Multislice computed tomography performance in differential diagnosis of high-density thymic cyst and thymoma in lesions less than 3 cm.

BACKGROUND: This study was conducted to evaluate the performance of multislice computed tomography (MSCT) to diagnose high-density thymic cysts and thymomas in lesions measuring < 3 cm. METHODS: The records of 42 patients admitted to Ningbo No. 2 Hospital with an anterior mediastinal mass (diameter < 3 cm) suspected of carcinoma originating from the thymus were retrospectively analyzed. All patients underwent surgery and pathological examination. Twenty-eight were diagnosed with thymic cysts and 14 with thymoma. The features of thymic cysts and thymomas revealed on MSCT were compared. RESULTS: Mediastinal masses with a triangular or teardrop shape and a straight mediastina-lung border were more likely to be diagnosed as thymic cysts (P < 0.05), while those with a bulging nodule-lung border were more likely thymomas (P < 0.05). Using the CT value as a reference for differential diagnosis, the diagnostic sensitivity, specificity, and area under the receiver operating characteristic curve for CT values of non-contrast CT images, enhanced CT values, and ΔCT values were 0.65 (0.47-0.84), 0.95(0.86-1.00), and 0.96 (0.89-1.00), respectively. CONCLUSION: MSCT of high-density thymus gland nodules (maximum diameter ≤ 3 cm) can reveal specific features that could be helpful for differential diagnosis.

Application of 16-detector row spiral CT for pulmonary angiography and reconstruction techniques in diagnosis of pulmonary embolism in elderly patients / 中华老年医学杂志

Objective To study the application of pulmonary angiography and reconstruction techniques with 16-detector row spiral CT in the diagnosis of pulmonary embolism (PE) in the elderly.Methods Twenty-four elderly patients with suspected pulmonary thromboembolism received detection of CT and pulmonary artery angiography ( CTPA ) on 16-detector MSCT.Post-reconstruction techniques included maximum intensity projection (MIP), volume rendering (VR)and multiple planar reformation (MPR). Results A total of 161 pulmonary artery thrombi were detected in 24 elderly patients. The direct signs of pulmonary embolism included total occlusion (16.8%, 27/161), partial filling defect (67.7%, 109/161) and central filling defect or track sign (15.5%, 25/161). A total of 161 pieces of pulmonary thrombi were detected in transect image, 153 (95.0%) in MPR, 113 (70.2%) in MIP and 69 (42.9%) in VR. The transect image excelled evidently MIP and VR image in displaying pulmonary thrombi, especially the thrombi in pulmonary lobe and pulmonary artery branch (χ2 =235.36 and 243.41, P＜0.05). Conclusions The 16-detector row spiral CT pulmonary angiography is non-invasive, fast and high sensitive, it should be the first choice for the diagnosis of PE in the elderly.