الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 183 |  |  |
| | | from | 183 | | |
Abstract
In conclusion, MR Enterography has emerged as a valuable tool in diagnosis and
follow up of small bowel diseases. It offers a non-invasive, radiation-free method
for visualizing small bowel and provide detailed information on morphology and
function of small bowel, despite small bowel imaging challenges related to its
long and tortuous anatomy, continuous peristaltic movement, complex histology.
MR Enterography has many indications including Crohn’s and inflammatory
bowel diseases “IBD” , un explained small bowel thickening, Un explained GIT
bleeding, suspected small bowel mass, looking for small bowel stricture or fistula
or abscess, asses small bowel obstruction, evaluated acute abdominal pain in
pregnant , assess small bowel injury in trauma that can’t be detected by CT.
While MR enterography is a safe Procedure, there are certain contraindications
must be considered before the procedure, which divided into two categories;
Absolute contraindications which include active magnetic, electric , mechanical
,metallic implants like cardiac pacemakers, cochlear implants, aneurysm clips
and insulin pump, artificial limbs, hearing aids, implantable neurostimulators,
infusion pump, Magnetic dental implants, Piercings. Eye metal fragments.
Relative contraindications include Coronary and peripheral artery stents, Stapes
implants, Surgical clips, Penile prosthesis, Joint replacement prosthesis, Ocular
prosthesis, Stainless steel Intrauterine device, Inferior vena cava filter.
MRE is done using multicoil surface receive arrays coil and the exam require
both oral and intra-venous contrast with bowel preparation and antispasmolytic
agent, MRE has wide variety of sequences including; Echoplanar imaging (EPI),
Rapid acquisition with relaxation enhancement (RARE), Single Shot RARE
(HASTE, TSE,FSE), Balanced steady-state free precession (bSSFP, FISP),
Spoiled gradient echo (FLASH, SPGR, T1FFE), 3D T1W (Volumetric
Interpolated Breath-hold Examination “VIBE, THRIVE”, Hydrographic
Projection Imaging, Fat Suppression and Dixon technique , dynamic and cine
imaging, DWI and perfusion technique.
MRI enterography has been found to be particularly useful in diagnosis and
follow up of Congenital disease (e.g duplications cyst), Inflammatory bowel disease (mainly Crohn’s disease), Autoimmune disease (mainly Celiac disease),
Small bowel tumors (include benign and pre-cancerous like polyposis syndrome
or malignant like small bowel adenocarcinoma). MR Enterography has a role in
follow up of post chemo/radiotherapy changes and complications and in post
operative adhesion detection and its complication. although CT is the main
imaging for small bowel obstruction diagnosis, MRE is more valuable in detected
of low grade or intermittent small bowel obstruction which can be missed on
CT.MRE has found to be helpful in detected of small bowel vasculitis and
ischemic conditions. MRE has a role like CT in correlated with laboratory test to
diagnosis of infections diseases likely TB. While CT is the main imaging
modality for acute GIT bleeding assessment, MRE is valuable in detection of
occult or obscure GIT bleeding. MRE has a valuable role in investigating causes
of abdominal pain in pregnancy.
Comparing MR Enterography with other diagnostic methods revealed that
although contrast enhanced ultrasound has similar safety features of MRE , MRE
is more practical and more accurate. Comparing MRE with other invasive
techniques likely, endoscopy capsule endoscopy, balloon assisted deep
enteroscopy revealed although they have advantage of real visualizing of bowel
mucosa and lumen and take tissue biopsy in case of endoscopy and enteroscopy ,
they lack MRE advantages of assessment of bowel sub-mucosa and musculosa
layer and extra bowel complications, even so there was a matching between
MRE and balloon assisted enteroscopy in detecting ileal lesions. MRE has found
to be of higher specificity, accuracy and positive predictive value than CT
Enterography and small bowel follow through, as Its ability to detect early
changes in small bowel and monitor disease progression and its safe non-ionizing
radiation techniques makes it a valuable tool in the long-term follow up of small
bowel diseases. Furthermore, As such, it has become an indispensable tool in the
assessment of small bowel diseases and is likely to continue to play an important
role in the future.