Magnetic resonance imaging (MRI)
Magnetic resonance imaging of abdomen and pelvis
Abdominal magnetic resonance imaging (MRI) is a noninvasive procedure that uses powerful magnets and radio waves to produce images of the inside of the abdomen without exposure to X-rays. There is no ionizing radiation involved in MRI.
Several sets of images are usually acquired, each sequence taking from two to four minutes. A complete scan, depending on the sequences performed, and need for contrast enhancement may take 30 minutes or more.
An MRI can be performed immediately after other imaging studies. Depending on the area of interest, the patient may be asked to fast for four to six hours prior to the scan. The colon may need to be cleansed (with preparations such as a laxative or an enema).
Because of the strong magnets used in MRI, certain metallic objects are not allowed into the room. Items such as jewelry, watches, credit cards, and hearing aids can be damaged. Pins, hairpins, metal zippers, and similar metallic items can distort the images. Removable dental work should be taken out just prior to the scan. Pens, pocketknives, and eyeglasses can become dangerous projectiles when the magnet is activated and should not accompany the patient into the scanner area.
Benefits of Diagnostic Capability of MRI in Abdomen & Pelvis
The sensitivity of MRI depends on the image quality and the experience of the radiologist.
MR imaging in the abdomen is superior to other modalities in differentiation of soft tissues abnormalities because of its ability to demonstrate superb soft tissue contrast. The combination of different imaging sequences enable definitive diagnosis of the abnormalities of various abdominal and pelvic organs. MRI also provides a fast noninvasive alternate to X-ray angiography for diagnosing problems of the abdominal vessels
MRI examinations of abdomen and pelvis performed with state of the art MR protocols are helpful in several conditions.
- Screening and surveillance of hepatocellular carcinoma
- Diagnosis of liver tumors- characterization of indeterminate liver lesions seen on Ultrasound and CT
- Distended bile ducts and pancreatic duct
- Bile duct stones
- Gall bladder mass
- Pancreatic cancer and pancreatitis
- Adrenal mass characterization
- Renal masses and complex cysts
- Intra-abdominal and retroperitoneal bleed of hematoma
- Aorta, Illiac arteries
- Renal artery obstruction or stenosis
- Abdominal arterial and venous angiography
- Aortic graft assessment
- Inferior vena cava or renal vein thrombosis
- Portal or hepatic vein thrombosis
- Uterine fibroids and adenomyosis
- Pre and post embolization assessment of uterine fibroids
- Endometrial polyps and submucosal fibroids
- Characterization of ovarian masses
- Staging of endometrial carcinoma
- Staging of cervical carcinoma
- Staging of ovarian carcinoma
- Staging of rectal carcinoma
- Urinary bladder tumors
- Abnormalities of male or female urethra
- Perianal fistulas
- Vesico-vaginal and recto-vaginal fistulas
- Fetal anomalies
- Assessment of placental abnormalities
- The most common MR intravenous contrast agent is gadolinium. Although safe, rarely there are a few reported allergic reactions
- Patients with asthma, history of allergic respiratory disorders, prior iodinated or gadolinium-based contrast reactions are at a higher risk of adverse reaction.
- Recently, a few patients with bad renal diseases have been reported to develop NSF (Nephrogenic Systemic Fibrosis). Therefore patients with history of renal disease are carefully selected for administration of Gadolinium contrast.
- People with claustrophobia or who are confused or anxious may have difficulty lying still for the relatively long scan times.
Strong magnetic fields can displace or disrupt the action of implanted metallic objects, so people with cardiac pacemakers cannot be scanned and should not enter the MRI area.
MRI is cautiously used for people with metallic objects in their bodies such as inner ear (cochlear) implants, brain aneurysm clips, some artificial heart valves, older vascular stents, and artificial joints.
Sheet metal workers, or those with similar potential exposure to small metal fragments, will first be screened for metal shards within the eyes with X-rays of the skull. The patient will be asked to sign a consent form confirming that none of the above issues apply before the study will be performed.
Body MRI faculty
- Michael Corwin, M.D. Director of Body MRI
- Eugenio Gerscovich, M.D.
- Ramit Lamba M.D.
- John McGahan, M.D.
- Sima Naderi, M.D.
- Simron Sekhon, M.D.
- Marijo Gillen, M.D.