatomic particles. This type of radiation carries enough direct energy that it causes electrons to detach from atoms or molecules, which is called ionization.
In medical imaging, X-ray technology emits these high-energy waves (similar to light) that pass through the body and generate images of structures within the body. These waves are absorbed in different amounts by different structures of the body. The denser an object in the body is, the more the waves will be absorbed. For instance, x-rays pass easily through soft tissue and organs, but are absorbed by highly dense structures like bones. Because the bones have absorbed most of the waves, they show up as white “shadows” on the radiograph.
Medical imaging exams that use radiation include traditional x-rays, CT, nuclear imaging exams, or fluoroscopy. However, there are other types of imaging exams that use technology that does not emit radiation. MRI and Ultrasound scans do not use radiation at all, and therefore do not pose any increased risk of cancer.
What are the Risks?
Exposure to too much radiation over time could be bad for you, but sometimes small doses are necessary for your well-being. The main risk associated with radiation is its ability for ionization. If exposed to a large amount of radiation in a short period of time, ionization can damage your DNA, which can lead to cancer. However, this has been observed only in survivors of atomic bombings, nuclear accidents, and early x-rays where a large amount of radiation was absorbed in a small period of time.
The dose of radiation you receive in an imaging exam is very low. At this time, there are no published studies that prove medical imaging is a direct cause of increased cancer risk. More often than not, the risk of not having an exam that is important for diagnosing your health issue is greater than the risk of a small exposure to radiation.
Images from exams that use radiation, such as X-ray, CT, nuclear imaging exams, or fluoroscopy, help your radiologist see what is happening inside of you. This helps them make an accurate diagnosis and recommend the next steps in your care. An accurate diagnosis is crucial to the quality of your health care and your well-being for many reasons—the most obvious being that it informs doctor’s decisions in order to properly treat your condition. Good medical images can save lives.
Since the right images are so important to your care, the vast benefits of necessary radiation far outweigh any slight risks. Almost always, when your doctor suggests you have a medical imaging exam that uses radiation, that radiation is necessary. You can always ask your doctor if the test is truly vital for the quality of your care, or check out this lifetime x-ray risk calculator here.
Machine shape
CT: Doughnut-shaped machine with a hole in the middle, open on both sides.
Strength indicators
In CT machines, the greater the number of ‘slices’, the sharper the quality of the scan. For example, a 128 slice CT machine produces very clear images as compared to a lower slice CT scanner.
Purpose
A CT scan is used when speed is important: for example, in the case of trauma and stroke. A CT scans enable imaging of bone, soft tissue and blood vessels at the same time, but they are not as detailed as an MRI – for example, a CT scan can pinpoint size and location of tumors but does not show differences between normal and abnormal tissue.
Claustrophobia (fear in closed spaces) : In a CT scan, claustrophobia is not an issue since the scanner is open on both sides.
Magnets and radiation
Though a CT scan uses X-rays, its radiation dose is small enough to be negligible. However, CT scans may not be recommended for pregnant women or very small children.
Time taken : Average Duration: 5-15 minutes
Caution to be taken
People with metal implants like pacemakers, cardioverter defibrillators, etc. can undergo a CT scan. However wearing other metal items should still be avoided, since they will interfere with the scan quality.
Fasting requirements
If patient is getting a CT scan with contrast, he/she will be required to fast for 3 hours prior to the scan
Contrast dye
CT scans can also be done with contrast. There are 2 contrats that could be advised to the patient, oral contrast as well as IV contrast. Then, typically an iodine-based IV contrast; or barium-sulfate-based agent is administered orally.
Why do I need a contrast dye, and what should I know?
A contrast agent helps highlight some internal structures of your body, allowing your doctor/radiologist to provide a more accurate diagnosis. It’s like holding a spotlight over certain problem areas in the body. If you’re getting a scan with contrast dye, you will be asked to fast for 3 hours prior to the procedure. The dye will be administered 45 minutes before the scan, either as a liquid that you need to consume, or as a liquid that is injected into your veins. Many patients worry about side effects from the contrast agent – however, complications are rare and can be taken care of easily. Some patients may experience loose bowel movements for 24 hours post the scan, but this will pass soon.
To keep in mind: Notify your doctor if you’re sensitive or allergic to certain medications, if you’re taking any medication for diabetes, if you’re suffering from kidney problems, or if you’ve faced issues with contrast dye in the past.
A contrast agent helps highlight some internal structures of your body, allowing your doctor/radiologist to provide a more accurate diagnosis. It’s like holding a spotlight over certain problem areas in the body. If you’re getting a scan with contrast dye, you will be asked to fast for 3 hours prior to the procedure. The dye will be administered 45 minutes before the scan, either as a liquid that you need to consume, or as a liquid that is injected into your veins. Many patients worry about side effects from the contrast agent – however, complications are rare and can be taken care of easily. Some patients may experience loose bowel movements for 24 hours post the scan, but this will pass soon. To keep in mind: Notify your doctor if you’re sensitive or allergic to certain medications, if you’re taking any medication for diabetes, if you’re suffering from kidney problems, or if you’ve faced issues with contrast dye in the past.
If you’re getting a CT scan with contrast, most imaging centers, ask for a serum creatinine report, which measures the amount of creatinine in your blood to check how well your kidneys are filtering toxins. This report is crucial because the contrast material may not suit people with impaired kidney function, since the kidneys may not filter the contrast out of the body.
Can you get a CT scan if I have a pacemaker?
Yes, you can! Unlike an MRI machine which has a powerful magnet that can be dangerous for people with medical implants, patients with pacemakers, cardioverter defibrillators, etc. can safely undergo a CT scan. However, wearing other metal items, like jewellery, should still be avoided. While these items may not prove fatal for a CT scan, they will interfere with the overall scan quality and results.
What about the radiation from the CT scan?
Many people worry about the radiation from a CT scan, since it uses powerful X-rays. However, the radiation dose from one CT scan is negligible, and further, newer machines minimize radiation dosages, while trained radiologists adjust the dosage for each patient, according to their specific case and age. Moreover, CT scans are only recommended in cases where the benefits greatly outweigh any potential threat, for example, to diagnose and treat life-threatening disorders.
Preparing for the Day of Your Abdominal CT Scan
Women need to know that they should not breastfeed for up to 48 hours after receiving contrast.
Be sure to tell your doctor if you are pregnant, diabetic or have previously had an allergic reaction to drinking oral contrast (barium) or other dyes.
Fast as directed by your doctor. For most abdominal CT scans, you will be instructed not to fast four hours prior to the imaging test.
Talk to your doctor regarding medications before the scan. Your doctor may ask you to take some morning medication, but he may tell you to avoid certain medications prior to your exam to get the most accurate results during the scan.
Remove jewelry. Leave jewelry at home. Before your scan, you may also be asked to remove eyeglasses, hairpins, hearing aids, undergarments with a metal underwire and piercings.
Take oral contrast or IV contrast. For some CT scans, you will be asked to drink a special liquid called an oral contrast between 60–90 minutes before your test. This liquid contains barium sulfate and will help your doctor get a better picture of your abdomen. Alternatively, you may receive contrast dye through an IV. Talk to your doctor about your health conditions. It is important that your doctor knows about any health conditions that could make an abdominal CT scan problematic.
Wear loose, comfortable clothing. Choose casual, comfortable clothing for your appointment. You will be lying down on a table, so you may be asked to change into a hospital gown for the procedure.
During Your Abdominal CT Scan
During the procedure, you will be asked to lie down on a table in a specific position. It’s important to lie still and stay in the same position long enough for the technician to get a good image. Pillows or straps may be used to help keep you in position.
The table will then be moved into the CT machine, which has a large doughnut-shaped opening. The machine will use x-ray beams and electronic x-ray detectors to take several cross-sectional images of your abdomen. You may be asked to hold your breath during the scan to prevent blurred images. The scan won’t take long—usually 30 minutes or less. The technician will review the images to ensure they are clear enough to provide your doctor with the information needed
MR & MRI
MRCP(click here)
MR Enterography (click here)
MR Defecography(click here)
How Magnetic Resonance (MR) works
An MRI uses a powerful magnet and uses radio waves to produce images of the internal parts of your body.
How is the MR Machine shaped?
It is shaped like a doughnut, with a hole in the middle, mostly closed on the other end. (Please know that “Closed MRIs”s is more powerful than an ‘Open MRI’.)
Is my MR the best?
Check the magnet strength at the place where you will have your MRI examination, it is denoted by ‘T’ for Tesla. Today, a 1.5 – 3T MRI (closed MRI) is the most widely accepted MRI scanner that produces images of maximum clarity.
What will be the time taken: Average Duration: 7-20 minutes, unless sedation is needed.
Will I be exposed to radiation: An MRI has no ionizing radiation since it works on magnetic fields and radio waves!
Do I have an alternative? Can I have an MRI/ultrasound scan instead of a CT scan? What’s the difference?
An MRI scan, an ultrasound, and a CT scan have very different purposes, and help doctors get a clearer picture of different parts of the body, in different ways. For example, parts of the body that contain calcium (like bones), or air (like lungs), may not be clearly visible on an MRI or ultrasound scan, which is when a CT scan is recommended.
Further, in emergency cases, such as when a patient has suffered an injury to the head, a CT scan is preferable, since it is quicker than an MRI scan. In trauma cases, patients may not be in a position to be sedated, and may move during the scan. MRI scans are highly sensitive to movement, resulting in ‘motion artifacts’ in the scan, which can affect the diagnosis. On the other hand, CT scans are relatively less susceptible to motion artifacts.
Your doctor and radiologist will suggest the best scan option for you, based on your specific case. However, never hesitate to ask your doctor for options.
Claustrophobia (A fear of closed spaces): Since the MRI scanner is closed on one end; many patients suffer from claustrophobia during the scan. However, newer 3T MRI scanners with ambient experience reduce the incidence of claustrophobia by allowing patients to see movies during the scan and creating an illusion of more space and light.
What else could help?
Familiarization
Sometimes, anxiety stems from the unfamiliarity of the situation. To tackle this, try taking part in a rehearsal of sorts, where you will be comfortable with the process of getting into and out of the machine. Ask the medical staff to help you get familiarized with the machine, which will make it seem like less of a threat. You will need to follow all Covid protocols while you enter the premises, thus; respect the instructions you are told to follow.
Company
Being in the company of friends or loved ones can greatly help reduce symptoms of claustrophobia. Having a loved one standing next to the patient and talking to them, it helps distract and calm the patient to a great extent. However, do remember that the companion will have to follow appropriate safety and Covid protocols too, such as removing all metallic items on their person and changing into a hospital gown.
Feet First
Positioning the patient is an important factor in halting the trigger of any claustrophobic attacks. Some scans do not require the head to enter the scanner, depending on the part of the body being scanned; and you could consult the radiologist on this matter. If the doctor agrees, then you could undergo the procedure without having your head enter the scanner, thereby minimizing your anxiety.
Cancelling Out Noise
Sometimes, the noises the machines make and the overall atmosphere at the diagnostic centre, with the machines beeping and the nurses and doctors going about their duties, can cause anxiety and claustrophobia to kick in. To reduce the ambient noise, we recommend you wear the ear plugs provided. Mentally distancing yourself from the noises can also help – to do this, focus on taking in deep, long breaths, or; thinking what you will be doing after the MR. You can also distract yourself by thinking about something that requires concentration – like the names of the last few movies or serials you saw.
Sedation
If the above methods do not work and you still find the experience unbearably claustrophobic, you could explore sedation options with your doctor. Patients whose claustrophobia and anxiety threaten to culminate into panic attacks could be given short-acting sedatives. However, the timing of the sedative administration is crucial and patients must also be given sufficient time for recovery. While sedation may be necessary in certain cases, especially for small children, please note that this is not always the solution and caution is to be exercised with this method. Sedated patients need to be closely monitored before, during and after the MRI process.
Buit, I have a child having an MRI!;
It is always better to prep them in advance, ideally a few days before the procedure. Pleae explain what is going to happen – in simple terms; honesty is the best policy here be open and transparent about the procedure – but explain it in a way that your child can grasp the concept.
To explain what an MRI scanner is, you can liken it to a big camera that takes a picture of the insides of their body, using a powerful magnet (like the one on the fridge, but much bigger) and radio waves (like the sounds coming out of the radio).
Show them a picture of the machine and explain that they’ll have to lie very still inside, just like when their picture is taken with the camera, so that the machine can take a good picture.
Remember to reassure them on the pain-free aspect – an MRI scan doesn’t hurt at all, but there may be some loud sounds and whirring noises. However, the nurse will give them headphones or earplugs which should muffle the sound.
Answer questions as accurately as possible: Your child may be wondering how long the procedure will take or may ask how they will feel after the test. One way to reassure them is to call the doctor together and have all the doubts cleared. Depending on whether or not a sedative is administered, and whether the scan requires fasting, you can say that they will feel totally normal or that they may feel sleepy or hungry.
OK, I’m ready, what is the caution to be taken:
Since the MRI has a powerful magnet, NO METALLIC OBJECTS should be taken inside the MRI room. Also, never enter the MRI room without a staff member accompanying you – remember, the MRI magnet is always ON, it is never switched off.
Fasting requirements: No fasting required, even for scans with contrast
Contrast dye: If you’re advised to get a scan with contrast, a dye will be injected into your body. This dye helps highlight the internal structures of your body better, making a more accurate diagnosis possible. The dye is generally a gadolinium dye and is injected through an intravenous canulla inserted in the vein in your hand.
Why should I have a contrast dye, and what should I know?
A contrast agent helps highlight some internal structures of your body, allowing your doctor/radiologist to provide a more accurate diagnosis. It’s like holding a spotlight over certain problem areas in the body. If you’re getting a scan with contrast dye, you will be asked to fast for 3 hours prior to the procedure. The dye will be administered 45 minutes before the scan, either as a liquid that you need to consume, or as a liquid that is injected into your veins. Many patients worry about side effects from the contrast agent – however, complications are rare and can be taken care of easily. Some patients needing to take oral contrast may experience loose bowel movements for 24 hours post the scan, but this will stop once the contrast have passed away.
To keep in mind: Notify your doctor if you’re sensitive or allergic to certain medications, if you’re taking any medication for diabetes, if you’re suffering from kidney problems, or if you’ve faced issues with contrast dye in the past.
Metal implants or fragments
Having something metallic in your body doesn’t necessarily mean you can’t have an MRI scan, but it’s important for medical staff carrying out the scan to be aware of it. They can decide on a case-by-case basis if there are any risks, or if further measures need to be taken to ensure the scan is as safe as possible. For example, it may be possible to make a pacemaker or defibrillator MRI-safe, or to monitor your heart rhythm during the procedure.
You may need to have an X-ray if you’re unsure about any metal fragments in your body.
Examples of metal implants or fragments include:
a pacemaker– a small electrical device used to control an irregular heartbeat
an implantable cardioverter-defibrillator (ICD)– a similar device to a pacemaker that uses electrical shocks to regulate heartbeats
metal plates, wires, screws or rods– used during surgery for bone fractures
a nerve stimulator– an electrical implant used to treat long-term nerve pain
a cochlear implant– a device similar to a hearing aid that’s surgically implanted inside the ear
a drug pump implant– used to treat long-term pain by delivering painkilling medication directly to an area of the body, such as the lower back
brain aneurysm clips– small metal clips used to seal blood vessels in the brain that would otherwise be at risk of rupturing (bursting)
metallic fragmentsin or near your eyes or blood vessels (common in people who do welding or metalwork for a living)
prosthetic (artificial) metal heart valves
penile implants– used to treat erectile dysfunction (impotence)
eye implants– such as small metal clips used to hold the retina in place
anintrauterine device (IUD) – a contraceptive device made of plastic and copper that fits inside the womb
artificial joints– such as those used for a hip replacement or knee replacement
dental fillings and bridges
tubal ligation clips– used in female sterilisation
surgical clips or staples– used to close wounds after an operation
Tattoos
Some tattoo ink contains traces of metal, but most tattoos are safe in an MRI scanner. Tell the radiographer immediately if you feel any discomfort or heat in your tattoo during the scan.
What is a PET-CT scan?
A positron emission tomography and computed tomography (PET-CT) scan is an imaging test used to learn more about cancer’s stage and where it has spread to. It is also used to:
Find the right place to do a biopsy
Find out how well treatment is working or has worked
Plan radiation therapy
Sometimes, your doctor may refer to a PET-CT scan as a PET scan or PET imaging.
A PET-CT scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Any tissue that uses energy actively will absorb more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body. A PET-CT scan is done by a nuclear medicine technologist or radiologic technologist, and a nuclear medicine physician or a radiologist, will read the scan and decide what it means. You will need to go to the nuclear medicine department or to an outpatient imaging centre to have a PET-CT scan.
Preparing for your PET-CT scan
When you are scheduling your PET-CT scan, remember to seek answers to the following questions:
Your current medications. Bring a list of all the medications you take, including any vitamins or supplements. Ask if you should keep taking them before the scan.
Any allergies or other medical conditions you may have.
If you have diabetes. You may need special preparation if you have diabetes. Better, to let the Nuclear medicine doctor decide with your doctor.
If you are breastfeeding or may be pregnant.
If you are claustrophobic and don’t like to be in small spaces.
The night before the scan: You will need to take specific steps, or preparations, before the scan. These may be different, depending on the specific scan you receive, but preparations often include:
Avoid exercising 24 hours before the scan.
Follow a special diet (low carbs – no rice, potatoes, etc) for 12 to 24 hours before the scan. We want your cells to take up the glucose when given, so, let’s starve them for some time!
Don’t drink or eat anything, except water, for 6 hours before the scan.
Before the PET-CT scan
Wear comfortable clothing for the scan. You may also need to change from your regular clothing into a hospital gown. Leave valuables at home, such as jewellery or a watch, so they don’t get misplaced. You may need to remove anything that contains metal, such as eyeglasses, dentures, or hearing aids, during the test.
An intravenous (IV) line will be placed into a vein.
16-FDG: You will then receive an injection of a radioactive substance, called a radiotracer or tracer (16 fluoros deoxyglucose – 16 FDG). It enters your body through the IV line. It takes 30 to 90 minutes for the substance to travel all over the body. During that time, you’ll need to remain still and stay relaxed.
Other Contrasts: You may also receive a special dye called a contrast medium before the scan. A contrast medium can make the images from a PET-CT scan easier to interpret. You might drink the contrast medium, or the technologist or a nurse may put it in your IV.
When the substance has travelled all over your body, it will be time to start the scan. Most people are asked to lie on their back on the exam table. But your position depends on where in the body the doctor wants to scan.
Some people feel more relaxed when they listen to music. If this applies to you, ask if you can listen to music during the scan. That way, you can prepare your music and device in advance.
You may need to sign a form that says you understand the risks and benefits of a PET-CT scan. It also says you agree to have the test. This is called a consent form. If you have concerns, talk with your doctor before you sign.
During the PET-CT scan
A scanning device is a large machine with a donut-shaped hole in the middle. When the exam starts, the table slides quickly through the hole. This first pass shows the technologist if you’re in the right body position to get the needed images. Then, the table slides slowly back and forth. You will need to stay still. Sometimes, the technologist may ask you to hold your breath. This prevents blurry pictures from the movement of your body breathing. The technologist might raise, lower, or tilt the table during the scan. This helps get pictures from different angles.
How much time?: The scan can take from 30 minutes to 1 hour. During the exam, you’ll be able to talk with the technologist, who will be in a nearby room monitoring your test through a window.
After a PET-CT scan
After the PET-CT scan, you can return to your usual diet and activities. This includes driving. Drink lots of water. It helps wash any leftover radioactive substance and dye out of your body.
The scan results will be interpreted by the nuclear medicine physician and/or a radiologist, and that report will be sent to your doctor.
Measuring Liver Stiffness
Measuring Liver Stiffness
Any organ when injured could heal and look like before. If the organ sustains repeated insult of injury, the healed may not be a perfect replica of before; it will heal with a scar. If the injury continues over months, there will be many scars, leading to stiffness in the organ.
Repeated injury to the liver will lead to deterioration of function; more the injury, the risk of losing function will be greater, evolving to liver cirrhosis.
The ‘gold standard” method of assessing stiffness is by a liver biopsy, in which a needle sample of the liver is taken under local anesthesia. It may need a “day-care” stay, and is an invasive procedure. Thus, patients may not be willing, and surely not in case it is advised repeatedly every year.
Technology exists where non invasive ultrasound can be used to examine the liver painlessly, and estimate the stiffness. This entails going for the test about 5 hours fasting, having an ultrasound examination, and receiving the report. We could do the test every 6 months to track the progress too.
In case any person in your family was told “his liver is already damaged beyond repair”, and no known cause of liver cirrhosis was found (like viral hepatitis or alcohol consumption), the cause could be his lifestyle. You may do well to meet a liver doctor and see in case you are at similar risk, and get advice before it is too late.
Risk of the Scan advised to me
How to assess the risk of the Radiologic procedure advised to me?