Automatic Optic Nerve Measurement: A New Tool to Standardize Optic Nerve Assessment in Ultrasound B-Mode Images.

Transorbital sonography provides reliable information about the estimation of intra-cranial pressure by measuring the optic nerve sheath diameter (ONSD), whereas the optic nerve (ON) diameter (OND) may reveal ON atrophy in patients with multiple sclerosis. Here, an AUTomatic Optic Nerve MeAsurement (AUTONoMA) system for OND and ONSD assessment in ultrasound B-mode images based on deformable models is presented. The automated measurements were compared with manual ones obtained by two operators, with no significant differences. AUTONoMA correctly segmented the ON and its sheath in 71 out of 75 images. The mean error compared with the expert operator was 0.06 ± 0.52 mm and 0.06 ± 0.35 mm for the ONSD and OND, respectively. The agreement between operators and AUTONoMA was good and a positive correlation was found between the readers and the algorithm with errors comparable with the inter-operator variability. The AUTONoMA system may allow for standardization of OND and ONSD measurements, reducing manual evaluation variability.

Longitudinal Assessment of Transorbital Sonography, Visual Acuity, and Biomarkers for Inflammation and Axonal Injury in Optic Neuritis.

BACKGROUND AND OBJECTIVE: To investigate the relationship between optic nerve sheath diameter, optic nerve diameter, visual acuity and osteopontin, and neurofilament heavy chain in patients with acute optic neuritis. PATIENTS AND METHODS: Sonographic and visual acuity assessment and biomarker measurements were executed in 23 patients with unilateral optic neuritis and in 19 sex- and age-matched healthy controls. RESULTS: ONSD was thicker on the affected side at symptom onset (median 6.3 mm; interquartile range 6.0-6.5) than after 12 months (5.3 mm; 4.9-5.6; p < 0.001) or than in controls (5.2 mm; 4.8-5.5; p < 0.001). OND was significantly increased in the affected side (3.4 mm; 2.9-3.8) compared to healthy controls (2.7 mm; 2.5-2.9; p < 0.001) and was thicker at baseline than after 12 months (2.8 mm; 2.7-3.0; p < 0.01). Visual acuity improved significantly after 12 months (1.00; 0.90-1.00) compared to onset of symptoms (0.80; 0.40-1.00; p < 0.001). OPN levels were significantly higher in patients at presentation (median 6.44 ng/ml; 2.05-10.06) compared to healthy controls (3.21 ng/ml, 1.34-4.34; p < 0.03). Concentrations of NfH were significantly higher in patients than in controls. CONCLUSION: ONSD and OND are increased in the affected eye. OPN and NfH are elevated in patients, confirming the presence of any underlying inflammation and axonal injury.

Intra- and interobserver reliability of transorbital sonographic assessment of the optic nerve sheath diameter and optic nerve diameter in healthy adults.

PURPOSE: Transorbital optic nerve sonography (TOS) can measure the optic nerve inclusive the sheath diameter (ONSD) and the optic nerve diameter (OND), which are useful parameters in the diagnosis of several neurological disorders. Data on the reproducibility of TOS are, however, required to use B-mode sonography for clinical purposes. The aim of this study was to assess intra- and interobserver reliability of ultrasound-based evaluations of both OND and ONSD in healthy subjects. METHODS: Using a 4-11-MHz linear array transducer, the OND and ONSD of 20 healthy subjects were independently measured by two expert investigators. RESULTS: Depicting the optic nerve and its sheath was possible in all subjects. The intra- and interobserver reliability was high for both ONSD and OND measurements. Intraobserver agreement, analyzed with Cronbach´s Alpha, was higher for ONSD (range: 0.69-0.72) than for OND measurements (range: 0.55-0.65). No differences in interobserver reliability between ONSD and OND measurements were found (p = 0.83 for right and 0.47 for left eye). CONCLUSIONS: Transorbital B-mode sonography is a feasible method to assess both ONSD and OND with a high intra- and interobserver reliability. Technical difficulties in differentiating the optic nerve from its sheaths may explain the lower intraobserver agreement for OND than that for ONSD measurements.

The Eligible study: ultrasound assessment in acute ischemic stroke within 3 hours.

AIMS OF THE STUDY: to identify with echo color Doppler ultrasound of the supra-aortic vessels and transcranial color-coded duplex sonography (TCCD) various patterns of vessel occlusion within 3 h from stroke onset, to compare each group defined at the admission with clinical findings and outcome, and to study the recanalization process, independent of therapy. METHODS: We enrolled 89 consecutive patients (mean age 68.9 years). Ultrasound evaluation was done within 3 h from stroke onset, and was repeated at 3-6 and 24-36 h, at day 5, and at 3 months. At admission, patients were divided into the following groups: internal carotid artery occlusions and stenoses (<50%, 50-69%, > or =70%, near occlusion), middle cerebral artery stenoses and occlusions, tandem occlusions and T occlusions. Vascular recanalization in each group was evaluated. Subgroups were compared for NIH Stroke Scale (NIHSS) and the outcome measures mortality, Barthel index (BI) and modified Rankin scale (mRS). Favorable outcome was defined as mRS < or =2 and BI > or =90. RESULTS: Each subgroup differed significantly for baseline NIHSS (p < 0.0001), 3-month mortality (p = 0.0235), BI at day 5 (p = 0.0458) and mRS at 3 months (p = 0.0028), even after adjustment for treatment. T and tandem occlusions were the subgroups with the highest NIHSS scores and the poorest outcomes, and the same subgroups had the worst recanalization rates. CONCLUSIONS: TCCD in the acute setting of stroke patients allows identification of the presence and site of clots, prediction of outcome and study of the dynamic process of vessel recanalization, in both the acute phase and follow-up.