NEURORADIOLOGY _ IMAGING MODALITY

Simple Radiography Cheaper Accuracy is low

Only bone not the brain is visualized

NEURORADIOLOGY _ IMAGING MODALITY

CT Scan/ Computerized Tomography Magnetic Resonance Imaging CT Angiography Nuclear medicine__ PET, SPECT Ultrasound__ mainly for neonates INTERVENTIONAL RADIOLOGY

WHAT IS CT SCAN

CT imaging uses X-rays to produce cross sectional images/slices of the brain.

As x-rays pass through the body they are absorbed or attenuated differently. These varying attenuation value / CT value give information on normal and abnormal structure in the brain and spine producing an image

WHEN IS CT PERFORMED

CT Scanner is work horse of neuroimaging and is the imaging method of choice

.Trauma . Cerebro- vascular accidents .Epilepsy/ Fit/ Seizure . Altered consciousness . Pyrexia of unknown origin .Intracranial mass/ Raised ICT

CONTD.

CT plays a critical role in the early screening of

diagnosis of many brain diseases in spine imaging and in orbital facial disease

ABSOLUTE CONTRAINDICATION

Avoid screening in pregnancy Allergy to contrast Renal impairment Hypothyrodism Phaeochromocytoma Myaesthenia gravis

ADVERSE EFFECT

Radiation dose Reaction to Contrast eg. Average effective dose chest x-ray is about 20mSV, brain CT 2200mSV which is close to amount of back ground radiation that an average person receives in a year from atmosphere even if they don’t have any diagnostic imaging of any kind 2400mSV

This exposure can be from an external source irradiating the whole body, an extremity, or other organ or tissue resulting in an external radiation dose. Alternately, internally deposited radioactive material may cause aninternal radiation dose to the whole body, an organ, or a tissue.Smaller fractions of these measured quantities often have a prefix, such as milli (m) that means 1/1,000. For example, 1 sievert = 1,000 mSv. Micro (μ) means 1/1,000,000. So, 1,000,000 μSv = 1 Sv, or 10 μSv = 0.000010 Sv.Conversions from the SI units to older units are as follows:1 Gy = 100 rad1 mGy = 100 mrad1 Sv = 100 rem1 mSv = 100 mrem

CT SCAN COULD BE

Plain : NCCT Contrast: CECT contrast is not used in case of TRAUMA and CVA contrast goes to vascular and viable tissue

TRAUMA FRACTURE

TRAUMA EXTRADURAL

HEMATOMA

TRAUMA SUBDURAL

HEMATOMA

INFECTION__ PYREXIA

BRAIN ABSCESS

RAISED ICT __ HEADACHE

BRAIN MASS

CEREBROVASCULAR ACCIDENT

INFARCTION

CEREBROVASCULAR ACCIDENT

HAEMORRHAGE

PARASITIC INFECTION

NEUROCYSTICERCOSIS

RAISED ICT ON SHUNT

HYDROCEPHALUS

DEGENERATIVE BRAIN

ATROPHY

MAGNETIC RESONANCE IMAGING

MRI uses a strong magnetic field ( not x-ray) to create images of the body Radiofrequency pulse(RF) are generated to

interrogate the hydrogen atoms that make up the human body

Powerful computer process the returning RF signal

to form medical images As a rule MRI produces high resolution images in multiple planes

CONTD.

Depending on the coils and pulse sequence

selected MRI examination can be tailored to yield the desired diagnostic information

Pulse sequence: T1, T2,DW, STIR, etc……

WHEN IS MRI PERFORMED

MRI is used extensively for the study of blood

vessel flow dynamics , 3D volume rendering and stereotactic surgical guidance

MRI FOR BRAIN Stroke Infection / Inflammation Tumour Multiple sclerosis Dementia Post trauma Metabolic disorder Congenital disorder Internal auditory canal pathology Nerve palsy Spinal cord lesion

MRI _ OTHER INDICATION

Abdomen/ Pelvis Musculoskeletal tissue Cardiac__ Ischaemia, Tumour ,Infiltrative

CCM Vascular study Obstetrics__ Fetal anomaly esp cerebral

anomaly no risk of radiation

ABSOLUTE CONTRAINDICATION

Pacemaker, metalic body, implant, aneurysmal repair etc

ADVERSE EFFECT

No known side effect

ADVANCED MRI TECHNIQUE

Research make use of cutting edge technologies to

visualize not only anatomical images but also early changes that occur in brain function before there is any visible abnormality in structural imaging

eg. Functional MRI include diffusion perfusion and task activation research pulse sequence

HAEMORRHAGE ON MRI

CEREBROVASCULAR ACCIDENT

SPINAL TRAUMA VERTEBRAL DISLOCATION

DISC PROLAPSE BACKACHE

ANGIOGRAPHY _ DSA DIGITAL SUBSTRACTION ANGIOGRAPHY

It uses X-rays and injected contrast media to demonstrate the arteries and vein in real time .

It is NEUROANGIOGRAPHY when technique is applied to the vessel in brain

To see the blood vessel clearer DSA uses computers to remove / substract bone and other structures so that blood vessels stand out

WHEN IS DSA PERFORMED

To study the architecture of blood vessels Detecting and diagnosing vascular

anomaly Bleeding in brain and spinal cord Narrowing / spasm of blood vessel Stroke /Paralysis/ Hemiplegia Mass

ANGIOGRAPHY RENAL

ANGIOGRAPHY CARDIAC

NUCLEAR MEDICINE

Nuclear Medicine uses very small amount of radioactive material called Radiopharmaceuticals

Isotopes are specific for the part, injected or

given orally

Isotopes are distributed throughout the blood stream and are attracted to specific organs/ tissue

NUCLEAR MEDICINE

Isotope in the tissue emit gamma radiation which is detected and counted by gamma camera

The processed data over time provides functional and anatomical information about the part being imaged

TYPE OF NUCLEAR MEDICINE

BRAIN SPECT__ single photon emission tomography for

cerebral ischaemia, epilepsy

MIBI HEART PERFUSION SCAN__For Ischaemic heart disease

BONE SCAN__ For cancer, stress Fracture

THYROID UPTAKE SCAN__ For Thyroid nodule

V/Q SCAN__ For Pulmonary embolism

SPECT IN BRAIN

SINGLE PHOTON EMISSION TOMOGRAPHY

Mapping of Dopamine transport system in movement disorder like Parkinsonism

Specific tracer working at neuromuscular junction

POSITRON EMISSION TOMOGRAPHY

It is expensive

Positron tracer like carbon, nitrogen , oxygen are used for focal brain metabolism

Main use in ONCOLOGY

ISOTOPE SCAN THYROID

ISOTOPE SCAN BONE

SINGLE PHOTON EMISSION

TOMOGRAPHY SPECT

ULTRASOUND

Neonatal head for__Big head/Hydrocephalus Hypoxia Haemorrhage Birth trauma Subdural Haematoma Fits Congenital anomaly

NEONATAL BRAIN ON ULTRASOUND

HYDROCEPHALUS

INTERVENTIONAL RADIOLOGY

It is the technique used to treat blood vessel disease, tumour , clot/ thrombus etc in the brain

and spinal canal

Procedure is like angiography and then pushing the therapeutic agent like Thrombolytic agent in case of Infarction

Thank you

Dr Rekha Khare MD Radiology