Area of ischemia assessed by physicians and software packages from myocardial perfusion scintigrams.
BACKGROUND
The European Society of Cardiology recommends that patients with >10% area of ischemia should receive revascularization. We investigated inter-observer variability for the extent of ischemic defects reported by different physicians and by different software tools, and if inter-observer variability was reduced when the physicians were provided with a computerized suggestion of the defects.


METHODS
Twenty-five myocardial perfusion single photon emission computed tomography (SPECT) patients who were regarded as ischemic according to the final report were included. Eleven physicians in nuclear medicine delineated the extent of the ischemic defects. After at least two weeks, they delineated the defects again, and were this time provided a suggestion of the defect delineation by EXINI HeartTM (EXINI). Summed difference scores and ischemic extent values were obtained from four software programs.


RESULTS
The median extent values obtained from the 11 physicians varied between 8% and 34%, and between 9% and 16% for the software programs. For all 25 patients, mean extent obtained from EXINI was 17.0% (± standard deviation (SD) 14.6%). Mean extent for physicians was 22.6% (± 15.6%) for the first delineation and 19.1% (± 14.9%) for the evaluation where they were provided computerized suggestion. Intra-class correlation (ICC) increased from 0.56 (95% confidence interval (CI) 0.41-0.72) to 0.81 (95% CI 0.71-0.90) between the first and the second delineation, and SD between physicians were 7.8 (first) and 5.9 (second delineation).


CONCLUSIONS
There was large variability in the estimated ischemic defect size obtained both from different physicians and from different software packages. When the physicians were provided with a suggested delineation, the inter-observer variability decreased significantly.
Lars
L
Edenbrandt
Peter
P
Höglund
Sophia
S
Frantz
Philip
P
Hasbak
Allan
A
Johansen
Lena
L
Johansson
Annett
A
Kammeier
Oliver
O
Lindner
Milan
M
Lomsky
Shinro
S
Matsuo
Kenichi
K
Nakajima
Karin
K
Nyström
Eva
E
Olsson
Karl
K
Sjöstrand
Sven-Eric
SE
Svensson
Hiroshi
H
Wakabayashi
Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Inga Marie Nilssons gata 49, 205 02 Malmö, Sweden. elin.tragardh@med.lu.se.
Elin
E
Trägårdh
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010820:Physicians; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D012986:Software Validation; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*