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Autologous 131I-labeled fibrinogen was administered to 17 patients during 19 episodes of suspected lower extremity deep vein thrombosis in an attempt to assess its diagnostic accuracy. Serial rectilinear scanning and probe counting of the lower extremities and pelvis were performed and compared with ascending contrast venography. The sensitivities of imaging and counting were 67% and 47%, respectively, and both had a specificity of 95%. The experience with evaluation of deep vein thrombosis of the pelvic and iliac veins was small but suggested that 131I fibrinogen will be of limited use in those vessels.

Eighty-five patients suspected of having lower-extremity deep venous thrombosis (DVT) participated in a prospective study to test the diagnostic accuracy of four noninvasive techniques: Doppler ultrasonic flow study, electrical impedance plethysmography, the serial dilution protamine sulfate test, and an extensive physical examination. Ascending radiocontrast phlebography was the diagnostic standard of reference. We found that (1) when both Doppler and impedance examinations were positive, the diagnosis of DVT could be considered virtually certain; (2) impedance and Doppler examinations, when used in combination, were reliable screening tests capable of establishing or excluding the presence of thigh DVT; (3) physical examination and the serial dilution protamine sulfate test were unreliable screening techniques for DVT; (4) techniques other than the noninvasive methods investigated were needed to reliably detect or to exclude popliteal and call DVT.

Largely on the basis of postmortem studies, pulmonary emboli have been implicated as an etiologic factor in the acute and chronic respiratory failure of chronic obstructive pulmonary disease (COPD). The diagnosis of pulmonary embolism clinically or by tests directed at the lungs (except pulmonary angiography) is likely to be inaccurate in the presence of COPD because of the underlying abnormalities. We reasoned that by directing tests at the lower extremities to determine the presence or absence of deep venous thrombosis (DVT), we might obtain an accurate reflection of the presence of pulmonary emboli (PE), since virtually all PE are believed to arise in those deep veins. Accordingly, in a group of 45 patients with decompensated COPD, we performed ascending contrast venography (12 patients), 125I-labeled fibrinogen scanning (6 patients), or both (27 patients). Only 2 patients had proximal DVT, which was probably present on admission (4.4%). Two other patients developed DVT (limited to the calf) while hospitalized, (overall incidence of 8.9%). Another patient developed superficial thrombophlebitis during the study but before venography. Noninvasive tests for DVT (Doppler ultrasound and impedance plethysmography) were performed in 40 subjects. A negative result had a high predictive value (94% for each), but contrary to findings in other settings, a positive test had a poor predictive value (Doppler = 33%, IPG = 25%).