Findings
    Chest radiograph shows miliary nodular shadows in the whole lung fields and normal heart size. Thin section CT scans show diffuse ground glass opacity and reticular opacity in both lungs. Miliary nodular opacities are not apparent on CT scans.

Dicussion
    Cytomegaloviral pneumonia frequently occurs in immunosupressed patients, especillay following organ transplantation. Clinical diagnosis of CMV pneumonia is often difficult because of many other pathogens may cause pneumonia in the immunocompromised patient and because signs and symptoms are nonspecific. CMV pneumonitits may cause fever, pumonary infiltrates,and hypoxia resulting in the adult respriatory distress syndrome. CMV infection may suppress T-cell mediated immunity and may cause sever neutorpenia. Therefore CMV infection often is associated with other pathogens including Pneumocystis carinii, aspergillus fumigatus, and cytptococcus neoformans.
    Cytomegaloviral infection has been frequently identified in renal transplantation patients. Moore et al. in a study of patients treated with cyclosporine-prednisone immunosuppression following renal transplantation, found that CMV was present in 8 of 17 cases of pneumonia, including 5 of 6 patients with diffuse pulmonary infiltrates and all 6 patients with multiple organism infection. CT findings include diffuse interstitial / fine nodular pattern, reticulonodular pattern, mixed air space and interstitial desease, bilateral airspace disease, masslike consolidation, and lobar consolidation. It has been speculated that CMV infection itself may compromise T-cell function causing further immunocompromise in this population. It usually diagnosed by bronchoscopic biopsy and BAL and typical cytopathologic change including cytomegalic change with intranuclear or intracytoplasmic inclusion body is more specific than isolation of organism by culture.
CMV is recognized as the most common viral pathogen to cause substantial morbity and mortality in patients with AIDS. In several large autopsy series, 49-81% of patients with AIDS have evidences of CMV infection. In some series, CMV is the most common AIDS?defining infection and the most common opportunistic infection in the lungs. Although the identification of cytopathologic changes of CMV in the lungs of transplant recipients is uniformly accepted as being indicative of clinical pneumonitis, in the settings of compromised immunitiy due to AIDS, the importance of the recovery of pulmonary CMV remains highly controversial. The identification of pahtognomonic cells with intranuclear or intracytoplamic inclusions is genreally considered a necessary criterion from the diagnosis of CMV pneumonitis. The risk of CMV pneumonitis is usually increased later in the course of disease after multiple episode of PCP or other pneumonias when the CD4 T-cell count below 50/mm3. CT patterns of CMV pneumonitis in AIDS patients reflect the pathologic changes of diffuse alveolar damage and focal interstitial pneumonitis and manifested most commonly as mixed alveolar-interstitial infiltrate. Ground-glass attenuation, dense condolidation, mass-lkie infiltrates are also obsereved on CT. Unlike the CMV pneumonitis in non-AIDS patients, masses or a mass-like infiltrate may be a sole or dominant findng in AIDS patients.

Reference
1. Moore EH, Webb WR, Amend WJC. Pulmonary infections in renal transplantation patients treated with cyclosporine. Radiology 1988;167:97-103