Diffusion-Sensitized Ophthalmic Magnetic Resonance Imaging Free of Geometric Distortion at 3.0 and 7.0 T

Paul, Katharina; Graessl, Andreas; Rieger, Jan; Lysiak, Darius; Huelnhagen, Till; Winter, Lukas; Heidemann, Robin M.; Lindner, Tobias; Hadlich, Stefan; Zimpfer, Annette; Pohlmann, Andreas; Endemann, Beate; Krüger, Paul-Christian; Langner, Sönke; Stachs, Oliver; Niendorf, Thoralf

doi:10.1097/rli.0000000000000129

Cited by 25 publications

(30 citation statements)

References 75 publications

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“…41, 42 Advanced sequences such as diffusion-sensitized multishot rapid acquisition with relaxation enhancement could also be promising with higher magnetic fields resolution. 43 The examination of deeper sections of the optic path (ON closer to the chiasm) would also benefit from such a non-distorted technique.…”

Section: Discussionmentioning

confidence: 99%

MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt

et al. 2017

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More than half of astronauts present with significant neuro-ophthalmic findings during 6-month missions onboard the International Space Station. Although the underlying cause of this Microgravity Ocular Syndrome is currently unknown, alterations in cerebrospinal fluid dynamics within the optic nerve sheath may play a role. In the presented study, diffusion tensor imaging was used to assess changes in diffusivity of the optic nerve and its surrounding sheath during head-down tilt, a ground-based model of microgravity. Nine healthy male subjects (mean age ± SD: 25 ± 2.4 years; mean body mass index ± SD: 24.1 ± 2.4 kg/m2) underwent 5 head-down tilt conditions: −6°,−12°, −18°,−12° and 1% CO2, and −12° and lower body negative pressure. Mean diffusivity, fractional anisotropy, axial diffusivity, radial diffusivity were quantified in the left and right optic nerves and surrounding sheaths at supine baseline and after 4.5 h head-down tilt for each condition. In the optic nerve sheath, mean diffusivity was increased with all head-down tilt conditions by (Best Linear Unbiased Predictors) 0.147 (SE: 0.04) × 10−3 mm2/s (P < 0.001), axial diffusivity by 0.188 (SE: 0.064) × 10−3 mm2/s (P < 0.001), and radial diffusivity by 0.126 (SE: 0.04) × 10−3 mm2/s (P = 0.0019). Within the optic nerve itself, fractional anisotropy was increased by 0.133 (SE: 0.047) (P = 0.0051) and axial diffusivity increased by 0.135 (SE: 0.08) × 10−3 mm2/s (P = 0.014) during head-down tilt, whilst mean diffusivity and radial diffusivity were unaffected (P > 0.3). These findings could be due to increased perioptic cerebral spinal fluid hydrodynamics during head-down tilt, as well as increased cerebral spinal fluid volume and movement within the optic nerve sheath.

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Section: Discussionmentioning

confidence: 99%

MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt

et al. 2017

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“…Contrast enhancement on MRI often facilitates the discrimination of the tumor adjacent to the subretinal fluid ( Figure 8 ). Diffusion-sensitized ms-RARE techniques are reported to acquire high-contrast, high-spatial resolution, distortion-free images at 3.0 and 7.0 T. 25 …”

Section: Discussionmentioning

confidence: 99%

Investigation into the quantitative and qualitative characteristics of choroidal melanoma through magnetic resonance imaging and B-scan ultrasound

Papayiannis

Tsaousis

Kouskouras

et al. 2017

OPTH

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ObjectiveTo investigate the homogeneity and vascularity of choroidal melanoma through magnetic resonance imaging (MRI) and brightness modulation (B-mode) ultrasound scan and their correlation with dimensions of tumor, as well as to measure the sensitivity of both modalities in retinal detachment (RD) detection.Materials and methodsThis retrospective chart review included patients diagnosed with choroidal melanoma. All these patients underwent MRI scans using T2-weighted (T2-WI) and T1-weighted (T1-WI) sequences, before and after an intravenous injection of paramagnetic contrast material. The patients were also examined using a B-mode ultrasound scan, and the results from both modalities were compared (tumor homogeneity, tumor height, tumor base diameter, and tumor vascularity).ResultsForty-two patients (mean age=65.33±12.51 years) with choroidal melanoma were included in the study. Homogeneity was confirmed in 16 patients through ultrasound scan, in 19 patients through T1-WI sequence, in 21 patients through T2-WI sequence, and in 25 patients through T1-WI sequence + contrast (gadolinium). Patients with homogenous tumors presented with lower (P=0.0045) mean height than that of those with nonhomogenous tumors, whereas no statistically significant difference was found for base diameter measurements (P=0.056). Patients with tumors of high vascularity presented with greater mean height (P=0.000638) and greater mean base diameter compared with those with tumors of low vascularity (P=0.019543). RD was detected in 26 patients through T1-WI sequence, in 13 patients through T2-WI sequence, in 26 patients through T1-WI sequence + contrast, and in 32 patients through ultrasound scan, which proved to be the most sensitive modality.ConclusionThe height of choroidal melanoma was positively correlated with tumor’s homogeneity. Melanomas of greater height were found to be less homogenous, due to increased degeneration and higher occurrence of intratumoral hemorrhage. In addition, choroidal melanoma’s height was also positively correlated with the level of its vascularity. Finally, ultrasound scan was found to be more sensitive than MRI in the detection of RD.

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“…Durch die Verwendung geeigneter Untersuchungs- [12] bzw. Sequenztechniken [13][14] können diese Limitationen minimiert werden. Bewegungsartefakte sind bei Exvivo-MRM methodenbedingt weitestgehend auszuschließen, es können jedoch Artefakte durch Verlagerungen wässriger Anteile oder Gewebedegeneration bei langen MR-Sequenzen auftreten.…”

Section: Magnetresonanzmikroskopie Des Akkommodationsapparatsunclassified

“…Im Vergleich zur konventionellen Histologie ist die Auflösung der MRM derzeit noch geringer, weshalb eine Darstellung auf zellulärer Ebene gegenwärtig nicht möglich ist. Jedoch erlaubt die MRM neben rein anatomischen Darstellungen auch die Durchführung funktioneller Untersuchungstechniken [14], die eine Quantifizierung von Gewebeeigenschaften ermöglicht. Gegenüber der konventionellen Histologie unterliegt die MRM nicht den Limitationen von konservierungsbedingten Schrumpfungs-und Schnittartefakten, wodurch eine exakte Biometrie anatomischer Strukturen möglich wird.…”

Section: Magnetresonanzmikroskopie Des Akkommodationsapparatsunclassified

Magnetresonanzmikroskopie des Akkommodationsapparats

Stahnke

Hadlich

Wree

et al. 2016

Klin Monatsbl Augenheilkd

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Magnetic resonance microscopy (MRM) at ultra-high magnetic fields allows acquisition of high resolution MR images in the micrometre range. The use of ultra-high magnetic fields opens the possibility of user-independent and artefact-free detailed characterisation of the anatomical tissue of the human eye, which is not achievable with classical imaging techniques. This article correlates MRM of the anterior eye segment and the accommodative apparatus at 9.4 Tesla with conventional histology.

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Diffusion-Sensitized Ophthalmic Magnetic Resonance Imaging Free of Geometric Distortion at 3.0 and 7.0 T

Cited by 25 publications

References 75 publications

MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt

MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt

Investigation into the quantitative and qualitative characteristics of choroidal melanoma through magnetic resonance imaging and B-scan ultrasound

Magnetresonanzmikroskopie des Akkommodationsapparats

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