Evaluation of elastase and antielastase balance in patients with chronic bronchitis and pulmonary emphysema

On the basis of the "protease-antiprotease imbalance" theory for the pathogenesis of pulmonary emphysema, we hypothesized that measurement of elastase burden and antielastase capacity in the alveolar space might correlate with emphysema. To evaluate this, the severity of emphysema, the elastase burden, and the elastase inhibitory capacity were estimated in 28 patients with chronic bronchitis and variable degrees of emphysema, none of whom had congenital deficiency of alpha-1-protease inhibitor, and all of whom underwent bronchoalveolar lavage. Emphysema was assessed by both computed tomography and diffusing capacity. To examine "elastase burden," elastase:alpha-1-protease inhibitor complex and free elastase activity in alveolar lavage fluids were measured. To evaluate "antielastase" capacity, elastase inhibiting capacity in alveolar lavage fluid was measured. Elastase burden correlated directly and antielastase capacity correlated inversely with emphysema. These data provide direct support for the "protease-antiprotease imbalance" theory of emphysema in a group of smokers without congenital deficiency of alpha-1-protease inhibitor.

Artifacts and diagnostic pitfalls on magnetic resonance imaging: a clinical review

High field MRI of the brain occasionally exhibits imaging artifacts; most artifacts are obvious and easily recognized, but some are subtle and mimic disease. A thorough understanding of brain MRI artifacts is important to avoid potential diagnostic pitfalls. Some imaging techniques or procedures could be utilized to remove or identify artifacts. These include additional projections, different pulse sequence, and 90 degree shift of phase-encoding gradient. The use of respiratory gating or cardiac gating may also improve image quality by reducing some of the motion-related artifacts.

Bronchoalveolar lavage: radiographic manifestations

Bronchoalveolar lavage (BAL) is a safe and well-tolerated procedure in which the lower respiratory tract is sampled through infusion and subsequent aspiration of sterile saline solution. To determine the radiographic changes consequent to this procedure, 25 patients undergoing fiberoptic bronchoscopy and BAL were evaluated prospectively. After lavage, anteroposterior radiographs were obtained immediately and after 30, 90, and 240 minutes, and 24 hours. The degree and site of opacification on the radiographs was graded on a 4+ subjective scale. Sixty-nine lobes were lavaged, but owing to overlap on the radiographs, 52 projected areas were evaluable for radiographic changes. Forty-seven areas of consolidation were identified on the radiographs obtained immediately after lavage. Consolidation was homogeneous and always corresponded to a projected site of lavage. There was a positive correlation between initial opacity on the radiograph and the volume of retained fluid (rs = .60, P less than .001). Consolidation cleared gradually over 24 hours. No patient had clinical pneumonitis. These benign, self-limited radiographic changes are common after BAL and may simulate pulmonary edema, aspiration, or hemorrhage.

Comprehensive radiological equipment management program

The increasing cost and complexity of state-of-the-art radiological equipment, and the need for more comprehensive safety and performance assurance, have increased maintenance expenditures to a level where they have become one of the largest operating expenses of radiology departments. To cope with this ever increasing expenditure, a comprehensive in-house maintenance program was implemented in our institution. This program properly balanced the capability of the radiology department's in-house technical personnel with support provided by equipment manufacturers' service organizations. Quality assurance activities are also included as an integral part of the entire program. Since the implementation of the program, an average 40% reduction in the annual maintenance expenditure has been observed.

Clinical signs of normal plasma volume expansion during pregnancy

A majority of cases of pregnancy complications are associated with a relative maternal hypovolemia. The records of 200 pregnant women who had had plasma volume determinations were reviewed in hopes of finding indicators of relative maternal hypovolemia other than the pregnancy complication itself. The signs of relative hypovolemia in pregnant women include those of decreased uterine growth, absence of a maternal systolic flow murmur, and absence of significant dependent ankle edema. Laboratory tests indicative of maternal hypovolemia include failure to develop a decline in maternal hematocrit, serum blood urea nitrogen/creatinine ratio greater than 15, a decreased creatinine clearance, abnormal platelet function, elevated serum glutamic oxaloacetic transaminase, ultrasonic evidence of oligohydramnios and/or decreased maternal heart size, and absence of hypervolemia on chest x-ray film. These findings and tests are only relative indicators of maternal hypovolemia, and it is suggested that, for an accurate defining of pregnant women who are at risk, the actual plasma volume determination has to be performed frequently in the pregnant population.

Pressure-infusion venography of the leg with remote-control fluoroscopy

A method for lower-extremity venography using remote-control fluoroscopy and radiography, as well as pressure infusion of contrast media, is described. This technique combines the advantages of fluoroscopically-timed and positioned radiographs with the improved image and size of overhead views. There is less radiation exposure to the patient, radiologist, and technologist than with venography performed with conventional fluoroscopy.