Optimization of pulmonary emphysema quantification on CT scans of COPD patients using hybrid iterative and post processing techniques: correlation with pulmonary function tests.

OBJECTIVES: The aim of this study was to assess the effect of hybrid iterative reconstruction and post processing on emphysema quantification in low-dose CT scans of COPD patients using pulmonary function tests (PFT) as a reference. METHODS: CT scans of 23 COPD patients diagnosed with GOLD I or higher were reconstructed with iDose4 level 1 to 7 in IntelliSpace Portal (ISP) 6 and 7. ISP7 was used with and without specific denoising filter for COPD. The extent of emphysema was measured as percentage of lung voxels with attenuation < - 950 Hounsfield units (%LAA-950). The correlation between %LAA-950 and PFT, age, BMI, pack years, and the Clinical COPD Questionnaire (CCQ) and Medical Research Council dyspnea scale (MRC) was determined. RESULTS: Denoising significantly reduced %LAA-950 as was demonstrated by lower %LAA-950 in ISP7 with denoising filter and a significant reduction in %LAA-950 with higher iDose4 levels. All PFT except forced vital capacity (FVC) were significantly inversely correlated with %LAA-950. There was a trend toward a stronger correlation at higher iDose4 levels. %LAA-950 was also significantly correlated with BMI, GOLD class, and CCQ scores. CONCLUSIONS: Our study showed that hybrid iterative reconstruction and use of post processing denoising can optimize the use of emphysema quantification in CT scans as a complimentary diagnostic tool to stage COPD in addition to PFT.

[Diagnostic delay of pulmonary embolism]. / Diagnostische delay bij longembolie.

OBJECTIVE: To quantify the different stages of diagnostic delay of pulmonary embolism (PE) in patients and to identify other clinical factors associated with this delay. DESIGN: Case series. METHOD: Medical records were reviewed for all patients diagnosed with PE in the period 1 January 2008 and 31 December 2009 in Isala Hospital in Zwolle (the Netherlands), and data was collated for: the dates of symptom onset, presentation to a GP, referral to secondary care, and diagnosis respectively. The relationship between diagnostic delay and other clinical parameters such as gender, age, risk factors, symptoms and co-morbidities was tested using multivariate logistic regression analysis. RESULTS: For the 261 patients included in the analysis, the average total delay was 8.6 days. Patient delay (4.2 days average) and delay in primary care (3.9 days) were the major contributors to this delay. Chest pain and symptoms of deep venous thrombosis were associated with an early diagnosis. Patient delay was shorter in patients with chest pain and longer in patients with dyspnoea. In primary care, chest pain and rales were associated with an early referral, whereas the presence of co-morbidity led to a delayed referral. Delay in secondary care was shorter when the patient presented with dyspnoea. CONCLUSION: The diagnostic delay of PE is substantial, especially patient delay and delays originating in primary care. Further research is needed to identify clinical factors that raise suspicion of PE in primary care, to aid the development of improved diagnostic models.

Reinforced racial integration in the first grade: a study in generalization.

This study investigated possible factors in promoting racial integration, a matter of practical concern in schools today. Specifically, the effect of social and tangible reinforcement was studied on the social integration of five black children in a predominantly white classroom. "Sitting and seating with a new friend" in the school cafeteria was manipulated by (a) teacher directive combined with reinforcement and (b) by positive reinforcement alone. Treatment effectiveness was studied in the cafeteria and as generalization effects to a free-play period. The results indicated that reinforcement produced significant generalization to integrated free play, although intersubject variability was present. Evidence suggests that reinforcement techniques can be used effectively to promote social integration.

Cognitive factors in sexual behavior.

Two major forms of cognitive behaviors are examined: perceptions and evaluations. By synthesizing the work of cognitive therapists such as Beck and Ellis, a feedback-loop model of sexual arousal is proposed. It is suggested that cognitive distortions of perception and evaluation operate in most cases of sexual dysfunction. Therefore, a more specific diagnostic schema and a more relevantly planned course of treatment may be designed by pinpointing the troublesome cognitive linkages between sexual stimuli and sexual responses.