Sabia virus incident at Yale University.

An incident involving a human exposure to a newly isolated arenavirus, Sabia virus, in the Yale Arbovirus Research Unit occurred at Yale University on August 8, 1994. A senior-level visiting research scientist was exposed to Sabia virus while purifying the virus from a large volume of tissue culture fluid. The exposure resulted in development of a Sabia virus infection followed by recovery of the patient.

Radiation safety as part of a comprehensive university occupational health and safety program.

Rutgers University has developed an integrated occupational health and safety program incorporating the disciplines of radiation protection, chemical hygiene, industrial hygiene, occupational safety, hazardous substance disposal, and environmental control. The program was implemented by the Department of Radiation and Environmental Health and Safety which was organized in a nontraditional way to provide an interdisciplinary resource and service to a large state university community. In the relatively short period of time that the new organization functioned at full capacity, the strengths of the new organization as well as a few weaknesses have become apparent.

The nature of the background in radionuclide ventriculography: deductions from the mathematical behaviour of the ejection fraction.

The relationship between the ejection fractions calculated from 'uncorrected' radionuclide time activity curves (UEF) and angiographic ejection fractions (AEF) in 200 catheterized patients yielded the regression equation AEF = 1.74 UEF + 0.21.

Differentiation of Charcot joint from osteomyelitis through dynamic bone imaging.

The bone scans of 25 patients with a clinical diagnosis of diabetic osteoarthropathy (Charcot joint) of the ankle and foot were analysed using the technique of dynamic bone imaging. The analysis of time-activity curves generated over the Charcot joint, the contralateral joint and the bone above the Charcot joint, produces characteristic patterns that are distinguishable from the ones observed for osteomyelitis. Recently it has been shown that the significance of dynamic bone imaging resides in its correlation to physiological and morphological components of bone.

Dynamic bone imaging in the differential diagnosis of skeletal lesions.

Dynamic bone imaging differs from routine multiphase bone scintigraphy by the use of time-activity curves (TACs) and quantitation of data. TACs were divided into an arterial plus blood pool phase (first 60 s at 1 frame/s) and a subsequent early bone uptake phase (24 min at 1 frame/min). Ratios of normalized integrals, from analogous regions were calculated to determine whether blood flow was abnormal.

Pathophysiologic interpretation of time activity curves in dynamic bone imaging.

Reported here is a theoretical model based on a literature review correlating the 60 sec/25 min time activity curves (TAC) of dynamic bone imaging with the histologic components of bone. Information regarding healing versus nonhealing as well as a histophysiologic description of ongoing disease is obtainable from TACs of paired disease and nondiseased limbs. The TACs reflect the movement of Tc-99m MDP complexes across histologic compartments to reach the amorphous calcium phosphate (ACP) regions.

Computerized blood flow analysis for decision making in the treatment of osteochondritis dissecans.

Patients presenting the radiologic appearance of osteochondritis dissecans (OCD) require a decision as to further treatment. This often requires an invasive procedure. The noninvasive technique of computerized blood flow analysis (CBFA) has been used in 13 patients with OCD.

Dynamic bone scintigraphy in osteochondritis dissecans.

We report a retrospective study of eighteen patients with pain in the knee or ankle, eleven of whom had osteochondritis dissecans. In these patients the bone-flow time-activity curves were observed after an intravenous injection of a bolus of 99mTc MDP. The curves varied according to the severity of the clinical signs and symptoms.

Asymmetric distribution of left ventricular asynergy in coronary artery disease and its relation to coronary stenoses.

In 100 patients with coronary artery disease (CAD), the prevalence and severity of asynergy was determined for 9 left ventricular (LV) segments by both radionuclide and contrast angiography. The anterior, septal and lateral LV walls had significantly more prevalent and more severe asynergy in the medial segments than in the basal segments. In contrast, the inferior LV wall exhibited equally severe asynergy in both the medial and basal segments.

Computerized blood-flow analysis in osteochondritis dissecans.

A retrospective review of static images and computerized blood flow studies (CBFS) in patients with osteochondritis dissecans (OCD) suggests that CBFS maybe useful in following the clinical course of this disease.

Congenital spleen thinning mimicking a space-occupying lesion.

By splenic imaging, a large focal defect was demonstrated in a symptomatic South American immigrant with simultaneous parasitic infestation of strongyloidiasis and entamebiasis. The CT scan also was thought to be abnormal. Pathologic findings reported a variation in splenic configuration.

Inferoseptal myocardial infarction: another cause of precordial ST-segment depression in transmural inferior wall myocardial infarction?

Electrocardiographic ST-segment depression in the anterior precordial leads is a frequent observation during the initial hospital phase of acute transmural inferior myocardial infarction (MI), but is of uncertain significance. No available clinical studies have examined the prevalence of inferoseptal necrosis complicating inferior MI. Therefore, the clinical course, electrocardiographic features, radionuclide angiograms and cardiac enzyme changes in 57 patients with transmural inferior MI who did not have prior anterior or concomitant "true posterior" MI, associated anterior or posterolateral asynergy by radionuclide ventriculography, or left or right bundle branch block were reviewed retrospectively.

Left ventricular asynergy in electrocardiographic "posterior" myocardial infarction.

P2 300 selected patients, scalar electrocardiograms and contemporaneous radionuclide angiograms were analyzed retrospectively to assess the association between prominent right precordial R waves (duration greater than or equal to 0.04 second, R greater than or equal to S in lead V1 or V2), traditionally considered diagnostic of "posterior" infarction, and asynergy in various left ventricular segments. Mathematical methods for analysis of association between nonparametric variables clearly demonstrated that prominent right precordial R waves were strongly associated with asynergy of the basal lateral left ventricular wall, although asynergy of adjacent inferior and lateral segments was common.

Atlas of computerized blood flow analysis in bone disease.

The role of computerized blood flow analysis in routine bone scanning is reviewed. Cases illustrating the technique include proven diagnoses of toxic synovitis, Legg-Perthes disease, arthritis, avascular necrosis of the hip, fractures, benign and malignant tumors, Paget's disease, cellulitis, osteomyelitis, and shin splints. Several examples also show the use of the technique in monitoring treatment.

The use of bone scanning for the diagnosis and management of musculoskeletal trauma.

Bone scanning provides a unique way of monitoring early metabolic changes in bone and its adjacent soft tissues after trauma. An abnormal scan may often precede radiographic changes by days or weeks. This accounts for its usefulness in the early diagnosis of occult fractures and in fractures not clinically suspected or seen on initial x-ray films in the patient with multiple trauma.

Calculation of the left ventricular ejection fraction by gated radionuclide angiography without direct background correction.

The mathematical characteristics of the cardiac background were studied in 50 patients who underwent both gated radionuclide angiography and cardiac catheterization. The background-corrected ejection fraction (BCEF) was calculated in the standard manner using an operator-defined periventricular background region. The "uncorrected" ejection fraction (UEF) was calculated from the uncorrected left ventricular time-activity curve and compared to both the BCEF and the angiographic ejection fraction (AEF), UEF exhibited remarkable linear correlation with both BCEF and AEF.

Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography.

Right ventricular function was studied in 60 patients with equilibrium gated radionuclide angiography. The mean (+/- standard deviation) right ventricular ejection fraction in 20 normal subjects was 53 +/- 6 percent, a value in agreement with previous data from both radionuclide and contrast angiographic studies. This value was similar (55 +/- 7 percent) in 11 patients with coronary artery disease but normal left ventricular function.

Measurement of normal left atrial function with gated radionuclide angiography.

A method is described for measuring relative left atrial volume changes with gated radionuclide angiography, using an approximate computer-generated functional image to locate the atrial region of interest. M mode echocardiographic measurements of left atrial and left ventricular distances from the chest wall allowed calculation of a correction factor for the differential attenuation of atrial and ventricular photons. Background-corrected left atrial time-activity curves obtained from normal subjects exhibited excellent temporal resolution and were used to identify and quantitate the reservoir and contractile phases of left atrial volume change.

Quantitative regional blood-flow analysis and its clinical application during routine bone-scanning.

A method of combined dynamic and static bone-imaging using technetium 99-labeled phosphonate is described. During the dynamic part of the study, immediately after intravenous injection of the radionuclide, counts per second were recorded over a period of time for analogous regions of normal and diseased bones. The counts per second then were plotted against time to give time-activity curves for each of these regions.

Measurement of the ventricular stroke volume ratio by gated radionuclide angiography.

The ventricular stroke volume ratio or VSVR (left/right) was measured by gated radionuclide angiography in 33 normal subjects, using a 30 degree caudal slant-hole collimator and computer-generated functional images to aid in definition of the right ventricle. The mean ratio was found to be 1.06 +/- 0.

Gated radionuclide angiographic evaluation of valve regurgitation.

Gated radionuclide angiography is a new noninvasive technique that can be used to calculate the ratio of left and right ventricular stroke volumes. This stroke volume ratio, which must be unity in normal subjects, increases in patients with aortic or mitral regurgitation in direct proportion to the degree of left ventricular volume overload, provided no shunts or regurgitant right heart lesions are present. In 22 patients with aortic or mitral regurgitation there was excellent correlation between the stroke volume ratio determined with gated radionuclide angiography and with standard quantitative catheterization methods (r = 0.