Hk. Nielsen et al., OBSERVER VARIATION IN THE INTERPRETATION OF VENTILATION-PERFUSION LUNG SCINTIGRAPHY, European journal of nuclear medicine, 21(2), 1994, pp. 103-107
The diagnosis of pulmonary embolism (PE) remains one of the most diffi
cult in clinical medicine, and the diagnostic value of lung scintigrap
hy has been questioned. To evaluate the observer variation in the inte
rpretation of ventilation-perfusion lung scanning in the diagnosis of
PE, 87 lung scintigrams from consecutive patients with phlebography-pr
oven deep venous thrombosis and without clinical signs of PE were rand
omly mixed with 50 reference lung scintigrams from patients with PE sy
mptoms. The scintigrams were reevaluated blind by two experienced clin
ical physiologists. Each observer evaluated each lung scintigram twice
and recorded whether the lung scan was normal or abnormal. If it was
abnormal, the location and number of segment defects were registered.
The intraobserver agreement, including number and location of segments
, ranged from 0.77 to 0.85 and for the diagnosis of PE from 0.88 to 0.
92 with a kappa of 0.80 - 0.84. The values for the interobserver agree
ment for the diagnosis of PE were 0.73 - 0.80 with a kappa of 0.56 - 0
.67. It is concluded that in the interpretation of ventilation-perfusi
on lung scintigraphy the use of a simple scheme - deciding whether the
re is segmental ventilation-perfusion mismatch or not - has a good rep
roducibility with a high kappa for inter- and intraobserver variation
and can serve as a simple routine method for diagnosing PE.