Radiology modalities
Download
1 / 18

Radiology Modalities - PowerPoint PPT Presentation


  • 155 Views
  • Updated On :

Radiology Modalities. Jeff Binder R.T. (R). Plain film. Strengths. Weaknesses. Readily available Low cost Well known uses Best line pair performance . False negatives (fx) Ionizing radiation Poor resolution Poor soft tissue visualization Poor spacial localization

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Radiology Modalities' - lamar


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Radiology modalities l.jpg

Radiology Modalities

Jeff Binder R.T. (R)


Plain film l.jpg
Plain film

Strengths

Weaknesses

  • Readily available

  • Low cost

  • Well known uses

  • Best line pair performance

  • False negatives (fx)

  • Ionizing radiation

  • Poor resolution

  • Poor soft tissue visualization

  • Poor spacial localization

  • C1/c2, c6/c7 hard to visualize

Attenuating technology


Proper uses l.jpg
Proper uses

Rule out advanced imaging

Introductory study

Evaluates IVF well

Not good for central canal stenosis


Tomography l.jpg
Tomography

Xray images taken in “sections” (slices)

Blurs areas that are not of interest

Similar strengths and weaknesses as plain film

Attenuating technology


Myelography l.jpg
Myelography

Xray images taken of spinal cord after radiopaque contrast is injected

When used with CT it is the best tool to visualize central canal stenosis

Dr. looks for displacement of contrast on xray

Attenuating technology


Complications l.jpg
Complications

Headache (most common)

Infections

Arterial bleeding

Arachnoiditis

First contrast used was air


Bone scan l.jpg
Bone Scan

Technetium 99 radio isotope used

Emission technology (from the patient)

“hot spots” on scan are osteoblastic activity

SPECT: Single Photon Emission Computerized Tomography

Phosphate used as carrier molecule

PET: Positron Emission Tomography

Glucose used as carrier molecule


Computerized tomography l.jpg
Computerized Tomography

Attenuating technology

Computer generated pictures

Hounsfield Units

Pixels and voxels

Volume averaging used

Slice thickness scout films used


Slide9 l.jpg

Strengths

Weaknesses

  • Widely available

  • Improved soft tissue visualization

  • 3d imaging

  • Accurately measure a variety of structures

  • Image manipulation possible (bone and soft tissue windowing)

  • May be combined with myelogram for canal stenosis exam

  • Ionizing radiation

  • Higher cost

  • Intracranial artifacts

  • Artifacts secondary to metallic implants

  • Radiation dose


Ultrasound l.jpg
Ultrasound

Sound waves used to form images

No radiation

Readily accessible

Lower cost

Interact with patient


Magnetic resonance imaging l.jpg
Magnetic Resonance Imaging

  • Emission technology (from the patient)

  • Hydrogen molecules used for emission

  • Cortex of bone=black

    • Due to lack of hydrogen (water molecules)

  • Evaluates Physiology


Slide12 l.jpg
Uses

Spinal fracture

Soft tissue injury

Skeletal survey for metastasis

Post traumatic complications

Peripheral entrapment

Central canal stenosis

Intracranial abnormalities

Vascular imaging (MRA first choice)


Slide13 l.jpg

  • Magnet (field) strength depicts image quality

    • 1.5 tesla magnetic minimum

    • Larger the magnet= better image quality

  • RF coils are placed on or near the patient to excite the tissue

  • Larmor equation

    • Frequency of procession= gyro magnetic ratio x strength of field


Relaxation times l.jpg
Relaxation Times

White= high signal, Many H+ emitting signal

Black= low signal, No H+ emitting signal

Tr= Repetition time

Te= echo time


Slide15 l.jpg
T1

Cortex=black

CSF=black

Fat=white

Tr= 200-600ms

Te= 25ms


Slide16 l.jpg
T2

Cortex=black

CSF=white

Tr= ~1500+ ms

Te= 50+ ms


Slide17 l.jpg
fMRI

  • BOLD: Blood Oxygen Level Dependant

  • Physiology presented

    • Cortical activation

    • Retinotopic organization of the visual cortex

    • Cerebral basis for language

    • Mapping of the motor cortex

    • Memory

    • Studying psychiatric disorders

  • Advantages over PET

    • No ionizing radiation, less expensive, widely available, studies can be frequently repeated


Slide18 l.jpg
FMRI

Fake functional

Computer tricks to make a study look like a motion study.

Really a series of static images


ad