Influence of inspiration level on bronchial lumen measurements with computed tomography

SummaryBackgroundBronchial dimensions measured in CT images generally do not take inspiration level into consideration. However, some studies showed that the bronchial membrane is distensible with airway inflation. Therefore, re-examination of the elasticity of bronchi is needed.PurposeTo assess the influence of respiration on bronchial lumen area (defined as distensibility) in different segmental bronchi and to explore the correlations between distensibility and both lung function and emphysema severity.Material and methodsIn 44 subjects with COPD related to alpha-1-antitrypsin deficiency (AATD), bronchial lumen area was measured in CT images, acquired at different inspiration levels. Measurements were done at matched locations in one apical and two basal segmental airways (RB1, RB10 and LB10). Airway distensibility was calculated as lumen area difference divided by lung volume difference.ResultsBronchial lumen area in the lower lobes (RB10 and LB10) correlated positively with FEV1%predicted (p=0.027 for RB10; and p=0.037 for LB10, respectively). Lumen area is influenced by respiration (p=0.006, p=0.045, and, p=0.005 for RB1, RB10 and LB10, respectively). Airway distensibility was different between upper and lower bronchi (p<0.001), but it was not correlated with lung function.ConclusionLumen area of third generation bronchi is dependent on inspiration level and this distensibility is different between bronchi in the upper and lower lobes. Therefore, changes in lumen area over time should be studied whilst accounting for the lung volume changes, in order to estimate the progression of bronchial disease while excluding the effects of hyperinflation

769-2 Progression and Regression of Coronary Atherosclerosis Occur within the Same Patient During Placebo Treatment and During Lipid-Lowering Therapy with Pravastatin

REGRESS (Regression Growth Evaluation Statin Study) is a placebo controlled multicenter study to asses the effect of 2-yr treatment with Pravastatin (PRAV) on progression and regression of angiographically documented coronary atherosclerosis (CA) in patients with a serum cholesterol between 4–8mmol/l (155-310mg/dl). Analyses of the coronary arteriograms were performed by quantitative computer analysis. The primary endpoints of the study, change in Mean Segment Diameter and Minimum Obstruction Diameter (MOD) averaged per patient, showed significant retardation of mean progression of CA in the PRAY-group as compared to the placebo (PLAC)-group. However, these mean changes per treatment group are hardly informative about individual CA-behavior. Therefore we determined for all 641 patients included in the primary MOD-analysis: 1. a mean progression score (MPS)-cumulative value of all &gt;0.4mm progressing obstructions divided by the number of contributing obstructions-, and 2. a mean regression score (MRS)-cumulative value of all&gt;0.4mm regressing obstructions divided by the number of contributing obstructions. Obstructions changing ≤0.4mm were considered stable and do not contribute to the scores. Thus, each patient is characterized by a MPS and a MRS. An overview of the patient MPS and MRS is presented in the figure below.Conclusionsignificant progression and regression of CA within the same patient occurred in 41 (13%) PRAY-patients and in 27 (9%) PLAC-patients. Thus, although pravastatin slows mean progression of CA, progression and regression of CA within the same patient still occurs in a considerable number of patients during lipid lowering therapy

Angiotensin-Converting Enzyme Inhibitor Therapy Affects Left Ventricular Mass in Patients With Ejection Fraction >40% After Acute Myocardial Infarction

AbstractObjectives. We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) >40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI).Background. Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF >35%. However, the effects on LV mass and volume in this patient population have not been studied.Methods. Thirty-five patients with a LVEF >40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices.Results. Left ventricular end-diastolic volume index did not change in ramipril-treated patients (62 ± 16 [SD] to 66 ± 17 ml/m2) or in control patients (62 ± 16 to 68 ± 17 ml/m2), and stroke volume index increased significantly in both groups. However, LV mass index decreased in ramipril-treated patients (82 ± 18 to 73 ± 19 g/m2, p = 0.0002) but not in the control patients (77 ± 15 to 79 ± 23 g/m2). Systolic arterial pressure did not change in either group at 3-month follow-up.Conclusions. In patients with a LVEF >40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.(J Am Coll Cardiol 1997;29:49–54)