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Diagnostic Imaging II Final > Infections > Flashcards

Flashcards in Infections Deck (71):
1

What does the "CATBITES" acronym stand for?

Congenital, Arthritis, Trauma, Blood, Infection, Tumor, Endocrine/Nutritional/Metabolic, Soft Tissue

2

What are the 4 major "S" joints affected with infection in drug addicts?

Spine, Sacroiliacs, Symphysis Pubis, Sternoclavicular

3

What is the most common organism to cause musculoskeletal infections?

Staphylococcus aureus (90%)

4

What is the most common route of dissemination for a musculoskeletal infection?

Hematogenous

5

Which population tends to have a more acute process of symptomatology with a musculoskeletal infection: infants/young adults or older adults?

Infants/young adults (fever, chills, pain, swelling, loss of limb function, elevated ESR, elevated white count with a shift to the left)

6

Which population tends to have a more insidious process of symptomatology with a musculoskeletal infection: infants/young adults or older adults?

Older adults (fever, malaise, edema, erythema, pain)

7

In 50% of musculoskeletal infection cases, there tends to be a preexisting infection in which organs?

Skin, respiratory tract, genitourinary tract

8

What is the most common age range and gender bias for suppurative osteomyelitis?

Males 2-12 years old

9

Which pattern tends to spare the epiphysis and joint: infantile, childhood, or adult?

Childhood (because the growth plates have not yet ossified)

10

What is the most common location for a musculoskeletal infection?

KNEE (then hip, ankle, shoulder, spine)

11

What are the two main categories of musculoskeletal infections?

Suppurative (OM) or non-suppurative (TB)

12

What kind of infection is suppurative osteomyelitis?

Bone marrow infection by (pyogenic) non-tubercular organism (aka anything but TB)

13

What is the most likely agent involved with OM?

Staph. aureus (could also be Step. pneumoniae, E. coli, or pseudomonas)

14

What are the four radiographic stages of a musculoskeletal infection?

1 latent/hidden (1-10 days), 2 early (10-21 days), 3 middle (weeks), 4 (months)

15

What are the radiographic signs of the early stage?

Soft tissue edema and swelling, osteopenia

16

What is the best way to differentiate between gout or infection?

AGE (gout is highly unlikely in children) but also time...gout takes year, infection is quick and acute

17

Moth eaten or permeative destruction is seen in which radiographic stage of a musculoskeletal infection?

Middle (along with periosteal responses)

18

What is the best way to differentiate between an infection or bone cancer when periosteal reactions are present?

Infection presents with FEVER

19

What is the best way to differentiate between a geographic infection or something like a simple bone cyst?

Infection will be accompanied with PAIN

20

Involucrum, sequestrum, and cloaca are seen in which radiographic stage?

Late

21

What is the term for the chalky, white area representing isolated dead bone in the infection?

Sequestrum

22

What is the term for the "bony collar" and chronic periosteal response where the pus lifts the periosteum and causes new bone formation in an attempt to wall off the infection?

Involucrum

23

What is the term for the opening of the involucrum that allows for drainage of necrotic and purulent material from the dead bone?

Cloaca

24

What can happen to the cloaca if left untreated?

Can turn into squamous cell carincoma

25

Brodie's abscess formation is similar to what other bone condition?

Osteoid osteoma

26

In what way is Brodie's abscess formation similar to an osteoid oteoma?

Similar in appearance but also has localized pain that is worse at night and relieved by aspirin

27

What condition is a localized, aborted form of suppurative osteomyelitis that can even be sterile with no infectious organism that also mimics an osteoid osteoma?

Brodie's abscess formation

28

What is the most common location for a Brodie's abscess formation?

Metaphysis, distal tibia

29

Which condition respects growth plates and deflects fascial planes: tumor or infection?

Tumor

30

Which condition has no respect for growth plates or joint spaces: tumor or infection?

Infection (cross joint spaces!)

31

What is the #1 most necessary treatment for a musculoskeletal infection?

ANTIBIOTIC MANAGEMENT

32

What imaging study is used to diagnose septic arthritis?

Bone sintography

33

What is the term for the changes to bone density that can result overtime to a conditions such as septic arthritis?

Juxtaarticular osteoporosis

34

What is the normal range for the Kohler's teardrop distance?

9-11 mm (also no more than 2 mm difference side to side)

35

If sacroiliitis is seen upon X-ray, but the clinical presentation doesn't reveal anything involving arthritides....what should we think?

INFECTION

36

In which age group are the IVDs still vascular and therefore if infected end up spreading to adjacent bodies?

Under 20 years of age

37

What is the order of infection in adult spines?

Starts in anterior vertebral endplates then goes to disc with vertebral collapse and soft tissue paraspinal mass

38

What is the most common region of the spine for infection?

Lumbars (of course)

39

SI joint infections are especially high in what population?

IV drug users

40

What are the early radiographic features of a spinal infection?

Rapid disc space loss and endplate destruction

41

What is the normal measurement of the retropharyngeal space?

Less than or equal to 7mm

42

What is the normal measurement of the retrotracheal space?

Less than or equal to 14 mm in kids, 22 in adults

43

How can we differentiate disc space loss due to something like DJD or infection?

Infectious disc space loss will occur QUICK...also consider age of patient (child is obviously not going to have DJD)

44

What would mostly likely be the condition involved when disc space loss is present with a fever but NO osteophytes are seen on X-ray?

Spinal infection

45

What is the major limit to pain films when trying to diagnose spinal infections?

Not sensitive, need significant loss of bone density into order to be detected

46

What are the most common patient symptoms involving a spinal infection?

Fever, night sweats, back pain

47

At what point do plain films have a 90% sensitivity to spinal infections?

3-4 weeks (yikes..)

48

What imaging study is sensitive to spinal infections and could be positive within HOURS?

Bone scintigraphy (technetium)

49

What imaging study usually follows a bone scintigraphy to diagnose a spinal infection?

MRI to evaluate soft tissue (then possibly lab work)

50

Computed tomography is more specific and suggestive for what kind of infection?

Osteomyelitis (increased marrow density, shows sclerosis and periosteal reactions)

51

What type of signal is seen for a positive osteomyelitis on MRI for T1 and T2?

T1: decreased signal intensity, T2: increased signal intensity

52

What replaces the fatty bone marrow causing the change in signal intensity with MRI for osteomyelitis?

Water signal due to edema and exudate

53

What is the radiographic latency period for osteomyelitis?

10 days

54

What is the name of the condition of tuberculosis in the spine?

Pott's disease

55

What is the infectious agent for tuberculosis?

Mycobacterium tuberculosis

56

What is the most common cause of infection-related death worldwide?

TB (15 million people infected in the USA)

57

What is the nickname for TB?

King of Disease

58

How frequent is Pott's disease?

1-3% of TB cases (MC secondary form of TB)

59

What is the most common location for Pott's disease?

Thoracolumbar junction

60

Does TB usually affect weight bearing joints or non-weight bearing joints?

Weight-bearing

61

Does TB usually affect one level of the spine or multiple?

Multiple

62

What is the early radiographic finding for TB of the spine?

Disc space

63

Where does adult TB in the spine typically start?

Anterior endplate region

64

What is the term for the over-kyphosis that occurs with 2 vertebrae as they collapse due to Pott's disease?

Gibbous formation

65

What are some clinical ways to measure/diagnose Pott's disease?

TB skin test (positive in 90%-100%) and chest film positive for granulomas (50%)

66

What is the Phemister's Triad?

Junta-Articular osteoporosis, marginal erosions, slow joint space loss

67

Phemister's Triad is associated with which condition?

Tuberculosis

68

What feature accompanies TB when in the spine?

Paraspinal cold abscesses with calcium deposits

69

Which has a slower progression of joint destruction: TB or suppurative infection?

TB

70

Which has a better response to therapy: TB or suppurative infection?

Suppurative

71

What is the treatment for Pott's disease?

Chemotherapy