Improved computerized quantitation of TI-201 myocardial scintigrams by combining two views.

An improved computerized procedure involving minimal operator intervention has been developed for the automated quantitative evaluation of circumferential profiles of TI-201 myocardial perfusion scintigrams to diagnose coronary artery disease. The optimal criteria for evaluating the profiles of the left anterior oblique and anterior views have been empirically determined for both immediate and delayed scintigrams. Information from both views is combined to determine values for sensitivity and specificity. In this study, 29 patients underwent both TI-201 scintigraphy and contrast coronary angiography. The computerized quantitative procedure to interpret TI-201 scintigrams was tested against the results of coronary angiography. The values of 95% for sensitivity and 100% for specificity compare well with the results of other methods and are free of most of the variables associated with visual interpretation or operator intervention on the computer.

Computerized quantitation of regional myocardial perfusion in man.

A computerized procedure has been developed for the generation, graphic presentation and quantitative evaluation of circumferential profiles of thallium-201 myocardial perfusion. The computer data are first filtered using a two-dimensional fast Fourier transform. The optimum criteria for evaluating the profiles of the left anterior oblique (LAO) view have been empirically determined for both rest and stress. The sensitivity of 89 percent and specificity of 75 percent compare well with the results of other methods and are free of the variables of visual interpretation.

Technical considerations in B-mode scanning with an aspiration transducer.

Proper orientation of the B-mode ultrasonic aspiration transducer is important for accurate imaging during aspiration biopsy. The transducer extension axis must be perpendicular to the plane of the scanning arm for accurate representation of reflector locations. Single pass scans without compound angulation of the transducer are recommended when perpendicularity is not absolute. A simple adaptor to maintain perpendicularity is described.

Quantitative methods in the evaluation of thallium-201 myocardial perfusion images.

Methods have been developed for on-line computer enhancement of a scintillation camera's myocardial images and for a graphical presentation showing relative thallium-201 activity in the myocardium. Enhancement uses fast Fourier transform techniques. The methods have been applied to multiple images obtained after stress and 4--5 hr rest. Patients with myocardial infarction and/or transient ischemia were evaluated and typical examples are presented.

Minicomputer enhancement of scintillation camera images using fast Fourier transform techniques.

Minicomputer methods were developed to enhance lesions in scintillation camera images. This study was directed towards improving the diagnostic quality of liver images. A PDP-12 digital computer was interfaced to a Pho/Gamma HP III scintillation camera and programmed to carry out two-dimensional frequency-domain analysis and processing as an on-line operation. A two-dimensional frequency spectrum is produced. An interactive program allows the operator to construct graphically a frequency-domain filter and apply it to the data matrix. The filter is optimized using the image of a known phantom and then applied unchanged to the clincial liver image. An inverse Fourier transform produces an enhances image in the spatial domain. Significant enhancement of both phantom and liver images has been obtained.