Medical imaging

•Overview of various medical imaging/treatment techniques•My History•Endoscopes.•Assessment

•Diagnostic X-Ray machine.

Assessment

Presentation Monday Look at assessment sheet 5 minute How are you going to present? 2 minute Draw mind map – Brianstorm how are

you covering all points in assessment sheet? 15-20 minutes

Start research http://www.radiologyinfo.org/

Assessment – Searching terminology CT = Computed Tomography Tomography CAT = Computed Axial Tomography PET = Positron Emission Tomography Tomography Nuclear medicine PET Ultrasound = Ultrasonography MRI = Medical Resonance Imaging

Assessment Google Search try key words with How does it work *Principals Explanation *Working

model Basic Info * Very basic

No equations or info on equations

Assessment

Look at assessment sheet 5 minute How are you going to present? 2 minute Draw mind map – Brainstorm how are

you covering all points in assessment sheet? 15-20 minutes

Start research http://www.radiologyinfo.org/

Assessment Start research When researching be sure to copy good notes

to word file so you have them later also copy URL

Download pictures as you go that may be useful.

Once you go through a website you should close it.

Go through each point in you mind map finding information once found move on to next.

Assessment Start research Literature 1st – Understanding needed

Images, you tube later – Confirm video correct

http://www.radiologyinfo.org/ http://onoimaging.blogspot.com.au/ www.britannica.com Google Search try key words with How does it work *Basic/Principals Explanation *Working model Basic Info *Role of

Assessment PET http://www.petnm.unimelb.edu.au/pet/de

tail/principle.html http://www.radiologyinfo.org/en/info.cfm

?pg=pet http://www.ncbi.nlm.nih.gov/pmc/articles

/PMC1126321/

Assessment Ustrasound, Ultrasonography http://onoimaging.blogspot.com.au/2008

/07/basic-principles-of-ultrasonography-usg.html

Assessment CT Computed Tomography http://www.impactscan.org/slides/

impactday/basicct/

Assessment MRI http://www.medindia.net/patients/patientinfo/

magneticresonanceimaging_working.htm - Very basic http://onoimaging.blogspot.com.au/2008/07/basic-

principles-of-magnetic-resonance.html http://www.refindia.net/rlinks/reviewedlinks/mri.htm - Great http://www.e-radiography.net/mrict/Basic_MR.pdf p1-2, 6, 12+ http://vimeo.com/15223414 - Not basic but take basics

from it http://www.simplyphysics.com/page2_1.html

Medical Imaging/treatment Radiation

Diagnostic X-ray, CT (Computed Tomography), PET (Positron Emission Tomography), LINEAC (Linear Accelerator)

Non-ionisingMRI (Magnetic Resonance Imaging),

Ultrasound/Sonography (Sound wave), Endoscope (light)

CT (Computed Tomography)Computed axial tomography (CAT)

Digital geometry processing is used to generate a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation

PET (Positron Emission Tomography)

The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide

LINIAC (linear accelerator)Is an accelerator that greatly increases the velocity of charged subatomic particles or ions by subjecting the charged particles to a series of oscillating electric potentials along a linear beam line.

LINIAC range in size from a cathode ray tube (which is a type of linac) to the 2-mile (3.2 km) long linac

MRI (Magnetic Resonance Imaging)Medical imaging to visualize detailed internal structures. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.

Uses the varying magnetic properties of atoms to produce an image

Ultrasound/ SonographyDiagnostic imaging technique used for visualizing subcutaneous body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions

Uses sound waves to produce an image

Assessment

Chose one modality each- no repeats Next class Wednesday - research/ask

questions. Friday – presentation Mark 80% teacher, 20% fellow peers

About Mr Rainbow

RMIT graduated 2004 – Bachelor Applied Science (Medical Science - Radiation Therapist)

Peter MacCallum 2005-2009Head & Neck Specialist

Radiation Therapy Treatment – LINIAC, X-Ray, Palliative,

Brachytherapy, Surgery, Chemotherapy

Radiation Therapy

Planning – CT, PET/CT, X-Ray, Planning software

Radiation Therapy

About Mr Rainbow

LINIACBramstraughn effect, 6mV – 21mVIonising radiation – Compton effect

Endoscopy

Means looking inside

Typically refers to looking inside the body for medical reasons using an endoscope

EndoscopyAn endoscope can consist of a rigid or flexible tube a light to illuminate the organ or object under

inspection. A lens system transmitting the image to the

viewer from the objective lens to the viewer, typically a relay lens system in the case of rigid endoscopes or a bundle of fiberoptics in the case of a fiberscope/flexible endoscope

an eyepiece an additional channel to allow entry of medical

instruments or manipulators

Endoscopy

An endoscope can consist of The ability to 'steer' the tip, remotely operated surgical instruments

contained within the body of the endoscope itself.

This is "key-hole surgery" as we know it today.

Endoscopy

Rigid Endoscope is solid metal tube with a series of lens inserted in the tube

Flexible Endoscope, the principle optical component is either a plastic or glass fibre bundle for delivery of the image, plus additional fibres for the light.

Endoscopy The gastrointestinal

tract (GI tract): The respiratory tract The nose (rhinoscopy) The ear (otoscope) The urinary tract

(cystoscopy) The female

reproductive system (gynoscopy)

Normally closed body cavities (through a small incision):

Plastic Surgery During pregnancy The interior of a joint Organs of the chest Orthopedic surgery Endodontic surgery

Endoscopy

Other uses

Endoscopes are also a tool helpful in the examination of improvised explosive devices by bomb disposal personnel

Search and rescue teams in natural disasters, mine collapse etc.

Endoscopy

Endoscopy

X-ray Machines

X-ray Machines

Discovery of X rays Production of X rays Dignostic X Ray interaction with matter Image aquisition Evolution of X ray machines Safety aspects of X ray machine X-ray usage today.

X-ray Machines

Rontgen Rays or X Rays1895 experimenting with Cathode rays Cupboard glowed painted in Barium

Platinocyanide Barium Platinocyanide screenTesting – small piece of lead while a

discharge was occurringFour photographs with his first paper;

○ The hand of his wife, a set of weights, a compass, and a piece of metal

X-ray Machines

X-ray Machines

Waves of Electromagnetic Radiation

X-ray machines – Cathode tube

Electrons are passed from the Cathode to the Anode

Electrons hit a tungsten target and through the interaction produce X rays.

X-ray machines – Filament/Cathode

•The Cathode is the negative side of the x-ray tube.

•The purpose of the cathode is to conduct a high voltage to gap between cathode and anode.

•Flow of electrons from cathode to anode.

X-ray machines – Anode

Tungsten Hi Atomic number

High melting point High-conducting

ability


•A target for high-voltage electrons from the filament; thereby becoming the source of the x-ray photons.•Conducts the high voltage from the Cathode back into the circuit.

•The purpose of the cathode is to conduct a high voltage to gap between cathode and anode.

•Flow of electrons from cathode to anode.


Tungsten – is the target surface is where the high speed electrons are attracted from the filament are suddenly stopped.

Braking radiation" or "deceleration radiation"

X-ray machines – X-ray production X rays are produced by 2 forms of

electron interaction with the tungsten target.

Bremsstrahlung Characteristic Photons

X-ray machines – X-ray Bremsstrahlung production

X-ray machines – X-ray Characteristic Photon

X-ray machines – X-ray Photon Energy

X-ray machines

The energy will be mono-energetic and so appear as a spike rather than a continuous spectrum. Electrons ejected come from the K, L or M orbits. The other corollary of this type of interaction is that the atom becomes an ion

The average energy of a bremsstrahlung-derived beam is approximately 1/3 of the maximum energy (or kVp)

X-ray machine - Filtration The bremsstrahlung photons generated within

the target material are attenuated as they pass through typically 50 microns of target material. The beam is further attenuated by the aluminum or beryllium vacuum window.

The results are an elimination of the low energy photons, 1 keV through l5 keV, and a significant reduction in the portion of the spectrum from 15 keV through 50 keV. The spectrum from an x-ray tube is further modified by the filtration caused by the selection of filters used in the setup.




X-ray Machines

A nail gun shot six nails into construction worker Isidro Mejia's head during an April 2004 accident. He not only survived but was

expected at the time to recover fully.

X-ray machines – Image

X-rays are directed at the area of interest at patient.

Correct kV is chosen. Film/image screen is placed behind the

patient Only the X-rays that have not been

attenuated (scattered) are wanted to form the image



X-ray Machines

A An 6-inch pair of surgical scissors appears in the abdomen of Australian Pat Skinner in April 2004 -- 18 months after

her initial operation.

The Black area of the film has

been exposed by x-rays.

The white area shows less radiation

exposed to that area of the film.

X-ray Machines

Python Gulps Down Queen-Size Electric Blanket. It took surgery to save a 12-foot Burmese python after it swallowed an entire queen-size

electric blanket - with the electrical cord and control box.

X-ray machines Security – ports, air ports, baggage,

container scans, product scans Dental, Vet, Aeroplane – small wing cracks. Manufacturing/industrial – check welds X-ray microscopic analysis, which uses

electromagnetic radiation in the soft X-ray band to produce images of very small objects.

X—ray hair removal 1920’s

X-ray machines - Evolution

Evolution Fixed Tungsten Target to rotating

X-ray machines - Evolution

Grid on imaging plate to decrease scatter.

Portable - power sources – E.R Digital image acquisition Internet Lower emissions

X-ray machine - Safety

Housing – designed to absorb scattered x-rays from tungsten target –Lead shielding

Operated behind lead glass, concrete walls.

TLD - Thermo Luminescent Dosimeter In Emergency Rooms – Lead aprons Inverse Square law I/R2

Emergency shutdown switches Qualified Staff

X-ray machines Serurity – ports, air ports, baggage,

container scans, product scans Dental, Vet, Aeroplane – small wing cracks. Manufacturing/industrial – check welds X-ray microscopic analysis, which uses

electromagnetic radiation in the soft X-ray band to produce images of very small objects.

X—ray hair removal 1920’s

X-ray machines


Tungsten Hi Atomic number

High melting point High-conducting

ability

X-ray machines – X-ray production X rays are produced by 2 forms of

electron interaction with the tungsten target.

Bremsstrahlung Characteristic Photons


X-ray Quiz

Organise these in terms of flow from electron source to X-ray. Start to finish.

Key terminology

Characteristic Photon, Patient, Anode, Tungsten Target, Film, Filament, Cathode, Bremsstrahlung, Scatter Filter, Casset.

X-ray Quiz

1. Cathode,1. Filament,2. Tungsten Target,2. Anode,3. Bremsstrahlung, Characteristic Photons, 4. Patient, 5. Scatter Filter, 6. Cassette, 7. Film.

Thank You

Thank You

Business

Medical imaging