10/23/12

1

1

Value of CT in Early Pneumonia in

Immunocompromised Patients

Nantaka Kiranantawat, PSU

2

Predisposing Factors Infection, Stress, Poor

nutrition, Systemic illness

Preventative Factors Phagocyts Cellular immunity

Humoral immunity

3

Immunocompromised patients

• Pulmonary complication: infection 75%

• Persistent infections during neutropenia: Mortality rate up to 100%

Rosenow EC, et al. Mayo Clin Proc 1985 Heussel CP, et al. AJR 1997

4

Immunocompromised patients

• Invasive aspergillosis

• Mortality 90% : treated >10 days after clinical or radiological sign

• Mortality 40%: early treatment

von Eiff M, et al. Ann Hematol 1995

5

Immunocompromised patients

• Localization of infection or microorganism Appropriate Rx Life saving

Aisner J, et al. Ann Intern Med 1977

6

Fever & neutropenia >48 hr

CXR

Normal Abnormal

Specific findings

Nonspecific findings

HRCT

Abnormal

BAL

Medical Rx

Fail Rx Nonspecific

HRCT

BAL BAL

Book: Imaging of Pulmonary Infection

10/23/12

2

7

CXR vs CT

2 wk later

8

Value of CT

9

• 48%: Normal CXR, Abnormal HRCT

• CT show findings suggestive of pneumonia about 5 days earlier than CXR

Heussel CP, et al. AJR 1997

10

Heussel CP, et al. AJR 1997

11

Heussel CP, et al. J Clin Oncol 1999

12

Value of CT

• Septic emboli

• 33% Negative CXR

Kuhlman JE, et al. Radiology. 1990

10/23/12

3

13

Role of Imaging • Identify pulmonary abnormality

• Location, Extension

• Course of pneumonia

• Associated complications

• Additional or alternative diagnosis Muller NL, et al. Imaging of Pulmonary Infections

14

Role of Imaging

Allen CM, et al. Ann Thorac Med 2010

HIV

15

CT Findings

HIV

Hartman TE, et al. AJR 1994

16

CT Findings

Febrile neutropenia

Heussel CP, et al. J Clin Oncol 1999

17

CT Findings

Kim EA, et al. Radiographic 2002 18

Term

• Pneumonia = Pulmonary infection

• Pneumonitis = Pulmonary inflammation or Noninfectious pneumonia

10/23/12

4

19

Classification

• Etiology: Bacteria, virus, etc.

• Environment: CAP, HAP

• Patient status

• Symptoms: Typical, Atypical

20

Classification • Morphology

• Lobar pneumonia

• Bronchopneumonia

•  Interstitial pneumonia

• Bronchiolitis

• Septic emboli

• Miliary infiltration

21

Pathophysiology

• Microaspiration from infected oropharyngeal secretion

• Aerosolization, directly inhaled

• Hematogenous spread

22

Classification • Morphology

• Lobar pneumonia

• Bronchopneumonia

•  Interstitial pneumonia

• Bronchiolitis

• Septic emboli

• Miliary infiltration

23

Ventilation

5-10 µm

1-2 µm

Mucociliary system

Phagocytic defense

24

Principle Patterns of Infection

10/23/12

5

25

Lobar pneumonia

Initial: Periphery, subpleura Muller NL, et al. Diseases of the lung: Radiologic and pathologic correlation

26

Lobar Pneumonia

27

Ground-glass opacity

• Dark bronchus sign: Early PCP Yadav P, et al. Ann Thorac Med 2007

28

PCP

Marchiori E, et al. AJR 2005

29

Ground-glass opacity • AIDS

• Extensive bilateral GGO: PCP

• HRCT Sensitivity 100%

Specificity 89%

Accuracy 90% Gruden JF, et al. AJR 1997

30

Ground-glass opacity

• Non-AIDS

• CMV

• Drug-induced lung disease

• Pulmonary hemorrhage

• Organizing pneumonia

10/23/12

6

31

Bronchopneumonia

Initial: Involve bronchioles 32

Tree-in-bud pattern

Bronchiolitis: Inflamed bronchiolar wall and intraluminal exudate

33

Bronchopneumonia

34

Bronchopneumonia

1 mo

35

Bronchopneumonia

• Early bronchopneumonia: Centrilobular nodules

Marchiori E, et al. AJR 2005 36

Bronchopneumonia

Itoh H, et al. AJR 1978

10/23/12

7

37

Bronchopneumonia: Aspergillosis

38

• Neutropenia

• Halo sign:

• Early Angioinvasive aspergillosis

Kuhlman JE, et al. Radiology 1985 Caillot D, et al. Clin Oncol 2001

Marchiori E, et al. AJR 2005

Angioinvasive Aspergillosis

39

• Occlusion of small to medium pul. a. •  Infected infarct

Angioinvasive Aspergillosis

40

Halo sign Air-crescent sign

Angioinvasive Aspergillosis

41

Septic Emboli

• Septic emboli

• Early: Well-defined nodules with feeding vessel signs

• 54-67% Huang RM, et al. AJR 1989

Kuhlman JE, et al. Radiology 1990 Iwasaki Y, et al. Eur J Radiol 2001

42

Septic emboli vs lung metastases

• Subpleural consolidation: Lung infarct

• Septic emboli: 50%-73%

• Lung metastases: Case report

Huang RM, et al. AJR 1989 Kuhlman JE, et al. Radiology 1990 Iwasaki Y, et al. Eur J Radiol 2001

Lew JW, et al. J Med Imaging Radiat Oncol. 2012

10/23/12

8

43

Pulmonary Host Defense

44

Immune System

• Phagocyte:

• Neutrophil, Macrophage

• Cell-mediated immunity:

• T cells

• Humoral immunity:

• B cell www.Nobelprize.org

Killer T cell Helper T cell

B cell

45

Immune System

www.Nobelprize.org

B cell

Activated Helper T cell

Killer T cell

Virus infected cell

Bac. infected cell

Cancer cell

Plasma cell

Memory cell

46

Mechanism of Immune Compromise

• Phagocyte: Decrease amount

• Acute leukemia

• Bone marrow failure

• Chemotherapy

Bacteria, Fungi

47

Mechanism of Immune Compromise

• Phagocyte: Impair function

• Hypoxia

• Alcoholism

• Tobacco smoke

• Corticosteroid therapy 48

Mechanism of Immune Compromise

• T Cells: CD4, CD8

• Viral infection, HIV

• Lymphoma

• Advanced age

• Malnutrition

• Drug, steroid

All, Intracellular organism

10/23/12

9

49

Intracellular organisms

• TB, Nocardia, Legionella species

• C neoformans, H capsulatum, PCP

• VZV, HSV, CMV, EBV

• T gondii

50

Mechanism of Immune Compromise

• B Cells

• Splenectomy

• Chronic lymphocytic leukemia

Encapsulated bacteria: S pneumoniae, H influenzae, and S aureus

51 52

53 54

Conclusions

• CXR: Recommend for all patients with suspected pulmonary infection

• CT/HRCT: Detection of occult lung diseases

10/23/12

10

55

Conclusions

• Patterns of infection

• Localized consolidation (Patchy, segmental, lobar)

• Nodules

• Diffuse pattern