In the February article “The Predictive Value of 3D Time-of-Flight MR Angiography in Assessment of Brain Arteriovenous Malformation Obliteration after Radiosurgery” by Buis et al (2012;33:232–38), the data in Table 4 contained an error. The correct data are presented below. As some of these data were mentioned in the Results and Discussion sections, and in the abstract, these sections have been corrected as well. These corrections do not affect the authors' conclusions.
Table 4:
Predictive value of MRI2 for ‘Definitive Obliteration (DO)' in comparison to DSA2C
| Observer 1 | Observer 2 | |
|---|---|---|
| Sensitivity | 0.62 | 0.55 |
| Specificity | 0.85 | 0.95 |
| Positive predictive value | 0.89 | 0.95 |
| Negative predictive value | 0.52 | 0.52 |
| Prevalence | 0.67 | 0.66 |
| False-positive rate | 0.15 | 0.05 |
| False-negative rate | 0.38 | 0.45 |
MRI2 indicates final follow-up MR imaging; DSA2c, final follow-up DSA imaging, after consensus meeting.
Corrections
Abstract, results, lines 5–8: PPVs of final follow-up MR-imaging for definitive obliteration varied between 0.89 and 0.95. NPV was 0.52. An average false-positive rate, meaning overestimation of nidus obliteration of 0.10 and an average false-negative rate, meaning underestimation of nidus obliteration of 0.42 were found.
Results, p. 234, line 9 and further: PPV of MR-imaging2 for definitive obliteration varied between 0.89 and 0.95. NPV was 0.52 (Table 4).
Results section, p. 234, line 13 and further:… patent nidus on DSA2c for an average false-positive rate of 0.10 (Fig 1A).
Results section, p. 234, line 20 and further:…. for a false-negative-rate of 0.42 (Fig 1C).
Discussion section, p. 234, lines 18–20:… rate of 0.10 for 2 observers, which is comparable with that in other studies. A false-negative rate of 0.42 was found.