MRI referral guidelines for GP

Question 1

Name 3 organs/anatomical locations that GPs can order MRIs for

Answer 1

Head, cervical spine, knee

Question 2

Name 3 C/I for ordering an MRI on a patient

Answer 2

If a patient has:

• metallic implant
• pacemaker
• eGFR less than 30 and contrast is required

Question 3

Name the 2 indications for ordering a head MRI as a GP

Answer 3

First presentation of unexplained seizure (looking for intracerebral lesions)
Unexplained chronic headache with suspected intracranial pathology

Question 4

Should an MRI be the first thing you order for someone with a seizure? Why/why not? Name 2 other investigations you could consider ordering.

Answer 4

Not always; if in an emergency situation (status epilepticus, unstable clinical condition, high suspicion of intracranial haemorrhage), CT is preferred (faster, more available). EEG should also be done first if available, and if you have a high suspicion of idiopathic epilepsy

Question 5

Name 2 things on Hx/Ex that would make you suspicious that a seizure was due to intracranial pathology rather than epilepsy

Answer 5

Adult onset first seizure

Symptoms/signs of a focal, not generalised seizure

Question 6

Name 3 clinical indications for ordering an MRI on someone with a chronic headache

Answer 6

Abnormal neurological examination
Headache worsened on Valsalva, waking from sleep, in older patient, progressively worsening
No clinical diagnosis of common chronic headaches (tension-type, cluster, migraine, medication overuse)

Question 7

Name the 8 clinical features that raise your suspicion of a headache being due to a sinister cause

Answer 7

SNOOP-4 mnemonic:
Systemic features (fever, weight loss, vomiting) or secondary risk factors (HIV, cancer)
Neurological symptoms or abnormalities (confusion, impaired consciousness, focal neurology)
Onset - sudden, abrupt (thunderclap)
Older patient - new-onset headache in over 50 year old (GCA)
Previous headache history - new-onset, or different to previous
Postural or positional aggravation
Precipitated by Valsalva or exertion
Papilloedema (blurred vision)

Question 8

Name indications for ordering an MRI of the cervical spine as a GP

Answer 8

Suspected cervical radiculopathy

Question 9

Name 3 clinical indications for ordering an MRI on someone with suspected cervical radiculopathy

Answer 9

Radiculopathy should be apparent on clinical examination (distinguished from musculoskeletal referred pain)
Patient should have attempted and failed conservative therapy, and be a candidate for surgical treatment
Cervical radiculopathy present for more than 6 weeks

Question 10

What is the usual presentation of someone with cervical radiculopathy? What usually causes it, and at what level? What is the natural course of the disease? How is the presentation different from referred musculoskeletal pain? Name 3 potential neurological signs of cervical radiculopathy.

Answer 10

Caused by compression or injury of nerve root by herniated disc or degenerative changes, usually C5 - T1. Can be asymptomatic, but usually presents as sharp, shooting pain travelling from neck down arm (in dermatomal distribution), usually severe. Often self-limiting over a few weeks (if resulting from degeneration).

Referred MS pain is usually more aching, and worse in neck than upper limb

May also present with abnormal sensation, motor dysfunction, or abnormal reflexes