NEW GP MRI INDICATIONS…WHAT DOES IT ALL MEAN (Part 1)

As of 1 November 2013, the GP MRI requesting rights have been extended to include indications for patients aged 16 years and over. These indications include Brain, Cervical spine and Knee.

This 3 part series will include case studies to help identify and highlight some appropriate senarios that MRI would be most useful. For more information please call our Randwick or Liverpool sites on 9399 5357 or 9600 9552.

Part 1 – MRI brain:


GPs can refer for a Medicare funded MRI head scan for unexplained chronic headache with suspected intracranial pathology and unexplained seizure(s), for adults 16 years and over.

CHRONIC HEADACHE

Case History 1

A 50 year old man presents with chronic headaches that have become progressively worse over the last 2 months.

He mentions that the headache wakes him from sleep, and is worse in the mornings but improves over the day. They have increased in frequency and have been associated with blurred vision and dizziness. He also mentions morning vomiting that is not associated with nausea.

Case History 2

A 26 year old female presents with chronic headaches that have persisted over the last two years.

Her weekly headaches are described as band like and are not associated with an aura. The headaches are not associated with vomiting, changes in vision, they do not wake her from sleep and they are not triggered by exercise or coughing. She has no history of trauma and the headaches have not changed in severity since two years ago. Her neurological examination showed no focal findings and the rest of the physical examination was normal. She takes paracetamol for headache relief. She is worried about intra cranial pathology.


unexplained seizure(s)

Case History 1

A 43 year old man presents with a friend after having a first time seizure at home.

The friend describes that the man’s right hand suddenly contracted, and the right arm then started jerking and his head turned to the other side. Soon after he lost consciousness, fell and his whole body started “shaking”. The episode was brief and regaining of consciousness was associated with confusion. The man had been incontinence during the event, and fortunately did not sustain any visible injuries. He has no previous history of seizures or a family history of epilepsy.

Case History 2

A 24 year old male with type 1 diabetes mellitus presents for follow up at the GP after hospitalisation 1 week ago for hypoglycaemia.

The man was at a music festival when his friends started to notice that he was becoming dizzy and dull. His friends mentioned that he lost consciousness and his body started ‘convulsing’. He was taken to the emergency department for treatment. On examination he has a normal neurological examination. He admits to having ‘hypos’ in the past but has never had convulsions before. He is worried about epilepsy and intra cranial pathology, and wants your opinion on an MRI scan.


discussion – chronic headache

Headaches are a common complaint presenting to primary care. Imaging can aid clinical decision making depending on the clinical picture and the pre-test probability. Intra cranial pathology is a rare but important cause to exclude, especially if the headache is associated with focal neurological findings, signs of increased ICP and progressive severity. When considering an imaging modality often CT is generally recommended in emergency situations. However MRI offers an imaging modality with no ionising radiation that is more sensitive in detecting white matter lesions than CT [1, 2].

MRI with its increased sensitivity may also increase detection of ‘incidentalomas’ which are often alarmingly anxiety provoking for the patient, regardless of its level of clinical significance. Imaging solely for patient reassurance has short term benefit- a study of 150 patients treated for chronic headache at a specialist clinic had returned to the same level of anxiety one year after an MRI excluded intracranial pathology[1]

1.National Guideline, C. Diagnosis and management of headache in adults. A national clinical guideline. 12/1/2013]; Available from: http://www.guideline.gov/content.aspx?id=13446.

2. Carville, S., et al., Diagnosis and management of headaches in young people and adults: summary of NICE guidance. BMJ, 2012. 345.



discussion – unexplained seizure(s)

A detailed clinical history, eyewitness account and examination is critical to recognise the need for imaging after a new onset seizure. If the history does not reveal any precipitating cause, determining the seizure type-particularly partial (focal) seizures- can help weigh the decision in favour of imaging to investigate aetiology.

MRI is the imaging modality of choice in the diagnostic workup of new onset, unexplained seizure. However, non-contrast CT is generally recommended for emergency situations or where MRI is contraindicated (e.g. prostheses, metallic foreign body). MRI imaging is indicated in new onset, unprovoked seizure particularly in patients with adult onset epilepsy, patients >25 years old and focal onset in history or examination.1

1 Clinical Guidance for MRI referral. East Melbourne: Royal Australian College of General Practitioners, 2013.