MRI Imaging of GP Medicare Eligible Conditions

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1 MRI Imaging of GP Medicare Eligible Conditions By Dr. Andrew Stuart Radiologist Sydney Adventist Hospital 0562/SAH/1112/SAH

2 Learning Objectives Indications for GP referred Medicare eligible MRI scans MRI imaging appearances of selected cases Benefits to patients in being able to access rebatable MRI Precautions and contraindications with MRI referral

3 Criteria for GP referred for Medicare eligible MRI scans MRI Head for unexplained Seizure(s) or Chronic Headaches MRI Cervical Spine for Cervical Radiculopathy or Trauma MRI Knee for Acute Knee Trauma with possible Meniscal Tear or Anterior Cruciate Tear

4 ABSOLUTE CONTRA-INDICATIONS FOR MRI Pacemaker or defribillator wires (now a pacemaker that is MRI safe) Metallic FB`s in the eye Swan-Ganz catheter Deep brain stimulator Bullets or gunshots pellets near great vessels or vital organs Cerebral aneurysm clips if magnetic (includes unknown) Cochlear implant Magnetic dental implant Drug infusion devices

5 RELATIVE CONTRAINDICATIONS FOR MRI AAA stent stapes implant implanted drug infusion device neuro or bone growth stimulator surgical clips, wire sutures, screws or mesh ocular prosthesis penile prosthesis joint replacement or prosthesis other implants, in particular mechanical devices too large patient claustrophic patient inability to lie still surgery in previous 6 weeks

6 Nephrogenic systemic fibrosis (NSF) Rare and serious condition involving fibrosis of skin, eyes, joints and internal organs. Occurs in patients exposed to gadolinium with severe renal disease. Please ensure if you are referring a patient for MRI who has suspected renal disease or who is elderly that there is a relatively recent creatinine. At the SAN we use Gadovist which has not had a definite case of NSF associated with its use.

7 28 yr old female Suspected cervical trauma playing netball p/w left sided neck pain Probable migraine Exclude spinal pathology

8 Sagittal water sensitive MRI sequences T2 STIR

9 TOF MRA of neck arteries

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12 Axial T1 fat saturation

13 Axial diffusion scan (DWI)

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16 Take home points: Diagnosis = Lt vertebral artery dissection with small embolic acute infarct Should have started with cervical spine X- ray Need to have a high index of suspicion for carotid or vertebral dissection CT angiogram has better spatial resolution than MR angiogram but radiation dose

17 66 yr male p/w focal epilepsy and increasing cognitive problems

18 Axial susceptibility weighted imaging (SWI)

19 Axial FLAIR Coronal

20 Take home points: Diagnosis = Cerebral amyloid angiopathy Any new onset epilepsy needs investigation CAA is common in the demented elderly normotensive pt. MRI susceptibilty imaging is needed to detect these multifocal microhaemorrhages ( CT occult ) Amyloid angiopathy is a common cause of spontaneous lobar haemorrhage in elderly

21 35 yr old female p/w severe headache in upright position

22 Coronal Imaging through posterior cranial fossa FLAIR Susceptibilty weighted image

23 Sagittal water sensitive sequences T2 STIR

24 Take home points: Diagnosis = Intracranial hypotension MRI (SWI) is good for detecting subtle haemorrhage- new and old CT is good for acute haemorrhage only Often need to image brain and spine as pathology is inter-related

25 38 yr female p/w common migraine over past few years better during pregnancy and lactation. Any vascular or pituitary abnormality?

26 Sagittal T1 post gadolinium Coronal s

27 Coronal SWI (susceptibility image)

28 Coronal T2 FLAIR Axial

29 MRV performed 4/12 later

30 Take home points: Diagnosis = Dural sinus thrombosis Venous thrombosis progresses to venous infarction in 50% cases Venous infarction is eliptogenic and is associated with headache, papilloedema and neurological deficits

31 50 yr female old p/w long standing migraines. Acute onset drowsiness. Cerebral sinus thrombosis?

32 TOF MR Venogram

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34 Take home points: Diagnosis = uncertain but probably vasculopathy associated with migraine T2 FLAIR hyperintense foci are a common finding > 60 yrs Felt usually to reflect chronic small vessel ischaemic change associated with ageing Significance controversial and findings non specific although associated with increased risk of CVA In the younger patient the differential includes vasculitis, demyelination, vasculopathy, migraine? perivascular demyelination around arteriosclerotic vessels? myelin pallor with dilated perivascular spaces? small lacunar infarcts

35 26 yr old male p/w headache

36 Sagittal T2(top) and T1 (below)

37 Take home points: Diagnosis = Chiari type 1 malformation MRI good for sagittal plane, anatomical detail at skull base as well as syrinx evaluation Fundamental problem is underdevelopment of posterior cranial fossa Numerous symptoms including subocciptal headache Usually present in 2 nd and 3 rd decade Treatment controversial do not usually intervene if asymptomatic unless syrinx

38 16 yr old male p/w locking knee

39 Sagittal PD fat sat Coronal PD fat sat

40 Axial PD fat sat Coronal PD

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42 Take home points: Diagnosis = bucket handle meniscal tear Displaced meniscal fragment resembles the handle of a bucket Pain/locking after single traumatic event Requires surgical intervention Locking associated with a meniscal tear indicates a displaced meniscal fragment

43 17 yr old female p/w acute knee injury with instability episode.? ACL.

44 ACL injury occurs when the femur and tibia rotate in opposite directions under full body weight

45 Normal knee Ruptured ACL with anterior tibial translation

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50 Avulsed intercondylar notch Segond fracture

51 Take home points: Injury usually caused by pivot shift mechanism Associated meniscal tears common Posterolateral corner injury associated with marked instability

52 24 yr old female p/w severe neck pain after fall

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54 Axial CT through C1 and C2

55 Sagittal CT reconstructions though Cervical spine

56 Sagittal T2 weighted scan through cervical spine

57 Coronal Stir and Axial T2

58 MRA of carotid and vertebral arteries in neck

59 Take home points: Usually perform X-Ray first CT performed next if X-ray normal but still clinical concern or if fracture and need to define MRI normally has role to define soft tissue injury including vascular injury MRI is not a substitute for CT in suspected cervical spine fracture

60 43 yr male present with left cervical radiculopathy

61 Sagittal T2 Sagittal T1

62 Oblique sagittal T2 Axial T2 at C5/6 level

63 Take home points: MRI best way to asses for cervical foraminal stenosis (oblique sagittal T2) History should if possible give nerve root level based on clinical examination A CT guided perineural steroid injection can be performed to relieve symptoms

64 SYDNEY ADVENTIST HOSPITAL PRESENTS Diagnostics GP Conference CONVENOR Dr James Cheatham SPEAKERS Dr Ross Bradbury Antibiotic Therapy for GPs: An Update Dr David McHarg Overview of PET-CT Dr Andrew Stuart MRI Imaging of Conditions that are Medicare Eligible for GP Referral Tuesday 18 th March 2014