OBJECTIVE: To assess clinical feasibility of low-attenuation cluster analysis in evaluation of chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Subjects were 199 current and former cigarette smokers that underwent CT for quantification of COPD and had physiological measurements. Quantitative CT (QCT) measurements included low-attenuation area percent (LAA%) (voxels ≤ −950 Hounsfield unit [HU]), and two-dimensional (2D) and three-dimensional D values of cluster analysis at three different thresholds of CT value (−856, −910, and −950 HU). Correlation coefficients between QCT measurements and physiological indices were calculated. Multivariable analyses for percentage of predicted forced expiratory volume at one second (%FEV1) was performed including sex, age, body mass index, LAA%, and D value had the highest correlation coefficient with %FEV1 as independent variables. These analyses were conducted in subjects including those with mild COPD (global initiative of chronic obstructive lung disease stage = 0–II). RESULTS: LAA% had a higher correlation coefficient (-0.549, p < 0.001) with %FEV1 than D values in subjects while 2D D−910HU (−0.350, p < 0.001) revealed slightly higher correlation coefficient than LAA% (−0.343, p < 0.001) in subjects with mild COPD. Multivariable analyses revealed that LAA% and 2D D value−910HU were significant independent predictors of %FEV1 in subjects and that only 2D D value−910HU revealed a marginal p value (0.05) among independent variables in subjects with mild COPD. CONCLUSION: Low-attenuation cluster analysis provides incremental information regarding physiologic severity of COPD, independent of LAA%, especially with mild COPD.
Body Mass Index ; Cluster Analysis ; Forced Expiratory Volume ; Pulmonary Disease, Chronic Obstructive ; Tobacco Products

PURPOSE: Historically, it was thought that hemorrhagic complications were increased with transrectal ultrasound-guided prostate biopsies (TRUS biopsy) of patients receiving anticoagulation/antiplatelet therapy. However, the current literature supports the continuation of anticoagulation/antiplatelet therapy without additional morbidity. We assessed our experience regarding the continuation of anticoagulation/antiplatelet therapy during TRUS biopsy. MATERIALS AND METHODS: A total of 91 and 98 patients were included in the anticoagulation/antiplatelet (group I) and control (group II) groups, respectively. Group I subgroups consisted of patients on monotherapy or dual therapy of aspirin, warfarin, clopidogrel, or low molecular weight heparin. The TRUS biopsy technique was standardized to 12 cores from the peripheral zones. Patients completed a questionnaire over the 7 days following TRUS biopsy. The questionnaire was designed to assess the presence of hematuria, rectal bleeding, and hematospermia. Development of rectal pain, fever, and emergency hospital admissions following TRUS biopsy were also recorded. RESULTS: The patients' mean age was 65 years (range, 52 to 74 years) and 63.5 years (range, 54 to 74 years) in groups I and II, respectively. The overall incidence of hematuria was 46% in group I compared with 63% in group II (p=0.018). The incidence of hematospermia was 6% and 10% in groups I and II, respectively. The incidence of rectal bleeding was similar in group I (40%) and group II (39%). Statistical analysis was conducted by using Fisher exact test. CONCLUSIONS: There were fewer hematuria episodes in anticoagulation/antiplatelet patients. This study suggests that it is not necessary to discontinue anticoagulation/antiplatelet treatment before TRUS biopsy.
Anticoagulants ; Aspirin ; Biopsy ; Emergencies ; Fever ; Hematuria ; Hemorrhage ; Hemospermia ; Heparin, Low-Molecular-Weight ; Humans ; Incidence ; Prostate ; Ticlopidine ; Warfarin