Prostate MRI allows for a layered examination of the prostate gland and surrounding tissues. It makes it possible to study the structure of the prostate, detect pathological foci, assess their location, diameter and relationship with nearby anatomical formations. MRI is used in the diagnosis of prostate cancer, prostatitis, abscesses and prostate adenomas. The procedure is painless and does not have a harmful effect on the patient’s body.
Prostate MRI is a diagnostic technique, the use of which has significantly improved the accuracy of staging oncological processes in the prostate gland. It is a more informative study compared to radiography and computed tomography. Prostate MRI does not involve the use of ionizing radiation. Unlike radiography and computed tomography, it does not involve injections of iodine-containing drugs during contrast examination, which allows using this technique without restrictions if the patient is allergic to iodine. The disadvantages of prostate MRI are weight restrictions, inability to use in the presence of metal implants, long duration of the procedure and relatively high cost compared to other diagnostic methods.
The main indication for prostate MRI is prostate cancer. The procedure is usually performed after examination of cytological or histological material obtained during a prostate biopsy. Prostate MRI is performed to differentiate stages II and III of the oncological process when determining indications for surgery or radiation therapy in patients with a high risk of neoplasia spreading beyond the organ.
The study is prescribed to assess the condition of regional lymph nodes and identify metastatic lesions of the lumbar spine and pelvic bones. Prostate MRI is also used to assess changes in the size of the primary tumor and regional metastases during treatment, with suspected local recurrence of neoplasia and recurrent tumors in the lymph nodes after surgical removal of the prostate gland. In addition, the study is used in the diagnosis of prostate adenoma, prostatitis and prostate abscesses.
Contraindications to the use of this diagnostic technique are the presence of:
- an inner ear implant;
- metal objects (metal structures, foreign bodies) in the chest, abdomen, head and neck;
- artificial heart valves;
- hemostatic clips;
- vascular shunts, stents or filters if less than 3 months have passed since the operation and if the patient cannot provide a document confirming the safety of the study in the presence of the listed implants.
With a body weight of more than 120 kg and a belly circumference of more than 160 cm, prostate MRI is not performed due to technical limitations of the equipment. In case of mental disorders that make it difficult to follow the doctor’s instructions on maintaining immobility, and diseases characterized by the presence of involuntary muscle activity, prostate MRI is performed after the administration of drugs that eliminate these symptoms, or is replaced by other diagnostic techniques.
Relative contraindications to prostate MRI are:
- tattoos using metal dyes
- implants and foreign bodies in the limbs and soft tissues that degrade the image quality and can cause unpleasant symptoms during the study.
Preparation for MRI
- for several days before the study, it is necessary to limit the use of products that promote gas formation;
- in the evening before the procedure, clean the intestines using an enema or laxatives;
- the study is carried out with a full bladder, so it is impossible to urinate before the procedure;
- going for an MRI of the prostate, you need to take all the medical documentation with you;
- you should choose clothes without metal parts (in some clinics, patients are not changed, and metal elements on clothes can reduce the informative value of the procedure).
Before starting prostate MRI, the patient removes all metal products: watches, jewelry, hearing aid, dentures, etc. The patient leaves all objects with metal elements, including a mobile phone and credit cards, in another room. If there are metal implants, a pacemaker and other devices in the patient’s body, it is necessary to warn the diagnostician about this before the start of prostate MRI. In the presence of titanium implants, it is recommended to provide the specialist with documents confirming the possibility of MRI.
Methodology of conducting
The study is performed in a lying position. Before starting an MRI of the prostate, an endorectal coil is inserted into the patient’s rectum. After insertion, the balloon of the coil is inflated so that it does not shift during the procedure. When conducting an MRI of the prostate with contrast, a contrast agent is injected. Then the patient is asked to remain motionless, the procedure is performed, the balloon is blown off and the coil is removed from the rectum. After completing the MRI of the prostate, the patient is asked to wait until the doctor deciphers the results in order to clarify the data in the course of an additional study, if necessary.
Interpretation of results
The presence of a malignant prostate tumor is indicated by a low-intensity signal in the neoplasia zone with a high-intensity signal from the surrounding healthy tissues in T1-weighted images. MRI of the prostate allows you to determine the exact localization, prevalence and direction of growth of the neoplasm. The degree of malignancy of the neoplasm can be estimated by the rate of accumulation and excretion of the contrast agent. In addition, MRI of the prostate makes it possible to establish the fact of extraorgan spread of the tumor, lesions of lymph nodes and nearby bone structures. With glandular adenomas, hyperintensive shadows in the area of hyperplasia are visible on the MRI of the prostate, with stromal ones – hypointensive. In prostatitis, cone-shaped hypointensive areas with clear contours are determined, there is no mass effect.