Neuroradiology. Peter Bogner Dept. of Radiology, chairman

Transcription

1 Neuroradiology Peter Bogner Dept. of Radiology, chairman

2 Imaging methods radiography - limited ultrasonography - neonatal, vascular imaging CT neurotrauma, stroke, spine imaging, CTA MRI almost anything nuclear medicine/multimodality SPECT/CT, PET/CT, PET/MRI functional/metabolic studies interventional neuroradiology image guided neurosurgery

3 skull xray indications Presence of a palpable vault abnormality which feels bony. As part of an imaging protocol for specific clinical problems eg. skeletal survey for myeloma. Many centres now prefer bone scans for this purpose. Facial views after trauma to the facial skeleton, mandible or orbit, or the possibility of a metallic foreign body.

4 How about spine x-rays? bony changes in degenerative disease spine trauma

5 Ultrasound is the main way of diagnosing carotid disease

6 Neuro CT exam quick w/ or w/o contrast CT angiography, perfusion imaging 3-5 mm slice th. general purpose 1-2 mm slice th. fine details, eg. inner ear good availability radiation dose concerns

7 Skull CT

8 Spine CT

9 MRI contrast factors spin density (water content) relaxivity (molecular motion) T1W, T2W, FLAIR diffusion (molecular motion) DWI, DTI susceptibility (magnetic properties) SWI, fmri chemical shift CSI chemical exchange MT flow MRA

10 T1W, T2W

11 SWI

12 MR angiography (TOF)

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14 Stroke - defintion a clinical syndrome consisting of rapidly developing clinical signs of focal (or global in case of coma) disturbance of cerebral function lasting more than 24 hours or leading to death with no apparent cause other than a vascular origin a transient ischaemic attack (TIA) is defined as stroke symptoms and signs that resolve within 24 hours ischaemic stroke typically presents neurological deficit, which is determined by the area of brain that is involved

15 Stroke - causes Ischemic (75%) thrombosis embolic hypoperfusion venous thrombosis Hemorrhagic intraparenchymal (15%) subarachnoidal aneurysm rupture (8%)

16 Vascular anatomy

17 Supratentorial arterial territories

18 Lenticulostriate Arteries Supply the Basal Ganglia and Internal Capsule

19 Role of CT It is essential to differentiate the bleeding and infarct different therapy CT scanning: diagnose or rule out bleeding Define location, extent and age of infarct BUT: to prove/verify the cerebral infarct in the hyperacute stage with CT is very difficult! Do so as rapidly as possible TIME IS BRAIN!

20 Ischemia acute phase Ischemia can be reliably detected after 24 hours

21 Ischemia chronic phase PCA territory watershed

22 Perfusion imaging - principle blood flow (CBF) - (ml/min/100 g tissue) time to peak (TTP) - (min) blood volume (CBV) - (ml/100 g tissue) mean transit time (MTT) - (min)

23 Perfusion imaging - CT CBV CBF TTP

24 Diffusion MR imaging (DWI) Conventional (T1/T2) MRI sequences may not demonstrate an infarct for 6 hours DWI shows ischemia within minutes Results in a reduction of tissue water diffusion

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26 Hypertensive ICH Spontaneous rupture of a small artery deep in the brain Typical sites Basal Ganglia Cerebellum Pons Typical clinical presentation Patient typically awake and often stressed, then abrupt onset of symptoms with acute decompensation

27 Ganglionic Bleed Contralateral hemiparesis Hemisensory loss Homonymous hemianopia Conjugate deviation of eyes toward the side of the bleed or downward AMS (stupor, coma)

28 Evolution of CT density of intracranial hemorrhage

29 Cerebellar Hemorrhage Vomiting (more common in ICH than SAH or Ischemic CVA) Ataxia Eye deviation toward the opposite side of the bleed Small sluggish pupils AMS

30 Pontine Hemorrhage Pin-point but reactive pupils Abrupt onset of coma Decerebrate posturing or flaccidity Ataxic breathing pattern

31 Subarachnoid Hemorrhage Worst headache of my life AMS Photophobia Nuchal rigidity Seizures Nausea and vomiting

32 Detection of aneurysm

33 Trauma

34 Traumatic Brain Injury - TBI closed head injury deceleration/rotation in the case of both direct and indirect force open head injury - penetration of the skull with direct injury diffuse axonal injury - diffuse cellular injury to the brain from rapid rotation/deceleration contusion bruise of the brain penetrating trauma - any object that enters the brain secondary injury - swelling and release of chemicals that promote inflammation and cell injury or death Intracranial hemorrhage (bleeding inside the skull) Brain swelling Increased intracranial pressure (pressure inside the skull) Brain damage associated with lack of oxygen Infection inside the skull, common with penetrating trauma Chemical changes leading to cell death Increased fluid inside the skull (hydrocephalus)

35 Intracranial Hemorrhage

36 Epidural/Extradural hematoma Blood collection within potential space between skull inner table & dura mater Originates from dural artery Best diagnostic clue: Hyperdense biconvex extra-axial mass on NECT in acute phase Does not cross sutures unless sutural diastasis/fracture present Can cross falx & tentorium Compresses & displaces underlying brain & subarachnoid space Low density "swirl sign" = actively/rapidly bleeding hematoma with unretracted semiliquid clot If MRI unavailable, consider coronal CT reconstructions to evaluate vertex EDH

37 Epidural/Extradural hematoma

38 Subdural hematoma Acute (± 6 hrs-3 days) hemorrhagic collection in subdural space Stretching & tearing of bridging cortical veins as they cross subdural space to drain into dural sinus Best diagnostic clue: Crescent-shaped, homogenously hyperdense on CT, extra-axial collection that spreads diffusely over affected hemisphere May cross sutures, not dural attachments May extend along falx & tentorium Compresses & displaces underlying brain Recurrent, mixed-age hemorrhage common -+ in a child raises suspicion of nonaccidental trauma! CT density & MR signal intensity vary with age & organization of hemorrhage

39 Subdural hematoma

40 Traumatic subarachnoid hematoma Best diagnostic clue: High density on CT, hyperintensity on FLAIR (MRI) within sulci/cisterns in setting of trauma FLAIR: Hyperintense sulci/cisterns FLAIR > CT in detection of small amounts of SAH

41 Head trauma brain contusion

42 Diffuse axonal injury Multifocal punctate hemorrhages at corticomedullary junction, corpus callosum, deep gray matter & upper brainstem Corpus callosum (20%) - 3/4 of which involve splenium/undersurface of posterior body Brainstem esp. dorsolateral midbrain & upper pons Multifocal hypointense foci on T2* GRE secondary to susceptibility from blood products at characteristic locations

43 Diffuse axonal injury

44 Types of Spinal Injuries

45 Spine trauma

46 C.V. fracture + cord lesion

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48 Meningitis Inflammatory infiltration of the pia mater, arachnoid and CSF Commonly related to hematogenous dissemination from a distant infection Can be divided into acute pyogenic (bacterial), lymphocytic (viral), and chronic (TB) meningitis Imaging may be normal early Imaging best delineates complications

49 Abscess Focal pyogenic infection of the brain parenchyma, typically bacterial Four pathologic stages : early cerebritis, late cerebritis, early capsule, late capsule Imaging varies with stage of abscess development: Early capsule : Well-defined, thin-walled enhancing rim High signal (restricted diffusion) on DWI, low ADC T2 hypointense abscess rim with surrounding edema Late capsule : Cavity collapses, thickened enhancement of capsule

50 Abscess

51 Multiple sclerosis Probable autoimmune-mediated demyelination in genetically susceptible individuals Most common disabling CNS disease of young adults; 1:1000 in Western world Best diagnostic clue : Multiple perpendicular callososeptal T2 hyperintensities Bilateral, asymmetric linear/ovoid FLAIR hyperintensities Perivenular extension ; "Dawson finger" Transient enhancement during active demyelination (> 90% disappear within 6 months) Rare : Large mass-like enhancing rings

52 Multiple sclerosis

53 Multiple sclerosis

54 Alzheimer dementia Progressive degenerative disease of brain due to abnormal accumulation of tau protein, which plays a key role in neuronal/filial dysfunction and cell death Best diagnostic clue : Parietal and temporal cortical atrophy w/disproportionate hippocampal volume loss Current role of imaging in AD is to exclude "treatable" dementias, identify early-onset cases for possible innovative therapy Coronal MRI documents atrophy of hippocampus and entorhinal cortex early in disease process and helps exclude other causes of dementia Identify early AD cases for possible therapy

55 Alzheimer dementia

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57 Location - children

58 Location - adults

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60 Pituitary microadenoma

61 Pilocytic astrocytoma

62 Cavernous sinus meningioma

63 Vestibular schwannoma Benign encapsulated nerve sheath tumor composed of differentiated neoplastic schwann cells 98% arise from cranial nerves (sensory) 90% 8th nerve; 10% 5th and 7th nerve hearing loss, tinnitus Slow growing extra-axial mass May enlarge bony foramina, most common CPA/IAC mass Intensive enhancement on CT and MRI

64 Vestibular schwannoma

65 Neurofibromatosis type 2 autosomal dominant, chromosome 22 lesion of Schwann cells, meninges CNS lesions in 15-20% bilateral acoustic neurinoma (typical), schwannoma of other cranial nerves meningiomas (multiple) cord ependymomas, bulky schwannomas of exiting roots orbital (and cutaneous) manifestation is absent

66 Neurofibromatosis type 2

67 Glioblastome multiforme

68 Metastasis

69 Maximum Signal Decrease map Knopp et al. Radiology :

70 rcbv=1.01 rcbv=1.42 Low-grade oligodendroglioma baseline and 68 weeks later (rcbv=1.42) weeks later

71 rcbv=13.37 rcbv=4.23 Low-grade mixed oligoastrocytoma baseline and 18 weeks later

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73 Table 2. National Society Consensus Guidelines for Headache Symptoms that Warrant Neuroimaging 1 Emergent neuroimaging recommended Neuroimaging recommended to determine if it is safe to do lumbar puncture "Thunderclap" headache with abnormal neurological exam Headache accompanied by signs of increased intracranial pressure Headache accompanied by fever and nuchal rigidity Neuroimaging should be considered Isolated "thunderclap" headache Headache radiating to neck Temporal headache in an older individual New onset headache in patient who is - HIV positive - has a prior diagnosis of cancer - is in a population at high risk for intracranial disease Headache accompanied by abnormal neurological examination, including papilledema or unilateral loss of sensation, weakness, or hyperflexia Neuroimaging not usually warranted No recommendation (Some evidence for increased risk of intracranial abnormality, not sufficient for recommendation) Migraine and normal neurological exam Headache worsened by Vasalva maneuver, wakes patient from sleep, or is progressively worsening No recommendation (insufficient data) Tension type headache and normal neurological exam

74 Spine imaging frequent indications Painful lumbar/cervical radiculopathy Spinal stenosis Sacro-iliac joint pain Vertebral compression fracture Spinal pain in cancer patients Mechanical back/neck pain Myelopathy Scoliosis Spondylolisthesis Postoperative imaging/failed back syndrome

75 Disc disease Standard medical practice would dictate that advanced imaging is generally not necessary if neck, back, or spine pain has resolved or is improving.

76 MRI of disc extrusion

77 Vertebral compression fracture

78 Vertebral metastasis

79 Spondylolisthesis

80 Interventional neuroradiology The following is a list of diseases and conditions typically treated by neurointerventionalists. Cerebral aneurysm Brain arteriovenous malformation (AVM) Carotid-cavernous fistula (CCF) Dural arteriovenous fistula Extracranial (brachiocephalic) atherosclerosis Extracranial (head and neck) and paraspinal vascular malformations Head and neck tumors Intracranial atherosclerosis Juvenile nasopharyngeal tumor Meningiomas Paragangliomas Stroke Spinal vascular malformations Traumatic vascular lesions Vasospasm Vertebral body tumors Vertebral body compression fractures

81 A stentelés Stenting lépései: of an internal előtágítás, carotid stent artery és stenoses utótágítás

82 Carotid cave aneurysm (coiled)

83 ACIbifurcation aneurysm

84 AVM

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86 Summary main imaging tools are CT and MRI CT is recommended primarily in trauma and in case of suspected intracranial hemorrhage MRI offers better tissue contrast and multiple contrast mechanisms MRI is necessary in pre-operative work-up CT- radiation issues neurointervention will have increasing role

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88 To describe the normal anatomy and physiology of the brain, skull, skull base, spine, spinal cord and nerve roots on cross-sectional imaging To describe the relative values of and indications for radiography, ultrasonography, CT and MRI in neuroradiology To explain when to refer a patient to ultrasonography/doppler sonography, CT or MRI in neuroradiology To list typical imaging features of ischaemic and haemorrhagic stroke on crosssectional imaging To describe common imaging features of traumatic brain injury and spinal trauma on cross-sectional imaging To list typical imaging features of white matter disease, inflammation and degeneration on cross-sectional imaging To describe typical imaging features of the most common tumours of the brain and spine To describe the anatomy and to describe typical imaging features of pathologies of pontocerebellar angle To describe the acute headache imaging management and to describe typical imaging features of related diseases To identify and describe the imaging features of brain complications: mass effect, infiltration, engagement, oedema, contrast enhancement To have a basic knowledge of neuroradiological interventions including revascularisation and coiling To have a basic understanding of the common indications, contraindications and limitations in neuroradiology