Indications for MRI brain

• Transient ischaemic attack (TIA), syncope, collapse , stroke
• Brain Tumour, Suspected brain tumour, metastases, papilloedema
• CNS infection, abscess, meningitis, AIDS,&TB
• Congenital malformation of brain or meninges
• Post-operative follow-up after brain surgery
• Dementia, neurodegenerative disorder
• Demyelinating disease of the brain
• Encephalopathy, encephalitis
• Cerebellar, or brainstem lesion 
• Head trauma, epilepsy,stroke
• CVA, altered mental status
• Suspected leukodystrophies
• Ataxia, bipolar disorder
• Multiple sclerosis
• ENT problems

Contraindications

• Any electrically, magnetically or mechanically activated implant (e.g. cardiac pacemaker, insulin pump biostimulator, neurostimulator, cochlear implant, and hearing aids)
• Intracranial aneurysm clips (unless made of titanium)
• Pregnancy (risk vs benefit ratio to be assessed)
• Ferromagnetic surgical clips or staples
• Metallic foreign body in the eye
• Metal shrapnel or bullet

Patient preparation for MRI brain

1. A satisfactory written consent form must be taken from the patient before entering the scanner room
2. Ask the patient to remove all metal objects including keys, coins, wallet, cards with magnetic strips, jewellery, hearing aid and hairpins
3. If possible provide a chaperone for claustrophobic patients (e.g. relative or staff )
4. Contrast injection risk and benefits must be explained to the patient before the scan 
5. Gadolinium should only be given to the patient if GFR is > 30
6. Offer earplugs or headphones, possibly with music for extra comfort
7. Explain the procedure to the patient
8. Instruct the patient to keep still
9. Note the weight of the patient

Positioning for MRI brain

1. Head first supine
2. Position the head in the head coil and immobilise with cushions
3. Give cushions under the legs for extra comfort 
4. Centre the laser beam localiser over the glabella

Protocols and planning

Localiser

A three plane localizer must be taken in the beginning to localise and plan the sequences. Localizers are usually less than 25sec. T1 weighted low resolution scans.


T2 tse axial

Plan the axial slices on the sagittal plane; angle the position block parallel to the genu and splenium of the corpus callosum. Slices must be sufficient to cover the whole brain from the vertex to the line of the foramen magnum. Check the positioning block in the other two planes. An appropriate angle must be given in coronal plane on a tilted head (perpendicular to the line of 3rd ventricle and brain stem).

T2 FLAIR axial

Plan the axial slices on the sagittal plane; angle the position block parallel to the genu and splenium of the corpus callosum. Slices must be sufficient to cover the whole brain from the vertex to the line of the foramen magnum. Check the positioning block in the other two planes. An appropriate angle must be given in coronal plane on a tilted head (perpendicular to the line of 3rd ventricle and brain stem).

T1 SE coronal

Plan the coronal slices on the sagittal plane; angle the position block parallel to the brain stem. Check the positioning block in the other two planes. An appropriate angle must be given in the axial plane on a tilted head (perpendicular to mid line of the brain). Slices must be sufficient to cover the whole brain from the frontal sinus to the line of the occipital protubernce.

T2 tse sagittal

Plan the sagittal slices on the axial plane; angle the position block parallel to midline of the brain. Check the positioning block in the other two planes. An appropriate angle must be given in the coronal plane on a tilted head (parallel to the line along 3rd ventricle and brain stem). Slices must be sufficient to cover the brain from temporal lobe to temporal lobe.

DWI epi3scan trace axial

Plan the DWI axial slices on the sagittal plane; angle the position block parallel to the line from the glabella to the foramen magnum. This angle will reduce air-bone interface artefacts from the Para nasal sinuses. Slices must be sufficient to cover the whole brain from the vertex to the foramen magnum. Check the positioning block in the other two planes. An appropriate angle must be given in the coronal plane on a tilted head (perpendicular to the line of 3rd ventricle and brain stem).


Indications for contrast enhancement brain scans

• Tumour, Metastases, Cranial nerve lesion, Indeterminate intracranial lesion, IAC mass  
• Cavernous angioma, Amyloid angiopathy, Neurocysticercosis 
• Meningitis, Encephalitis, Leptomeningeal spread 
• Multiple Sclerosis, AVM, HIV, Infection Abscess 
• Leukodystrophies, Delayed development 
• Syringomyelia(Syrinx)

Use T1 SE axial and coronal after the administration of IV gadolinium DTPA injection(copy the planning outlined above). The recommended dose of gadolinium DTPA injection is 0.1 mmol/kg, i.e. 0.2 mL/kg in adults, children and infants.

Magnetic Resonance Enterography (MRE) is a radiological technique that has evolved in the last decade. It involves the use of magnetic resonance imaging (MRI) to assess the small bowel, following distension with an oral contrast agent.
The advantages of this technique are that it involves no ionising radiation, is capable of multi-planar imaging, affords high-contrast resolution (with more detailed evaluation of bowel wall changes) and allows for cine-imaging.
Its main indication at present is to evaluate small bowel involvement in patients with Crohn’s disease ( is a chronic inflammatory bowel condition with onset usually in young adulthood. Twenty to thirty percent of patients are younger than 20 years old)