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The levator aponeurosis shown on MC-MR imaging T1-weighted sagittal image. SOR indicates superior orbital rim; LPS, levator palpebrae superioris; FS, fibrous orbital septum; LA, levator aponeurosis; OO, orbicularis oculi.
Source publication
Microscopy coil MR imaging of the orbits has been described previously as a technique for anatomic depiction. In the first part of this 2-part series, the improvement in spatial resolution that the technique offers compared with conventional MR imaging of the orbits is demonstrated. We provide a guide to implementing the technique, sharing pearls a...
Contexts in source publication
Context 1
... elevation and closure of the eyelids are undertaken by the suspensory connective tissue system of the orbit. Primarily, this consists of the levator palpebrae superioris, which traverses the orbit, in conjunction with the superior rectus muscle, before terminating as the levator aponeurosis (Fig 9). ...
Context 2
... elevation and closure of the eyelids are undertaken by the suspensory connective tissue system of the orbit. Primarily, this consists of the levator palpebrae superioris, which traverses the orbit, in conjunction with the superior rectus muscle, before terminating as the levator aponeurosis (Fig 9). ...
Citations
... However, these characteristics vary according to ethnicity, for example, this distance increases in some Asian groups. 19,20 In addition to other studies done in Indian-Malaysian and Japanese populations, in both sexes a significant difference was found in upper-and lower-eyelid height, but in our study, these parameters were higher than in those populations. 9,21 On the other hand, these parameters in the present study were found to be similar to a US population. ...
Purpose
We performed an assessment of the rejuvenation effect of an amino acid and hyaluronic acid mixture in the periorbital area.
Methods
A total of 23 of the 35 participants completed all application sessions and measurements. These 23 women were aged 30–55 years. A hyaluronic acid and amino acid mixture was injected into the participants’ periorbital area. Three sessions of application with 15-day intervals were undertaken. Subjects’ age, height, weight, smoking status, and sport participation were recorded. A photonumeric dark circle scale and Fitzpatrick’s periorbital wrinkling classification were used for evaluation of dark circles and wrinkles in the periorbital area. Anatomical measurements (height of upper and lower eyelids) were done using ImageJ and a skin-analysis system (Observ 520).
Results
The 23 women had a mean age of 42.46±9.33 years, mean height 164.46±4.96 cm, and mean weight 63.94±8.26 kg. Before the sessions, the mean heights of the upper eyelids were 1.24±013 cm (right) and 1.21±013 cm (left), while those of the lower eyelids were 0.98±014 cm (right) and 0.97±0.17 cm (left). One month after the third session, mean upper-eyelid heights were 1.30±0.09 cm (right) and 1.28±0.11 cm (left) and lower-eyelid ones 1.02±0.11 cm (right) and 1.02±0.13 cm (left). Dark-circle and wrinkle-scale scores showed significantly positive results between before the sessions and 1 month after the third session.
Conclusion
A hyaluronic acid and amino acid mixture can be used to rejuvenation of the periorbital area in women aged 30–55 years.
... Innovative radiofrequency coil technology in head coils has largely supplanted the need for surface coils; however, dedicated orbital coils could be applied for the imaging of selected orbital anatomical structures. 6,94 Novel sequences speed up image acquisition through under-sampling, in-slice acceleration using parallel imaging, and multi-band simultaneous slice acquisition, which mitigates eye movement and head motion artifacts. In the future, real-time motion-correction and artificial intelligencebased image reconstruction could advance the boundaries of fast, high-resolution, motion-insensitive orbital MRI. ...
Over the past decade, ocular imaging strategies have greatly advanced the diagnosis and follow-up of patients with optic neuropathies. Developments in optic nerve imaging have specifically improved the care of patients with papilloedema and idiopathic intracranial hypertension, inflammatory optic neuropathies, and compressive optic neuropathies. For example, optic nerve imaging with optical coherence tomography (OCT) is now widely used as an outcome measure in clinical trials of neurological disorders (eg, demyelinating diseases), and OCT findings could be informative of disease progression in patients with various neurodegenerative disorders (eg, Alzheimer's disease or Parkinson's disease). In the past 5 years, multimodality optic nerve imaging has expanded to systematically include focused and wide-field colour and autofluorescence fundus photographs; various types of optic nerve, macular, and vascular OCT; and specific MRI techniques. Such multimodality imaging makes the diagnosis of optic neuropathies easier and provides objective information on optic nerve damage, which is useful for prognosis. Non-mydriatic ocular fundus cameras and OCT have become readily available in non-ophthalmic settings and could easily be implemented in neurological clinics and emergency departments, allowing for direct access to optic nerve imaging and enabling teleconsultations. In the future, these imaging studies could be used in association with artificial intelligence deep-learning systems, which are already transforming the field of ocular imaging.
... Recent studies establish the advantage of high-resolution (HR) microscopy-coil MRI [32][33][34]. HR-MRI considerably improves the spatial resolution and signal-to-noise ratio. The depth of tumors measured by HR-MRI has a strong correlation with histopathological depth, and HR-MRI provides an accurate prediction of the involvement of the bone, cartilage, subcutaneous fat, or muscle [33,34]. ...
... HR-MRI considerably improves the spatial resolution and signal-to-noise ratio. The depth of tumors measured by HR-MRI has a strong correlation with histopathological depth, and HR-MRI provides an accurate prediction of the involvement of the bone, cartilage, subcutaneous fat, or muscle [33,34]. Although the utility of HR-MRI for diagnosing MSTs has not yet been established, HR-MRI is expected to enhance microstructural characterization such as superficial depression, tumor margins, and microcystic foci. ...
Sometimes, radiologists encounter malignant skin tumors (MSTs) during image interpretation. As MSTs require different clinical management modalities for each histological subtype, accurate preoperative diagnosis is essential. The histological subtypes of MST can be easily assessed by visual inspection or biopsy. Therefore, the significant role of radiological imaging in MSTs is to evaluate the extent of local invasion, nodal involvement, and distant metastasis, and the histological estimation of MSTs by radiological imaging has not been reported until a few years ago. However, recent studies have revealed characteristic radiological features for differential diagnosis of MSTs, such as configuration, intratumoral homogeneity, signal intensity, cyst formation, and hemorrhage. Other important clinical data for determining the histological subtype of MST include age, gender, and site of occurrence. MSTs can be categorized as epidermal, melanocytic, adnexal, and mesenchymal tumors based on the origin and have distinctive characteristics. Hence, this review article was designed to describe the clinical and radiological features of MSTs.
... Their custom built 10-channel coil produced optic nerve images with increased SNR up to 36% compared with the manufacturer's 20-channel head coil. Dobbs et al. also demonstrated high resolution optic nerve images using a 40 mm inner diameter small-loop RF receiver coil [94]. The high-resolution orbit surface coil was clinically used to evaluate the metastatic risk factors for Fig. 6. ...
The optic nerve is known to be one of the largest nerve bundles in the human central nervous system. There have been many studies of optic nerve imaging and post-processing that have provided insights into pathophysiology of optic neuritis related to multiple sclerosis and neuromyelitis optica spectrum disorder, glaucoma, and Leber's hereditary optic neuropathy. There are many challenges in optic nerve imaging, due to the morphology of the nerve through its course to the optic chiasm, its mobility due to eye movements and the high signal from cerebrospinal fluid and orbital fat surrounding the optic nerve. Recently, many advanced and fast imaging sequences have been used with post-processing techniques in attempts to produce higher resolution images of the optic nerve for evaluating various diseases. Magnetic resonance imaging (MRI) is one of the most common imaging methodologies for the optic nerve. This review paper will focus on recent MRI advances in optic nerve imaging and explain several post-processing techniques being used for analysis of optic nerve images. Finally, some challenges and potential for future optic nerve studies will be discussed.
... Their custom built 10-channel coil produced optic nerve images with increased SNR up to 36% compared with the manufacturer's 20-channel head coil. Dobbs et al. also demonstrated high resolution optic nerve images using a 40 mm inner diameter small-loop RF receiver coil [94]. The high-resolution orbit surface coil was clinically used to evaluate the metastatic risk factors for Fig. 6. ...
The neuronal (ionic) current caused by nerve firing induces subtle and transient magnetic flux density changes that potentially modulate the MR signal over successive gradient echo planar image frames. Frequency spectra derived from Fourier transformation of experimental data down these time frames show evidence of a strobe stimulus localized to regions containing the optic nerve and visual cortex, which suggests that direct detection of the magnetic fields emanating from these regions has been achieved.
This chapter aims to describe the essential aspects of normal anatomy and its variants on cross‐sectional imaging from a radiological perspective. It reviews the imaging techniques such as, computed tomography (CT) and magnetic resonance imaging (MRI). In general, it can be stated that CT is superior in defining bony structures, while MRI is more advantageous for studying soft tissues, including bone marrow, due to its higher contrast resolution. For an adequate knowledge of the radiological anatomy, it is first convenient to conduct a brief review of the radiological semiology of the brain, that is, how the different structures that make up the brain are depicted in different techniques or sequences. The most accepted approach to study the neck distinguishes two anatomical spaces: the supra‐hyoid and the infra‐hyoid neck. Chest CT is the most sensitive and precise diagnostic imaging method both for depiction of anatomical structures and detection of thoracic pathology.
Each orbit is a complex structure housing the globe, multiple cranial nerves, muscles, vascular structures, which support the visual sense. Many of these structures have been delineated in careful detail by anatomists but remain beyond the resolution of conventional imaging techniques. With the advances of higher resolution MR, surface coil usage, and thinner section computed tomographic images, the ability to resolve these small structures continues to improve, allowing radiologists to provide more detailed anatomic descriptions for preoperative and pretreatment planning.
Purpose
We analyze the detectability of intraorbital foreign bodies (OrbFBs) of various types and sizes using computed tomography (CT) and magnetic resonance imaging using a three-Tesla machine (MRI 3 T).
Methods
An ex vivo model of sheep eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of the human skull was created for this study. Foreign bodies made of four different materials – plastic, bottle glass, stone and wood – each in three different sizes (large, intermediate and small) were inserted into the soft tissue of the orbit in the extraocular space. Each orbit was scanned by CT and MRI. Images were analyzed by a senior radiologist and underwent masked review by three oculoplastic surgeons.
Results
Analysis of MRI and CT scans identified distinguishing characteristics for each of the four materials. This information was further integrated into a clinical algorithm. CT allowed easier identification of most of the embedded materials compared to MRI. Smaller OrbFB size was associated with lower detectability. Review of CT yielded 94.4% agreement between oculoplastic specialists in detecting OrbFbs using CT scans and allowed detection of most OrbFBs. In contrast, the overall agreement with MRI was lower: 66.7% with T1 MPRAGE, 50% with T1TSE, 88.9% with T2 TSE and 72.2% with T2 TSE FS. Plastic was the most difficult material to detect in all size categories.
Conclusions
CT offers a clear advantage over MRI for detecting and localizing nonmetallic OrbFBs of all sizes, except for plastic. Plastic OrbFBs can be detected with CT depending on size but are more visible in MRI scans.
Magnetic resonance imaging of the eye and orbit (MReye) is a cross-domain research field, combining (bio)physics, (bio)engineering, physiology, data sciences and ophthalmology. A growing number of reports document technical innovations of MReye and promote their application in preclinical research and clinical science. Realizing the progress and promises, this review outlines current trends in MReye. Examples of MReye strategies and their clinical relevance are demonstrated. Frontier applications in ocular oncology, refractive surgery, ocular muscle disorders and orbital inflammation are presented and their implications for explorations into ophthalmic diseases are provided. Substantial progress in anatomically detailed, high-spatial resolution MReye of the eye, orbit and optic nerve is demonstrated. Recent developments in MReye of ocular tumors are explored, and its value for personalized eye models derived from machine learning in the treatment planning of uveal melanoma and evaluation of retinoblastoma is highlighted. The potential of MReye for monitoring drug distribution and for improving treatment management and the assessment of individual responses is discussed. To open a window into the eye and into (patho)physiological processes that in the past have been largely inaccessible, advances in MReye at ultrahigh magnetic field strengths are discussed. A concluding section ventures a glance beyond the horizon and explores future directions of MReye across multiple scales, including in vivo electrolyte mapping of sodium and other nuclei. This review underscores the need for the (bio)medical imaging and ophthalmic communities to expand efforts to find solutions to the remaining unsolved problems and technical obstacles of MReye, with the objective to transfer methodological advancements driven by MR physics into genuine clinical value.
