Orbital inflammation can be idiopathic or in the context of a specific disease and it can involve different anatomical orbital structures. On imaging, inflammatory disease is frequently mistaken for infection and malignant tumors, and its underlying cause is often not determined. Through this article we aim to improve orbital inflammation diagnosis and underlying inflammatory diseases recognition.
25 February 2016 in Magnetic Resonance Materials in Physics, Biology and Medicine
Objectives To assess the tumour dimensions in uveal melanoma patients using 7-T ocular MRI and compare these values with conventional ultrasound imaging to provide improved information for treatment options. Materials and methods Ten uveal melanoma patients were examined on a 7-T MRI system using a custom-built eye coil and dedicated 3D scan sequences to minimise eye-motion-induced image artefacts. The maximum tumour prominence was estimated from the three-dimensional images and compared with the standard clinical evaluation from 2D ultrasound images. Results The MRI protocols resulted in high-resolution motion-free images of the eye in which the tumour and surrounding tissues could clearly be discriminated. For eight of the ten patients the MR images showed a slightly different value of tumour prominence (average 1.0 mm difference) compared to the ultrasound measurements, which can be attributed to the oblique cuts through the tumour made by the ultrasound. For two of these patients the more accurate results from the MR images changed the treatment plan, with the smaller tumour dimensions making them eligible for eye-preserving therapy. Conclusion High-field ocular MRI can yield a more accurate measurement of the tumour dimensions than conventional ultrasound, which can result in significant changes in the prescribed treatment.
Purpose. To separately measure the optical densities of lutein (L) and zeaxanthin (Z) in the human retina in vivo. L and Z are the basic constituents of the macular pigment (MP). methods. Spectral fundus reflectance was measured in 23 subjects (group 1) at 0°, 1°, 2°, 4°, and 8° eccentricity with a modified macular pigment reflectometer. A model generated the optical densities of L (LOD) and Z (ZOD), using their slightly different absorption spectra. Three other subjects (group 2) took 20 mg/d zeaxanthin for 6 months; they were measured approximately monthly for 18 months. results. Mean LOD for group 1 at the central fovea was 0.200 ± 0.061 (range, 0.085–0.305), mean ZOD was 0.494 ± 0.169 (range, 0.169–0.806), resulting in a mean Z fraction [ZOD/(LOD + ZOD)] of 0.71. ZOD dropped faster toward the periphery than LOD, measuring 0.044 and 0.010 (Z fraction 0.18) at 8°, respectively. Zeaxanthin supplementation in group 2 caused a significant increase in ZOD, and no or minor changes in LOD. ZOD further increased over a 10-month period after supplementation in all subjects. conclusions. LOD and ZOD had different spatial profiles that, apart from scaling factors, showed similarity to in vitro literature data. Supplementation with Z caused LOD to decrease and ZOD to increase. These results strongly suggest that the optical densities of L and Z can be assessed in vivo by fundus reflectometry, opening new ways of investigating the putative protective roles of L and Z in retinal disease.
Purpose: The effectiveness and safety of surgery for spheno‐orbital meningiomas remains subject of debate, as studies often describe different surgical approaches and reconstruction techniques with very heterogeneous outcomes. We aimed to systematically summarize and analyse the literature on spheno‐orbital meningiomas regarding presenting symptoms, surgical techniques, outcomes and complications.Methods: Studies were retrieved from eight databases. Original articles were included if in ≥5 patients presenting symptoms, surgical treatment and outcomes were described. Fixed‐ and random‐effects meta‐analysis was performed to estimate weighted percentages with 95%CIs of presenting symptoms, outcomes and complications.Results: Thirty‐eight articles were included describing 1486 patients. Proptosis was the most common presenting symptom (84%; 95%CI 76–91%), followed by unilateral visual acuity deficits (46%; 95%CI 40–51%) and visual field deficits (31%; 95%CI 20–43%). In 35/38 studies (92%), a pterional craniotomy was used. Decompression of the optic canal (82%) and the superior orbital fissure (66%) was most often performed, and usually dural (47%) and bony defects (76%) were reconstructed. In almost all patients, visual acuity (91%; 95%CI 86–96%), visual fields (87%; 95%CI 70–99%) and proptosis (96%; 95%CI 90–100%) improved. Furthermore, surgery showed improvement in 96% (95%CI 78–100%) for both diplopia and ophthalmoplegia. The most common surgical complications were hypesthesia (19%; 95%CI 10–30%), ptosis and diplopia (both 17%; 95%CI, respectively, 10–26% and 5–33%) and ophthalmoplegia (16%; 95%CI 10–24).Conclusion: Patients with spheno‐orbital meningioma usually present with proptosis or unilateral decreased visual acuity. Surgery shows to be effective in improving visual acuity and visual field deficits with mostly minor and well‐tolerated complications.
Although quantitative MRI can be instrumental in the diagnosis and assessment of disease progression in orbital diseases involving the extra‐ocular muscles (EOM), acquisition can be challenging as EOM are small and prone to eye‐motion artefacts. We explored the feasibility of assessing fat fractions (FF), muscle volumes and water T2 (T2water) of EOM in healthy controls (HC), myasthenia gravis (MG) and Graves' orbitopathy (GO) patients. FF, EOM volumes and T2water values were determined in 12 HC (aged 22‐65 years), 11 MG (aged 28‐71 years) and six GO (aged 28‐64 years) patients at 7 T using Dixon and multi‐echo spin‐echo sequences. The EOM were semi‐automatically 3D‐segmented by two independent observers. MANOVA and t‐tests were used to assess differences in FF, T2water and volume of EOM between groups (P < .05). Bland–Altman limits of agreement (LoA) were used to assess the reproducibility of segmentations and Dixon scans. The scans were well tolerated by all subjects. The bias in FF between the repeated Dixon scans was −0.7% (LoA: ±2.1%) for the different observers; the bias in FF was −0.3% (LoA: ±2.8%) and 0.03 cm3 (LoA: ± 0.36 cm3) for volume. Mean FF of EOM in MG (14.1% ± 1.6%) was higher than in HC (10.4% ± 2.5%). Mean muscle volume was higher in both GO (1.2 ± 0.4 cm3) and MG (0.8 ± 0.2 cm3) compared with HC (0.6 ± 0.2 cm3). The average T2water for all EOM was 24.6 ± 4.0 ms for HC, 24.0 ± 4.7 ms for MG patients and 27.4 ± 4.2 ms for the GO patient. Quantitative MRI at 7 T is feasible for measuring FF and muscle volumes of EOM in HC, MG and GO patients. The measured T2water was on average comparable with skeletal muscle, although with higher variation between subjects. The increased FF in the EOM in MG patients suggests that EOM involvement in MG is accompanied by fat replacement. The unexpected EOM volume increase in MG may provide novel insights into underlying pathophysiological processes.