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DIAGNOSTIC RADIOLOGY & BODY SCANS

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DIAGNOSTIC RADIOLOGY & BODY SCANS CHAPTERS 20 & 21 X-RAYS Electromagnetic radiation of short wavelength. Penetrate most substances, including tissue. – PowerPoint PPT presentation

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Title: DIAGNOSTIC RADIOLOGY & BODY SCANS


1
DIAGNOSTIC RADIOLOGY BODY SCANS
  • CHAPTERS 20 21

2
X-RAYS
  • Electromagnetic radiation of short wavelength.
  • Penetrate most substances, including tissue.
  • Also called ionizing radiation.
  • Cause fluorescence (emission of light) on
    photographic plates.
  • Harmful, in a dose-dependent fashion.

3
X-RAYS AS A DIAGNOSTIC TOOL
  • 3 PRIMARY WAYS
  • 1) Radiography.
  • 2) Fluoroscopy.
  • 3) Tomography.

4
RADIOGRAPHY
  • Radiograph an X-Ray image (picture), or what we
    call the X-Ray.
  • Like negatives of photographs.
  • X-Rays that penetrate the tissues and reach the
    film turn the film black. As such
  • AIR BLACK (ISH)
  • FAT DARK GRAY
  • WATER LIGHTER GRAY
  • BONE WHITE (ISH)

5
FLUOROSCOPY
  • See text. Not recommended
  • A real-time X-Ray
  • Typically used with dye studies such as barium
    swallow, angiography, etc.
  • Prolongs radiation exposure.

6
TOMOGRAPHY
  • A tomogram is a radiograph that generates
    cross-sectional images at different tissue
    planes.
  • CT computed tomography, or CAT scan computed
    axial tomography uses computers, produces
    digital images. (More later)

7
DIGITAL RADIOGRAPH
  • A digital image without film.
  • Stored in a computer database.
  • Can be accessed by anyone with access to the
    database, can be emailed, etc.
  • No need to chase down the hard copy films.

8
RADIATION SAFETY
  • Exposure is cumulative.
  • RISKS
  • 1) Genetic damage, cancer.
  • 2) Sterility.
  • 3) Alterations in the composition of individual
    cells.
  • 4) Bone marrow production.

9
RADIATION SAFETY
  • Occupational exposure to ionizing radiation is
    associated with
  • 1) Leukemia.
  • 2) Skin cancer.
  • See text re
  • The rem, the rad, and the gray.
  • X-Ray exposure is measured in millirads.

10
RADIATION SAFETY
  • 3 ways to protect against ionizing radiation
  • 1) Time - as short as possible.
  • 2) Distance - as far away as possible.
  • 3) Shielding.

11
RADIATION SAFETY
  • PREGNANCY potential for teratogenesis etc. is
    highest during organogenesis, which occurs during
    the 1st 12 weeks.
  • Need to ask about pregnancy.
  • In a perfect world, X-Rays would be done between
    menses and ovulation.
  • Shielding the pelvis advised when uncertain.

12
BODY SCANS
  • CT
  • MRI
  • DEXA
  • PET
  • SPECT

13
CT / CAT
  • Computed tomography, computerized axial
    tomography.
  • Uses X-Rays in a 180 fashion.
  • Radiation exposure is small.
  • Image generated based on amount of radiation
    absorbed.
  • Can depict all types of tissues except nerves.

14
CT / CAT
  • ADVANTAGES
  • 1) Excellent detail.
  • 2) Quick results.
  • DISADVANTAGES
  • 1) Cost.
  • 2) Time of exposure to radiation.

15
CT / CAT
  • 1st CT developed in 1972 to evaluate brain
    abnormalities.
  • Now in widespread use for other organ systems.
  • USES evaluation of neoplasms / masses,
    hematomas, abscesses, foreign body localization,
    trauma.
  • Quicker than MRI.

16
MRI
  • Magnetic resonance imaging.
  • See text for details of the physics involved.
  • In short, uses radio waves and a magnetic field
    that detects changes in absorption of energy by
    hydrogen ions.
  • As such, no radiation exposure.

17
MRI
  • ADVANTAGES
  • 1) No radiation exposure. Can be used during
    pregnancy.
  • 2) Better detail than CT.
  • 3) Imaging modality of choice for the CNS.
  • DISADVANTAGES
  • 1) Cost 1/3 more than CT.
  • 2) Takes longer, results not available as fast as
    CT.

18
?
19
CIRRHOSIS
20
STONE RIGHT URETER
?
21
MRI Absolute Contraindications
  • Brain Aneurysm Clip
  • Implanted neural stimulator
  • Implanted cardiac pacemaker or defibrillator
  • Cochlear implant
  • Ocular foreign body (e.g. metal shavings)
  • Other implanted medical devices (e.g. Swan Ganz
    catheter)
  • Insulin pump
  • Metal shrapnel or bullet.

22
MRI Relative Contraindications
  • 1) Penile and non metallic valve prosthesis
  • 2) Pregnancy We try to avoid scanning in the
    first trimester since we are not sure if there
    are any adverse effects to MRI. (Pregnant women
    never receive the contrast agent gadolinium)
  • 3) Claustrophobic or anxious patients can not
    tolerate the MRI scanner.
  • 4) Obese patients may not fit into the small
    opening of the scanner. In addition the maximum
    weight that the MRI table can sustain is 350 lbs.

23
DEXA
  • Dual Energy X-Ray Absorptiometry.
  • The modality of choice for measuring bone mineral
    density (BMD) in evaluating osteoporosis.
  • Low radiation exposure, quick.

24
Dexa T Scores
25
PET SCAN
  • Positron emission tomography.
  • The positron is the antiparticle or the
    antimatter counterpart of the electron. The
    positron has an electric charge of 1, a spin of
    1/2, and the same mass as an electron.
    (Wikipedia)
  • Measures function rather than structure.

26
PET SCAN
  • Patient is injected with a metabolically active
    biochemical substance, such as glucose, water,
    ammonia, which has been tagged with a radioactive
    isotope that emits a positron.
  • Binding of these substances with electrons found
    in the tissue being studied causes emission of
    gamma rays, which are converted into color-coded
    images.
  • Degree of gamma ray production reflects cellular
    utilization / metabolism of the tagged substance.

27
PET SCAN
28
APPLICATIONS OF PET SCANS
  • High dollar machine, high dollar test.
  • Costs 1/3 more than MRI.
  • Availability typically limited to research
    institutions, and used more as a research tool
    than a diagnostic one.
  • Findings of altered metabolic function can direct
    innovations in treatment.

29
APPLICATIONS OF PET SCANS
  • Neuroimaging - dementia, stroke, epilepsy,
    Parkinsons disease.
  • Cardiac to assess myocardial viability.
  • Psychiatric schizophrenia, mood disorders,
    substance abuse.
  • See http//en.wikipedia.org/wiki/Positron_emission
    _tomography

30
SPECT
  • Single Photon Emission Computed Tomography
  • Uses radiopharmaceuticals labeled with a
    positron-emitting isotope such as Technitium 99
    (Tc-99m).
  • Detects gamma rays emitted by the natural
    radioactive decay of the isotope.
  • Degree of gamma ray production reflects more the
    degree of perfusion of the organ being studied
    than its function.

31
APPLICATIONS OF SPECT SCANS
  • Neuroimaging- dementia, neoplasms, infection,
    epilepsy.
  • Cardiac- ischemic heart disease.
  • Others- thyroid, bone, white cells.
  • See http//en.wikipedia.org/wiki/SPECT

32
63 YOM W/ PROSTATE CANCER
33
Tc-99 Scan
34
(No Transcript)
35
FUNCTIONAL MRI
  • Measures signal changes in the brain that are due
    to changes in neural activity.
  • Increased neural activity ? need for increased
    oxygen ? increased oxygenated hemoglobin as
    relative to deoxygenated hemoglobin.
  • Because deoxygenated hemoglobin attenuates the MR
    signal, the vascular response leads to a signal
    increase that is related to the neural activity.

36
FUNCTIONAL MRI
  • A fMRI scan showing regions of activation in
    orange, including the primary visual cortex.

37
IMAGES
  • Images compliments of the Department of Radiology
    at the Uniformed Services University of the
    Health Sciences (USUHS), Bethesda, Md.
  • See www.rad.usuhs.edu

38
THE CHEST X-RAY
  • Can be used to assess a wide variety of
    pathologic conditions of the chest heart, lungs,
    mediastinum, bone, esophagus, trachea, diaphragm.
  • Such as infection, tumor, lymphoma, foreign
    bodies, rib fractures, cardiac enlargement,
    presence of free air (pneumothorax,
    pneumomediastinum), fluid accumulation (pulmonary
    edema, pleural effusion), changes such as
    sarcoid, amyloid.

39
THE CHEST X-RAY
  • Usually take an AP (antero-posterior), or PA
    (postero-anterior), and a lateral view.
  • Can also take an oblique view.
  • If known, the part youre interested in should be
    closest to the film.
  • To assess free air or fluid, patients position
    can be manipulated to allow gravity to affect
    layering of the fluid or air.

40
?
22 YEAR OLD SMOKER W/ COUGH, WHEEZING
41
?
22 YEAR OLD SMOKER W/ COUGH, WHEEZING
42
?
CYSTIC TERATOMA
22 YEAR OLD SMOKER W/ COUGH, WHEEZING
43
?
?
46 YOF W/ CHEST PAIN AFTER A ROUND OF GOLF
44
?
?
22 YOM W/ NIGHT SWEATS, WT LOSS
45
ABDOMINAL X-RAYS
  • The flat plate, or scout film, done as the sole
    diagnostic film or prior to a contrast study.
  • Manipulation of position of the patient can
    assess presence of free air (under the
    diaphragm), fluid, or the presence of air-fluid
    levels as seen in bowel obstruction.
  • KUB- kidneys, ureter, bladder. Term used
    interchangeably w/ flat plate.

46
AIR-FLUID LEVELS IN BOWEL OBSTRUCTION
47
43 YOF W/ ABDOMINAL PAIN
48
32 YOF W/ G. E. REFLUX
49
32 YOF W/ REFLUX
50
32 YOF W/ REFLUX
51
32 YOF W/ REFLUX
52
SKELETAL X-RAYS
  • Most useful in assessing fractures, but also good
    for joint dislocation / subluxation, changes in
    bone architecture (erosions, thickening,
    density), presence of abnormal calcifications /
    deposits (osteophytes, tophi), etc

53
18 YOM W/ RIGHT THIGH PAIN
54
18 YOM W/ RIGHT THIGH PAIN
55
OSTEOSARCOMA
56
53 YOM W/ SWELLING, LEFT MIDDLE FINGER
57
TOPHACEOUS GOUT ?
58
18 YOM FELT SOMETHING POP WHEN THROWING A
SPLIT-FINGER FASTBALL
59
UNICAMERAL BONE CYST W/ PATHOLOGIC FRACTURE
60
MAMMOGRAPHY
  • Radiographic images of the breast, primarily for
    early detection of breast cancer, prior to the
    appearance of a palpable mass.
  • Also useful for evaluation of palpable masses
    benign neoplasms, fibrocystic breast disease,
    etc.
  • Used as an aid in placement of the biopsy needle.

61
SCREENING MAMMOGRAPHY
  • For early detection of breast cancer.
  • Guidelines as to who, when, and how often vary by
    organization, and depend on the patients risk
    status.
  • American Cancer Society baseline between 35 and
    40, every 1-2 years between 40-50, and yearly
    after 50, along with monthly self-breast
    examination and annual physical exam.

62
SCREENING MAMMOGRAPHY
?
63
CONTRAST STUDIES
  • Involves the introduction of a radiopaque
    substance (barium, dye, etc) into an organ,
    vessel, duct, etc
  • Allows for the identification of the anatomy of
    the structure being studied, its shape, contour,
    size, etc.
  • Filling defect describes an area where dye
    should be but isnt.

64
CONTRAST STUDIES
  • Barium swallow, upper GI, small bowel series.
  • Barium enema (B.E.)
  • Oral cholecystograms (OCG).
  • Cholangiograms.
  • Intravenous pyelogram (IVP).
  • Angiograms- arteriograms, venograms.
  • Lymphangiograms.
  • Hysterosalpingograms (HSG).
  • Myelograms.
  • Arthrograms.

65
AIR-CONTRAST B.E.
APPLE CORE LESION OF ADVANCED COLON CANCER
?
?
66
ACHALASIA
67
2 DAY OLD INFANT W/ INCREASING ABDOMINAL
DISTENTION
68
2 DAY OLD INFANT W/ INCREASING ABDOMINAL
DISTENTION
69
16 YOF W/ RLQ PAIN
?
70
16 YOF W/ RLQ PAIN
?
71
HSG BICORNUATE UTERUS
72
30 YOF W/ NEW ONSET SEIZURES
73
ANGIOGRAM MENINGIOMA
74
ANGIOGRAM 19 YOF W/ HYPERTENSION
75
RENAL ARTERY STENOSIS
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