Pulmonary embolism in patients with intermediate probability lung scans: diagnosis with Doppler venous US and D-dimer measurement.
OBJECTIVE
To test the usefulness of lower limb Doppler venous compression ultrasound (US) and serum D-dimer measurements in diagnosis of pulmonary embolism in patients in whom ventilation-perfusion (V-P) scans indicate intermediate probability of pulmonary embolism.


METHODS
V-P scanning, pulmonary angiography, US, and D-dimer measurements were performed in 36 patients without known deep venous thrombosis but with intermediate probability of having a pulmonary embolism.


RESULTS
Pulmonary angiography demonstrated pulmonary embolism in 15 (41%) of 36 patients. US demonstrated deep venous thrombosis in only two patients, both with pulmonary embolism. Sensitivity of US was only 13%, but specificity was 100%. Five (14%) of the 36 patients had normal (< 220 micrograms/L) D-dimer levels; none of the five had pulmonary embolism. Sensitivity and specificity of D-dimer values were 100% and 16%, respectively, with a negative predictive value of 100%.


CONCLUSIONS
Combined D-dimer measurement and US were helpful in correctly diagnosing pulmonary embolism in only seven (20%) of 36 patients. Pulmonary angiography is still required to diagnose pulmonary embolism in the majority of patients.
Quinn
R J
RJ
Department of Nuclear Medicine, St George Hospital, Kogarah, New South Wales, Australia.
Nour
R
R
Butler
S P
SP
Glenn
D W
DW
Travers
P L
PL
Wellings
G
G
Kwan
Y L
YL
D004797:Enzyme-Linked Immunosorbent Assay; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013924:Thrombophlebitis / Q000175:diagnosis / Q000000981:diagnostic imaging; D014463:Ultrasonography
D005338:Fibrin Fibrinogen Degradation Products