Your doctor may recommend a magnetic resonance (MR) defecography to determine how well your pelvic muscles are working and provide insight into your rectal function. This non-invasive test provides images at various stages of defecation. In addition, it helps determine the cause of constipation, fecal incontinence, and other medical conditions like pelvic organ prolapse that could hinder your ability to pass stool. For reliable MR defecography services, contact Los Angeles Diagnostics.
If you are to undergo a magnetic resonance defecography, it is essential to ensure that you inform your doctor about your medical health issues, allergies, recent surgeries, and if there is a possibility that you are pregnant. You should also tell your doctor if you have any implants. Even if the magnetic field is not harmful, it could pose a risk; you should inform your doctor about them or any other metal in your body.
Different healthy facilities may give varying guidelines regarding whether you should eat or drink before imaging. You should take all your medications as usual unless your doctor advises you otherwise. On the imaging day, ensure that you wear comfortable clothing and leave your jewelry at home. The hospital may provide you with a gown to wear during the procedure. If you have anxiety or claustrophobia, you may request your doctor to recommend a mild sedative for you.
Understanding Magnetic Resonance Defecography
Magnetic resonance imaging, commonly abbreviated as MRI, is a standard non-invasive imaging test that doctors use to diagnose a wide range of medical conditions. An MRI produces detailed pictures of the internal body structures using a magnetic field, radiofrequency pulses, and a computer. Unlike x-rays, an MRI does not use radiation. The detailed MRI images allow doctors to examine the body and detect illness.
A magnetic resonance (MR) defecography is a particular type of imaging that helps obtain images at different stages of defecation. It provides detailed images during your bowel movement to help your doctor understand your rectum's structure and function. It also helps the doctor understand the structure and the function of the pelvic floor. The pelvic floor refers to the muscles that stretch between your pubic bone and spine and the abdominal organs they support.
The Common Uses of MR Defecography
Your doctor may use an MR defecography to:
- Gather information to help them understand how well your pelvic muscles are working during defecation or bowel movement
- Gather insight into your rectal function
- Determine the underlying cause of fecal incontinence
- Determine the underlying cause of constipation
- Evaluate and diagnose diseases affecting your rectal function
- Determine the underlying pelvic floor dysfunction like pelvic floor prolapse, hernia, or rectal wall slides out of place.
How To Prepare For A Magnetic Resonance Defecography
Before undergoing the test, you may change into a hospital gown. This will help prevent artifacts from appearing on the final images. Wearing a gown also complies with the safety regulations related to strong magnetic fields. Different exams and facilities may have different guidelines on whether you should eat or drink before the procedure. Unless your doctor advises you otherwise, you should take your food and medication as usual.
Some MRI exams may require the imaging technician to inject you with a contrast material to help them get more precise images. Your doctor may ask whether you have asthma or allergies to avoid adversely reacting to the contrast material. The doctor may also ask about your allergic reactions to food, drugs, and certain environments. Most MRI examinations involve using a contrast material known as gadolinium. The doctor may use gadolinium, especially if you are allergic to iodine contrast. Most patients are less likely to be allergic to gadolinium than iodine contrast. Even if you are allergic to gadolinium contrast, the doctor can still use it after subjecting you to the appropriate pre-medication.
You should inform your doctor or the MRI technician if you have undergone recent surgery and any serious health issues. You cannot safely receive gadolinium contrast if you have certain medical conditions like severe kidney disease. You may have to undergo a blood test to determine whether your kidneys function properly.
You should inform your doctor if there is a chance that you are pregnant. Since the 1980s, MRIs have been in use with no ill impacts on pregnant women and babies. However, the unborn baby will be in a strong magnetic field during the imaging. Therefore, you should not undergo an MRI in the first trimester if you are pregnant. You should only undergo an MRI in the first trimester if the benefit of the exam outweighs the potential risks. It is also advisable that pregnant women should not receive gadolinium contrast. A pregnant woman should only receive gadolinium contrast if it is indispensable.
Ask your doctor to prescribe a mild sedative if you have claustrophobia (fear of enclosed spaces) or any other form of anxiety. Ensure that you leave all accessories and jewelry at home or remove them on the day of the MRI. Metallic and electronic items are not allowed into the exam room. These items could interfere with the magnetic fields of the MRI unit. Metallic objects could also cause burns or become harmful projectiles. Some of the things that you should not carry into the MRI room are:
- Removable dental work
- Metal zippers, hairpins, pins, and other similar metallic items that could distort MRI images
- The magnetic fields could damage watches, jewelry, hearing aids, credit cards, all these.
- Pocket knives, pens, and eyeglasses
- Body piercings
- Electronic watches, mobile phones, and tracking devices
Usually, MRI scans are safe for people with metal implants, except in rare cases. People with these implants should not undergo a scan and should avoid entering the MRI scanning area:
- Some ear (cochlear) implants
- Some types of metal coils placed within the blood vessels
- Some types of clips used for brain aneurysms
- Some older cardiac defibrillators and pacemakers
- Vagal nerve stimulators
Inform the technologist if you have any electronic or medical devices in your body. These devices could pose a risk or interfere with the exam. Many implants have an accompanying pamphlet that explains the MRI risks of the device. If you have such a pamphlet, you should present it to your doctor before the MRI exam. Your doctor should only perform the MRI after the confirmation and documentation of the type of implant you have and its MRI compatibility. You should also carry these pamphlets to the exam room if the technologist or the radiologist has some questions.
If you are not sure whether you have metal objects in your body, your doctor may recommend an x-ray to detect any metal objects. Many metal objects used in orthopedic surgery do not pose a risk during an MRI scan. However, if you have a recently placed artificial joint, you may need to undergo a different form of imaging. Inform the radiologist or the technologist about any bullets, shrapnel, and other metal that could be in your body.
Foreign bodies or objects are critical, especially near or lodged in the eyes. These objects may heat up or move during an MRI scan, thus causing blindness. For example, certain dyes used in tattoos that contain iron might heat up during an MRI scan, but this is rare. In addition, the magnetic fields will not affect braces, tooth fillings, eye shadows, or other cosmetics. However, these cosmetics could distort the MRI images, mainly if the MRI is being conducted in the facial area or the brain. Therefore, you should inform the radiologist about these items in advance.
How MRI Equipment Looks Like
The conventional MRI unit consists of a large cylinder-shaped tube. A circular magnet surrounds the tube. The patient lies on a table that slides into the tunnel towards the magnet. In some MRI units known as short-bore systems, the magnet does not surround the patient. Some newer MRI units have a larger diameter bore. These units are more comfortable for patients with claustrophobia or larger patients.
Open MRI units are ideal and provide high-quality images for many MRI exams. However, the open MRI systems may not be suitable for specific exams. You should consult your doctor for more information on the ideal MRI unit. For example, an MR defecography may be performed in an open MRI or a conventional MRI (a large cylinder tube surrounded by a circular magnet). In an open MRI unit, two large magnets surround the patient. The unit also contains a removable chair, which simulates a toilet. This chair is located in the space between the two large magnets.
How The MRI Procedure Works
Unlike computed tomography (CT) exams and x-rays, an MRI exam does not involve radiation. Instead, this test uses radio waves, which re-align hydrogen atoms that naturally exist within the body. This procedure does not cause any chemical changes in the patient’s tissues. As the re-aligned hydrogen atoms return to their usual alignment, they emit different amounts of energy. The energy emitted by the atoms will depend on the tissue they are located in. The MRI scanner captures this energy and produces an image using the information.
Most MRI units produce magnetic fields by passing an electric current through wire coils. The coils are located inside the MRI machine. In some cases, some coils may be placed around the body part being imaged. These coils send radio waves and produce signals detected by the imaging machine. The electric current doesn’t contact the patient during the imaging.
A computer processes the signals and produces a series of images, each showing a small body slice. The radiologist can observe and study these images from different angles. Compared to ultrasound, CT scan, and x-ray, an MRI scan can better tell the difference between normal and diseased tissue.
Performing The MRI Procedure
Usually, doctors perform an MRI procedure on an outpatient basis. The technologist may request you to drink water 30 minutes before the exam. Next, the technologist will fill your rectum with a soft substance with the same consistency as feces. This substance may contain a contrast material. Finally, the technologist may request the patient to place a liquid gel in their vagina for females. These substances play a crucial role in helping obtain more precise and more detailed images.
A towel is placed beneath the patient to hold any feces or urine that might leak during the exam. If the technologist performs the procedure in a conventional MRI unit, they will position the patient on a moveable examination table. The patient will lie on their back with their knees bent. The technician may use straps and bolsters to help the patient maintain the correct position and remain still during the imaging.
If the procedure is being performed in an open MRI, the patient will sit on an adjustable chair within the unit; the chair is located between two large magnets. The technician will place a blanket-like device around the patients’ pelvic area in a traditional MRI. In an open MRI, the technician places this device on the seat beneath the patient. This device contains coils that help create clear MRI images.
The technician will obtain the images at different phases as the patient contracts their pelvis muscles as they would during a bowel movement. These images are crucial and help the technician determine what is happening and why you are having problems passing feces. The technician will also take pictures when your muscles are relaxed. Finally, the technologist gives the patient instructions regarding their expectations during the exam. An MR defecography takes around 30 minutes to one hour to complete.
What To Experience During And After the Procedure
An MRI procedure is painless; you will not experience any discomfort during the imaging. However, some patients may have a hard time staying still. You may also feel claustrophobic or closed in, especially in a traditional MRI unit. In addition, the scanner can be noisy, but in some clinics, you may have access to noise-canceling headphones.
It is normal to feel warm around the area being examined. However, if this warmth feels uncomfortable, ensure that you inform the technologist or the radiologist. The radiologist will take the images in phases of a few seconds to a few minutes. It would help if you stayed still when the images were taken to ensure that you got clear images. You will hear loud thumping and tapping sounds when the images are recorded. This sound results from the activation of the coils that generate radiofrequency pulses. You will have some time to relax in between imaging sequences. The radiologist may request you to stay still and avoid movements as much as possible.
The patient is alone in the MRI room during the imaging. However, the technologist can see, hear, and speak with the patient through an intercom. In addition, some MRI centers may allow a friend or a relative to stay with the patient in the room provided the accompanying person is screened for safety.
MRI units are well lit and air-conditioned to ensure that the patient is comfortable during the imaging. For children, MRI clinics provided appropriately sized headphones or earplugs. In addition, some music could be played through the headphones to keep the patient busy and help them pass the time.
When the contrast material is inserted into your rectum, you may experience mild cramping and bloating. However, immediately after the MRI exam, patients can resume their regular diet and usual activities.
A doctor trained to inspect and interpret MRI results or a radiologist will interpret the results of the MRI exam. The radiologist will then send a signed copy of the MRI report to your primary doctor or the physician who referred you to them.
The Benefits And Risks Of An MRI Scan
Some of the leading benefits of an MR defecography are:
- First, the MR defecography helps examine the pelvic floor abnormalities. These abnormalities may be difficult to examine using a physical exam or other tests like computed tomography, manometry, sigmoidoscopy, and colonoscopy.
- MRI is a non-invasive imaging technique, and unlike x-ray and CT scan, it doesn't expose a patient to radiation
- The MR images of the pelvic organs and muscles are clearer when obtained through an MR defecography than when obtained using other imaging techniques.
- The MR defecography enables the technician to examine the pelvic floor and the rectum structure and how they are working.
- It helps detect abnormalities that might be hard to detect with other imaging techniques, especially if the abnormalities are obscured by bone.
The MRI exam almost poses no risk provided the patient and the radiologist adhere to safety guidelines. Even if the unit produces strong magnetic fields, the magnetic fields are not harmful. However, if the patient has implanted medical devices, the devices may malfunction or interfere with the results of the MRI exam.
Limitations Of The Procedure
The quality of the MRI images will depend on the patient’s ability to stay still and follow the technologist’s instructions during the imaging. If the patient is in pain, confused, or anxious, they may find it challenging to stay still during the imaging.
If a patient is huge, they might not fit in specific MRI units. MRI scanners also have weight limits
Metallic objects and other implants might distort the images, and so can the patient's movements. In addition, if the patient has an irregular heartbeat, it might affect the quality of the pictures because some MRI units time the imaging based on the heart’s electrical activity.
Find An MR Defecography Technologist Near Me
If you need reliable and high-quality MR defecography services, we invite you to contact Los Angeles Diagnostics. We have state-of-the-art MRI equipment and highly trained and experienced MRI technologists. Call us at 323-486-7502 and speak to one of our technologists.
