Extravaganza Radiology - Copymedia.scuhs.edu/extravaganza/speaker_uploads/Dr._Rivera...10/28/2013 9...

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.


• 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.


• 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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• 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.


• Scatter Radiation

• The more tissue exposed to x-rays, the more scatter is produced.

• Therefore collimation is your best friend in eliminating scatter radiation.



• Grids are also an effective way of removing scatter



• Grids can present issues with x-ray quality if not installed correctly.




• Properly aligned focused grid • Upside down focused grid




• Properly aligned crossed grid • Upside down crossed grid

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• Alternatively, an air gap technique can sometimes be used…

• But only at long FFDs


• Remember to use the anode heel to your advantage





ARTIFACTS, WHERE DO THEY COME FROM?

• Static Electricity

• Static discharge occurs in low humidity environments.



• Static discharge occurs in low humidity environments.

• The artifacts may appear branching or circular.

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• They don’t always occur as a result of human error.


• Technician Error

• It’s easy to forget to properly gown the patient, but it is extremely important.

• Anatomy is covered.

• Is pathology covered?


• Drops of liquid

• In this case, drops of developer landed on the unexposed film, causing excessive exposure where they landed.


• Drops of liquid

• In this case, drops of fixer (or some other acidic liquid) landed on the unexposed film, preventing exposure where they landed.


• 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

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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


• 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


• 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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• T1 • T1+C • STIR


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

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