RT Journal Article
SR Electronic
T1 Very Low Probability Interpretation of V/Q Lung Scans in Combination with Low Probability Objective Clinical Assessment Reliably Excludes Pulmonary Embolism: Data from PIOPED II
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1411
OP 1415
DO 10.2967/jnumed.107.040998
VO 48
IS 9
A1 Alexander Gottschalk
A1 Paul D. Stein
A1 H. Dirk Sostman
A1 Fadi Matta
A1 Afzal Beemath
YR 2007
UL http://jnm.snmjournals.org/content/48/9/1411.abstract
AB Use of a very low probability interpretation of ventilation/perfusion (V/Q) lung scans, if verified by prospective evaluation to have a low positive predictive value (PPV), will reduce the number of nondiagnostic interpretations of V/Q scans and may be particularly useful in patients with a relative contraindication to CT. The purpose of this investigation was to test the hypothesis that a very low probability interpretation of the V/Q scan has a PPV of <10%. Methods: Data are from PIOPED II (Prospective Investigation of Pulmonary Embolism Diagnosis II). Very low probability criteria are (a) nonsegmental perfusion abnormalities, (b) perfusion defect smaller than corresponding radiographic lesion, (c) ≥2 matched V/Q defects with regionally normal chest radiograph, (d) 1–3 small segmental perfusion defects (<25% of a segment), (e) solitary triple matched defect in middle or upper lung zones, (f) stripe sign around the perfusion defect(s), and (g) perfusion defect from pleural effusion equal to one third or more of the pleural cavity with no other perfusion defect. Results: A very low probability consensus interpretation of the V/Q scan was made in 56% of patients. The PPV of a very low probability interpretation of the V/Q scans was 36 of 440 patients (8.2%). Among patients with suspected pulmonary embolism who had a low clinical probability objective clinical assessment and a very low probability V/Q scan, the PPV was 8 of 259 patients (3.1%). Among women ≤40 y, the PPV of the very low probability V/Q with a low objective clinical assessment was 1 of 50 (2%). Conclusion: The very low probability V/Q scan together with a low probability clinical assessment reliably excludes pulmonary embolism.