This work presents a deep learning approach for rapid and accurate muscle water T
with subject-specific fat T
calibration using multi-spin-echo acquisitions. This method addresses the computational ...limitations of conventional bi-component Extended Phase Graph fitting methods (nonlinear-least-squares and dictionary-based) by leveraging fully connected neural networks for fast processing with minimal computational resources. We validated the approach through in vivo experiments using two different MRI vendors. The results showed strong agreement of our deep learning approach with reference methods, summarized by Lin's concordance correlation coefficients ranging from 0.89 to 0.97. Further, the deep learning method achieved a significant computational time improvement, processing data 116 and 33 times faster than the nonlinear least squares and dictionary methods, respectively. In conclusion, the proposed approach demonstrated significant time and resource efficiency improvements over conventional methods while maintaining similar accuracy. This methodology makes the processing of water T
data faster and easier for the user and will facilitate the utilization of the use of a quantitative water T
map of muscle in clinical and research studies.
The purpose of this study was to develop a DTI-based method to quantitatively assess fiber angles and changes therein in leg muscles in order to facilitate longitudinal studies on muscle fiber ...architectural adaptations in healthy subjects.
The upper legs of five volunteers were scanned twice on the same day. The right lower legs of five volunteers were scanned twice with the ankle in three positions, i.e. -15° dorsiflexion, 0° neutral position, and 30° plantarflexion. The MRI protocols consisted of a noise scan, a 3-point mDixon scan and a DTI scan. Fiber-angle color maps were generated for four muscles in the upper legs and two muscles in the lower leg. Voxel-wise fiber angles (θ) were calculated from the angle between the principal eigenvector of the diffusion tensor and a reference line defined between the origo and insertion points of each muscle. Bland-Altman analysis, intraclass correlation coefficient (ICC), coefficient of variation (CV%), minimal detectable change (MDC), standard error (SE) and Friedman test were used for assessing the feasibility of this method and in order to have an indication of the repeatability and the sensitivity.
Bland-Altman analysis showed good repeatability (CV%<10 and 0.7≤ICC≤0.9) with exception of the Tibialis Anterior (TA) muscle in dorsiflexion position(CV%: 12.2) and the Semitendinosus (ST) muscle (left leg) (CV%: 11.4). The best repeatability metrics were found for the SOL muscle in neutral position (CV%: 2.6). Changes in average θ in TA and SOL with ankle positions were observed in accordance with expected agonist and antagonist functions of both muscles. For example, for the anterior left compartment the change in fiber angle Δθ with respect to the neutral position Δθ = -1.6° ± 0.8° and 2.2° ± 2.8° (p = 0.008), for dorsiflexion and plantarflexion, respectively.
Our method facilitates fast inspection and quantification of muscle fiber angles in the lower and upper leg muscles in rest and detection of changes in lower-leg muscle fiber angles with varying ankle angles.
This paper aims to understand how user-generated content (UGC) affects the process of place branding by identifying the main associations of various actors related to London and Florence, both ...traditionally linked to the fashion industry. In particular, this study focuses on fashion as a city image component that contributes to the construction of the image of London and Florence. This research applies a content analysis of visual information (pictures) and textual information (hashtags) available on social networks (i.e. Instagram), typing the hashtags #London and #Florence, to reconstruct the brand image of these two cities. As the recent literature has argued for brands or products, even for places and cities, it is important to monitor the perceived city brand image resulting from the overall online experience, especially on social media. This paper is one of the first to apply content analysis on Instagram in relation to city branding, where the core of communication is based on images. Therefore, in contrast to previous studies, this work principally focuses on visual communication, as a form of textual paralanguage communication, for the construction of a city image for London and Florence.
Why do fashion brands enter the metaverse when the benefits of using this virtual reality space are not yet clear to the industry? What motivates them to venture into the complex world of digital ...platforms and ecosystems? Do luxury and fast fashion companies share the same motivations for entering the metaverse? These research questions guide the study which seeks to understand the motivational factors driving fashion brands to establish a presence in the metaverse. To achieve our research objective, we employ qualitative research methods and follow a grounded theory approach. Through a content analysis of publicly available website publications containing insights from fashion industry leaders, we identify commonalities and distinctions in the motivational factors leading luxury and fast fashion brands into the metaverse. The study contributes to the theoretical comprehension of the metaverse as a new strategic platform for the fashion industry and highlights practical implications intended to assist industry managers contemplating entry into this virtual reality space.
Background
Ongoing arthritis in children with juvenile idiopathic arthritis (JIA) can result in cartilage damage.
Objective
To study the feasibility and repeatability of T
1ρ
for assessing knee ...cartilage in JIA and also to describe T
1ρ
values and study correlation between T
1ρ
and conventional MRI scores for disease activity.
Materials and methods
Thirteen children with JIA or suspected JIA underwent 3-tesla (T) knee MRI that included conventional sequences and a T
1ρ
sequence. Segmentation of knee cartilage was carried out on T
1ρ
images. We used intraclass correlation coefficient to study the repeatability of segmentation in a subset of five children. We used the juvenile arthritis MRI scoring system to discriminate inflamed from non-inflamed knees. The Mann-Whitney
U
and Spearman correlation compared T
1ρ
between children with and without arthritis on MRI and correlated T
1ρ
with the juvenile arthritis MRI score.
Results
All children successfully completed the MRI examination. No images were excluded because of poor quality. Repeatability of T
1ρ
measurement had an intraclass correlation coefficient (ICC) of 0.99 (
P
<0.001). We observed no structural cartilage damage and found no differences in T
1ρ
between children with (
n
=7) and without (
n
=6) inflamed knees (37.8 ms vs. 31.7 ms,
P
=0.20). However, we observed a moderate correlation between T
1ρ
values and the juvenile arthritis MRI synovitis score (r=0.59,
P
=0.04).
Conclusion
This pilot study suggests that T
1ρ
is a feasible and repeatable quantitative imaging technique in children. T
1ρ
values were associated with the juvenile arthritis MRI synovitis score.
Diffusion tensor imaging (DTI) measures water diffusion in skeletal muscle tissue and allows for muscle assessment in a broad range of neuromuscular diseases. However, current DTI measurements, ...typically performed using pulsed gradient spin echo (PGSE) diffusion encoding, are limited to the assessment of non-contracted musculature, therefore providing limited insight into muscle contraction mechanisms and contraction abnormalities. In this study, we propose the use of an oscillating gradient spin echo (OGSE) diffusion encoding strategy for DTI measurements to mitigate the effect of signal voids in contracted muscle and to obtain reliable diffusivity values. Two OGSE sequences with encoding frequencies of 25 and 50 Hz were tested in the lower leg of five healthy volunteers with relaxed musculature and during active dorsiflexion and plantarflexion, and compared with a conventional PGSE approach. A significant reduction of areas of signal voids using OGSE compared with PGSE was observed in the tibialis anterior for the scans obtained in active dorsiflexion and in the soleus during active plantarflexion. The use of PGSE sequences led to unrealistically elevated axial diffusivity values in the tibialis anterior during dorsiflexion and in the soleus during plantarflexion, while the corresponding values obtained using the OGSE sequences were significantly reduced. Similar findings were seen for radial diffusivity, with significantly higher diffusivity measured in plantarflexion in the soleus muscle using the PGSE sequence. Our preliminary results indicate that DTI with OGSE diffusion encoding is feasible in human musculature and allows to quantitatively assess diffusion properties in actively contracting skeletal muscle. OGSE holds great potential to assess microstructural changes occurring in the skeletal muscle during contraction, and for non-invasive assessment of contraction abnormalities in patients with muscle diseases.
Background
Surgical resection of tongue cancer may impair swallowing and speech. Knowledge of tongue muscle architecture affected by the resection could aid in patient counseling. Diffusion tensor ...imaging (DTI) enables reconstructions of muscle architecture in vivo. Reconstructing crossing fibers in the tongue requires a higher‐order diffusion model.
Purpose
To develop a clinically feasible diffusion imaging protocol, which facilitates both DTI and constrained spherical deconvolution (CSD) reconstructions of tongue muscle architecture in vivo.
Study Type
Cross‐sectional study.
Subjects/Specimen
One ex vivo bovine tongue resected en bloc from mandible to hyoid bone. Ten healthy volunteers (mean age 25.5 years; range 21–34 years; four female).
Field Strength/Sequence
Diffusion‐weighted echo planar imaging at 3 T using a high‐angular resolution diffusion imaging scheme acquired twice with opposing phase‐encoding for B0‐field inhomogeneity correction. The scan of the healthy volunteers was divided into four parts, in between which the volunteers were allowed to swallow, resulting in a total acquisition time of 10 minutes.
Assessment
The ability of resolving crossing muscle fibers using CSD was determined on the bovine tongue specimen. A reproducible response function was estimated and the optimal peak threshold was determined for the in vivo tongue. The quality of tractography of the in vivo tongue was graded by three experts.
Statistical Tests
The within‐subject coefficient of variance was calculated for the response function. The qualitative results of the grading of DTI and CSD tractography were analyzed using a multilevel proportional odds model.
Results
Fiber orientation distributions in the bovine tongue specimen showed that CSD was able to resolve crossing muscle fibers. The response function could be determined reproducibly in vivo. CSD tractography displayed significantly improved tractography compared with DTI tractography (P = 0.015).
Data Conclusion
The 10‐minute diffusion imaging protocol facilitates CSD fiber tracking with improved reconstructions of crossing tongue muscle fibers compared with DTI.
Level of Evidence: 2
Technical Efficacy: Stage 1
J. Magn. Reson. Imaging 2019;50:96–105.
Pierre Robin Sequence (PRS) is a heterogeneous pathological condition characterized by the coexistence of micrognathia, glossoptosis, and cleft palate, resulting in upper airway tract obstruction. ...Among the treatment modalities, the orthodontic approach is one part of the comprehensive care of those patients and will be present in the treatment modalities during all the growth period of the child.
All patients with PRS observed in the period 2013-2017 were treated with a definite functional approach. The results were retrospectively analyzed with regard to functional outcome, total treatment time, and number of plates provided for a single patient.
In all the patients, the indicated treatment protocol has been applied as early impression and plate supply, stimulation of bottle feeding with the use of the plate, eventual substitution of the plate if no more adequate to the transverse and sagittal growth of the palate, and continuing the use until the surgical closure of the cleft. All the patients showed a positive outcome to the proposed treatment approach, evaluated with regard to the incidence of feeding improvement and weight gain, to the limit for the surgical phase, in the absence of adverse effects.
The use of a functional obturator plate, removing functional alterations to mandibular growth, reduces and, in some cases, eliminates the need for surgical intervention. As also stated in the literature, if despite the presence of the plate nutritional problems persist, immediate different surgical approaches, mainly mandibular osteodistraction, become necessary.
Our aim is to test the Nahoum Index as a support in the cephalometric study of vertical dimension and therapeutic orientation in adult patients suffering from Class II malocclusion, deep bite, or ...short face syndrome.
Twenty-three patients with molar Class II and an overbite >4 mm were stratified into two groups: orthodontic (G2) and surgical orthodontic (G1). The ANB angle and Nahoum Index were calculated for cephalometric tracing pre- and post-treatment. The difference between the ANB and Nahoum Index values were analyzed using the Statistical Package for the Social Sciences software.
In G1, the Nahoum Index decreased from 0.954 to 0.797, and the ANB angle decreased from 5.2° to 3.2°. In G2, the Nahoum Index decreased from 0.825 to 0.817, and the ANB angle decreased from 4.4° to 4°.
In G1, the difference between before and after treatment was significant for the Nahoum Index only. The difference between before and after values was not significant in the G2 group. It is possible to indicate the Nahoum Index of 0.934 as the limit value in case of which a patient may be treated with orthodontics only. This limit is the opposite of the limit proposed by Nahoum for vertical excess cases and respect the same interval. Therefore, we can consider the range 0.81-0.934 to indicate borderline patients, and >0.934 to indicate surgical patients. If the ratio is close to the normal value as 0.81, the treatment will be orthodontic; if it is further increased, the treatment will be surgical.
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