MODALITY EXPLORATION AND RADIATION THERAPY

Magnetic Resonance Imaging

A radiologic examination that involves the use of strong magnets, radiofrequency waves, and computer to create an image of the internal structures of the body.

Nuclear Magnetic Resonance (NMR)

MRI was once called as ____

1947

(year)

MRI or NMR was discovered simultaneously in ________

* Felix Bloch
* Edward Mills Purcell

MRI or NMR was discovered simultaneously in 1947 by:

1971; Raymond Damadian

In _________, ________ provided an impetus to the development of actual clinical imaging using strong magnetic fields by suggesting that radio wave signal relaxation times of different tissues might be indicative of tumour malignancy

Paul Lauterbur; 1973

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_____________ provided the first 2D MR image of chemical sample in ______

* Primary Magnet
* Gradient Magnet
* Radiofrequency (RF) Coils
* Computer System

MRI Components (4)

Precession

The slow movement of the axis of a spinning body around another axis due to a torque acting to change the direction of the first axis.

Larmor or precessional frequency

The __________ in MRI refers to the rate of precession of the magnetic moment of the proton around the external magnetic field

magnetic moment

in Larmor Frequency,

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The _______ is the magnetic strength and orientation of a magnet or other object that produces a magnetic field.

Fourier transform

The ________ is a mathematical technique that allows an MR signal to be decomposed into a sum of sine waves of different frequencies, phases, and amplitudes.

Nuclear medicine

____________ is a specialized area of radiology that uses very small amounts of radioactive materials, or radiopharmaceuticals, to examine organ function and structure.

* Introduction of suitable radionuclide into the patient
* Concentration of radionuclide in the specific organ
* Scanning of organ using appropriate scanner

Three-Stage Process of Radionuclide Imaging (3)

* Irradiating materials in a nuclear reactor
* Using technetium generator
* Using a medical cyclotron

Common Ways on How to Produce Artificial Radionuclide (3)

nuclear reactor

A _________ produces and controls the release of energy from splitting the atoms of certain elements.

(1) nuclear power reactor

(2) heat

(3) electricity

In a _________, the energy released is used as _________ to make steam to generate _________.

technetium-99m generator, or colloquially a technetium cow or moly cow

A _____________ is a device used to extract the metastable isotope 99mTc of technetium from a decaying sample of molybdenum-99.

Cyclotron

____________ is an apparatus in which charged atomic and subatomic particles are accelerated by an alternating electric field while following an outward spiral or circular path in a magnetic field.

Gamma Camera

First developed by Hal Oscar Anger in 1958

(1) Hal Oscar Anger

(2) 1958

Gamma Camera is First developed by _________ in _________

(1) Gamma Camera

(2) NaI crystal (or multiple crystals)

(3) photomultipliers

____________ is a Specialized type of scintillation counter where the position as well as the count of the scintillations within a thin _____________ are obtained using a number of _____________

(1) scintillation camera or Anger camera

(2) scintigraphy

Also called a ____________, is a device used to image gamma radiation emitting radioisotopes, a technique known as ____________.

Scintillation

The process or state of emitting flashes of light

Scintillation

A small flash of visible or ultraviolet light emitted by fluorescence in a phosphor when struck by a charged particle or high-energy photon.

(1) visible or ultraviolet

(2) fluorescence

(3) high-energy photon

Scintillation is a small flash of _____________ light emitted by _____________ in a phosphor when struck by a charged particle or _____________.

1. Collimator
2. Scintillation Crystal
3. Array of Photomultiplier Tubes (PMTs)
4. Preamplifiers 3
5. Pulse Height Analyzer (PHA)
6. Digital Correction Circuitry
7. Cathode Ray Tube (CRT)
8. Control Console
9. Computer
10. Picture Archiving Communication System (PACS)

Gamma Camera System Components (10)

Pulse Height Analyzer (PHA)

An instrument that records or counts an electrical pulse if its amplitude falls within specified limits

Pulse Height Analyzer (PHA)

used in nuclear physics research for the determination of energy spectra of nuclear radiations

basic principle of the PHA

The _____________ is to discard signals from background and scattered radiation and/or radiation interfering isotopes so that the only primary photons known to come from the photopeak of the isotope being image and recorded.

(1) signals

(2) primary photons

The basic principle of the PHA is to discard __________ from background and scattered radiation and/or radiation interfering isotopes so that the only __________ known to come from the photopeak of the isotope being image and recorded.

PHA

The _________ discriminates between events occurring in the crystal that will be displayed or stored in the computer and events that will be rejected.

(1) displayed or stored

(2) rejected

The PHA discriminates between events occurring in the crystal that will be _____________ in the computer and events that will be _____________.

lead

Collimator is made from _________

Collimator

Maintains the quality of the image.

Collimator

___________ consisting of a series of holes in a lead plate can be used to select the direction of the rays falling on the crystal.

1. Parallel-hole collimator
2. Pin-hole collimator
3. Diverging collimator
4. Converging collimator

Four types of collimator

Ultrasonography

____________ is a diagnostic medical procedure that uses sound waves to produce images on a screen, which allows medical providers to view internal structures of the body.

sound waves

Ultrasonography is a diagnostic medical procedure that uses __________ to produce images on a screen, which allows medical providers to view internal structures of the body.

340 m/s

Approximate Speed of Sound

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1. Air –

650 m/s

Approximate Speed of Sound

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2. Lung –

1460 m/s

Approximate Speed of Sound

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3. Fat –

1500 m/s

Approximate Speed of Sound

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4. Pure water –

1530 m/s

Approximate Speed of Sound

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5. Salt water –

1560 m/s

Approximate Speed of Sound

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6. Kidney –

1570 m/s

Approximate Speed of Sound

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7. Blood –

1580 m/s

Approximate Speed of Sound

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8. Muscle –

3000 m/s

Approximate Speed of Sound

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9. Bone –

Echogenicity or echogeneity

___________ is the ability to bounce an echo

echogenecity

Echogenicity is misspelled sometimes as __________

1. Hypoechoic
2. Hyperechoic
3. Anechoic

Three types of Echogenicity

Transducer

A device that produces sound waves that bounce off body tissues and make echoes.

(1) transducer

(2) receives

(3) sends

(4) sonogram

The _________ also _________ the echoes and _________ them to a computer that uses them to create a picture called a _________.

sonogram

The transducer also receives the echoes and sends them to a computer that uses them to create a picture called a _______.

Piezoelectric Effect

____________ is the ability of certain materials to generate an electric charge in response to applied mechanical stress.

(1) piezein

(2) squeeze or press

(3) piezo

(4) “push”

The word Piezoelectric is derived from the Greek _______, which means to _______, and _______, which is Greek for _______.

piezoelectric effect

The ____________ converts kinetic or mechanical energy, due to crystal deformation, into electrical energy.

The piezoelectric effect converts kinetic or mechanical energy, due to crystal deformation, into electrical energy.

This is how ultrasound transducers receive the sound waves.

inverse piezoelectric effect

the application of an electric field to a crystal causes realignment of the internal dipole structure. This realignment results in crystal lengthening or contraction, converting electrical energy into kinetic or mechanical energy.

(1) internal dipole structure

(2) lengthening or contraction

The same effect can be used in reverse – inverse piezoelectric effect – whereby the application of an electric field to a crystal causes realignment of the ______________. This realignment results in crystal ______________, converting electrical energy into kinetic or mechanical energy.

realignment of the internal dipole structure that results in crystal lengthening or contraction, converting electrical energy into kinetic or mechanical energy.

This is how ultrasound transducers produce sound waves

Ultrasound gel

________________ is a conductive medium that creates a bond between the skin and the ultrasound transducer.

(1) sound waves

(2) air

(3) gel

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The ultrasound ___________ have a hard time traveling through ___________, so the ___________ prevents any extra air space between the probe and your skin in order to create a clear image

Transducer damping

a material (damping element, damping material) bonded to the back of the piezoelectric element of a transducer to limit the duration of vibration

* Inexpensive
* Quick
* Mobile
* Non-invasive
* Can depict free fluid and aneurysms, e.g. in acute aneurysms
* Can differentiate between solid and fluid structures
* Can depict flow and motion
* Good for shallow structures

Ultrasonography

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Strengths (8)

* Operator dependent
* Images may be hard to interpret
* Suffers from image artefacts
* May be prone to giving “false positives”
* Not good for deep structures
* Cannot penetrate through bone or air

Ultrasonography

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Weaknesses (6)

Interventional Radiology

Began in 1930s with angiography

Mason Jones

(early 1960s) pioneered transbrachial selective coronary angiography

Melvin Judkins

introduced coronary angiography

Charles Dotter

introduced visceral angiography

Angiography

Refers to the opacification of vessels through injection of contrast media

* Imaging Procedures
* Interventional Procedures

Procedures in IR Suite (2)

* Angiography
* Aortography
* Arteriography
* Cardiac catheterization
* Myelography
* Venography

Procedures in IR Suite

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Imaging Procedures (6)

* Stent Placement
* Embolization
* Intravascular Stent
* Thrombolysis
* Balloon Angioplasty
* Atherectomy
* Electrophysiology

Procedures in IR Suite

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Interventional Procedures (7)

Atherectomy

_________ is a minimally invasive endovascular surgery technique for removing atherosclerosis from blood vessels within the body.

angioplasty

Atherectomy is an alternative to ________ for the treatment of peripheral artery disease, but the studies that exist are not adequate to determine if it is superior to angioplasty.

angioplasty

treatment of peripheral artery disease

stent

A _______ is a tiny tube that your doctor can insert into a blocked passageway to keep it open.

stent

The _______ restores the flow of blood or other fluids, depending on where it's placed.

metal or plastic

Stents are made of either ____________

Stent grafts

________ are larger stents used for larger arteries.

Electrophysiology

__________ is the branch of physiology that pertains broadly to the flow of ions (ion current) in biological tissues and, in particular, to the electrical recording techniques that enable the measurement of this flow.

Balloon angioplasty

__________ is the surgical widening of a blocked or narrowed blood vessel, especially a coronary artery, by means of a balloon catheter.

balloon catheter

Balloon angioplasty is the surgical widening of a blocked or narrowed blood vessel, especially a coronary artery, by means of a _________.

Embolization

_________ is the artificial or natural formation or development of an embolus.

Sven Ivar Seldinger

___________ described a method of arterial access in which catheter was used.

1953

in _________ Sven Ivar Seldinger – described a method of arterial access in which catheter was used.

Seldinger needle

18 gauge hollow needle with stylet

Guidewires

Allows safe introduction of the catheter into the vessel

Guidewires

Fabricated of stainless steel and contain an inner core wire that is tapered at the end to a soft flexible tip

145 cm

Conventional guidewires are _______ long

Catheters

Categorized in French (Fr) sizes

(1) 3 Fr

(2) 1 mm

Catheters are Categorized in French (Fr) sizes; _____ equal to _____ in diameter

H1 or headhunter tip

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used for femoral approach to the brachiocephalic vessels

Vincent Hinck

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H1 or headhunter tip is designed by _______

Simmons catheter

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highly curved designed for cerebral angiography

C2 or Cobra Catheter

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has angled tip for celiac, renal, and mesenteric arteries

Pigtail

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have side holes for ejecting contrast media into a compact bolus

(1) 20 feet

(2) 500 ft2

In Interventional Radiology Suite, Procedure room should not be less than _______ along any wall and not less than _______

(1) large

(2) 100 ft2

In Interventional Radiology Suite, Control room must be ______, perhaps ______

Interventional Radiology Suite

have 2 or 3 radiographers, interventional radiologist, radiology nurse