Interobserver Reliability of Baseline Noncontrast CT Alberta Stroke Program Early CT Score for Intra-Arterial Stroke Treatment Selection • A.C. Gupta, P.W. Schaefer, Z.A. Chaudhry, T.M. Leslie-Mazwi, R.V. Chandra, R.G. González, J.A. Hirsch, and A.J. Yoo
The ASPECTS has been shown to predict outcomes of early ischemic patients after intra-arterial therapy by providing semiquantitative data regarding infarction core. In this article the authors assessed the interobserver reliability of this scale in patients with proximal occlusions. CT studies in 155 patients were retrospectively analyzed by 2 independent observers. Among patients with anterior circulation proximal artery occlusions who were eligible for intra-arterial therapy, interrater reliability for ASPECTS grading was substantial across the entire scale. When using the dichotomized ASPECTS (≤ 7 versus >7) for treatment selection, agreement was only moderate, limiting its utility. In the patient cohort, approximately 25% of treatment decisions would have been affected by interrater reliability.
Survival Analysis of Patients with High-Grade Gliomas Based on Data Mining of Imaging Variables • E.I. Zacharaki, N. Morita, P. Bhatt, D.M. O’Rourke, E.R. Melhem, and C. Davatzikos
The authors compared survival prediction using machine-learning data-mining techniques versus traditional histopathologic analysis in a group of 74 tumors. They looked at 55 imaging variables, extracting the most important ones and comparing these with standard histology. The most important variables were: extent of resection, mass effects, volume of enhancing tumor, maximum T2 intensity, and mean trace intensity in non-enhancing or edematous surrounding areas. The accuracy of the data-mining method was 85% and based on Kaplan-Meier curves this predicted survival better than histology.
Endovascular Treatment of Ruptured Brain AVMs in the Acute Phase of Hemorrhage • W.J. van Rooij, S. Jacobs, M. Sluzewski, G.N. Beute, and B. van der Pol
Although there is risk of re-bleeding from a ruptured AVM, most are not treated in the acute period. Here, the authors acutely treated 23 ruptured AVMs. They achieved complete obliteration in 57%; 3 contained intranidal aneurysms, presumably the cause of the presenting hemorrhage. Of the 43% that were incompletely obliterated, 6 had intranidal aneurysms. During a mean follow-up of 21 months, no repeat hemorrhages occurred. Thus, endovascular treatment in the acute phase cured most ruptured AVMs. All 9 AVM-associated aneurysms that were considered the source of hemorrhage were excluded from the circulation. In patients with AVM-related hemorrhagic stroke, prompt angiographic diagnosis and treatment may improve prognosis by reducing repeat hemorrhage rate.
Fellows’ Journal Club
Low Kilovoltage CT of the Neck with 70 kVp: Comparison with a Standard Protocol • R. Gnannt, A. Winklehner, R. Goetti, B. Schmidt, S. Kollias, and H. Alkadhi
These authors imaged 27 patients with neck CT using 70 kVp and compared the scans with previous studies obtained using the typical 120-kVp technique on the same scanner. Two observers studied image quality and artifacts in 3 neck regions (upper, middle, and lower). They concluded that CT of the cervical soft tissues at 70 kVp is feasible, provides diagnostic image quality with improved contrast to noise, and reduces radiation dose by approximately 34% compared with a standard protocol at 120 kVp. In contrast, low kVp CT of the lower cervical spine suffers from compromised image quality.
Radiation Dose Reduction in Temporal Bone CT with Iterative Reconstruction Technique • Y.T. Niu, D. Mehta, Z.R. Zhang, Y.X. Zhang, Y.F. Liu, T.L. Kang, J.F. Xian, and Z.C. Wang
These investigators used 8 cadaver heads and a 3D spatial resolution phantom to test the quality of temporal bone CT studies done using standard filtered back-projection versus an iterative reconstruction technique. They then validated their results in 50 consecutive patients. The iterative reconstruction technique helped reduce radiation dose by 50% while maintaining adequate image quality and spatial resolution. Results were consistent among cadavers, phantom, and patients.
Quality Control in Neuroradiology: Impact of Trainees on Discrepancy Rates • V.G. Viertel, L.S. Babiarz, M. Carone, J.S. Lewin, and D.M. Yousem
The authors compared discrepancy rates of studies interpreted by academic neuroradiologists working with and without trainees in 2162 studies. Discrepancies were categorized from mildest (no changes needed in report) to most important (clinically significant interpretation discrepancies). Faculty working alone versus faculty plus trainee discrepancies were calculated. There was a 1.8% rate of clinically significant detection or interpretation discrepancy among neuroradiologists. The difference in the discrepancy rates between faculty only (1.7%), fellows and faculty (1.6%), and residents and faculty (2.2%) was not statistically significant but showed a trend indicating that reading with a resident increased the odds of a discrepant result.