DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores) and DWI-FLAIR (Diffusion-Weighted Imaging-Fluid Attenuated Inversion Recovery) Mismatch in Thrombectomy Candidates: An Intrarater and Interrater Agreement Study.

BACKGROUND AND PURPOSE: We aimed to study the intrarater and interrater agreement of clinicians attributing DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores) and DWI-FLAIR (Diffusion-Weighted Imaging-Fluid Attenuated Inversion Recovery) mismatch in patients with acute ischemic stroke referred for mechanical thrombectomy. METHODS: Eighteen raters independently scored anonymized magnetic resonance imaging scans of 30 participants from a multicentre thrombectomy trial, in 2 different reading sessions. Agreement was measured using Fleiss κ and Cohen κ statistics. RESULTS: Interrater agreement for DWI-ASPECTS was slight (κ=0.17 [0.14-0.21]). Four raters (22.2%) had a substantial (or higher) intrarater agreement. Dichotomization of the DWI-ASPECTS (0-5 versus 6-10 or 0-6 versus 7-10) increased the interrater agreement to a substantial level (κ=0.62 [0.48-0.75] and 0.68 [0.55-0.79], respectively) and more raters reached a substantial (or higher) intrarater agreement (17/18 raters [94.4%]). Interrater agreement for DWI-FLAIR mismatch was moderate (κ=0.43 [0.33-0.57]); 11 raters (61.1%) reached a substantial (or higher) intrarater agreement. CONCLUSIONS: Agreement between clinicians assessing DWI-ASPECTS and DWI-FLAIR mismatch may not be sufficient to make repeatable clinical decisions in mechanical thrombectomy. The dichotomization of the DWI-ASPECTS (0-5 versus 0-6 or 0-6 versus 7-10) improved interrater and intrarater agreement, however, its relevance for patients selection for mechanical thrombectomy needs to be validated in a randomized trial.

Comparison between contrast-enhanced fat-suppressed 3D FLAIR brain MR images and T2-weighted orbital MR images at 3 Tesla for the diagnosis of acute optic neuritis.

PURPOSE: The purpose of this study was to compare the capabilities of contrast-enhanced fat-suppressed (CE FS) three-dimensional fluid-attenuated inversion recovery (3D FLAIR) brain magnetic resonance imaging (MRI) with those of coronal T2-weighted orbital MRI obtained at 3 Tesla for the diagnosis of optic neuritis (ON). MATERIALS AND METHODS: Patients who presented to our center with acute visual loss and underwent MRI examination of the orbits and the brain between November 2014 and February 2020 were retrospectively included. Three radiologists independently and blindly analyzed CE FS 3D FLAIR and coronal T2-weighted images. Disagreements in image interpretation were resolved by consensus with an independent neuroradiologist who was not involved in the initial reading sessions. The primary adjudication criterion for the diagnosis of ON was the presence of an optic nerve hypersignal. Sensitivity, specificity, and accuracy of CE 3D FLAIR brain images were compared with those of coronal T2-weighted orbital images using McNemar test. Artifacts were classified into three categories and compared between the two image sets. RESULTS: A total of 1023 patients were included. There were 638 women and 385 men with a mean age of 42 ± 18.3 (standard deviation) years (age range: 6-92 years). Optic nerve hyperintensities were identified in 375/400 (94%) patients with ON using both 3D FLAIR and coronal T2-weighted images. Sensitivity, specificity, and accuracy of both sequences were 94% (95% CI: 91.3-96.1), 79% (95% CI: 75.5-82.2), and 89% (95% CI: 86.8-90.7), respectively. Optic disc hypersignal was detected in 120/400 patients (30%) using 3D FLAIR compared to 3/400 (0.75%) using coronal T2-weighted images (P < 0.001). Optic radiation hypersignal was observed in 2/400 (0.5%) patients using 3D FLAIR images. Significantly more artifacts (moderate or severe) were observed on coronal T2-weighted images (801/1023; 78%) by comparison with 3D FLAIR images (448/1023; 44%) (P < 0.001). CONCLUSION: The performance of 3D FLAIR brain MRI for the diagnosis of ON is not different from that of coronal T2-weighted orbital MRI and its use for optic nerve analysis may be beneficial.

Visual assessment of diffusion weighted imaging infarct volume lacks accuracy and reliability.

PURPOSE: The DAWN trial (Diffusion weighted imaging or CT perfusion Assessment with clinical mismatch in the triage of Wake-up and late presenting strokes undergoing Neurointervention with Trevo) has demonstrated the benefits of thrombectomy in patients with unknown or late onset strokes, using automated software (RAPID) for measurement of infarct volume. Because RAPID is not available in all centers, we aimed to assess the accuracy and repeatability of visual infarct volume estimation by clinicians and the consequences for thrombectomy decisions based on the DAWN criteria. MATERIALS AND METHODS: 18 physicians, who routinely depend on MRI for acute stroke imaging, assessed 32 MR scans selected from a prospective databaseover two independent sessions. Raters were asked to visually estimate the diffusion weighted imaging (DWI) infarct volume for each case. Sensitivity, specificity, and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-off points. Thrombectomy decisions based on DAWN criteria with RAPID measurements and raters' visual estimates were compared. Inter-rater and intra-rater agreement was measured using kappa statistics. RESULTS: The mean accuracy of raters was <90% for all volume cut-points. Inter-rater agreement was below substantial for each DWI infarct volume cut-off points. Intra-rater agreement was substantial for 55-83% of raters, depending on the selected cut-off points. Applying DAWN criteria with visual estimates instead of RAPID measurements led to 19% erroneous thrombectomy decisions, and showed a lack of reproducibility. CONCLUSION: The visual assessment of DWI infarct volume lacks accuracy and repeatability, and could lead to a significant number of erroneous decisions when applying the DAWN criteria.

Orbital color Doppler imaging in embolic central retinal artery obliteration associated with neovascular glaucoma.

PURPOSE: To describe the detection of an embolism in the retrobulbar circulation using orbital color Doppler imaging (OCDI) in a patient with an inaccessible fundus because of neovascular glaucoma. METHODS: Review of the clinical, laboratory, photographic, and orbital color Doppler imaging records of a patient with central retinal artery occlusion (CRAO) associated with neovascular glaucoma. RESULTS: A 42-year-old man had no light perception in the left eye secondary to neovascular glaucoma. The fundus was not visible because of corneal edema. Orbital color Doppler imaging established the diagnosis of embolic CRAO as the cause of neovascular glaucoma. CONCLUSION: Orbital color Doppler imaging is an important diagnostic procedure for establishing CRAO as the cause of neovascular glaucoma when the fundus is not accessible. This noninvasive technology enables differentiation of embolic disease from other conditions as the cause of CRAO.

Color Doppler imaging of orbital vessels: personal experience and literature review.

Many Doppler imaging studies have been performed in recent years in a large number of ocular disorders because of improvements in the Doppler equipment used for detecting and measuring the low blood-flow velocities that are a requisite for the quantitative evaluation of blood flow in the orbital vessels. The ophthalmic artery, central retinal artery and vein, posterior ciliary arteries, and the superior ophthalmic vein can be easily identified using color Doppler sonography. The changes in local blood flow in these vessels assessed by spectral analysis pulsed Doppler sonography have been used to characterize and to obtain new insights into different nontumoral vascular disorders including carotid artery stenosis, central retinal vein occlusion, giant cell arteritis, glaucoma, diabetes, fistulas, and tumoral processes of the eye and orbit. Our experience has confirmed the important role of Doppler sonography in the assessment of subclinical changes in the vascular bed, in the understanding of different processes, for following up after specific treatments, and for determining the long-term prognosis of these various conditions.