Characteristics of integrated 18F-FDG PET/CT in Pulmonary Cryptococcosis.

BACKGROUND: Pulmonary cryptococcosis is an uncommon cause of pulmonary nodules found by (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) scans. It is rarely reported but may mislead interpretation. PURPOSE: To describe the (18)F-FDG PET/CT findings of pulmonary cryptococcosis. MATERIAL AND METHODS: The (18)F-FDG PET/CT images of seven patients with pulmonary cryptococcosis were evaluated. RESULTS: The (18)F-FDG PET/CT exams showed single or multiple nodular lesions. The standardized uptake values (SUV) in early images varied significantly for the seven patients (ranging from 2.2 to 11.6). Delayed SUVs showed significant increases in four patients. CONCLUSION: Pulmonary cryptococcosis mimics primary or metastatic lung cancer on (18)F-FDG PET/CT scan. Tissue confirmation should be considered for any suspicious pulmonary nodules found on (18)F-FDG PET/CT scan with an SUV score higher than 2.5, in order to avoid overdiagnosis or overstaging.

Improving diagnosis of central venous catheter-related bloodstream infection by using differential time to positivity as a hospital-wide approach at a cancer hospital.

OBJECTIVES: Considering the difficulty of diagnosing catheter-related bloodstream infection (CRBSI), Koo Foundation Sun Yat-Sen Cancer Center uses differential time to positivity (DTP) as a hospital-wide approach to improve the diagnosis of CRBSI in febrile patients with indwelling central venous catheters (CVCs). This study describes the result of a hospital-wide use of DTP in a real practice setting. METHODS: During January 2003-August 2007, 142 positive paired blood cultures from 125 patients without infection focus other than CVC were included. These were evaluated by DTP and semi-quantitative catheter culture (SQCC) to confirm the diagnosis of CRBSI, and were further divided into two groups: confirmed (either by DTP or SQCC) and non-confirmed CRBSI (neither DTP nor SQCC positive). RESULTS: Fifty-nine point two percent (84/142) of episodes were confirmed as CRBSI, of which DTP was positive in 83.3% (n=70). Non-confirmed CRBSI was associated with hematologic malignancy, neutropenia status, previous antibiotics exposure and a lower CVC removal rate. CONCLUSIONS: A hospital-wide approach of DTP was practical and feasible in improving the diagnosis of CRBSI in a real practice setting.