About 75% of persistent pulmonary GGO nodules are attributed to BAC or adenocarcinoma with predominant BAC component, and at thin-section CT, these nodules do not manifest morphologic features that distinguish them from other GGO nodules with different histopathologic diagnoses.

Dynamic enhancement with multi-detector row CT shows high sensitivity and negative predictive values for diagnosis of malignant nodules but low specificity because of highly enhancing benign nodules. Extent of enhancement reflects underlying nodule angiogenesis.

No abstract

Both PET/CT and 3.0-T whole-body MR imaging appear to provide acceptable accuracy and comparable efficacy for NSCLC staging, but for M-stage determination, each modality has its own advantages.

No abstract

The presence of pulmonary vasculitis can be suggested by a clinical presentation that includes diffuse pulmonary hemorrhage, acute glomerulonephritis, chronic refractory sinusitis or rhinorrhea, imaging findings of nodules or cavities, mononeuritis multiplex, multisystemic disease, and palpable purpura. Serologic tests, including the use of cytoplasmic antineutrophil cytoplasmic antibody (ANCA) and perinuclear ANCA, are performed for the differential diagnosis of the diseases. A positive cytoplasmic ANCA test result is specific enough to make a diagnosis of ANCA-associated granulomatous vasculitis if the clinical features are typical. Perinuclear ANCA positivity raises the possibility of Churg-Strauss syndrome or microscopic polyangiitis. Imaging findings of pulmonary vasculitis are diverse and often poorly specific. The use of a pattern-based approach to the imaging findings may help narrow the differential diagnosis of various pulmonary vasculitides. Integration of clinical, laboratory, and imaging findings is mandatory for making a reasonably specific diagnosis.

BACKGROUNDIntegrated 18fluorine fluorodeoxyglucose (18F‐FDG) positron emission tomography/computed tomography (PET/CT) has shown somewhat variable sensitivity and specificity for mediastinal nodal staging in granulomatous disease endemic areas. The purpose of the study was to prospectively evaluate the efficacy of PET/CT for mediastinal nodal staging in nonsmall cell lung cancer (NSCLC) patients in a tuberculosis‐endemic country.METHODSProspective assessment of the diagnostic efficacy of integrated PET/CT for detecting mediastinal nodal metastasis was performed in 674 patients (M:F ratio = 502:172; mean age, 61 years) with NSCLC. Patients underwent an integrated PET/CT examination and subsequent surgical nodal staging (by mediastinoscopy only in 121 patients and by thoracotomy in 553). Nodes showing greater 18F‐FDG uptake than mediastinum at PET without benign calcification or high attenuation >70 household unit (HU) at unenhanced CT were regarded as being positive for malignancy. The histologic nodal assessment results were used as reference standards.RESULTSOf 2477 mediastinal nodal stations evaluated in 674 patients, 275 (11%) stations in 180 (27%) patients proved to be malignant. On a per‐person basis, the overall sensitivity, specificity, and accuracy of PET/CT for mediastinal nodal staging were 61% (110 of 180), 96% (473 of 494), and 86% (583 of 674), respectively. On a per‐nodal station basis, they were 46% (126 of 275), 98% (2154 of 2202), and 92% (2280 of 2477).CONCLUSIONSIntegrated PET/CT provides high specificity and reasonably high accuracy, but somewhat low sensitivity for mediastinal nodal staging of NSCLCs. The high specificity is achieved at the expense of sensitivity by interpreting calcified nodes or nodes with high attenuation at CT, even with high FDG uptake at PET, as benign in a tuberculosis‐endemic region. Cancer 2007. © 2007 American Cancer Society.

Volume-based parameters of (18)F-FDG PET/CT have the potential to provide prognostic information in MPM patients who are receiving surgery or palliative chemotherapy.