Residents Review Course

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Residents Review Course

• Common Radiology Procedures
• An Incomplete Positioning Guide

George David, MS, FAAPM Lou Ann Burnett,
BSRT Department of Radiology Medical College of
Georgia Augusta, Georgia
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The Radiology DepartmentsInner Workings
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The Language of Diagnostic Radiology
LAO
Bucky
All the KUBs looked light this morning?
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The Language of Diagnostic Radiology
Grids
Phototiming
Hes gotta be taller than that!
Did we use a 40 SID?
40?
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The Language of Diagnostic Radiology
Decub
Barium Enema
Did they quit?
Well, man, did you think to checkfixer
retention?
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Common Practice40 SID for Table Bucky
X

• Used for
• table bucky
• table top
• compromise between
• intensity fall-off with square of SID
• geometric unsharpness

SID
Patient
Cassette in Bucky
SID source-image (receptor) distance
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Common Practice72 SID for Chest

• compromise between
• intensity fall-off
• geometric unsharpness
• undesirable magnification of heart

SID
X
Cassette in Chest Bucky
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More Common Practice Phototiming

• Exposure time controlled by generator
• based on sampled radiation
• Used only for bucky exposures
• not tabletop
• Positioning critical

Fixed Technique kVp kVp mA mAs time
Phototimed kVp density sensor cell location
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Bucky Imaging

• uses moving grid
• reduces scatter
• blurs grid lines
• increases patient exposure
• phototiming available

X
SID
Patient
Grid
Cassette in Bucky
Phototimer Sensor
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Non-Bucky Imaging

• small body parts / extremities
• minimal scatter
• situation precludes bucky use
• portables
• cross-table lateral
• phototiming not available

X
SID
Body Part
Cassette
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Automatic Artifact

• Occurs whenever we image a 3D object in 2D
• Work-around
• Multiple views

?
?
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Distortion Types
minimal distortion when object near central beam
close to film
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Common Projection Terminology
A Anterior (front) P Posterior (back)
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Common Projection Terminology

• RAO
• LAO
• RPO
• LPO

Can you identify this man?
R Right L Left A Anterior (front) P
Posterior (back) O Oblique
Left Posterior of Patient Closest to Film
LPO
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Welcome to Quark's!
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Decubitus Projection

• Patient on side
• Causes changes in fluid levels
• Visualizes
• plural effusion
• air in abdomen

Patient
Cassette
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Common Positioning Landmarks
orbitomeatal line
coracoid process
manubrial notch
iliac crest
symphysis
patella
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Chest Plain X-Ray
Technique

• High kVp
• high latitude required
• Phototimed
• patient upright
• fluid levels / air

• PA
• LAT

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Chest Plain X-Ray

• Minimizes heart magnification
• 72 SID
• PA view
• LAT with left side toward receptor

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Chest Plain X-Ray

• Shoulders rolled forward to remove scapulae
  shadows
• Include both lung apices and costophrenic
  angles
• Full inspiration

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Chest Plain X-Ray
Lordotic view

• Shows lung apices below clavicles
• Patient AP, leaning back
• or tube angled 15-200 cephalic

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Chest Plain X-Ray
Cassette
Pigg-O-Stat used for pediatric immobilization
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Chest CT
Technique

• Axial images
• Patient supine
• Feet first, arms raised
• Scan from above lung apices to below diaphragm
• Routinely- 3 mm cuts
• Contrast
• may be IV
• highlights blood vessels

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Chest CT
Scout image
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Abdomen Imaging
Studies

• Plain X-Ray
• Fluoroscopy
• Upper GI
• Lower GI (Barium enema)
• Abdominal CT
• Nuclear Medicine
• Ultrasound

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Contrast Agents
Upper GI
Lower GI

• Water soluble (Hypaque)
• better if leak suspected
• Barium
• highlights GI tract
• Air

• Given orally
• Anatomy
• esophagus
• stomach
• small bowel

• Given by enema
• Anatomy
• Colon

Post fluoro views determined by radiologist
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Abdomen Plain X-Ray
Technique

• Mid-range kVp
• 40 SID
• Phototimed

• AP (KUB)
• Upright or decubitus for air/fluid levels

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KUB

• Patient supine
• Center on iliac crest
• Include diaphragm and symphysis

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Decubitus Abdomen

• Side of interest up
• Center on iliac crest
• Include diaphragm

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Abdominal CT
Technique

• Routinely- 3mm cuts
• Patient generally supine, feet first
• Scan from top of diaphragm to iliac crest
• IV Contrast highlights
• blood vessels
• organs
• Dilute oral or rectal contrast highlights
• GI tract
• air not used
• streak artifact

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Abdominal CT
Scout Image
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Urinary Studies
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Urinary Tract Studies

• Retrograde pyelogram / cystogram
• contrast delivered through catheter
• Voiding Cystogram
• CT
• kidneys
• Nuclear Medicine
• Ultrasound

• Intravenous Pyelogram (IVP)

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IVP
Technique

• IV Contrast
• Mid-Range kVp
• retain dye contrast
• Images made at intervals post injection
• Post Void Image

• AP
• Obliques
• Center at iliac crest
• Include bladder and top of kidneys

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Retrograde Studies

• AP
• Obliques
• Center on iliac crest for pyelogram
• Cystogram/urethrogram-include bladder and entire
  urethra

• Mid-Range kVp
• 40 SID

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Kidney CT
Technique

• Patient positioned same as CT Abdomen
• Thin (1-2 mm) cuts
• IV contrast used
• if not post IVP

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Circulatory Studies
Angiography

• Arteriogram
• carotid / aortic arch
• runoff (leg)
• renal
• Venogram
• much less common
• extremity
• Heart Catheterization

Patient supine, centered over area of interest
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Neuroradiology Studies

• Skull Plain X-Rays
• Spine Plain X-Rays
• CT
• MRI
• Ultrasound
• Myelogram
• Contrast injected into spinal canal
• Mostly replaced by non-invasive MRI

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Skull

• PA
• facial bones close to receptor
• reduces magnification
• LAT
• Many specialized views
• Waters
• Townes
• Basal

Technique

• Mid-Range kVp
• 40 SID

40
Skull/Sinuses

• PA
• Head rests on forehead and nose
• Orbitomeatal line (OML) perpendicular to receptor
• Angle tube 150 caudal
• Townes
• Chin tucked, OML perpendicular to receptor
• Tube angled 400 caudal w/ patient AP

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Skull/Sinuses

• Waters
• Routinely PA, chin up
• OML angled 300 to receptor
  and nose 1 cm from receptor

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Skull/Sinuses

• Basal
• Routinely AP
• If patient can tilt head back
• position tube / receptor lateral
• OML parallel to image receptor
• If patient cannot tilt head back
• tube / receptor tilted to achieve right
  angle to OML
• Shows zygomatic arches

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Head CT
Technique

• 2 mm cuts
• Orbitomeatal line perpendicular to floor
• IV Contrast highlights
• blood vessels
• lesions (metastases)
• aneurysms
• AVMs

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MRI Brain Protocol

• 5 mm cuts, 1 mm spaces
• minimizes crosstalk
• 1st study without contrast
• If lesion suspected, study repeated with contrast
• Gadolinium injected IV
• provides tumor edge enhancement
• aids in border determination

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Spine

• AP
• LAT
• Oblique
• Coned spot
• C-spine
• flexion
• chin toward chest
• extension
• head back
• open mouth odontoid

Technique

• Mid-Range kVp
• Usually 40 SID
• Phototimed

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AP Cervical Spine

• Occlusal plane and mastoid tips aligned- to
  remove mandible shadow
• Angle tube 15-200 cephalic to open transverse
  foramina
• Center at thyroid cartilage

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Lateral C-spine Imaging

• Routine- 72 SID to reduce magnification
• Consider weight to lower shoulders

Swimmers view for C7/T1
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Odontoid Imaging

• Upper occlusal plane even with base of skull
• Mouth wide open

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Thoracic Spine

• Patient AP
• Upright or supine
• Center 3-4 below manubrial notch

• Breathing technique to blur rib/lung markings

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Lumbar Spine

• AP
• center on iliac crest

• Lateral
• center on iliac crest
• for spot, use 5-80 caudal tube angle to open
  L5/S1 space

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AP Scoliosis Imaging

• Patient AP, standing
• Include thoracic and lumbar
• Use long cassette or pieced method

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Myelograms

• Fluoro with patient prone, knees and shoulders
  supported
• Cross-table lateral images at level of dye
• May CT while dye still present

Table
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Skeletal

• Skull
• plain film
• CT
• MRI
• Other
• ribs
• pelvis / hip

• Extremity
• usually plain film
• Spine
• plain film
• CT
• MRI

• Pain
• Trauma

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Extremity
Technique

• Lower kVp
• 40 SID
• Not phototimed
• No grid

• AP
• LAT
• Oblique

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Hand/Wrist
PA
Lateral- fingers spread
Center to 3rd metacarpophalangeal joint
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Elbow

• AP
• Palm up to prevent forearm rotation

• Lateral
• Elbow flexed 900
• Hand in lateral position

Center to joint
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Shoulder Projections

• Axillary projection
• Arm abducted at right angle to body
• Shows glenoid/humerus joint

• AP
• upright or supine
• Palm out to rotate shoulder to true AP

Center on coracoid process
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Foot/Ankle

• AP foot
• Sole flat on table
• Center to base of 3rd metatarsal

• Weight-bearing lateral
• Demonstrate arch
• Center to base of 5th metatarsal

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Knee Projections
Tunnel view of the intercondyloid fossa

• or PA
• Angle x-ray tube 15-200 caudal

• Can be done AP
• Angle x-ray tube 15-200 cephalic

Center on patella
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Knee Projections
Sunrise view of the patella

• Can be done PA
• Angle 10-150 cephalic

or AP- standing, sitting or lying
Center on patella
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Pelvis/Hips

• AP
• Patient supine
• Toes turned inward to show femoral neck
• Pelvis- Include top of crest and bottom of
  ischium
• Hip- center to joint

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Pelvis/Hips

• Frog Leg view
• Patient supine
• Knee(s) bent up and out
• Hip- center on joint

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Cross-table Lateral Hip
Seen from overhead
Seen from side

• Cant frog leg/fractures
• Tube and receptor parallel
• Angle into joint

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Mammography

• Compression to even out tissue densities
• Low range kVp
• Low dose film/screen combination

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Mammography

• Craniocaudad (CC)
• Shoulder back, arm supported
• Nipple in profile
• Skin folds smoothed

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Mammography
Mediolateral (ML)

• Unit angled
• Arm supported
• Nipple in profile
• Skin folds smoothed

Spot Compression
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