CT Scan vs MRI: MRI or CT scan of the abdomen: what to choose?
CT Scan vs MRI: In the article, we analyze in detail under which diseases magnetic resonance imaging is necessary, and under which computed tomography. We talk about contraindications for the procedures and the necessary preparation.
Magnetic resonance imaging and computed tomography are extremely informative methods for studying the body. The procedures have many similarities and differences. If you need to undergo an abdominal examination, what to choose – MRI or CT?
CT Scan vs MRI: What are MRI and CT Scan?
Both methods are a layered study of the body. This is what the term “tomography” (from other – “section”) reflects in the title.
Despite the general principle, the physical methods of obtaining images are different, so some organs and systems inside the body are better visible when performing x-ray computed tomography, others – when using magnetic resonance imaging. (CT Scan vs MRI)
To assess the blood supply to organs or pathological foci of the disease in both procedures, intravenous contrast enhancement can be used. To do this, a catheter is inserted into the ulnar vein and a special contrasting “coloring” substance is introduced during “photography”.
Computed tomography has established itself as a procedure that quickly gives results of very high accuracy, especially with contrast enhancement of the study. The resulting images reflect bone structures, lymph nodes, blood vessels, and the formation of various organs of the study area. CT scan does not require special preparation and preliminary examinations.
With computed tomography, the method is based on x-rays. MRI is a non-beam research method. With magnetic resonance imaging, a person is exposed to a strong magnetic field, and the image is based on the effect of magnetic resonance from atoms of hydrogen protons. (CT Scan vs MRI)
Since both methods create layered images with which you can create a 3D model of the studied area. The resulting models can be printed on film or transferred to media in the desired projection and scale.
Similarities and differences in procedures
Three similarities of MRI and CT
There are few similarities in the two types of tomography, and they relate to the organization of research:
- Both procedures are performed in externally similar tomographic apparatuses, while the patient lies on a special movable table;
- During the study, the laboratory technician observes the progress of the diagnostic process. If a person feels bad, he can at any time give a signal to the laboratory assistant and stop the procedure. When conducting an MRI, the patient is given a special pear to give a signal. (CT Scan vs MRI)
- Both types of tomography are often performed with a contrast medium for a clearer understanding of the nature of the identified pathology (benign or malignant). The result of the procedures is the same – a set of layered images of the examination area on a digital medium and a printed version of the doctor’s opinion. These results are also available in your personal account, a specially protected area in the Internet space. This is convenient if you need to send the results of the study to a clinic in another city or country for consultation with your doctor. (CT Scan vs MRI)
5 differences between MRI and CT
The differences in the procedures are greater than the similarities. There are both in conducting and in contraindications:
- The time of the study. Computed tomography is performed on average in 3-5 minutes (with contrast amplification up to 15-20). While magnetic resonance imaging of the abdominal cavity can be performed up to 40 minutes without contrast and up to 60 minutes with it. (CT Scan vs MRI)
- One of the limitations of MRI follows from the duration of the study: it is difficult to tolerate for people with claustrophobia, young children, people with mental illness, or acute pain when it is difficult for a person to be in a sedentary state. After all, everything happens here as with ordinary photography: if the subject moves, then the pictures are blurry.In such a situation, it is better to perform a CT scan, discuss with your doctor preliminary anesthesia, or the selection of an alternative diagnostic method. (CT Scan vs MRI)
- Sounds during the study. The MRI procedure is quite loud, and the laboratory technician will put noise-canceling headphones on you or issue protective earplugs to avoid discomfort. Computed tomography is silent.
- The attraction of metal by a magnetic field. Since a strong magnetic field acts on the entire patient’s body during an MRI, people with metal objects should approach the procedure with caution:pacemakers
intracranial ferromagnetic hemostatic clips of cerebral vessels;
ferromagnetic metal implants;
metal structures in the anatomical region to be investigated (metal plates, distractors, etc.);
ferromagnetic or electronic middle ear implants;
metal shavings in the eyes.
All these elements have magnetic properties. Before an MRI, you need to provide a passport for the implanted device, which should indicate its MRI compatibility. An absolute contraindication to MRI is the presence in the patient’s body of metal objects with magnetic properties (implants, prostheses, foreign bodies) and devices (for example, pacemakers). There is no such contraindication for computed tomography. (CT Scan vs MRI)
Dental metalwork and intrauterine contraceptives are not a contraindication for MRI.
- Restrictions during pregnancy. CT Scan is not recommended for children and pregnant women. Radiation exposure to pregnant women is contraindicated and possible only when there is vital evidence. The decision is made by a consultation of doctors. It is highly recommended that you do an MRI in the first trimester (the first 12 weeks of pregnancy). During this period, the formation of internal organs in the fetus is taking place, and, in connection with this, it is undesirable to change environmental conditions. Subsequent MRI scans are permissible if there is a referral from the attending physician. (CT Scan vs MRI)CT Scan with contrast is also prescribed with caution in cases of damage to the kidneys and thyroid gland, as well as for people with an increased allergic background and diabetes mellitus (often an endocrinologist’s preliminary consultation is necessary to correct therapy).
If you have a reaction to 4 or more allergens, exacerbation of bronchial asthma, severe allergic reactions in history (Quincke’s edema, bronchospasm, anaphylactic shock), inform the attending physician and conduct a study in a hospital. (CT Scan vs MRI)
Preparation for abdominal examinations
When examining the organs of the abdominal cavity, retroperitoneal space and pelvis for two to three days, stop eating foods rich in fiber and contributing to gas formation:
bean vegetables and canned food,
carbonated drinks and sweets,
Take activated charcoal before the procedure.
The study is carried out on an empty stomach, the last meal should occur 6 hours before the procedures. You can drink water in small quantities and take medicine. Also, the attending physician may recommend that you take two tablets of antispasmodic drugs, for example, No-Shpa, 30 minutes before the study, to eliminate artifacts from intestinal motility (movement). (CT Scan vs MRI)
For three to four days, completely before computed tomography, exclude heavy, fatty foods, nuts, sweets, and any flour products. Refuse strong tea and coffee. The best diet will be boiled fish, vegetables, light soups, and broths. The last meal can be done 6 hours before the procedure. During CT, antispasmodic drugs may also be needed to eliminate artifacts from intestinal motility (movement).
What is the difference between an abdominal MRI and CT?
Since different technologies are used in research, MRI and CT are sensitive to various tissues.
Computed tomography provides more information about dense formations, bone tissue, and the state of blood vessels. When evaluating chest organs, kidney stones, CT is the method of choice. (CT Scan vs MRI)
Magnetic resonance imaging is more sensitive to soft tissues and fluids. In the images, the doctor will be able to consider the early stages of neoplasms, circulatory disorders, metastases and hematomas, abscesses, chronic organ damage.
Does the choice of procedure depend on the disease?
The first thing to do is to consult a doctor! Only a doctor who has the entirety of information about your problems will be able to correctly make a choice of diagnostic technique. (CT Scan vs MRI)
But life sometimes dictates its own corrections, and if you decide to undergo an examination yourself, it is important to understand what diseases each type of tomography will be more informative of.
Computed tomography should be chosen for diseases such as:
injuries, damage to the ureters, kidneys, ruptures of the renal capsule;
X-ray positive stones in the kidneys and ureters, in the biliary tract;
weight loss, pain, and other symptoms indicating possible diseases of the organs of this zone;
signs of any pathologies detected as a result of radiography, ultrasound, and so on, requiring clarification;
ambiguous or questionable results from other studies;
if there are contraindications to MRI;
enlarged liver (non-obvious origin);
symptoms of obstructive jaundice;
evaluation of the effectiveness of cancer treatment;
thrombosis, aneurysms, ruptures, and deformations of blood vessels.
Also, computed tomography is advisable in preparation for surgery, because a study with contrast reveals the features of the blood supply to the organ and allows you to plan access and the volume of surgery. (CT Scan vs MRI)
Magnetic tomography will give better results in the following cases:
suspicions of oncology;
size and structure of abdominal organs: spleen and liver, gall bladder and pancreas, adrenal glands and kidneys, biliary tract, lymph nodes;
inflammatory, degenerative, obstructive and cystic processes;
circulatory disorders, heart attacks;
congenital abnormalities in the structure of the organs of the abdominal cavity;
malignant or benign neoplasms;
thrombosis, aneurysms, ruptures, and deformations of large vessels;
stones and pathological changes in the biliary tract and gall bladder
What to choose for an examination of the abdominal cavity – MRI or CT?
Only your healthcare provider can answer this question. Only having a complete picture of the disease on hand, he can determine the need for certain procedures. And after consultation with a specialist, you can sign up for an MRI or CT scan of the abdominal cavity in our medical centers. (CT Scan vs MRI)