Pelvic Magnetic Resonance Imaging
A pelvic MRI allows visualization of the internal structures located between the hip bones. It is a non-invasive diagnostic test that does not use ionizing radiation.
General Description
Pelvic MRI is a diagnostic test that obtains images of the organs and tissues situated within the pelvic bones (pelvic region). This technique uses radiofrequency waves and a high-powered electromagnetic field but emits no ionizing radiation, making it safe for the patient.
Because it studies a lower body area, it is not necessary for the patient to be fully inserted into the machine. Therefore, a closed MRI can always be performed, producing more detailed images due to a stronger magnetic field and reducing the risk of claustrophobia-related crises.
In some cases, gadolinium—a contrast agent—is used to more accurately visualize certain tissues.
When is it indicated?
Pelvic MRI is performed to assess the condition of organs and structures in the pelvic region. It is indicated for evaluation in cases of:
- Pelvic pain
- Trauma
- Urinary or fecal incontinence
- Abnormal findings in prior X-rays
- Malignant tumors
- Congenital hip defects
In men:
- Testicular inflammation
- Scrotal inflammation
- Cryptorchidism (undescended testicle)
In women:
- Abnormal vaginal bleeding
- Fibroids
- Endometriosis
- Infertility
Pelvic MRI is used to stage cancers of the bladder, rectum, uterus, cervix, prostate, or testicles. Besides determining disease stage, it helps assess whether cancer cells have spread to other organs.
How is it performed?
The pelvic MRI procedure involves:
- Placing the device around the patient’s pelvic area to generate an electromagnetic field inside the tube.
- Protons in body tissues align with the magnetic field.
- Radiofrequency waves are emitted, causing protons to spin against the magnetic pull.
- When the radiofrequency pulses stop, protons realign with the magnetic field, releasing energy.
- Each tissue type emits a different amount of energy depending on its chemical composition.
- A computer receives this data and transforms it into images shown in varying shades of gray depending on intensity, so each tissue appears distinct.
- When contrast is used, some cells absorb it more, causing tissues and organs (such as tumors) to appear brighter on images.
Risks
Pelvic MRI poses no health risk.
Some patients may experience allergic reactions to the contrast agent, manifesting as itching, nausea, or headache.
What to expect during a pelvic MRI
On the day of the test, the patient signs informed consent and changes into a hospital gown. All metal objects (jewelry, glasses, dentures, hearing aids) and makeup containing metal must be removed.
If contrast is required, it is injected into a vein in the arm, often causing a mild pinch and brief sensation of warmth or cold. Although the patient may not be fully inserted into the tube, earplugs are typically provided to reduce noise from the device generating the magnetic field. The patient should expect loud knocking sounds during the procedure.
Remaining completely still for 30 to 60 minutes is essential to ensure clear images. After the exam, the patient can immediately resume their normal activities.
Medical specialties requesting pelvic MRI
Pelvic MRI is performed by radiologists, usually requested by oncology, urology, or gynecology specialists.
How to prepare
No special preparation is required before a pelvic MRI.
Specialists recommend wearing easy-to-remove clothing and arriving at the center without makeup or metallic objects.
