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1.
Cureus ; 16(8): e66081, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39224739

RESUMO

The hip and lumbar spine are closely related and can create similar patterns of pain and dysfunction. Furthermore, diagnosing and treating hip and spine conditions can be challenging due to the overlap of symptoms. This report describes the successful treatment of a 54-year-old male with hip-spine syndrome following multiple surgeries for spondylolytic spondylolisthesis. The patient presented with low back pain (LBP) and bilateral hip pain, with radiological findings indicating spinal deformity and hip joint synovitis. Two years after two-stage corrective surgery, including pedicle subtraction osteotomy (PSO), the hip synovitis resolved and the symptoms improved. This case emphasizes the need to consider hip-spine syndrome as a possible complication of lumbosacral spine fusion surgery and demonstrates the efficacy of two-stage corrective surgery with pedicle subtraction osteotomy in treating this condition.

2.
J Colloid Interface Sci ; 678(Pt A): 979-986, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39226838

RESUMO

Precise deposition of metal-organic framework (MOF) materials is important for fabricating high-performing MOF-based devices. Electric-field assisted drop-casting of poly(3,4-ethylenedioxythiophene)-functionalized (PEDOT) MIL-101(Cr) nanoparticles onto interdigitated electrodes allowed their precise spatioselective deposition as percolating nanoparticle chains in the interelectrode gaps. The resulting aligned materials were investigated for resistive and capacitive humidity sensing and compared with unaligned samples prepared via regular drop-casting. The spatioselective deposition of MOFs resulted in up to over 500 times improved conductivity and approximately 6 times increased responsivity during resistive humidity sensing. The aligned samples also showed good capacitive humidity sensing performance, with up to 310 times capacitance gain at 10 versus 90 % relative humidity. In contrast, the resistive behavior of the unaligned samples rendered them unsuitable for capacitive sensing. This work demonstrates that applying an alternating potential during drop-casting is a simple yet effective method to control MOF deposition for greater efficiency, conductivity, and enhanced humidity sensing performance.

3.
Artigo em Inglês | MEDLINE | ID: mdl-39224029

RESUMO

PURPOSE: Different methods for quantifying joint-line obliquity (JLO) have been described, including joint-line obliquity angle (JLOA), Mikulicz joint-line angle (MJLA) and medial proximal tibial angle (MPTA). The goal of the present study was to quantify the variation of JLOA based on the position of the hip. The hypothesis of our study is that JLO is significantly influenced by the abduction/adduction of the limb, unlike MJLA. METHODS: One hundred long-leg-weightbearing X-rays were used. At time 0 and after 30 days, two observers performed different measurements, including (1) distance between pubic symphysis and center of the femoral head, (2) distance between center of the femoral head and center of the ankle joint, (3) distance between center of the ankle and medial malleolus, (4) hip-knee-ankle angle, (5) MPTA, (6) lateral distal femoral angle, (7) joint-line congruency angle, (8) JLOA, (9) MJL and (10) angle between Mikulicz line and line perpendicular to the ground. The changes of the JLOA based on the position of the hip (abducted, neutral, bipedal stance adduction and monopodal stance adduction) were calculated with trigonometric formulas and with simulation on an orthopaedic planning digital software. RESULTS: The JLOA change between adducted and abducted positions was on average 12.8° (SD 0.9 mm). The MJL did not vary significantly based on hip position. CONCLUSIONS: The adduction/abduction of the lower limb has a considerable impact on JLOA. Methods like MJLA which are not affected by hip position should be preferred for JLO evaluation. LEVEL OF EVIDENCE: Diagnostic study, level III.

4.
Nano Lett ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39225661

RESUMO

The utilization of perovskite materials in flexible optoelectronics is experiencing distinct diversification including X-ray detection applications. Here, we report the oriented alignment of cesium lead bromide (CsPbBr3) single-crystal arrays on flexible polydimethylsiloxane (PDMS) substrates. By precisely confining the crystallization process within spatially delimited precursor droplets, we achieve a well-oriented crystal alignment through the spontaneous rotation of the CsPbBr3 microcuboids. This approach allows for precise control over the microcuboid morphologies by varying the growth temperature. We design flexible X-ray detector arrays by seamlessly integrating CsPbBr3 microcuboids with electrode arrays. The flexible X-ray detector can output a high sensitivity of 1.97 × 105 µC·Gyair-1·cm-2 and a low detection limit of 89 nGyair·s-1 after the surface passivation process. The excellent mechanical properties, outstanding X-ray detection capabilities, and high pixel uniformity are also demonstrated in conformal X-ray imaging of curved surfaces.

5.
Med Image Anal ; 99: 103333, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39244795

RESUMO

Partially-supervised multi-organ medical image segmentation aims to develop a unified semantic segmentation model by utilizing multiple partially-labeled datasets, with each dataset providing labels for a single class of organs. However, the limited availability of labeled foreground organs and the absence of supervision to distinguish unlabeled foreground organs from the background pose a significant challenge, which leads to a distribution mismatch between labeled and unlabeled pixels. Although existing pseudo-labeling methods can be employed to learn from both labeled and unlabeled pixels, they are prone to performance degradation in this task, as they rely on the assumption that labeled and unlabeled pixels have the same distribution. In this paper, to address the problem of distribution mismatch, we propose a labeled-to-unlabeled distribution alignment (LTUDA) framework that aligns feature distributions and enhances discriminative capability. Specifically, we introduce a cross-set data augmentation strategy, which performs region-level mixing between labeled and unlabeled organs to reduce distribution discrepancy and enrich the training set. Besides, we propose a prototype-based distribution alignment method that implicitly reduces intra-class variation and increases the separation between the unlabeled foreground and background. This can be achieved by encouraging consistency between the outputs of two prototype classifiers and a linear classifier. Extensive experimental results on the AbdomenCT-1K dataset and a union of four benchmark datasets (including LiTS, MSD-Spleen, KiTS, and NIH82) demonstrate that our method outperforms the state-of-the-art partially-supervised methods by a considerable margin, and even surpasses the fully-supervised methods. The source code is publicly available at LTUDA.

6.
Eur Spine J ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39222081

RESUMO

PURPOSE: While existing adult spinal deformity (ASD) alignment schemas acknowledge the dynamic relationship between the pelvis and spine, consideration of vertebral pelvic angles (VPA) thresholds for PJK may provide further insight into the relationship of each individual vertebra to the pelvis, which may allow for greater individualization of operative targets. Herein, we examine VPA's utility in preventing mechanical complications and its possible unification with prevalent scoring systems. METHODS: In a retrospective cohort study of a prospectively collected database, operative ASD patients ≥ 18 years with complete baseline (BL) and two-year (Y) operative, radiographic, and health-related quality of life data were included. Descriptive analyses, means comparison, and logistic regression tests were applied to explore demographic and surgical differences, as well as the impact of alignment goals on outcomes. Cohorts were grouped as patients who met VPA non-PJK thresholds, as defined by Duvvuri et al. 2023 alone versus traditional GAP/SAAS alignment matching versus combined VPA + SAAS + GAP. The Non-PJK VPA validated mean for L1PA was 10.4 ± 7.0 and T9PA 8.9 ± 7.5. RESULTS: 398 patients met inclusion criteria (mean age 61 ± 14 years, 78% female, BL BMI 27 ± 6, BL CCI 2 ± 2). At baseline, mean vertebral pelvic angles were as follows: T1PA: 24 ± 14; T4PA 20 ± 13, T9PA 15 ± 12, L1PA 11 ± 10, L4PA 11 ± 6. Mean vertebral pelvic angles at 6 W postoperatively: T1PA 16 ± 10, T4PA 12 ± 10, T9PA 8 ± 9, L1PA 9 ± 8, L4PA 11 ± 5. 240 (60%) patients attained optimal L1PA, while 104 patients (26.1%) reached non-PJK mean for T9PA. 89 patients (22%) were optimal by both VPA standards. VPA-Optimal group demonstrated significantly lower rates of 1Y PJK (17% v 83%, p = 0.042) and PJF by 2Y (7% v. 93%, p = 0.038). When patients attained VPA goals in addition to GAP/SAAS goals at 6 W, they demonstrated significantly lower rates of Y1 PJK (p = 0.026) and Y1 and Y2 PJF. Those with optimal VPA registered greater SRS-22 scores across multiple domains (p < 0.02) as well as a greater rate of normal neurological examination at 6 W (p = 0.048). CONCLUSIONS: Vertebral pelvic angles are a reliable measure of global alignment, and respecting certain targets may help prevent development of PJK/PJF. The value of VPA can be augmented through integration with GAP/SAAS frameworks to prevent complications and improve quality of life.

7.
Phonetica ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39248125

RESUMO

Given an orthographic transcription, forced alignment systems automatically determine boundaries between segments in speech, facilitating the use of large corpora. In the present paper, we introduce a neural network-based forced alignment system, the Mason-Alberta Phonetic Segmenter (MAPS). MAPS serves as a testbed for two possible improvements we pursue for forced alignment systems. The first is treating the acoustic model as a tagger, rather than a classifier, motivated by the common understanding that segments are not truly discrete and often overlap. The second is an interpolation technique to allow more precise boundaries than the typical 10 ms limit in modern systems. During testing, all system configurations we trained significantly outperformed the state-of-the-art Montreal Forced Aligner in the 10 ms boundary placement tolerance threshold. The greatest difference achieved was a 28.13 % relative performance increase. The Montreal Forced Aligner began to slightly outperform our models at around a 30 ms tolerance. We also reflect on the training process for acoustic modeling in forced alignment, highlighting how the output targets for these models do not match phoneticians' conception of similarity between phones and that reconciling this tension may require rethinking the task and output targets or how speech itself should be segmented.

8.
Artigo em Inglês | MEDLINE | ID: mdl-39248217

RESUMO

PURPOSE: During kinematically aligned (KA) total knee arthroplasty (TKA), the surgeon may need to rectify an over-resection of the medial, lateral or posterior tibia. This study tested the hypothesis that a bone graft taken from the tibial resection or patella and impacted beneath a tibial baseplate would heal, regardless of whether the tibial component and knee were in outlier ranges according to mechanical alignment (MA) criteria. The study also tested the hypothesis that the Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) would improve beyond the substantial clinical benefit and that the source and thickness of the bone graft would not influence their improvement. METHODS: This retrospective study radiographically assessed the healing of a bone graft from the tibial resection (n = 19) or patella (n = 10) in 29 KA TKAs (18 females, mean age 65 years). The tibial component and knee alignment were categorized as in-range or outliers based on reported MA criteria for bone graft healing and implant survival. The one-sample t test identified differences in the improvement of the OKS and KOOS JR from their reported substantial clinical benefit of 16 and 20 points, respectively. RESULTS: At an average follow-up of 37 months, all bone grafts healed even though ≥55% of tibial components and 34% of knees were varus outliers according to MA criteria for bone healing and implant survival. Amongst the 29 patients, the mean OKS and KOOS JR improvements of 25 ± 11 and 47 ± 21 points, respectively, surpassed the threshold of their respective substantial clinical benefit (p < 0.01) and were not influenced by the bone graft's source and thickness (p ≥ 0.51). CONCLUSIONS: During cemented KA TKA, the surgeon can use a bone graft from the tibial resection or patella to rectify a tibial over-resection. This technique led to consistent bone healing and improved outcome scores. LEVEL OF EVIDENCE: Level IV.

9.
Artigo em Inglês | MEDLINE | ID: mdl-39248213

RESUMO

PURPOSE: While restricted kinematic alignment (rKA) total knee arthroplasty (TKA) with cemented implants has been shown to provide a similar survivorship rate to mechanical alignment (MA) in the short term, no studies have reported on the long-term survivorship and function. METHODS: One hundred four consecutive cemented cruciate retaining TKAs implanted using computer navigation and following the rKA principles proposed by Vendittoli were reviewed at a minimum of 10 years after surgery. Implant revisions, reoperations and clinical outcomes were assessed using knee injury and osteoarthritis outcome score (KOOS), forgotten joint score (FJS), patients' satisfaction and joint perception questionnaires. Radiographs were analyzed to identify signs of osteolysis and implant loosening. RESULTS: Implant survivorship was 99.0% at a mean follow-up of 11.3 years (range: 10.3-12.9) with one early revision for instability. Patients perceived their TKA as natural or artificial without limitation in 50.0% of cases, and 95.3% were satisfied or very satisfied with their TKA. The mean FJS was 67.6 (range: 0-100). The mean KOOS were as follows: pain 84.7 (range: 38-100), symptoms 85.5 (range: 46-100), function in daily activities 82.6 (range: 40-100), function in sport and recreation 35.2 (range: 0-100) and quality of life 79.1 (range: 0-100). No radiological evidence of implant aseptic loosening or osteolysis was identified. CONCLUSION: Cemented TKA implanted with the rKA alignment protocol demonstrated excellent long-term implant survivorship and is a safe alternative to MA to improve patient function and satisfaction. LEVEL OF EVIDENCE: IV, continuous case series with no comparison group.

10.
Front Bioinform ; 4: 1358374, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39221004

RESUMO

Sequence alignments are often used to analyze genomic data. However, such alignments are often only calculated and compared on small sequence intervals for analysis purposes. When comparing longer sequences, these are usually divided into shorter sequence intervals for better alignment results. This usually means that the order context of the original sequence is lost. To prevent this, it is possible to use a graph structure to represent the order of the original sequence on the alignment blocks. The visualization of these graph structures can provide insights into the structural variations of genomes in a semi-global context. In this paper, we propose a new graph drawing framework for representing gMSA data. We produce a hierarchical graph layout that supports the comparative analysis of genomes. Based on a reference, the differences and similarities of the different genome orders are visualized. In this work, we present a complete graph drawing framework for gMSA graphs together with the respective algorithms for each of the steps. Additionally, we provide a prototype and an example data set for analyzing gMSA graphs. Based on this data set, we demonstrate the functionalities of the framework using two examples.

11.
N Am Spine Soc J ; 19: 100529, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39221091

RESUMO

Background: Thoracolumbar spinal fractures (TLSF) can cause pain, neurological deficits, and functional disability. Operative treatments aim to preserve neurological function, improve functional status, and restore spinal alignment and stability. In this review, we evaluate the relationship between spinal alignment and functional impairment in patients with TLSF. Methods: We performed a systematic review in accordance with the PRISMA guidelines to identify full-text articles that evaluate the correlation between spinal alignment and functional outcomes of TLSF. The artificial intelligence software Rayyan assisted the screening process. Functional outcomes referred to activity/disability, quality of life, and pain scores, as well as return to work metrics. Radiological assessments included were vertebral compression angle, Cobb and Gardner angles, sagittal vertical axis, pelvic incidence, and pelvic tilt. Statistical analyses were performed for the data provided by articles using the SPSS v24. Results: Of 1,616 articles reviewed, 6 were included for final analysis. Only 1 study primarily addressed the effects of spinopelvic parameters and functional outcomes. Four studies correlated Cobb angles with functional outcome, while 3 others compared vertebral compression angles with functional outcomes. Outcomes were assessed using work status or a combination of VAS pain and spine score, ODI, SF-36, and RMDQ-24. Neither the analysis done within the articles, nor the one made with the raw data provided by them, showed a significant correlation between the radiological measurements assessed at time of injury and final functional outcomes. Conclusions: A correlation between the assessed spinal radiological measurements assessed with the functional outcomes of TLSF was not found in this review. Further well-designed prospective studies are necessary to evaluate spinal alignment measurements in TLSF with functional outcomes.

12.
J Rehabil Assist Technol Eng ; 11: 20556683241277179, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39221172

RESUMO

Introduction: The purpose of this study was to compare the impact of three types of orthoses (knee orthosis, ankle foot orthosis (AFO), and foot orthosis) on knee alignment, pain, function, and quality of life in individuals with medial knee osteoarthritis (MKOA). Method: Thirty patients took part in this study and were randomly assigned to three groups (n = 10 in each group) based on the type of intervention. Knee function was assessed using the knee injury and osteoarthritis outcome score (KOOS) questionnaire, and knee alignment was evaluated by measuring angles using the images of bony prominence (AMI) method. Results: After using knee orthosis and AFO, all subscales of KOOS showed significant improvement (p < .05). However, there was no significant difference in the results after using foot orthosis (p > .05). Conclusion: The findings indicate that knee orthosis or AFO for 6 weeks can improve clinical outcomes for individuals with MKOA. This suggests that clinicians can consider using knee orthosis and AFO among the available treatment options to improve clinical outcomes.

13.
Open Mind (Camb) ; 8: 1084-1106, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39229608

RESUMO

All talkers show some flexibility in their speech, and the ability to imitate an unfamiliar accent is a skill that shows vast individual differences. Yet the source of these individual differences, in particular whether they originate from perceptual, motor, or social/personality factors, is not yet clear. In the current study, we ask how individual differences in these factors predict individual differences in deliberate accent imitation. Participants imitated three accents, and attempts were rated for accuracy. A set of measures tracking individual differences in perceptual, motor, cognitive, personality, and demographic factors were also acquired. Imitation ability was related to differences in musical perception, vocal articulation, and the personality characteristic of "openness to experience," and was affected by attitudes towards the imitated talkers. Taken together, results suggest that deliberate accent imitation skill is modulated not only by core perceptual and motor skills, but also by personality and affinity to the talker, suggesting that some aspects of deliberate imitation are a function of domain-general constraints on perceptual-motor systems, while others may be modulated by social context.

14.
Artigo em Inglês | MEDLINE | ID: mdl-39235951

RESUMO

We theoretically identify the ScSeI monolayer as a promising new 2D material for photocatalysis through first-principles calculations. The most notable feature is the significant difference in carrier mobility, with electron mobility in the horizontal direction being 20.66 times higher than hole mobility, minimizing electron-hole recombination. The ScSeI monolayer exhibits a bandgap of 2.51 eV, with the valence band maximum at -6.37 eV and the conduction band minimum at -3.86 eV, meeting the requirements for water splitting. Phosphorus doping lowers the Gibbs free energy by 1.63 eV, enhancing the catalytic activity. The ScSeI monolayer achieves a hydrogen production efficiency of 17%, surpassing the commercial threshold of 10% and shows excellent mechanical, thermal, and dynamic stability, indicating feasibility for experimental synthesis and practical application. Additionally, the monolayer maintains its photocatalytic properties under tensile strain (-6% to 6%) and in aqueous environments, reinforcing its potential as an effective photocatalyst. Based on these findings, we believe the ScSeI monolayer is a highly promising photocatalyst.

15.
Knee ; 51: 58-64, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39236638

RESUMO

BACKGROUND: An open wedge high tibial osteotomy (OWHTO) may lead to gait alteration, which change the contact loading in the contralateral knee, while clear evidence about the impact on contralateral knee still lacks. The purpose of the current study was to evaluate the change in scintigraphic uptake using SPECT-CT in the medial compartment of the contralateral knee following OWHTO. METHODS: Contralateral radiographic measurements were performed for patients with medial osteoarthritis and varus malalignment of >5° treated with OWHTO in this retrospective analysis. The medial compartmental changes according to SPECT/CT analysis before and 1-year after OWHTO were evaluated on the contralateral side. RESULTS: The study comprised 72 patients. The mean preoperative mechanical femorotibial angle was a mean varus of 7.6° (range, 5.1° - 13.0°), corrected to a mean valgus of 2.5° (range, 1.9° - -8.5°) postoperatively. The average grading of the scintigraphic uptakes in the medial compartment of the contralateral knee was significantly decreased 1 year postoperatively than after the surgery (from 2.8 ± 0.4 to 2.1 ± 0.6, p < 0.001). Measurable differences in varus alignment on radiographs of the contralateral limb were identified. The preoperative mechanical axis value decreased from 8.0° ± 2.4° to 6.7° ± 2.6° at the 3-month postoperative visit (p = 0.011). The overall decrease in varus alignment remained at the 2-year final postoperative follow-up. CONCLUSION: Alignment correction by OWHTO results in reducing scintigraphy uptakes in medial compartment and improvement in mechanical alignment of the contralateral knee. LEVEL OF EVIDENCE: Therapeutic Level IV.

16.
Clin Podiatr Med Surg ; 41(4): 665-684, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39237178

RESUMO

Weight-bearing computed tomography has multiple advantages in evaluating the hindfoot and ankle. It can assess hindfoot and ankle alignment, pathology in ankle arthritis, and complications related to total ankle replacements. It is an essential tool in ankle osteoarthritis diagnostic, preoperative planning, and total ankle replacement outcomes. It allows for better accuracy and reproducibility of alignment and implant size. In addition, it has the potential to more assertively detect complications related to weight bearing.


Assuntos
Articulação do Tornozelo , Artroplastia de Substituição do Tornozelo , Tomografia Computadorizada de Feixe Cônico , Osteoartrite , Suporte de Carga , Humanos , Artroplastia de Substituição do Tornozelo/efeitos adversos , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Osteoartrite/diagnóstico por imagem , Osteoartrite/cirurgia
17.
Orthop Rev (Pavia) ; 16: 122318, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39219731

RESUMO

Background: Kinematic alignment is an emerging approach for total knee arthroplasty, with the aim to restore patient's individual pre-arthritic joint kinematics. In this systematic review and meta-analysis, we compared the kinematic alignment with the conventional mechanical alignment for total knee arthroplasty. Methods: We searched PubMed, Web of Science, Cochrane Library, and Scopus on June 2, 2024. We screened the retrieved studies for eligibility. Then extracted the data from the included studies, and then pooled the data as mean difference (MD) or odds ratio (OR) with a 95% confidence interval using Review Manager Software (ver. 3.5). Results: There was no significant difference between KA and MA in the different reported scores: combined KSS score at 6 months (P = 0.23) and 1 years (P = 0.60), KSS Patient satisfaction (P = 0.33), KSS function score (P = 0.07), Oxford score at 6 months (P = 0.45) and 2 years (P = 0.41), KOOS score (P = 0.26). Moreover, there was statistically significant difference in range of motion for flexion and extension at 1 and 2 years, incision length, the length of hospital stay, or the duration of surgery. Conclusion: Although kinematic alignment showed slightly better clinical outcomes than mechanical alignment, the difference between the two techniques is not statistically significant.

18.
Adv Mater ; : e2410464, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39235583

RESUMO

The interfacial management in perovskite solar cells (PSCs), including mitigating the carrier transport barrier and suppressing non-radiative recombination, still remains a significant challenge for efficiency and stability enhancement. Herein, by screening a family of fluorine (F) terminated dual-site organic dipole molecules, the study aims to gain insight into the molecular dipole array toward tunable interfacial field. Both experimental and theoretical results reveal that these functional interfacial dipole molecules can effectively anchor on perovskite surface through Lewis acid-base interaction. In addition, the tailored side-chain with terminated F atoms allows for altering and constructing a well matched perovskite/Spiro-OMeTAD interfacial contact. As a result, the inserting dual-site organic dipole array effectively modulates the interface to deliver a gradient energy level alignment, facilitating carrier extraction and transport. The optimal dual-site dipole trifluoro-methanesulfonamide mediated N-i-P PSCs achieve the highest efficiency of 25.47%, together with enhanced operational stability under 1000 h of the simulated 1-sun illumination exposure. These findings are believed to provide insight into the design of dual-site molecular dipole with sufficient interfacial tunability for perovskite-based optoelectronic devices.

19.
Biomed Eng Lett ; 14(5): 1137-1146, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39220031

RESUMO

In medical clinical scenarios for reasons such as patient privacy, information protection and data migration, when domain adaptation is needed for real scenarios, the source-domain data is often inaccessible and only the pre-trained source model on the source-domain is available. Existing solutions for this type of problem tend to forget the rich task experience previously learned on the source domain after adapting, which means that the model simply overfits the target-domain data when adapting and does not learn robust features that facilitate real task decisions. We address this problem by exploring the particular application of source-free domain adaptation in medical image segmentation and propose a two-stage additive source-free adaptation framework. We generalize the domain-invariant features by constraining the core pathological structure and semantic consistency between different perspectives. And we reduce the segmentation generated by locating and filtering elements that may have errors through Monte-Carlo uncertainty estimation. We conduct comparison experiments with some other methods on a cross-device polyp segmentation and a cross-modal brain tumor segmentation dataset, the results in both the target and source domains verify that the proposed method can effectively solve the domain offset problem and the model retains its dominance on the source domain after learning new knowledge of the target domain.This work provides valuable exploration for achieving additive learning on the target and source domains in the absence of source data and offers new ideas and methods for adaptation research in the field of medical image segmentation.

20.
Med Image Anal ; 99: 103331, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39243598

RESUMO

Multi-modal Magnetic Resonance Imaging (MRI) offers complementary diagnostic information, but some modalities are limited by the long scanning time. To accelerate the whole acquisition process, MRI reconstruction of one modality from highly under-sampled k-space data with another fully-sampled reference modality is an efficient solution. However, the misalignment between modalities, which is common in clinic practice, can negatively affect reconstruction quality. Existing deep learning-based methods that account for inter-modality misalignment perform better, but still share two main common limitations: (1) The spatial alignment task is not adaptively integrated with the reconstruction process, resulting in insufficient complementarity between the two tasks; (2) the entire framework has weak interpretability. In this paper, we construct a novel Deep Unfolding Network with Spatial Alignment, termed DUN-SA, to appropriately embed the spatial alignment task into the reconstruction process. Concretely, we derive a novel joint alignment-reconstruction model with a specially designed aligned cross-modal prior term. By relaxing the model into cross-modal spatial alignment and multi-modal reconstruction tasks, we propose an effective algorithm to solve this model alternatively. Then, we unfold the iterative stages of the proposed algorithm and design corresponding network modules to build DUN-SA with interpretability. Through end-to-end training, we effectively compensate for spatial misalignment using only reconstruction loss, and utilize the progressively aligned reference modality to provide inter-modality prior to improve the reconstruction of the target modality. Comprehensive experiments on four real datasets demonstrate that our method exhibits superior reconstruction performance compared to state-of-the-art methods.

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