Post on 16-Jul-2020
10/28/2013
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Radiology
Hector RiveraMelo, DC, DACBR
Director, Center for Diagnostic Imaging
Southern California University of Health Sciences
REVIEW OF BASICX-RAY PHYSICS
COLLIMATION CAN IMPROVE YOUR IMAGES
• This film demonstrates limited collimation.
• This allows for more scatter radiation to blur the image.
COLLIMATION CAN IMPROVE YOUR IMAGES
• This film demonstrates more collimation.
• Otherwise, the same factors were used.
REVIEW OF BASICX-RAY PHYSICS
• Know your patients
• The patient’s size, shape and physical condition greatly influence the required radiographic technique.
Most radiographictechnique charts are based on the sthenicpatient.
REVIEW OF BASICX-RAY PHYSICS
• Factors that influence the sharpness of an image
• Focal spot size
• Source to Image-Receptor Distance (SID or FFD)
• Object to Image-Receptor Distance (OID)
• Geometric factors of the object
• Patient motion
• Scatter radiation
• Darkroom fog
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REVIEW OF BASICX-RAY PHYSICS
• Object to Image-Receptor Distance (OID)
• The closer the patient is to the image receptor, the less penumbra and the clearer the image.
• In addition to being blurrier around the edges, the object will be magnified, giving lager measurements on x-ray.
REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• The more tissue exposed to x-rays, the more scatter is produced.
• Therefore collimation is your best friend in eliminating scatter radiation.
REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• Grids are also an effective way of removing scatter
REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• Grids can present issues with x-ray quality if not installed correctly.
REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• Grids can present issues with x-ray quality if not installed correctly.
• Properly aligned focused grid • Upside down focused grid
REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• Grids can present issues with x-ray quality if not installed correctly.
• Properly aligned crossed grid • Upside down crossed grid
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REVIEW OF BASICX-RAY PHYSICS
• Scatter Radiation
• Alternatively, an air gap technique can sometimes be used…
• But only at long FFDs
REVIEW OF BASICX-RAY PHYSICS
• Remember to use the anode heel to your advantage
REVIEW OF BASICX-RAY PHYSICS
• Remember to use the anode heel to your advantage
REVIEW OF BASICX-RAY PHYSICS
• Remember to use the anode heel to your advantage
ARTIFACTS, WHERE DO THEY COME FROM?
• Static Electricity
• Static discharge occurs in low humidity environments.
ARTIFACTS, WHERE DO THEY COME FROM?
• Static Electricity
• Static discharge occurs in low humidity environments.
• The artifacts may appear branching or circular.
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ARTIFACTS, WHERE DO THEY COME FROM?
• Static Electricity
• They don’t always occur as a result of human error.
ARTIFACTS, WHERE DO THEY COME FROM?
• Technician Error
• It’s easy to forget to properly gown the patient, but it is extremely important.
• Anatomy is covered.
• Is pathology covered?
ARTIFACTS, WHERE DO THEY COME FROM?
• Drops of liquid
• In this case, drops of developer landed on the unexposed film, causing excessive exposure where they landed.
ARTIFACTS, WHERE DO THEY COME FROM?
• Drops of liquid
• In this case, drops of fixer (or some other acidic liquid) landed on the unexposed film, preventing exposure where they landed.
ARTIFACTS, WHERE DO THEY COME FROM?
• Patient Motion
• Reducing the total amount of time for the exposure will help prevent this artifact.
• 50mA @ 1.0s = 50mAs
• 100mA @ 0.5s = 50mAs
• 500mA @ 0.1s = 50mAs
TROUBLESHOOTING• Poor quality image. What
went wrong?
• Patient not in the central ray.
• Solution?
• Place the patient in the central ray!
• Tell the patient not to move!
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TROUBLESHOOTING• Poor quality image.
What went wrong?
• Underexposed
• mAs too low
• FFD too far
• Solution?
• Increase (double) mAs
• Correct FFD
TROUBLESHOOTING• Poor quality image. What
went wrong?
• Patient not in the central ray.
• Image grossly underexposed.
• Solutions?
• Tell the patient not to move (or take supine)
• Increase (double) mAs
TROUBLESHOOTING
• Funny looking image… What went wrong?
• Double Exposure.
• Solution?
• Remember to remove/process film before exposing next image.
TROUBLESHOOTING• What went wrong?
• Multiple metallic artifacts.
• Earrings, Necklace
• Solutions?
• Have patient properly gowned and remove jewelry.
TROUBLESHOOTING
• Poor quality image… What went wrong?
• Over Exposure.
• mAs too high
• FFD too close
• Solutions?
• Decrease (half) mAs.
• Correct FFD
TROUBLESHOOTING• What went wrong?
• Multiple branching dark lines
• Static artifact
• Solutions?
• Ground yourself before opening the cassette
• Humidify the dark room
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AP EXTERNAL ROTATION SHOULDER
• Arm is externally rotated.
• Profiles the greater tubercle laterally.
• CR @ coracoid process.
AP EXTERNAL ROTATION SHOULDER
AP INTERNAL ROTATION SHOULDER
• Arm is internally rotated.
• Profiles the lesser tubercle medially.
• CR @ coracoid process.
AP INTERNAL ROTATION SHOULDER
AP ELBOW
• Forearm supinated.
• Radius and Ulna do not cross.
• CR @ antecubitalfossa.
AP ELBOW
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LATERAL ELBOW
• Must be flexed to 90 degrees.
• Thumbs UP!
LATERAL ELBOW
41 YOM WITH ELBOW SWELLING• DDx for soft tissue
calcifications near a joint:
• HADD
• CPPD
• Gout
• Hemochromatosis
• Synovial chondromatosis
• Scleroderma
• Hyperparathyroidism
• Hypervitaminosis D
• Myositis Ossificans
41 YOM WITH ELBOW SWELLING
SYNOVIAL CHONDROMATOSIS
• Multiple calcified intra-articular loose bodies.
• More common in the large joints of the lower extremities.
• 2:1 Male predominant.
PA WRIST
• Best for evaluating overall anatomy.
• Taken with a loose fist.
• CR @ Lunate.
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PA WRIST LATERAL WRIST
• Great for seeing carpal alignment
• Able to evaluate anterior and posterior soft tissues
LATERAL WRIST 12 YOM W/ TRAUMA AND WRIST PAIN
R
L
12 YOM W/ TRAUMA AND WRIST PAIN
RL
BILATERAL TORUS FRACTURES
• Typically seen in patients under the age of 20.
• Cortical buckling of the lateral radius.
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36 YOM W/ TRAUMA AND WRIST PAIN 36 YOM W/ TRAUMA AND WRIST PAIN
SCAPHOID FRACTURE
• Typically seen in patients between the ages of 20-40.
• Anatomic snuff box pain.
• Pain with wrist extension.
• May see deviation of the scaphoid fat pad.
59YOF WITH ‘FOOSH’
COLLES FRACTURE
• Fracture of the radius with distal radius with posterior angulation.
• Commonly seen in patients >40 yo.
• Is often accompanied by fractures of the ulnar styloid process.
AP PELVIS
• Used to compare hips bilaterally.
• Hips should be internally rotated 10 degrees.
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AP PELVIS FROG LEG HIP
• Hip is abducted and externally rotated.
• Used to evaluate the femur in a lateral projection.
• The posterior femur is projected inferiorly.
FROG LEG HIP 60 YOM WITH RIGHT HIP PAIN
60 YOM WITH RIGHT HIP PAIN SEPTIC ARTHRITIS
• The hip is the most common extra-axial location.
• Phemister’s triad seen in % of cases.
• Maintained joint space
• Erosions
• Something else
• Tuberculosis is a very common organism.
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4 YOF WITH FLEXION CONTRACTURES OF THE KNEES AND HIPS CAUDAL REGRESSION SYNDROME
• Sacrum, coccyx and multiple lumbar segments may be absent.
• Ilia will articulate with one another.
• Associated with numerous other neurological and genitourniary anomalies.
49 YOF WITH LEFT HIP PAIN• Tumor or Infection?
• Tumor
• Benign or Aggressive?
• Aggressive
• Large ST mass
• What type of tumor tissue?
• Cartilaginous
CHONDROSARCOMA
• The average age is 45.
• It is the 3rd most common primary aggressive bone tumor.
• Classically will have calcification within the lesion.
• May or may not see a large soft tissue mass.
AP KNEE
• Best for evaluating tibiofemoral joint space.
• Can be taken standing or recumbent.
• CR @ apex of patella.
AP KNEE
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LATERAL KNEE
• Knee must be flexed to 45 degrees
• Good for evaluating suprapatellar bursa distension
LATERAL KNEE
39 YOF WITH LEFT KNEE PAIN AGGRESSIVE GIANT CELL TUMOR
• Typically age range for is 20-40.
• Can be highly expansile.
• Classically will involve a metaphysis of a long bone and extend into an epiphysis.
15 YOM WITH RIGHT KNEE PAIN 15 YOM WITH RIGHT KNEE PAIN
10/28/2013
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BONE SCAN• Areas of elevated uptake
“Hot Spots” indicate regions of increased metabolic activity
• DDx
• Infection
• Tumor
• Fracture
15 YOM WITH RIGHT KNEE PAIN
15 YOM WITH RIGHT KNEE PAIN 15 YOM WITH RIGHT KNEE PAIN
OSTEOSARCOMA
• Age range is typically <25
• May have purely blasticresponse.
• May see periosteal reaction or soft tissue mass.
44 YOF WITH RIGHT KNEE PAIN
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SCLERODERMA
• Typically age range for is 20-40.
• Periarticular calcifications tend to be sheet-like.
• Distribution.
AP ANKLE
• Best for evaluating overall anatomy.
• Not to be confused with a DP foot view.
• CR between malleoli.
AP ANKLE LATERAL ANKLE
• Gives good assessment of sagittal anatomy
• CR @ medial malleolus
LATERAL ANKLE MEDIAL OBLIQUE ANKLE
• Great for seeing carpal alignment
• Able to evaluate anterior and posterior soft tissues
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MEDIAL OBLIQUE ANKLE DP FOOT
• Best for evaluating overall anatomy.
• Foot should be flat on the cassette.
• Tube tilt of 10 degrees towards the head.
• Remember to place the anode towards the toes.
DP FOOT LATERAL FOOT
• Great for seeing sagittal alignment
• Able to evaluate calcaneus well
• CR @ navicular
LATERAL FOOT MEDIAL OBLIQUE FOOT
• Used to evaluate lateral mid-foot anatomy without overlap
• Especially good at evaluation the styloidof the 5th metatarsal
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MEDIAL OBLIQUE FOOT 25 YOM WITH LEG PAIN
LINEAR BAND OF SCLEROSIS
• DDx for linear regions of sclerosis:
• Stress fx
• Heavy metal toxicity
• Scurvy
• Normal variant
25 YOM WITH LEG PAIN
STRESS FRACTURE
• X-Rays may be normal or show linear sclerosis with or without callous formation
• On MRI, T2 weighted sequences will demonstrate a high signal region of bone marrow edema.
• Linear region of low signal on all MRI sequences.
10 YOM WITH LEFT ANKLE PAIN
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10 YOM WITH LEFT ANKLE PAIN
• T1 • T1+C • STIR
10 YOM WITH LEFT ANKLE PAIN
BRODIES ABSCESS
• Most common in male children.
• Classic clinical presentation of localized limb pain which is often nocturnal.
• May preset and appear similar to an osteoid osteoma.
• Staphylococcus aureus is the most common bacterial agent.
54 YOM WITH FOOT PAIN
GOUT
• Prominent soft tissue masses around the joints.
• Late in the disease process will show osseous erosions with overhanging margins.
• Male predominant.
57 YOM WITH FOOT PAIN
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NECROTISING FASCIITIS• Extensive gas in the subcutaneous soft tissues.
• More likely to occur in patients with compromised immune systems.
• Can be fatal if not treated quickly.
19 YOM WITH RIGHT TOE PAIN