Development and implementation of a quality assurance program for mammography.

As a pilot study for a national campaign to promote the use of screening mammography, the Virginia Division of the American Cancer Society conducted a breast cancer awareness project with mammography screening. An important part of the program was the development of a quality assurance program for mammography. Guidelines were established for equipment, image recorders, processing, dose, and patient positioning. A survey of information about the mammographic equipment was conducted, and the mammograms from each facility were reviewed. A total of 63 mammographic units in 56 facilities statewide were included in the month-long program during which approximately 9,000 women were screened.

Gamma scintigraphic analysis of albumin flux in patients with acute respiratory distress syndrome.

Computerized gamma-scintigraphy provides a new method for the analysis of albumin flux in patients with pulmonary permeability edema. In this technique, 10 mCi of 99mTc -tagged human serum albumin is administered and lung:heart radioactivity ratios are determined. This ratio remains constant unless there is a leak of albumin, when a rising ratio with time, called the "slope index" (SI), is seen. Thirty-five scintigraphic studies were obtained in 28 patients by means of a portable computerized gamma-camera. Thirteen of these patients had clinical evidence of the acute respiratory distress syndrome (ARDS) and six had or were recovering from left ventricular induced congestive heart failure (CHF). Five of the patients with CHF and pulmonary capillary wedge pressure (PCWP) below 30 mm Hg had normal scintigraphic studies. One patient in florid CHF with a PCWP of 40 mm Hg had a positive SI of 1.6 X 10(-3) U/min. The patients with ARDS were found to have significantly higher SIs than patients who did not have, or had recovered from, ARDS. The arterial:alveolar oxygen tension ratio (a/A)O2 was 0.30 +/- 0.14 in patients with positive SIs while receiving 11.0 +/- 6.8 m H2O positive end-expiratory pressure (PEEP). Both the (a/A)O2 and level of PEEP were significantly (P less than 0.01) worse in these patients than in patients with normal SIs. Positive SIs were present from 1 to 8 days following the apparent onset of ARDS in seven studies in five patients. Recovery of gas exchange was associated with a return to a normal SI in four patients. In conclusion, computerized gamma-scintigraphy was a sensitive, noninvasive tool for the detection of a pathologic increase in pulmonary protein flux. Positive scintigraphic findings were associated with significantly impaired gas exchange. The method documented that the leak of albumin in patients with ARDS may last for days but resolves with recovery.

Modification of cradle angiographic tables to more easily obtain axial coronary views.

With greater utilization of angled coronary views for better elucidation of coronary anatomy, many laboratories are still limited by the rotating cradle systems which make angulation for these views somewhat difficult. The following report describes a simple, inexpensive way to modify existing cradle structures to accommodate easy cranial angulation.

Failure of various agents to decrease oleic acid pulmonary albumin leak.

Computerized pulmonary gamma scintigraphy has been shown to be a sensitive technique for the measurement of albumin flux in oleic acid pulmonary microvascular injury. In this technique technetium-99m-tagged human serum albumin is administered intravenously and lung:heart radioactivity ratios are constructed. This ratio remains constant unless there is a net flux of albumin from the vascular space into the lung, when a rising ratio is seen, called the "slope of injury" or SI. Gamma scintigraphy provides a method to rapidly screen the ability of various possible therapeutic agents to reduce the flux of albumin in experimental ARDS. In this study, 0.05 ml/kg oleic acid produced a significant increase in the SI. None of the agents tested (30 mg/kg methylprednisolone, 12.5 mg/kg ibuprofen, 4 mg/kg MK-447, a superoxide radical scavenger, or 140 mg/kg calcium gluconate) were able to alter the scintigraphically measured increased albumin flux produced by 0.05 ml/kg oleic acid.

Computerized scintigraphic technique for the evaluation of adult respiratory distress syndrome: initial clinical trials.

Eleven patients with suspected adult respiratory distress syndrome (ARDS) and five control patients were studied using a computerized gamma imaging and analysis technique and 99mTc-labeled human serum albumin. The heart and right lung were imaged, lung:heart ratio was plotted vs. time, and a linear regression was fitted to the data points displayed. The slope of this fit was termed the "slope index." An index value of 2 standard deviations greater than the control mean was considered positive. Radiographs from the six positive studies revealed typical diffuse air-space disease. Radiographs from two of the five negative studies demonstrated air-space consolidation. Both of these patients had elevated pulmonary capillary wedge pressure, cardiomegaly, and clinical course consistent with cardiogenic pulmonary edema. These preliminary data demonstrated a good correlation between positive slope index and clinical ARDS.

Scintigraphy and radiography in oleic acid pulmonary microvascular injury: effects of positive end-expiratory pressure (PEEP).

Using computerized gamma scintigraphy, 10-cm H2O PEEP did not alter the rate of capillary protein leakage in dogs following pulmonary microvascular injury with 0.01 to 0.2 ml/kg oleic acid. A rising lung:heart radioactivity ratio, or 'slope of injury,' was seen during PEEP which paralleled the 'slope of injury' had PEEP not been used. A sudden decrease in lung and heart count activity (p less than 0.001) and decreased lung:heart radioactivity ratio (p less than 0.001) occurred with PEEP at all doses of oleic acid studied. An apparent improvement in the standard chest roentgenogram was seen within 2 minutes following PEEP in dogs given 0.2 ml/kg oleic acid. However, progression of the radiographic infiltrate occurred in these animals during 30 minutes of PEEP. When all vessels leading to and from the heart and lungs were ligated, PEEP produced a 60% fall in count activity over the lung without any change in cardiac radioactivity. The apparent radiographic improvement and 2/3 of the fall in lung radioactivity with PEEP were due to an increased pulmonary air volume and 1/3 due to a decreased pulmonary blood volume. The decreased cardiac output with PEEP must be secondary to decreased ventricular filling rather than decreased ventricular function.

Comparative scintigraphy in oleic acid pulmonary microvascular injury.

Computerized gamma scintigraphy revealed a significant (p less than 0.001) rising lung:heart radioactivity ratio, which has been called "slope of injury" or "slope index", with both 99mTechnetium-tagged human serum albumin (99mTc-HSA) and 99mTechnetium-tagged red blood cells (99Tc-RBC) after 0.05 or 0.2 ml/kg iv oleic acid administration to dogs. This slope index was significantly greater with 99mTc-HSA than 99mTc-RBC (p less than 0.001). These findings verify that the scintigraphic 99mTc-HSA slope of injury is a result of a pulmonary capillary protein leak and not oleic acid induced changes in pulmonary blood or air volume. The leak of red blood cells noted with scintigraphy was confirmed by light microscopy and examination of the tracheal edema fluid. The leak of albumin, however, was much greater than the leak of red blood cells by microscopy and tracheal fluid examination, confirming the scintigraphic data. This study provides further evidence that computerized gamma scintigraphy will be of value for the diagnosis of permeability pulmonary edema and its response to treatment.

Single isotope evaluation of pulmonary capillary protein leak (ARDS model) using computerized gamma scintigraphy.

Using a canine oleic acid model, a computerized gamma scintigraphic technique was evaluated to determine 1) ability to detect pulmonary capillary protein leak in a model temporally consistent with clinical adult respiratory distress syndrome (ARDS), 2) the possibility of providing a quantitative index of leak, and 3) the feasibility of closely spaced repeat evaluations. Study animals received oleic acid (controls, n = 10; 0.05 ml/kg, n = 10; 0.10 ml/kg, n = 12; 0.15 ml/kg, n = 6) 3 hours prior to a tracer dose of technetium-990m (99mTc) HSA. One animal in each dose group also received two repeat tracer injections spaced a minimum of 45 minutes apart. Digital images were obtained with a conventional gamma camera interfaced to a dedicated medical computer. Lung: heart ratio versus time curves were generated, and a slope index was calculated for each curve. Slope index values for all doses were significantly greater than control values (P(t) less than 0.0001). Each incremental dose increase was also significantly greater than the previous dose level. Oleic acid dose versus slope index fitted a linear regression model with r = 0.94. Repeat dosing produced index values with standard deviations less than the group sample standard deviations. We feel this technique may have application in the clinical study of pulmonary permeability edema.

Effects of pulmonary vascular recruitment on gamma scintigraphy and pulmonary capillary protein leak.

Pulmonary vascular recruitment (PVR) was altered and lung-heart radioactivity ratio (L:H) measured using 99mTc-tagged human serum albumin (Tc-HSA) in five dogs each by inflating a left atrial balloon (LAB) to produce a 20 mm Hg pulmonary capillary wedge pressure (PCWP) or opening a 5 mm diameter aortoinferior caval shunt (ACS) before and after oleic and injury. Cardiac output (CO), pulmonary arterial pressure (PAP), and PCWP were measured with each alteration in PVR. In an additional 10 dogs, multiple doses of Tc-HSA, administered over 5 hours, 2 hours after 0.1 ml/kg oleic acid, produced parallel "slopes of injury" over the 5-hour period. Each rise in PVR was associated with an acute increase in L:H but demonstrated no significant increase in slope after equilibration. Closure of the ACS or LAB deflation returned the L:H to projected baseline. A "slope of injury" (P less than 0.001) was seen after the administration of oleic acid, which was significantly (P less than 0.01) steeper with an increased PVR. This was confirmed by repeat doses of Tc-HSA. This study confirmed the following hypotheses: (1) the "slope of injury" curves were reproducible so that the effects of experimental interventions on the rate of protein leak could be determined; (2) the L:H rapidly became constant after an acute change in PVR prior to oleic acid injury: and (3) a raised PVR would increase the rate of albumin leak after pulmonary microvascular injury.

Sensitivity of scintigraphy for detection of pulmonary capillary albumin leak in canine oleic acid ARDS.

Computerized gamma scintigraphy was shown in this study to be a sensitive technique for the detection and kinetic analysis of a pulmonary capillary protein leak. A rising lung:heart radioactivity of 'slope of injury' was found at each dose of intravenous oleic acid in dogs from 0.01 to 0.20 ml/kg (p less than 0.01). This 'slope of injury' was proportional to the dose of oleic acid (r = +0.97; p less than 0.004) and was more sensitive than changes in arterial oxygen tension, standard chest radiography, bloodless wet:dry lung weight, or alveolar epithelial membrane permeability. Only standard light microscopy and right lymphatic duct flow were able to document the leakage of protein detected by gamma scintigraphy at 0.01 ml/kg oleic acid.