Table 3:

Readers' performance in evaluating PCT and C-arm CT imagesa

Reader 1Reader 2Reader 3Mean
TP readings of PCT75.0%70%75%73.3%
TP readings of C-arm CT83.3%83.3%86.7%84.4%
FP readings of PCT0%5%0%1.7%
FP readings of C-arm CT0%3.3%6.7%3.3%
FN readings of PCT25%25%25%25%
FN readings of C-arm CT16.7%13.3%6.7%12.2%
  • a Percentage of TP (infarct was correctly identified), FP (CBV abnormality identified in a location where there was no DWI abnormality), and FN (no abnormality identified in location where there was a DWI abnormality) readings are given for each reader individually and the mean of all 3 readers. C-arm CT readings demonstrate a better correlation with the criterion standard DWI. Most interesting, the rate of FP readings is very low. Please note the discrepancy of FN PCT and FN C-arm CT readings.