Can multislice CT alone rule out reliably pulmonary embolism? A prospective study.
OBJECTIVE
To evaluate the safety of withholding anticoagulation in patients with suspected acute pulmonary embolism after negative multislice computed tomography (MSCT) pulmonary angiography and lower-limb venography.


METHODS
A total of 383 consecutive patients with suspected acute pulmonary embolism were prospectively studied. Patients underwent MSCT pulmonary angiography and lower-limb venography, as well as pulmonary scintigraphy and lower-limb ultrasound examination. Patients with negative MSCT results for both pulmonary embolism and venous thrombosis were not administered anticoagulants and were followed up for 6 months to rule out thromboembolism.


RESULTS
At MSCT, 156 patients were positive for pulmonary embolism, venous thrombosis, or both; 224 were negative; and findings were inconclusive in three. False-negatives were five patients with high probability scintigram and two with venous thrombosis detected at US. A total of 184 patients with negative MSCT and without anticoagulation were followed up for 6 months. During this period of time just one recurrence of pulmonary embolism was detected. The negative predictive value of MSCT pulmonary angiography plus lower-limb venography was 95.8% (183/191).


CONCLUSIONS
MSCT is efficacious in diagnosing pulmonary embolism, with negative predictive values reported in the literature ranging from 94% to 100%. This enables omission of anticoagulation in patients with suspected pulmonary embolism after negative MSCT findings without the need for other diagnostic tests.
Guilabert
Jose Pamies
JP
Department of Diagnostic Imaging, Hospital Universitario La Fe, Spain. pamies_jos@gva.es
Manzur
Dolores Nauffal
DN
Tarrasa
Maria J Torres
MJ
Llorens
Maximiliano Lloret
ML
Braun
Petra
P
Arques
Maria P Bello
MP
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D005188:False Negative Reactions; D005260:Female; D005268:Femoral Vein / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D011152:Popliteal Vein / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy; D028761:Withholding Treatment
D000925:Anticoagulants