Cytomegalovirus (CMV) pneumonia is a type of viral pneumonitis and occurs due to infection with cytomegalovirus (CMV), which is a member of the Herpetoviridae family.
CMV infection is particularly important in those who are immunocompromised (e.g. those with AIDS / allogenic bone marrow transplantation 3). In recipients of hematopoietic cell transplantations, the incidence of CMV can be around 20-35% 8.
A major biological characteristic of CMV (as with other herpes viruses) is its ability to become latent in the human host and therefore the potential for reactivation.
Findings on chest radiographs are usually non-specific.
CT findings are non-specific and diverse and have been described without distinction between AIDS and non-AIDS patients. Commonly described findings include:
- mixed alveolar-interstitial infiltrative opacification
ground-glass opacities 1
- relatively common feature, may be seen in ~67% of cases 5
- ground-glass opacities 1
- small pulmonary nodules 4,7
- nodules tend to have bilateral symmetrical distribution and involve all zones 6
- confluent consolidation 1
- may be more marked towards the lower lobes 6
- bronchiectasis 1
- interstitial reticulation without air space opacification 1,4
Other described features include:
The imaging differential is broad but in the immunosuppressed population consider:
- 1. Moon JH, Kim EA, Lee KS et-al. Cytomegalovirus pneumonia: high-resolution CT findings in ten non-AIDS immunocompromised patients. Korean J Radiol. 2002;1 (2): 73-8. Free text at pubmed - Pubmed citation
- 2. Aafedt BC, Halvorsen RA, Tylën U et-al. Cytomegalovirus pneumonia: computed tomography findings. Can Assoc Radiol J. 1990;41 (5): 276-80. Pubmed citation
- 3. Horger MS, Pfannenberg C, Einsele H et-al. Cytomegalovirus pneumonia after stem cell transplantation: correlation of CT findings with clinical outcome in 30 patients. AJR Am J Roentgenol. 2006;187 (6): W636-43. doi:10.2214/AJR.04.1592 - Pubmed citation
- 4. McGuinness G, Scholes JV, Garay SM et-al. Cytomegalovirus pneumonitis: spectrum of parenchymal CT findings with pathologic correlation in 21 AIDS patients. Radiology. 1994;192 (2): 451-9. Pubmed citation
- 5. Franquet T, Lee KS, Müller NL. Thin-section CT findings in 32 immunocompromised patients with cytomegalovirus pneumonia who do not have AIDS. AJR Am J Roentgenol. 2003;181 (4): 1059-63. doi:10.2214/ajr.181.4.1811059 - Pubmed citation
- 6. Kang EY, Patz EF, Müller NL. Cytomegalovirus pneumonia in transplant patients: CT findings. J Comput Assist Tomogr. 1996;20 (2): 295-9. Pubmed citation
- 7. Gasparetto EL, Ono SE, Escuissato D et-al. Cytomegalovirus pneumonia after bone marrow transplantation: high resolution CT findings. Br J Radiol. 2004;77 (921): 724-7. Pubmed citation
- 8. Vogel MN, Brodoefel H, Hierl T et-al. Differences and similarities of cytomegalovirus and pneumocystis pneumonia in HIV-negative immunocompromised patients thin section CT morphology in the early phase of the disease. Br J Radiol. 2007;80 (955): 516-23. doi:10.1259/bjr/39696316 - Pubmed citation