MRI Brain — tumour protocol
Whole brain vertex to foramen magnum. Extend to the whole neuraxis where leptomeningeal spread is a concern.
Typical, not policy
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Suspected primary brain tumour on a previous study or on CT.
- Pre-operative planning and post-operative baseline for a resected tumour.
- Response assessment on treatment, where a standardised repeatable protocol matters more than any single sequence.
- Suspected cerebral metastases in a patient with known extracranial malignancy.
- Differentiating tumour progression from treatment effect, where perfusion and spectroscopy are added.
Technique
- Volumetric 3D T1 before and after contrast in the same geometry, with isotropic voxels of about 1 mm so that reformats and volumetry are possible.
- Axial T2 and 3D FLAIR for the non-enhancing component; DWI with ADC for cellularity and for post-operative infarction.
- Susceptibility-weighted imaging for haemorrhage and calcification.
- Dynamic susceptibility contrast perfusion is commonly added for grading and for treatment-effect questions; it requires its own bolus and injector.
- The international standardised brain tumour imaging protocol is widely adopted for trials and increasingly for routine care; sequence lists vary between institutions.
Where it goes wrong
- Non-volumetric or differently angled post-contrast imaging between studies, which makes small changes uninterpretable.
- Post-operative baseline delayed beyond roughly 24-72 hours, after which surgical-bed enhancement makes residual tumour indistinguishable.
- Changing gadolinium dose or post-injection delay between serial studies.
- Omitting DWI after surgery and mistaking peri-operative infarct for residual enhancing tumour on later scans.
Clinical questions that reach this study
Known or suspected lung cancer — stagingSuspected acute ischaemic strokeSuspected intracranial haemorrhage (non-traumatic)Suspected subarachnoid haemorrhageFirst unprovoked seizureDrug-resistant epilepsy — pre-surgical assessmentSuspected brain metastasesSuspected primary brain tumourSuspected multiple sclerosis or first demyelinating eventSuspected meningitis or encephalitisHeadache with red flag featuresHeadache without red flags (migraine, tension-type, chronic stable)Suspected normal pressure hydrocephalusCognitive impairment or suspected dementiaHead injury in childrenSuspected inflammatory spinal cord lesion (transverse myelitis)Chronic rhinosinusitis and pre-operative sinus CTSuspected physical abuse in a child — skeletal survey
Contrast
Gadolinium, intravenous
Macrocyclic gadolinium agent at a typical single dose of about 0.1 mmol/kg with saline flush; confirm agent and dose locally.
- For serial response assessment, keep agent, dose and post-injection delay constant between studies or the enhancement comparison is unreliable.
Acquisition
- Breathing
- Free breathing.
- Preparation
- No fasting or bowel preparation for an unenhanced brain study. Establish whether gadolinium is actually needed before booking an IV slot — most brain questions do not require it. Young children and patients unable to keep still for 20-30 minutes need a sedation or general anaesthetic pathway agreed in advance.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- MR safety screening for implants and foreign bodies· radiographer at scan
- Sedation or anaesthesia for a child· nurse pre scan