The document discusses the importance of physiotherapists understanding basic MRI interpretation. It notes that some patients come for treatment without their MRI interpretation sheet, leaving blank images for the physiotherapist to interpret. Having a basic understanding of MRI principles, machine components, image types and interpretation helps physiotherapists confirm assessments when the interpretation sheet is missing. The document aims to provide this foundational MRI knowledge for physiotherapists.
1. Basic Understanding on
Magnetic Resonance Imaging
(MRI) & Interpretation of MRI
Images
By : QF Gan, PT, MSc Human Anatomy (Batch
2. Is MRI Important
I am a Physiotherapist. During my student years, I used
to think that MRI is totally not important for a
Physiotherapist. The reason behind this is because in
every patient with MRI, there is a interpretation sheet that
comes along to tell the clinician exactly what exactly is the
findings from MRI.
However, there are times where some patient’s who walk
in for treatment with his/her MRI but forgotten the MRI
interpretation sheet. Without the knowledge, how am I to
interpret those MRIs images given in order to confirm my
assessment? Of course, everything I see is blank and
white images not knowing what are those, where to start
and how it goes.
Hence, the question is, ‘Is the basic understanding and
ability to interpret MRI images important for
physiotherapist?’
3. Content
Brief History
Introduction to MRI
MRI Machine
Principles of MRI
Advantages & Disadvantages
Indications for MRI
Contraindications
Types Of MRI Machine
Strength of Magnetic Field Used in MRI
MRI Contrast Agent
Types of MRI Images
Basic Interpretation of MRI
Q & A Session
By: Gan Quan Fu, PT
4. Brief History
Invented by Paul C.
Lauterbur in September
1971
Paul Lauterbur of the
University of Illinois at
Urbana-Champaign & Sir
Peter Mansfield of the
University of Nottingham
were awarded the 2003
Nobel Prize in Physiology
or Medicine for their
discoveries of MRI. By: Gan Quan Fu, PT
5. Introduction to MRI
Uses magnetic field & radio waves to
create detailed images of organs &
tissues within the body.
Also known as nuclear magnetic
resonance (NMR).
No ionizing radiation
Employs radiofrequency pulse ranging
from 1 to 80MHz
By: Gan Quan Fu, PT
8. Principles of MRI
Human body made up of chemical
composition (ie: hydrogen, carbon,
nitrogen sodium, phosphotus, potassium
etc.)
Atoms these elements have different
number of protons in their nucleus and
possess different magnetic property.
Protons of hydrogen atom are the most
abundant in the body in the form of
water.
Magnetic properties of these atoms have
been utilized to produce magnetic
resonance signals and images.
By: Gan Quan Fu, PT
9. Principles of MRI
When a patient is placed in a strong
magnetic field in MR scanner,
hydrogen nucleus in the body align
with the applied external magnetic
field.
Hydrogen nuclei in the patients body
absorbs the energy and then
generates the MR signal when
exposed to short bursts of
electromagnetic energy in form of
radio frequency pulse.By: Gan Quan Fu, PT
10. Principles of MRI
The magnet creates a strong magnetic
field which aligns the protons of
hydrogen atoms which are then
exposed to a beam of radio waves.
This spins the various protons of the
body and produce a faint signal which
is detected by receiver portion of the
MRI scanner.
The receiver information is processed
by computer and image is produced.
By: Gan Quan Fu, PT
12. Advantages & Disadvantages
Advantages Disadvantages
1. Excellent soft tissue
contrast resolution
2. Ability to obtain direct
transverse, sagittal,
coronal and oblique
images
3. Does not use ionizing
radiation
4. Does not produce
bone/air artefacts
1. Longer imaging time
2. Complexity of the equipment
and scan acquisition
3. High Cost
4. Inability to demonstrate
calcification or cortical bone
details
5. Bullet shrapnel and metallic
fragments may move and
become projectile
(Contraindicated for patients
with Cardiac pacemakers,
dental implants, heart valve
prosthesis and aneurysm
clips)By: Gan Quan Fu, PT
13. Indications for MRI
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By: Gan Quan Fu, PT
14. Contraindications
Cardiac pacemakers
Brain aneurysm clip
Aortic clip
Artificial heart valve
Insulin pump
IUD
Joint replacement
Prostheses (such as cochlear implant)
Wire sutures
Dentures (Must be Removed)
Claustrophobia (Can be sedated or use open
MRI)
By: Gan Quan Fu, PT
15. Types of MRI Machine
Most MRI scanners, patient examination
table fits inside a long cylindrical tube.
3 Common Types of MRI Machine:
◦ Open MRI Units
Patient placed between two plates
Early versions had low magnetic field strength, gave
poorer image quality
Required longer examination times.
◦ Closed MRI Units
Short magnets and wide bore tubes offer improved
comfort.
Alternative to open scanners.
Gives better Image than open MRI units.
◦ High field MRI
Uses very strong magnet
Higher picture resolution, fast scans, and ability to
visualize physiological processes.By: Gan Quan Fu, PT
17. Strength of Magnetic Field Used
in MRI
Measured in Tesla (T)
[Developed by Nikola
Tesla]
Open MRI units
◦ 0.1T to 0.3 T
Closed MRI unit
◦ 0.5 T to 0.6 T
High field MRI
◦ 1.0 T to 3.0 T or higher
By: Gan Quan Fu, PT
18. MRI Contrast Agent
Group of contrast media used to improve
visibility of internal body structures in
magnetic resonance imaging (MRI).
Examples are:
◦ Gadolinium
◦ Paramagnetic agent
Shortens the T1 relaxation time and produces
increased signal intensity on T1W images.
Dose 0.1 to 0.2 mmol/kg body weight.
Side Effect:
◦ Nausea
◦ Vomiting,
◦ Headache,
◦ Seizures,
◦ Anaphylaxis
By: Gan Quan Fu, PT
19. Types of MRI Images
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By: Gan Quan Fu, PT
20. Basic Interpretation of MRI
T1
◦ Bright
Fat
Blood
Contrast
◦ Dark
Fluid
Cortical Bone
T2
◦ Bright
Fluid
◦ Dark
Cortical bone
By: Gan Quan Fu, PT
21. T1W MRI Image Interpretation
(Neuro)
T1
◦ Bright
Fat
Blood
Contrast
Dark
Fluid
Cortical Bone
Skull
Bone
Fat in
SCALP Fluid CSF
By: Gan Quan Fu, PT
22. T2W MR1 Image Interpretation
(Neuro)
T2
◦ Bright
Fluid
◦ Dark
Cortical bone
Skull Bone Fluid CSF
By: Gan Quan Fu, PT
23. T1W Image vs T2W Image
(Neuro)
By: Gan Quan Fu, PT
24. Multiple Sclerosis
Useful for diagnosis
and to assess
progress of the
disease.
Plaques of
demyelination are
seen in the white
matter.
By: Gan Quan Fu, PT
25. Magnetic Resonance Angiogram
(MRA)
Type of MRI scan which
uses a magnetic field and
pulses of radio wave
energy to provide pictures
of blood vessels inside the
body.
Images are generated in
which only structures
containing flowing blood
are visualized.
Can demonstrate:
◦ Occlusions
◦ Stenosis
By: Gan Quan Fu, PT
31. Magnetic Resonance
Cholangiopancreatogram
(MRCP)
Technique uses magnetic resonance
imaging to visualize the biliary and
pancreatic ducts in a non-invasive
manner.
Can be used to determine if gallstones
are lodged in any of the ducts
surrounding the gallbladder.
Excellent for demonstration of:
◦ Biliary tract
◦ Pancreatic duct
◦ Gallbladder
By: Gan Quan Fu, PT
32. Advantages & Disadvantages
MRCP
Advantages Disadvantages
► Rapid imaging-single
breath hold
► Noninvasive vs.
Endoscopic retrograde
cholangiopancreatograph
y (ERCP)
► No complications
► No IV or PO contrast
► Less expensive than
ERCP
► Sensitivity & specificity
►Purely diagnostic
►Does not provide access
for treatment
►ERCP better at
demonstrating bile duct
leaks
– Contrast introduced
directly into ducts
By: Gan Quan Fu, PT
34. MRI of Pancreas
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By: Gan Quan Fu, PT
35. MRI of Breast
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By: Gan Quan Fu, PT
36. MRI Breast Cancer
Very large lymph node (arrow) in Patient with
breast cancer
By: Gan Quan Fu, PT
37. MRI in Musculoskeletal
To demonstrate disc herniation and
spinal cord or nerve root compression
To diagnose bone metastasis
Extent of primary bone tumour and to
demonstrate myeloma and lymphoma
To image soft tissue masses
To image Osteomyelitis
Joint pathologies and injuries to
cartilages and ligaments
By: Gan Quan Fu, PT
38. Spine
MRI is a better way of looking in
detail at the inner ear, cranial and
spinal nerves.
MRI also looks at the state of
vertebrae and discs.
By: Gan Quan Fu, PT
39. Spine
By: Gan Quan Fu, PT
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41. Joints Tendon and Ligaments
Most accurate examination available
for joints and the surrounding tendons,
ligaments and cartilage.
Helpful for sports related injuries.
By: Gan Quan Fu, PT
45. Pelvis
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By: Gan Quan Fu, PT
46. Pelvis Male & Female (Sagittal)
Male Female
By: Gan Quan Fu, PT
47. Pelvis
By: Gan Quan Fu, PT
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48. Full Body MRI
Allows high resolution
regional MRI scans to
be added creating a
composite study.
Purpose:
◦ Search for tumors or
secondary spread.
◦ Ideal for follow up of
systemic disease.
Head, chest, abdomen
and pelvis are zipped
together.
By: Gan Quan Fu, PT
Spectroscopy = Study of the interaction between matter and radiated energy.
Non-ionizing (or non-ionising) radiation = Any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule.
Ionize = Convert (an atom, molecule, or substance) into an ion or ions, typically by removing one or more electrons.
Fluid Attenuated Inversion Recovery (FLAIR) is an inversion-recovery pulse sequence used to nullify the signal from fluids. For example, it can be used in brain imaging to suppress cerebrospinal fluid (CSF) so as to bring out periventricular hyper intense lesions, such as multiple sclerosis (MS) plaques. By carefully choosing the inversion time TI (the time between the inversion and excitation pulses), the signal from any particular tissue can be suppressed.