imaging of fungal pneumonia in the icu

Avraham Cooper, HMS IIIGillian Lieberman, MD

Imaging of fungal pneumonia in the ICU


1/23/12


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Outline• ICU patients and their susceptibility to fungal

pneumonia• Common fungal etiologies in ICUs• Index Case• Radiologic hallmarks of fungal pneumonias• Summary


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Immuno-susceptibility and the ICU• Changes in innate and adaptive immune function (1) • Use of immunosuppressant drugs such as

corticosteroids• Many patients have secondary pre-disposing diseases

such as neutropenia, malignancy (2), or late sepsis (3) • Frequent ventilation introduces pathogens directly into

lungs

Monneret G et al, 2010.Nseir S et al, 2011.Boomer JS et al, 2011.


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Outline•ICU patients and their susceptibility to fungal pneumonia•Common fungal etiologies in ICUs•Index Case•Radiologic hallmarks of fungal pneumonias•Summary


Common fungal etiologies in ICUs•Aspergillus•Candida•Fusarium•Zygomycetes

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Aspergillus•Aerobic mold•Fumigatus is most common species•Causes invasive pulmonary aspergillosis (IPA)•Also causes semi-invasive pulmonary aspergillosis, allergic bronchopulmonary aspergillosis (ABPA), as well as aspergillomas (asymptomatic fungus balls) in pre-exisiting lung cavitations


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IPA• Presents with symptoms of pneumonia including

fever, dyspnea, and productive cough (4)• Pleuritic chest pain is a common complaint

(angio-invasive infection leads to infarction) (4)• The most common fungal pnuemonia in the ICU• Sputum cultures only positive in 10% of affected

patients (7) making imaging key to diagnosis

Miller, 1996.Abramson S, 2001.


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Index Patient: HPI •Our index patient is a 75 year old man with a history of MDS/AML, Wegener’s (in remission), and CKD on HD•At time of admission he had recently taken a course of Revlimid (thalidomide analogue) with resultant pancytopenia•He presented with one week of anorexia, headache, fatigue, fevers, cough with brown sputum, and left-sided “rib” pain with coughing

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Index Patient: Physical Exam

•Vitals: T 102.5, HR 80, BP 140/80, Sp02 92%•Poor dentition noted in oropharynx•On chest auscultation, musical rhonchi heard in inspiration. Tenderness over 5th ribs present in mid-axillary line•Spleen tip was palpable

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Index Patient: Pertinent labs•WBC 3.1 (76% neutrophils)•Creat 4.6•ANCA negative

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Index Patient: Chest radiograph at presentation

Left upper lobeconsolidation

PACS, BIDMC


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Index Patient: CT chest at presentation

Ground-glass opacityindicating likely siteof hemorrhage with

multiple consolidationsin both lung fields

14Axial chest CT, C-PACS, BIDMC


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Index Patient: Differential diagnosis• Recurrence of Wegener’s vasculitis• Opportunistic infections such as fungal, viral,

nocardia, PCP and mycobacteriurm• Pyogenic infection• Hemorrhage


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Index Patient: Decompensation

•After admission, he de-saturated to mid 80’s on low-flow nasal cannula•Out of concern for tenuous respiratory status he was transferred to the ICU.

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Index Patient: Chest radiograph in the ICU

Almost complete opacification of the

left lung field withright-sided shift

of the mediastinum

PACS, BIDMC


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Index Patient: Chest CT in the ICU

Expansile consolidative opacityin the left upper lobe. Density is 40 HU, indicating intermediate density, with central hypodensity which may be necrotic.There is evident mediastinal shift.

Axial CT chest, C-PACS, BIDMC


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Index Patient: ICU course•His respiratory status continued to decline and he was intubated and treated with broad spectrum antibiotics and anti-fungals•Per the patient’s previous wishes care was withdrawn and he passed away•Post-mortem bronchoscopy revealed aspergillus


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Companion Patient 1: The Halo Sign in IPA

The Halo Sign

Solid nodular coresurrounded by

ground glass opacity

Greene R E et al, 2007.


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The Halo sign• Results from a necrotic nodule surrounded by a

hemorrhagic/necrotic rim (6)• Specific for invasive aspergillosis, allowing for

early diagnosis and institution of therapy(7)

Hruban RH et al, 1987Abramson S, 2001.


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The Halo Sign: Clinical Implications

The halo sign isassociated with

decreased mortalityin patients with IPA

Greene R E et al, 2007


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Index patient: Halo Sign on initial presentation?

Nodule surrounded by ground glass opacities

24Axial CT chest, C-PACS, BIDMC


Companion Patient 2: Initial Radiograph

Invasive aspergillosis in a6-year-old girl with neutropenia

and acute lymphocytic leukemia,revealing a lingular infiltrate

25Abramson S, 2001.


Companion Patient 2: The Air Crescent Sign

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One week later there aremultiple crescentic

lucencies surrounded by soft-tissue

density opacities

Abramson S, 2001.


The Air-Crescent Sign•Specific for IPA (7)•Crescentic lucency surrounded by soft-tissue density opacities (7)•Results from air in between necrotic/hemorrhagic lung (7)

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Abramson S, 2001.


Companion Patient 2: Air Crescent sign on CT

Crescentic lucency surrounded

by enhancing opacities (box)

28Axial CT chest, C+Abramson S, 2001.


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Candida Pneumonia•Yeast•Albicans is the most common species•Candida was isolated from respiratory secretions in 26% of ICU patients in one series (8)•This usually represents colonization rather than infection, except rarely in severely immunosuppressed patients (8)

C H E SAzoulay E et al, 2006.


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Candida Pneumonia• Radiographic appearance depends on route of spread

(4)• Hematogenous spread (99%[9]) from disseminated

infection produces diffuse miliary, nodular (4) microabscesses (10)

• Primary pneumonia (1% [9] ) usually reveals non- specific alveolar consolidations from pharyngeal aspiration of overgrown candida in the oropharynx of immunosuppressed patients (4)

Haron E et al, 1993. Kauffman C, UptoDate.Miller, 1996.


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Companion Patient 4: Candida - Hematogenous Spread

Miller, 1996.

Diffuse bilateral nodularopacities representinglikely micro-abscesses


Companion Patient 5: Candida - Aspiration

Fluffy right-sided infiltrate (box) in a patient who

aspirated and laterdeveloped candidemia

32Kobayashi T et al, 2005.


Fusarium sp.•Filamentous mold •Solani is the most common species•Second most common mold infection in immunosuppressed patients after Aspergillus (12)• Imaging reveals non-specific infiltrates and nodular or cavitary lesions (12)

33Gorman SR et al, 2006.


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Axial CT chest, C-

Gorman SR et al, 2006.

Multiple small right apical nodules in an

immunocompetentpatient who cleanedbird droppings (box)

Companion Patient 6: Primary Fusarium Pneumonia


Zygomycetes•Spore-forming, commonly found on decaying vegetation and soil (13)•Rhizopus and Mucor are most common species•Inhalation of spores by immuncompromised patients leads to rapidly progressive pneumonia with infarction and necrosis, and can spread to nearby structures such as the mediastinum and heart (13)•Characteristic finding is the reverse-halo sign: a focal ground glass opacity surrounded by a ring of consolidation – non-specific, as also seen in COP

35Cox GM, UptoDate.Busca A et al, 2011.


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Companion Patient 7: Zygomycosis

Axial CT chest, C-

Busca A et al, 2011

The Reverse Halo SignGround glass opacitysurrounded by a ring

of consolidationin a stem cell

transplant recipient


Compare Reverse halo sign vs. Halo sign

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Axial CT chest, C-Busca A et al, 2011.

Greene R E et al, 2007.

Ground glass opacity surrounded by consolidation Consolidation surrounded

by ground glass opacity



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Summary•Fungal pneumonia is a relatively common concern in ICUs, especially in immunosuppressed patients•Distinguishing invasive disease vs. colonization can be difficult, especially regarding candida sp.•Radiographic hallmarks can aid in early diagnosis, such as the halo and air-crescent signs in Aspergillus and reverse-halo sign in Zygomycosis

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1. Monneret G, Venet F, Kullberg BJ, Netea MG: Med Mycol. 2011 Apr;49 Suppl 1:S17-23. Epub 2010 Aug 18.2. Nseir S, Di Pompeo C, Diarra M, et al. Relationship between immunosuppression and intensive care unit-

acquired multidrug-resistant bacteria: a case-control study. Crit Care Med 2007;35:1318-233. Boomer JS et al. JAMA. 2011;306(23):2594-26054. Seminars in Roentgenology, Wallace T. Miller, vol XXXXI, No. 1, January 1996 5. Greene R E et al. Clin Infect Dis. 2007;44:373-3796. Hruban RH, Meziane MA, Zerhouni EA, et al. Radiologic-pathologic correlation of the CT-halo sign in invasive

pulmonary aspergillosis. J Comp. Assist. Tomogr.-1987; 11; 534-536. 7. Abramson S Radiology 2001;218:230-2328. Azoulay E et al. CHEST January 2006 vol. 129 no. 1:110-1179. Haron E et al. Medicine (Baltimore). 1993 May;72(3):137-42.10. Kauffman C. Candida Infections in the Abdomen and Thorax. UptoDate.

http://www.uptodate.com/contents/candida-infections-of-the-abdomen-and- thorax?source=search_result&search=candida+pneumonia&selectedTitle=1%7E4#H4. 1/18/12.

11. Kobayashi T et al. Intern Med. 2005 Nov;44(11):1191-4.12. Gorman SR et al. South Med J. 2006 Jun;99(6):613-6.13. Cox GM. Mucormycosis (zygomycosis). UptoDate. http://www.uptodate.com/contents mucormycosis-

zygomycosissource=search_result&search=zygomycetes&selectedTitle=1%7E55. 1/22/12.

14. Busca A et al. Infection. 2011 Jul 7. [Epub ahead of print].

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References


Acknowledgements •Dr. Paul Spirn, MD•Dr. Woodrow Weiss, MD•Dr. Praveen Akuthota, MD•Dr. Gillian Lieberman, MD•Dr. Mai-Lan Ho, MD•Dr. Patrick Redmond, MD•Claire Odom•Narie Storer•Susan Mcgirr•Mekeme Utuk

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imaging of fungal pneumonia in the icu

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