Characteristics Of Lesions In Patients Research Articles

Differentiating Solitary Pulmonary Metastases in Patients with Extrapulmonary Neoplasmas Using FDG–PET

The purpose of this preliminary study is to evaluate the characteristics of solitary pulmonary lesions in patients using extrapulmonary neoplasmas with 18F-fluoro-2-deoxyglucose positron emission tomography (FDG–PET). Thirty-two patients with extrapulmonary neoplasmas who had solitary pulmonary lesions and were suspected for pulmonary metastasis underwent an oncological survey with FDG–PET. Standard uptake value (SUV) and the ratio of lesion-to-background (L/B ratio) were used as parameters to differentiate and characterize the solitary pulmonary lesions. Using SUV >2.5 or L/B ratio >3 as the cutoff to diagnose malignancy, FDG–PET correctly identified 29 true-positive cases. However, FDG–PET failed to interpret two false-positive and one false-negative cases. The accuracy of FDG–PET was 91%. We concluded that FDG–PET is an accurate modality to differentiate solitary pulmonary lesions in patients with extrapulmonary neoplasmas.

Platelet scintigraphy in the diagnosis of arteriosclerosis obliterans.

We evaluated the efficacy of platelet scintigraphy using autologous platelets labeled with 111In-oxine, to assess the degree of arteriosclerotic activity in arteriosclerosis obliterans (ASO). Thirty-three patients with clinical signs of ASO, seen between January 1996 and August 1999, were enrolled in this study. Scintigraphic imaging results were compared with the findings of contrast angiography in 26 patients, 17 of whom were taking antiplatelet and/or anticoagulant drugs during the platelet imaging study. Angiography demonstrated atherosclerotic lesions at 38 sites from the abdominal aorta to the popliteal arteries in 23 patients. There was an accumulation of platelets at 17 of these sites (45%) and at 6 other sites without definite angiographic abnormalities. Lesions that resulted in less than 50% stenosis were detected slightly, but not significantly, less often than lesions with higher degrees of stenosis and occlusion (50% vs 30%, P = 0.73). The frequency of true-positive scintigraphic results was statistically higher in patients not taking antithrombotic agents than in those taking antithrombotic agents (70% vs 32%, P = 0.02). Our results suggest that imaging with 111In-oxine-labeled platelets may be useful for evaluating the pathophysiologic characteristics of atherosclerotic lesions in patients with ASO.

Pathophysiological Insight Into the Possible Optimal Therapies for Acute Myocardial Infarction and Unstable Angina

The optimal treatment of unstable ischemic coronary syndromes has not been settled, and little in vivo pathological information in humans has been available to help guide the care of patients with these complicated problems. Dr Van Belle and colleagues1 have given us new insight into the underlying pathophysiological substrate in patients sustaining acute myocardial infarction who then underwent coronary angioscopy before coronary interventions up to 1 month after their index event. Of these patients, 98% were treated with aspirin, 66% had thrombolytic therapy, and 100% had been treated with heparin for at least 72 hours after admission. Despite this intense antithrombotic regimen, the residual lesions were angiographically severe in 76%, and complete occlusions were found in 14% of the patients. By angioscopy, the majority of the infarct-related lesions were yellow (79%), and many were ulcerated (36%) or had visible residual thrombus (77%). Eighteen percent of the patients had large clumps of platelets adherent to the plaque, even late in the course after infarction. The fact that these plaques remained “active” for up to 30 days is quite interesting and unsettling. There was an equal prevalence of yellow ulcerated …