MRI of the hip: what does it show and how do they do it?

Among the visualizing methods of hardware diagnosis, the hip MRI plays a leading role in identifying lesions and pathological changes in the largest joint of the human musculoskeletal system.

Magnetic resonance imaging provides the most accurate and detailed images, that is, the maximum information for setting the right diagnosis, and also facilitates differential diagnosis of joint syndromes.

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Indications for the procedure

In traumatology, orthopedics and rheumatology, indications for hip joint examination with the help of an MR-tomograph include the identification of:

• injuries (fractures, cracks, dislocations and ligament ruptures) and anomalies (hip dysplasia or congenital dislocation);
• Coxarthrosis (deforming hip osteoarthritis);
• osteomyelitis of the femoral and / or ilium;
• rheumatic lesions of the joint (arthritis), including in systemic autoimmune diseases;
• osteoporosis, changes in articular structures of a degenerative and necrotic nature;
• foci of inflammation of the periarticular tissues with tendenitis,  bursitis of the hip joint , etc .;
• bone metastasis of cancer.

MRI of the pelvis and hip joints is prescribed for suspected development of ankylosing spondylitis of sacroiliac joints (Bechterew's disease).

MRI can be used to evaluate the results of corrective orthopedic procedures. This examination is mandatory before the forthcoming installation of the hip joint endoprosthesis.

[3], [4], [5]

Preparation

Special preparation for magnetic resonance imaging of this joint is not required: just any metal products should be removed and changed from oneself (usually, one-time medical clothes are given or brought with them).

This examination is completely painless, the patient is lying down, does not move, so there is no need to carry out anesthesia before the MRI procedure of the hip joint. But, if the patient feels intense pain after a trauma or a recent operation, analgesics are taken shortly before the procedure, and with strong excitement - mild sedatives.

When MRI is prescribed with contrast, the doctor warns the patient about the need to stop eating and drinking fluids five to six hours before the test begins.

Technique MRI of the hip joint

Magnetic resonance imaging creates images using a combination of a strong electromagnetic field around the body with induced resonant pulses of radio waves perceived by a scanner connected to a computer system for recording response signals and processing them - visualization transformation.

The patient is placed on the surface, which is pushed into the large round tunnel of the MR-tomograph. To prevent the patient from moving during the procedure (as any movement can cause image distortion), belts and cushions can be used.

The technician who manages the movement of the scanner, provided by the technique of carrying out the MR scan, is in the next room, but he is watching the patient, and with him there is a connection for communication.

Duration of examination - 15-20 minutes, with MRI with contrast - 25-30 minutes.

Contraindications to the procedure

Due to the use of a strong magnet, the pelvic and pelvic MRI is contraindicated in patients with surgical clips, plates, pins, screws, clips or implanted devices made of metal and metal alloys in the body, including  

Pacemaker or cochlear implant. Do not perform an MRI with a hip joint prosthesis.

Contraindications for carrying out this diagnostic procedure concern people with mental illnesses and severe somatic pathologies.

MRI of the hip joint in pregnancy is never performed in the first half of the term, and MRI with a contrast to pregnant women is strictly prohibited.

With insufficient kidneys and hemolytic anemia, as well as patients with renal dialysis, an MRI with a contrasting substance is contraindicated, which helps to determine the condition of the periarticular tissues and blood vessels.

For patients suffering from claustrophobia (fear of enclosed spaces), and also when it is necessary to perform MRI of the hip joint for children (especially younger children, who are difficult to maintain immobility), an alternative is open-type MRI of the hip joint. This examination is performed on an MR scanner of another modification - with an open design of the scanning part of the apparatus (without the subject being placed in the tunnel chamber). For example, next to the child there may be a mother who will restrain his attempts to change the position of the body or an individual limb.

[6], [7], [8], [9]

Normal performance

There are atlases of normal anatomy of MRI and CT (for all systems and organs), human anatomy in sections and images on CT and MRI, as well as sectional anatomy in the example of CT and MRI sections. Their images compare the MRI of the anatomy of the hip to specific patients, and this allows specialists to accurately establish the abnormal abnormalities that result from various diseases or traumatic injuries.

MRI shows all the structures of the  hip joint : the joint head of the femur with the topography of the bone and cartilaginous tissue; The acetabulum (where the femoral and pelvic bones are jointed); the neck of the thigh; an articular bag with an internal synovial membrane (as well as the presence or absence of an inflammatory exudate in it); bone marrow canal of the femur; the entire ligamentous apparatus of the joint; adjacent soft tissues and blood vessels.

Also, the iliac, pubic and sciatic bones and their ligaments, which are related to the hip apparatus, are displayed.

[10], [11], [12], [13], [14], [15], [16]

Complications after the procedure

In MRI, ionizing radiation is not used, therefore, when the scanning protocol is strictly executed, there are no negative consequences after the procedure.

Special care after the procedure is also not provided, and patients do not receive from the doctors restrictive recommendations. Just - to avoid dizziness - do not need to make sudden movements, rising from the scanner table.

Possible complications after the procedure concern only MRI with a contrast agent, which at best can cause an allergic reaction, bouts of breathing difficulties and a decrease in blood pressure, and in case of kidney problems - nephrogenic fibrosis and sickle cell anemia.

Patients' feedback after MR scan of the pelvis and hip joints indicates that there are no unpleasant sensations or worsening of well-being.

[17], [18], [19], [20]

Which is better: X-ray, CT or MRI of the hip joint?

Specialists in the field of hardware diagnostics believe that when choosing a CT or MRI of the hip joint, most orthopedists are prescribed an MRI: because of the absence of radiation in the MRI and the high quality of the volume layered image.

X-ray image does not go to any comparison with the visualization of all structures and tissues, which give MR-tomographs. So, choosing for examination X-ray or MRI of the hip joint, doctors take into account the degree of complexity of each specific case and estimate the probability of an erroneous diagnosis in the absence of a detailed joint tomogram.