Quantification of Optic Nerve Cross Sectional Area on MRI: A Novel Protocol using Fiji Software

10.3791/62752 ◽  
2021 ◽  
Author(s):  
Nosaiba Al-Ryalat ◽  
Saif Aldeen AlRyalat ◽  
Lna Malkawi ◽  
Muayad Azzam ◽  
Sana Mohsen
Keyword(s):  
Optic Nerve ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional

scholarly journals Quantitative magnetic resonance image assessment of the optic nerve and surrounding sheath after spaceflight

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jesse J. Rohr ◽  
Stuart Sater ◽  
Austin M. Sass ◽  
Karina Marshall-Goebel ◽  
Robert J. Ploutz-Snyder ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Magnetic Resonance ◽  
Recovery Period ◽  
Space Station ◽  
Cross Sectional Area ◽  
Quantitative Mri ◽  
Sectional Area ◽  
Cross Sectional ◽  
Before And After ◽  
Increased Icp

Abstract A subset of long-duration spaceflight astronauts have experienced ophthalmic abnormalities, collectively termed spaceflight-associated neuro-ocular syndrome (SANS). Little is understood about the pathophysiology of SANS; however, microgravity-induced alterations in intracranial pressure (ICP) due to headward fluid shifts is the primary hypothesized contributor. In particular, potential changes in optic nerve (ON) tortuosity and ON sheath (ONS) distension may indicate altered cerebrospinal fluid dynamics during weightlessness. The present longitudinal study aims to provide a quantitative analysis of ON and ONS cross-sectional areas, and ON deviation, an indication of tortuosity, before and after spaceflight. Ten astronauts undergoing ~6-month missions on the International Space Station (ISS) underwent high-resolution magnetic resonance imaging (MRI) preflight and at five recovery time points extending to 1 year after return from the ISS. The mean changes in ON deviation, ON cross-sectional area, and ONS cross-sectional area immediately post flight were −0.14 mm (95% CI: −0.36 to 0.08, Bonferroni-adjusted P = 1.00), 0.13 mm2 (95% CI −0.66 to 0.91, Bonferroni-adjusted P = 1.00), and −0.22 mm2 (95% CI: −1.78 to 1.34, Bonferroni-adjusted P = 1.00), respectively, and remained consistent during the recovery period. Terrestrially, ONS distension is associated with increased ICP; therefore, these results suggest that, on average, ICP was not pathologically elevated immediately after spaceflight. However, a subject diagnosed with optic disc edema (Frisen Grade 1, right eye) displayed increased ONS area post flight, although this increase is relatively small compared to clinical populations with increased ICP. Advanced quantitative MRI-based assessment of the ON and ONS could help our understanding of SANS and the role of ICP.

Effect of a neck collar on brain turgor: a potential role in preventing concussions?

2021 ◽  
pp. bjsports-2021-103961
Author(s):  
Michael Dinsmore ◽  
Zakir Hajat ◽  
Connor TA Brenna ◽  
Joseph Fisher ◽  
Lashmi Venkatraghavan
Keyword(s):  
Brain Injury ◽  
Optic Nerve ◽  
Brain Injuries ◽  
Cricoid Cartilage ◽  
Optic Nerve Sheath Diameter ◽  
Cross Sectional Area ◽  
Intracranial Volume ◽  
Sectional Area ◽  
Cross Sectional ◽  
Before And After

BackgroundMild internal jugular vein (IJV) compression, aimed at increasing intracranial fluid volume to prevent motion of the brain relative to the skull, has reduced brain injury markers in athletes suffering repeated traumatic brain injuries. However, an increase in intracranial volume with IJV compression has not been well demonstrated. This study used transorbital ultrasound to identify changes in optic nerve sheath diameter (ONSD) as a direct marker of accompanying changes in intracranial volume.MethodsNineteen young, healthy adult volunteers (13 males and 6 females) underwent IJV compression of 20 cm H2O low in the neck, while in upright posture. IJV cross-sectional area at the level of the cricoid cartilage, and the change in right ONSD 3 mm behind the papillary segment of the optic nerve, were measured by ultrasound. Statistical analysis was performed using a paired t-test with Bonferroni correction.ResultsMean (SD) cross-sectional area for the right IJV before and after IJV compression was 0.10 (0.05) cm2 and 0.57 (0.37) cm2, respectively (p=0.001). ONSD before and after IJV compression was 4.6 (0.5) mm and 4.9 (0.5) mm, respectively (p=0.001).ConclusionsThese data verify increased cerebral volume following IJV compression, supporting the potential for reduced brain ‘slosh’ as a mechanism connecting IJV compression to possibly reducing traumatic brain injury following head trauma.

scholarly journals OCT-Detected Optic Nerve Head Neural Canal Direction, Obliqueness, and Minimum Cross-Sectional Area in Healthy Eyes

2019 ◽  
Vol 208 ◽  
pp. 185-205 ◽  
Author(s):  
Seungwoo Hong ◽  
Hongli Yang ◽  
Stuart K. Gardiner ◽  
Haomin Luo ◽  
Christy Hardin ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Neural Canal ◽  
Healthy Eyes

scholarly journals A method for measuring the cross sectional area of the anterior portion of the optic nerve in vivo using a fast 3D MRI sequence

2010 ◽  
Vol 31 (6) ◽  
pp. 1486-1491 ◽  
Author(s):  
Marios C. Yiannakas ◽  
Claudia A.M. Wheeler-Kingshott ◽  
Alaine M. Berry ◽  
Karyn Chappell ◽  
Andrew Henderson ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
3D Mri ◽  
Anterior Portion ◽  
Cross Sectional ◽  
The Cross

scholarly journals MRI-based quantification of ophthalmic changes in healthy volunteers during acute 15° head-down tilt as an analogue to microgravity

2021 ◽  
Vol 18 (177) ◽  
Author(s):  
Stuart H. Sater ◽  
Austin M. Sass ◽  
Akari Seiner ◽  
Gabryel Conley Natividad ◽  
Dev Shrestha ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Young’S Modulus ◽  
Structural Changes ◽  
Young's Modulus ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fluid Shifts ◽  
Magnetic Resonance Imaging Mri ◽  
Ophthalmic Changes

Spaceflight is known to cause ophthalmic changes in a condition known as spaceflight-associated neuro-ocular syndrome (SANS). It is hypothesized that SANS is caused by cephalad fluid shifts and potentially mild elevation of intracranial pressure (ICP) in microgravity. Head-down tilt (HDT) studies are a ground-based spaceflight analogue to create cephalad fluid shifts. Here, we developed non-invasive magnetic resonance imaging (MRI)-based techniques to quantify ophthalmic structural changes under acute 15° HDT. We specifically quantified: (i) change in optic nerve sheath (ONS) and optic nerve (ON) cross-sectional area, (ii) change in ON deviation, an indicator of ON tortuosity, (iii) change in vitreous chamber depth, and (iv) an estimated ONS Young's modulus. Under acute HDT, ONS cross-sectional area increased by 4.04 mm 2 (95% CI 2.88–5.21 mm 2 , p < 0. 000), while ON cross-sectional area remained nearly unchanged (95% CI −0.12 to 0.43 mm 2 , p = 0.271). ON deviation increased under HDT by 0.20 mm (95% CI 0.08–0.33 mm, p = 0.002). Vitreous chamber depth decreased under HDT by −0.11 mm (95% CI −0.21 to −0.03 mm, p = 0.009). ONS Young's modulus was estimated to be 85.0 kPa. We observed a significant effect of sex and BMI on ONS parameters, of interest since they are known risk factors for idiopathic intracranial hypertension. The tools developed herein will be useful for future analyses of ON changes in various conditions.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

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