title: What a differential a virus makes: a practical approach to thoracic imaging findings in the context of HIV infection--part 2, extrapulmonary findings, chronic lung disease, and immune reconstitution syndrome.
abstract: OBJECTIVE
  The Centers for Disease Control and Prevention reported more than one million people with HIV infection in the United States in 2006, an increase of 11% over 3 years. Worldwide, nearly 34 million people are infected with HIV. Pulmonary disease accounts for 30-40% of acute hospitalizations of HIV-seropositive patients, underscoring the importance of understanding the range of cardiothoracic imaging findings associated with HIV infection. This article will cover extrapulmonary thoracic diseases, chronic lung diseases, and immune reconstitution inflammatory syndrome in HIV-infected patients. Our approach is focused on the radiologist's perspective by recognizing and categorizing key imaging findings to generate a differential diagnosis. The differential diagnosis can be further refined by incorporating clinical data, such as patient demographics, CD4 count, and presenting symptoms. In addition, with prolonged survival of HIV-infected patients in the era of highly active antiretroviral therapy, radiologists can also benefit from awareness of imaging features of a myriad of chronic cardiopulmonary diseases in this patient population. Finally, the change of imaging findings and clinical status in response to treatment provides important diagnostic information, such as in immune reconstitution syndrome.
  
  
  CONCLUSIONS
  Developing a practical approach to key cardiothoracic imaging findings in HIV-infected patients will aid the radiologist in generating a clinically relevant differential diagnosis and interpretation, thereby improving patient care.
authors.affiliation: Department of Radiology, Division of Thoracic Imaging and Intervention, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA. john.lichtenberger@gmail.com
authors.forename: John P
authors.initials: JP
authors.lastname: Lichtenberger
authors.forename: Amita
authors.initials: A
authors.lastname: Sharma
authors.forename: Kimon C
authors.initials: KC
authors.lastname: Zachary
authors.forename: Mayil S
authors.initials: MS
authors.lastname: Krishnam
authors.forename: Reginald E
authors.initials: RE
authors.lastname: Greene
authors.forename: Jo-Anne O
authors.initials: JA
authors.lastname: Shepard
authors.forename: Carol C
authors.initials: CC
authors.lastname: Wu
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000000981:diagnostic imaging*; D018791:CD4 Lymphocyte Count; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging* / Q000821:virology; D002908:Chronic Disease; D003937:Diagnosis, Differential; D015658:HIV Infections / Q000000981:diagnostic imaging*; D006801:Humans; D054019:Immune Reconstitution Inflammatory Syndrome / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000821:virology*; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging* / Q000821:virology; D013902:Radiography, Thoracic; D014057:Tomography, X-Ray Computed