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1.
ArXiv ; 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38947933

ABSTRACT

Feature attribution, the ability to localize regions of the input data that are relevant for classification, is an important capability for ML models in scientific and biomedical domains. Current methods for feature attribution, which rely on "explaining" the predictions of end-to-end classifiers, suffer from imprecise feature localization and are inadequate for use with small sample sizes and high-dimensional datasets due to computational challenges. We introduce prospector heads, an efficient and interpretable alternative to explanation-based attribution methods that can be applied to any encoder and any data modality. Prospector heads generalize across modalities through experiments on sequences (text), images (pathology), and graphs (protein structures), outperforming baseline attribution methods by up to 26.3 points in mean localization AUPRC. We also demonstrate how prospector heads enable improved interpretation and discovery of class-specific patterns in input data. Through their high performance, flexibility, and generalizability, prospectors provide a framework for improving trust and transparency for ML models in complex domains.

2.
J Magn Reson Imaging ; 2024 May 04.
Article in English | MEDLINE | ID: mdl-38703134

ABSTRACT

BACKGROUND: Cartilage T2 can detect joints at risk of developing osteoarthritis. The quantitative double-echo steady state (qDESS) sequence is attractive for knee cartilage T2 mapping because of its acquisition time of under 5 minutes. Understanding the reproducibility errors associated with qDESS T2 is essential to profiling the technical performance of this biomarker. PURPOSE: To examine the combined acquisition and segmentation reproducibility of knee cartilage qDESS T2 using two different regional analysis schemes: 1) manual segmentation of subregions loaded during common activities and 2) automatic subregional segmentation. STUDY TYPE: Prospective. SUBJECTS: 11 uninjured participants (age: 28 ± 3 years; 8 (73%) female). FIELD STRENGTH/SEQUENCE: 3-T, qDESS. ASSESSMENT: Test-retest T2 maps were acquired twice on the same day and with a 1-week interval between scans. For each acquisition, average cartilage T2 was calculated in four manually segmented regions encompassing tibiofemoral contact areas during common activities and 12 automatically segmented regions from the deep-learning open-source framework for musculoskeletal MRI analysis (DOSMA) encompassing medial and lateral anterior, central, and posterior tibiofemoral regions. Test-retest T2 values from matching regions were used to evaluate reproducibility. STATISTICAL TESTS: Coefficients of variation (%CV), root-mean-square-average-CV (%RMSA-CV), and intraclass correlation coefficients (ICCs) assessed test-retest T2 reproducibility. The median of test-retest standard deviations was used for T2 precision. Bland-Altman (BA) analyses examined test-retest biases. The smallest detectable difference (SDD) was defined as the BA limit of agreement of largest magnitude. Significance was accepted for P < 0.05. RESULTS: All cartilage regions across both segmentation schemes demonstrated intraday and interday qDESS T2 CVs and RMSA-CVs of ≤5%. T2 ICC values >0.75 were observed in the majority of regions but were more variable in interday tibial comparisons. Test-retest T2 precision was <1.3 msec. The T2 SDD was 3.8 msec. DATA CONCLUSION: Excellent CV and RMSA-CV reproducibility may suggest that qDESS T2 increases or decreases >5% (3.8 msec) could represent changes to cartilage composition. TECHNICAL EFFICACY: Stage 2.

3.
Semin Ophthalmol ; : 1-7, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38629866

ABSTRACT

BACKGROUND: Bioadhesion is the ability of materials to adhere to biological surfaces. Bioadhesives are substances which induce or promote bioadhesion. The internal application of bioadhesives is gaining popularity in recent years and is being increasingly utilized in vitreoretinal surgeries. The aim of this review is to discuss the various bioadhesives and their applications in vitreoretinal surgeries. METHODS: PubMed, Google Scholar, ePub and Cochrane library database were used for literature selection. Keywords such as vitreoretinal surgery, bioadhesives, intraocular bioadhesives, glue, fibrin glue, cyanoacrylate glue and transforming growth factor were used individually and in differing combinations to perform a comprehensive systematic literature search. RESULTS: A total of 47 papers were retrieved and included in this review. Cyanoacrylate glue was the first bioadhesive to be utilized for vitreoretinal surgery in human eyes in 1976. The most common indications for the use of bioadhesives were in optic disc pit maculopathy, macular holes and rhegmatogenous retinal detachments. CONCLUSION: The use of intraocular bioadhesives in vitreoretinal surgery represents a significant and evolving area of interest within ophthalmic research. While the pioneering use of cyanoacrylate glue, fibrin glue and transforming growth factor beta demonstrated the possible use of intraocular adhesives, fibrin glue is the most widely used intraocular bioadhesive in vitreoretinal surgery.

4.
J Cataract Refract Surg ; 50(2): 128-133, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38259132

ABSTRACT

PURPOSE: To describe long-term visual and anatomical outcomes of sutured scleral-fixated intraocular lens (SF IOL) implantation. SETTING: Tertiary eyecare hospital in India. DESIGN: Retrospective interventional noncomparative study. METHODS: Postoperative change in corrected distance visual acuity (CDVA) and occurrence of complications were assessed from the patient medical records. Long-term SF IOL survival rates and factors affecting the occurrence of postoperative IOL-related complications were assessed. Patients with postoperative follow-up less than 10 years or incomplete medical records were excluded. RESULTS: 64 eyes of 53 patients were included. Follow-up duration was 11.4 ± 1.2 years. Mean preoperative CDVA was 0.71 ± 0.43 logMAR (Snellen equivalent: 6/30), and mean CDVA at the final visit was 0.52 ± 0.49 logMAR (Snellen equivalent: 6/18) (P < .01). 48% cases had CDVA of 6/12 or better at the last follow-up. 58% cases had coexistent ocular pathology affecting the final visual outcome. IOL and suture-related complications were the commonest and included IOL decentration (17% cases), IOL drop (14%), and suture exposure (6%). The probability of IOL survival (postoperative period without IOL-related complications) was 90.6% at 8 years and 81.2% at 10 years (Kaplan-Meier analysis). Occurrence of postoperative IOL-related complications was unaffected by patient sex, age, indication for surgery (trauma or other), previous intraocular surgery, or technique of scleral fixation (2-point or 4-point) (multivariate regression analysis). CONCLUSIONS: Although sutured SF IOL implantation is viable with favorable long-term visual outcomes, there is a risk of postoperative IOL-related complications. Occurrence of postoperative IOL-related complications is unaffected by patient and ocular factors.


Subject(s)
Lens Implantation, Intraocular , Polypropylenes , Humans , Retrospective Studies , Sclera/surgery , Postoperative Complications
5.
BMJ Case Rep ; 16(12)2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38129084

ABSTRACT

We describe the clinical course and serial evolution of bacillary layer detachment (BALAD) on optical coherence tomography (OCT) in toxoplasmosis retinochoroiditis and its importance as an inflammatory biomarker. Colour fundus photography and swept-source OCT of the BALAD were done at the time of presentation and subsequently at 1 week, 2 weeks, 4 weeks and at 11 weeks. Treatment involved oral trimethoprim (160 mg) + sulphamethoxazole (800 mg) two times per day, started at presentation for 2 months. Oral prednisolone was started after 1 week at a dose of 50 mg a day and tapered weekly over the next 5 weeks. The BALAD initially increased after starting treatment with trimethoprim-sulphamethoxazole and regressed within 1 week after initiation of oral prednisolone. Best corrected visual acuity improved to 20/40 from 20/160 at presentation (Snellen equivalent). This suggests that BALAD is an indicator of an acute inflammatory event and the accumulated fluid is secondary to retinal and choroidal inflammation.


Subject(s)
Bacillus , Retinal Detachment , Toxoplasmosis, Ocular , Humans , Tomography, Optical Coherence/methods , Retina , Toxoplasmosis, Ocular/diagnostic imaging , Toxoplasmosis, Ocular/drug therapy , Firmicutes , Prednisolone/therapeutic use
6.
Sci Rep ; 13(1): 21034, 2023 11 29.
Article in English | MEDLINE | ID: mdl-38030716

ABSTRACT

Current risk scores using clinical risk factors for predicting ischemic heart disease (IHD) events-the leading cause of global mortality-have known limitations and may be improved by imaging biomarkers. While body composition (BC) imaging biomarkers derived from abdominopelvic computed tomography (CT) correlate with IHD risk, they are impractical to measure manually. Here, in a retrospective cohort of 8139 contrast-enhanced abdominopelvic CT examinations undergoing up to 5 years of follow-up, we developed multimodal opportunistic risk assessment models for IHD by automatically extracting BC features from abdominal CT images and integrating these with features from each patient's electronic medical record (EMR). Our predictive methods match and, in some cases, outperform clinical risk scores currently used in IHD risk assessment. We provide clinical interpretability of our model using a new method of determining tissue-level contributions from CT along with weightings of EMR features contributing to IHD risk. We conclude that such a multimodal approach, which automatically integrates BC biomarkers and EMR data, can enhance IHD risk assessment and aid primary prevention efforts for IHD. To further promote research, we release the Opportunistic L3 Ischemic heart disease (OL3I) dataset, the first public multimodal dataset for opportunistic CT prediction of IHD.


Subject(s)
Artificial Intelligence , Myocardial Ischemia , Humans , Retrospective Studies , Myocardial Ischemia/diagnostic imaging , Myocardial Ischemia/etiology , Tomography, X-Ray Computed/adverse effects , Risk Factors , Risk Assessment , Biomarkers , Medical Records
7.
Magn Reson Med ; 90(5): 2052-2070, 2023 11.
Article in English | MEDLINE | ID: mdl-37427449

ABSTRACT

PURPOSE: To develop a method for building MRI reconstruction neural networks robust to changes in signal-to-noise ratio (SNR) and trainable with a limited number of fully sampled scans. METHODS: We propose Noise2Recon, a consistency training method for SNR-robust accelerated MRI reconstruction that can use both fully sampled (labeled) and undersampled (unlabeled) scans. Noise2Recon uses unlabeled data by enforcing consistency between model reconstructions of undersampled scans and their noise-augmented counterparts. Noise2Recon was compared to compressed sensing and both supervised and self-supervised deep learning baselines. Experiments were conducted using retrospectively accelerated data from the mridata three-dimensional fast-spin-echo knee and two-dimensional fastMRI brain datasets. All methods were evaluated in label-limited settings and among out-of-distribution (OOD) shifts, including changes in SNR, acceleration factors, and datasets. An extensive ablation study was conducted to characterize the sensitivity of Noise2Recon to hyperparameter choices. RESULTS: In label-limited settings, Noise2Recon achieved better structural similarity, peak signal-to-noise ratio, and normalized-RMS error than all baselines and matched performance of supervised models, which were trained with 14 × $$ 14\times $$ more fully sampled scans. Noise2Recon outperformed all baselines, including state-of-the-art fine-tuning and augmentation techniques, among low-SNR scans and when generalizing to OOD acceleration factors. Augmentation extent and loss weighting hyperparameters had negligible impact on Noise2Recon compared to supervised methods, which may indicate increased training stability. CONCLUSION: Noise2Recon is a label-efficient reconstruction method that is robust to distribution shifts, such as changes in SNR, acceleration factors, and others, with limited or no fully sampled training data.


Subject(s)
Deep Learning , Image Processing, Computer-Assisted , Humans , Image Processing, Computer-Assisted/methods , Signal-To-Noise Ratio , Retrospective Studies , Magnetic Resonance Imaging/methods , Supervised Machine Learning
8.
MAGMA ; 36(5): 711-724, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37142852

ABSTRACT

PURPOSE: [Formula: see text] mapping is a powerful tool for studying osteoarthritis (OA) changes and bilateral imaging may be useful in investigating the role of between-knee asymmetry in OA onset and progression. The quantitative double-echo in steady-state (qDESS) can provide fast simultaneous bilateral knee [Formula: see text] and high-resolution morphometry for cartilage and meniscus. The qDESS uses an analytical signal model to compute [Formula: see text] relaxometry maps, which require knowledge of the flip angle (FA). In the presence of [Formula: see text] inhomogeneities, inconsistencies between the nominal and actual FA can affect the accuracy of [Formula: see text] measurements. We propose a pixel-wise [Formula: see text] correction method for qDESS [Formula: see text] mapping exploiting an auxiliary [Formula: see text] map to compute the actual FA used in the model. METHODS: The technique was validated in a phantom and in vivo with simultaneous bilateral knee imaging. [Formula: see text] measurements of femoral cartilage (FC) of both knees of six healthy participants were repeated longitudinally to investigate the association between [Formula: see text] variation and [Formula: see text]. RESULTS: The results showed that applying the [Formula: see text] correction mitigated [Formula: see text] variations that were driven by [Formula: see text] inhomogeneities. Specifically, [Formula: see text] left-right symmetry increased following the [Formula: see text] correction ([Formula: see text] = 0.74 > [Formula: see text] = 0.69). Without the [Formula: see text] correction, [Formula: see text] values showed a linear dependence with [Formula: see text]. The linear coefficient decreased using the [Formula: see text] correction (from 24.3 ± 1.6 ms to 4.1 ± 1.8) and the correlation was not statistically significant after the application of the Bonferroni correction (p value > 0.01). CONCLUSION: The study showed that [Formula: see text] correction could mitigate variations driven by the sensitivity of the qDESS [Formula: see text] mapping method to [Formula: see text], therefore, increasing the sensitivity to detect real biological changes. The proposed method may improve the robustness of bilateral qDESS [Formula: see text] mapping, allowing for an accurate and more efficient evaluation of OA pathways and pathophysiology through longitudinal and cross-sectional studies.


Subject(s)
Knee Joint , Magnetic Resonance Imaging , Humans , Cross-Sectional Studies , Magnetic Resonance Imaging/methods , Knee Joint/diagnostic imaging , Imaging, Three-Dimensional , Phantoms, Imaging
9.
Bioengineering (Basel) ; 10(2)2023 Feb 04.
Article in English | MEDLINE | ID: mdl-36829701

ABSTRACT

We systematically evaluate the training methodology and efficacy of two inpainting-based pretext tasks of context prediction and context restoration for medical image segmentation using self-supervised learning (SSL). Multiple versions of self-supervised U-Net models were trained to segment MRI and CT datasets, each using a different combination of design choices and pretext tasks to determine the effect of these design choices on segmentation performance. The optimal design choices were used to train SSL models that were then compared with baseline supervised models for computing clinically-relevant metrics in label-limited scenarios. We observed that SSL pretraining with context restoration using 32 × 32 patches and Poission-disc sampling, transferring only the pretrained encoder weights, and fine-tuning immediately with an initial learning rate of 1 × 10-3 provided the most benefit over supervised learning for MRI and CT tissue segmentation accuracy (p < 0.001). For both datasets and most label-limited scenarios, scaling the size of unlabeled pretraining data resulted in improved segmentation performance. SSL models pretrained with this amount of data outperformed baseline supervised models in the computation of clinically-relevant metrics, especially when the performance of supervised learning was low. Our results demonstrate that SSL pretraining using inpainting-based pretext tasks can help increase the robustness of models in label-limited scenarios and reduce worst-case errors that occur with supervised learning.

10.
J Magn Reson Imaging ; 57(4): 1029-1039, 2023 04.
Article in English | MEDLINE | ID: mdl-35852498

ABSTRACT

BACKGROUND: Deep learning (DL)-based automatic segmentation models can expedite manual segmentation yet require resource-intensive fine-tuning before deployment on new datasets. The generalizability of DL methods to new datasets without fine-tuning is not well characterized. PURPOSE: Evaluate the generalizability of DL-based models by deploying pretrained models on independent datasets varying by MR scanner, acquisition parameters, and subject population. STUDY TYPE: Retrospective based on prospectively acquired data. POPULATION: Overall test dataset: 59 subjects (26 females); Study 1: 5 healthy subjects (zero females), Study 2: 8 healthy subjects (eight females), Study 3: 10 subjects with osteoarthritis (eight females), Study 4: 36 subjects with various knee pathology (10 females). FIELD STRENGTH/SEQUENCE: A 3-T, quantitative double-echo steady state (qDESS). ASSESSMENT: Four annotators manually segmented knee cartilage. Each reader segmented one of four qDESS datasets in the test dataset. Two DL models, one trained on qDESS data and another on Osteoarthritis Initiative (OAI)-DESS data, were assessed. Manual and automatic segmentations were compared by quantifying variations in segmentation accuracy, volume, and T2 relaxation times for superficial and deep cartilage. STATISTICAL TESTS: Dice similarity coefficient (DSC) for segmentation accuracy. Lin's concordance correlation coefficient (CCC), Wilcoxon rank-sum tests, root-mean-squared error-coefficient-of-variation to quantify manual vs. automatic T2 and volume variations. Bland-Altman plots for manual vs. automatic T2 agreement. A P value < 0.05 was considered statistically significant. RESULTS: DSCs for the qDESS-trained model, 0.79-0.93, were higher than those for the OAI-DESS-trained model, 0.59-0.79. T2 and volume CCCs for the qDESS-trained model, 0.75-0.98 and 0.47-0.95, were higher than respective CCCs for the OAI-DESS-trained model, 0.35-0.90 and 0.13-0.84. Bland-Altman 95% limits of agreement for superficial and deep cartilage T2 were lower for the qDESS-trained model, ±2.4 msec and ±4.0 msec, than the OAI-DESS-trained model, ±4.4 msec and ±5.2 msec. DATA CONCLUSION: The qDESS-trained model may generalize well to independent qDESS datasets regardless of MR scanner, acquisition parameters, and subject population. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.


Subject(s)
Cartilage, Articular , Deep Learning , Osteoarthritis, Knee , Female , Humans , Retrospective Studies , Cartilage, Articular/pathology , Magnetic Resonance Imaging/methods , Algorithms , Osteoarthritis, Knee/pathology
11.
Eur J Ophthalmol ; 33(3): 1467-1472, 2023 May.
Article in English | MEDLINE | ID: mdl-36524252

ABSTRACT

PURPOSE: To describe the outcomes of fovea-sparing internal limiting membrane peeling for idiopathic macular holes. METHOD: This was a prospective, interventional case series in patients with idiopathic macular holes. Patients underwent fovea-sparing internal limiting membrane (ILM) peeling with the help of a finesse loop. The primary outcome measure was successful anatomical closure. Secondary outcome measures were postoperative improvement in best corrected visual acuity (BCVA) or any surgical complications. RESULTS: The study included 22 eyes of 22 patients (median age of 61 (IQR 58 to 66) years). The median basal diameter of the holes was 1054 (IQR 961.5 to 1278) microns, while the median minimal linear diameter was 697 (IQR 461.5 to 786) microns. Successful anatomic closure was achieved in nine cases out of 22 (40.9%). BCVA improved from 20/125 preoperatively to 20/80 at the end of the follow-up. There was no difference in baseline parameters between eyes with closure, versus eyes with an open hole. One eye had an iatrogenic break in an attempt to reinitiate peeling and create a fovea-sparing flap. One of the eyes had an ERM formation at end of 3 months. CONCLUSION: Our outcomes of fovea-sparing ILM peeling in idiopathic macular holes were unfavourable. The residual ILM could be causing tangential traction resulting in non-closure.


Subject(s)
Epiretinal Membrane , Retinal Perforations , Humans , Middle Aged , Aged , Retinal Perforations/diagnosis , Retinal Perforations/surgery , Vitrectomy/methods , Prospective Studies , Treatment Outcome , Basement Membrane/surgery , Retrospective Studies , Epiretinal Membrane/surgery , Tomography, Optical Coherence
12.
Indian J Ophthalmol ; 70(12): 4349-4356, 2022 12.
Article in English | MEDLINE | ID: mdl-36453343

ABSTRACT

Purpose: To describe the clinical features and treatment outcomes in spontaneous uveal effusion syndrome (UES). Methods: A 10-year retrospective chart review of UES patients from a tertiary eye center was carried out. Optical coherence tomography (OCT), fundus fluorescein angiography, and ultrasound biomicroscopy (UBM) scans were performed. UES was managed based on presenting best-corrected visual acuity (BCVA), symptoms, and fundus findings. Patients with secondary causes of uveal effusion were excluded. Results: Twenty-five eyes of 16 patients were included. Of the 16 patients, 14 (88%) were male and 9 (56%) had bilateral disease. Fifteen of 25 affected eyes had nanophthalmos (axial length (AL) <20.5 mm) and 6 had hyperopia with AL >20.5 mm. The presenting mean distance BCVA was 0.74 ± 0.64 logMAR (mean Snellen: 20/100). Eleven eyes had exudative retinal detachment, and 4 also had exudative choroidal detachment (CD). Choroidal thickness (CT) was increased in 11 eyes on B-scan ultrasonography, and the mean CT was 1.74 ± 0.38 mm. Sub-retinal fluid (SRF) and retinal folds were the most common OCT findings. UBM findings included shallow angles, peripheral CD, and supra-ciliary effusion. A combination of local and systemic corticosteroids was used to successfully treat 12 eyes, 6 needed surgery, and 7 were observed. Partial sclerectomy with anterior chamber maintainer-assisted SRF drainage was the favored surgery. The median period of follow-up was 6.5 months (0.1-76 months), and the mean distance BCVA at the last follow-up was 0.58 ± 0.42 logMAR (mean Snellen: 20/80). Conclusion: UES can be suitably managed both medically and surgically based on clinical presentation.


Subject(s)
Uveal Effusion Syndrome , Humans , Male , Female , Retrospective Studies , Treatment Outcome , Choroid , Fluorescein Angiography
13.
Curr Eye Res ; 47(8): 1200-1208, 2022 08.
Article in English | MEDLINE | ID: mdl-35502999

ABSTRACT

PURPOSE: To highlight the magnitude of ocular higher order aberrations (HOA) and lower order aberrations (LOA), including component contributions from corneal and internal planes in Primary Congenital Glaucoma (PCG) patients. METHODS: Consecutive treated PCG patients co-operative for ocular examination and aberrometry, were enrolled over two years for this cross-sectional, comparative, single-center, unmasked study. Best-corrected visual acuity, refraction, IOP, wavefront aberrometry and topography (iTrace) were performed and results were compared with unaffected fellow eyes of unilateral glaucoma patients as well as age and sex-matched controls with no ocular anomalies other than treatable refractive error. RESULTS: Both eyes of 32 consecutive PCG patients (17 unilateral, 15 bilateral) and 39 controls were enrolled. The median LogMAR corrected distance visual acuity of PCG eyes was 0.68 (IQR: 0.2-1.8). Total ocular (Root mean square (RMS) 1.7 µm vs 0.3 µm, p = 0.014), corneal (RMS 1.1 µm vs 0.3 µm, p = 0.004) and internal (RMS 1.1 µm vs 0.2 µm, p = 0.013) aberrations, as well as HOAs and LOAs at each plane, were significantly higher in PCG eyes than in controls. Component HOAs from corneal and internal planes were positively correlated with each other (p < 0.001; rs: 0.7). Total aberrations were greater in the affected eyes of PCG compared to the rest. The predominant subtype of HOAs in PCG was coma and trefoil. PCG with corneal opacity/Haab's striae had significantly higher astigmatism than the affected eyes with clear corneae at the corneal plane (p = 0.02). The aberrations were not statistically associated with the corneal diameter or refractive error in PCG eyes. CONCLUSIONS: Significantly greater aberrations (Total, HOAs and LOAs, at corneal as well as an internal plane) were seen among eyes affected with PCG. Though the exact impact of these aberrations on the final visual outcome is difficult to determine, these could play a pertinent role in compromising visual function, thus impacting the management of visual rehabilitation in these patients.


Subject(s)
Corneal Wavefront Aberration , Glaucoma , Aberrometry , Corneal Topography , Corneal Wavefront Aberration/diagnosis , Cross-Sectional Studies , Glaucoma/diagnosis , Humans , Refraction, Ocular
15.
Radiol Artif Intell ; 3(3): e200078, 2021 May.
Article in English | MEDLINE | ID: mdl-34235438

ABSTRACT

PURPOSE: To organize a multi-institute knee MRI segmentation challenge for characterizing the semantic and clinical efficacy of automatic segmentation methods relevant for monitoring osteoarthritis progression. MATERIALS AND METHODS: A dataset partition consisting of three-dimensional knee MRI from 88 retrospective patients at two time points (baseline and 1-year follow-up) with ground truth articular (femoral, tibial, and patellar) cartilage and meniscus segmentations was standardized. Challenge submissions and a majority-vote ensemble were evaluated against ground truth segmentations using Dice score, average symmetric surface distance, volumetric overlap error, and coefficient of variation on a holdout test set. Similarities in automated segmentations were measured using pairwise Dice coefficient correlations. Articular cartilage thickness was computed longitudinally and with scans. Correlation between thickness error and segmentation metrics was measured using the Pearson correlation coefficient. Two empirical upper bounds for ensemble performance were computed using combinations of model outputs that consolidated true positives and true negatives. RESULTS: Six teams (T 1-T 6) submitted entries for the challenge. No differences were observed across any segmentation metrics for any tissues (P = .99) among the four top-performing networks (T 2, T 3, T 4, T 6). Dice coefficient correlations between network pairs were high (> 0.85). Per-scan thickness errors were negligible among networks T 1-T 4 (P = .99), and longitudinal changes showed minimal bias (< 0.03 mm). Low correlations (ρ < 0.41) were observed between segmentation metrics and thickness error. The majority-vote ensemble was comparable to top-performing networks (P = .99). Empirical upper-bound performances were similar for both combinations (P = .99). CONCLUSION: Diverse networks learned to segment the knee similarly, where high segmentation accuracy did not correlate with cartilage thickness accuracy and voting ensembles did not exceed individual network performance.See also the commentary by Elhalawani and Mak in this issue.Keywords: Cartilage, Knee, MR-Imaging, Segmentation © RSNA, 2020Supplemental material is available for this article.

16.
J Magn Reson Imaging ; 54(3): 840-851, 2021 09.
Article in English | MEDLINE | ID: mdl-33763929

ABSTRACT

BACKGROUND: Injuries to the articular cartilage in the knee are common in jumping athletes, particularly high-level basketball players. Unfortunately, these are often diagnosed at a late stage of the disease process, after tissue loss has already occurred. PURPOSE/HYPOTHESIS: To evaluate longitudinal changes in knee articular cartilage and knee function in National Collegiate Athletic Association (NCAA) basketball players and their evolution over the competitive season and off-season. STUDY TYPE: Longitudinal, multisite cohort study. POPULATION: Thirty-two NCAA Division 1 athletes: 22 basketball players and 10 swimmers. FIELD STRENGTH/SEQUENCE: Bilateral magnetic resonance imaging (MRI) using a combined T1ρ and T2 magnetization-prepared angle-modulated portioned k-space spoiled gradient-echo snapshots (MAPSS) sequence at 3T. ASSESSMENT: We calculated T2 and T1ρ relaxation times to compare compositional cartilage changes between three timepoints: preseason 1, postseason 1, and preseason 2. Knee Osteoarthritis Outcome Scores (KOOS) were used to assess knee health. STATISTICAL TESTS: One-way variance model hypothesis test, general linear model, and chi-squared test. RESULTS: In the femoral articular cartilage of all athletes, we saw a global decrease in T2 and T1ρ relaxation times during the competitive season (all P < 0.05) and an increase in T2 and T1ρ relaxation times during the off-season (all P < 0.05). In the basketball players' femoral cartilage, the anterior and central compartments respectively had the highest T2 and T1ρ relaxation times following the competitive season and off-season. The basketball players had significantly lower KOOS measures in every domain compared with the swimmers: Pain (P < 0.05), Symptoms (P < 0.05), Function in Daily Living (P < 0.05), Function in Sport/Recreation (P < 0.05), and Quality of Life (P < 0.05). CONCLUSION: Our results indicate that T2 and T1ρ MRI can detect significant seasonal changes in the articular cartilage of basketball players and that there are regional differences in the articular cartilage that are indicative of basketball-specific stress on the femoral cartilage. This study demonstrates the potential of quantitative MRI to monitor global and regional cartilage health in athletes at risk of developing cartilage problems. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 2.


Subject(s)
Basketball , Cartilage, Articular , Osteoarthritis, Knee , Cartilage, Articular/diagnostic imaging , Cohort Studies , Humans , Knee Joint/diagnostic imaging , Magnetic Resonance Imaging , Quality of Life , Seasons
17.
Trop Doct ; 51(2): 235-237, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32777991

ABSTRACT

Orbital trauma is often associated with foreign bodies. Wooden foreign bodies pose an urgent need for removal owing to their reactive nature and the high risk for infection. Though visual prognosis depends on associated ocular trauma, in selected cases, excellent visual and cosmetic outcomes are possible. An 18-year-old woman presented to our trauma facility with a history of fall directly onto a wooden stick from a height. On examination, there was a large wooden foreign body in the left medial orbit, extending into the ethmoidal sinus as visualised on imaging. After administration of perioperative antibiotics, the foreign body was removed in toto using careful tissue dissection and the soft tissue was closed in layers. Postoperatively at six months, the vision in the left eye was 20/20 with mild ptosis. Early surgery, careful dissection of soft tissues and adequate infection prophylaxis can lead to good outcomes in such cases.


Subject(s)
Eye Foreign Bodies/etiology , Orbit/injuries , Wood/adverse effects , Adolescent , Ethmoid Sinus/diagnostic imaging , Ethmoid Sinus/injuries , Ethmoid Sinus/surgery , Eye Foreign Bodies/diagnosis , Eye Foreign Bodies/surgery , Female , Humans , Orbit/diagnostic imaging , Orbit/surgery , Treatment Outcome
18.
Eur J Ophthalmol ; 31(6): 3223-3230, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33238760

ABSTRACT

OBJECTIVE: To investigate the systemic associations of central serous chorioretinopathy (CSCR) with help of clinical and biochemical investigations. DESIGN: Case-control study. PARTICIPANTS: Eighty seven CSCR patients (case) and 82 Asian-Indian patients with primary non-traumatic rhegmatogenous retinal detachment (control) were recruited between July 2017 and December 2018 at a tertiary eye-care center in North India. METHODS: The patients underwent ophthalmological examination and systemic evaluation based on history and biochemical investigations. Logistic regression was performed to identify the associations of CSCR. RESULTS: The age was similar between cases and controls (36.9 ± 7.8 years vs 35.7 ± 10.8 years, p = 0.38). On univariate analysis, the significant factors with higher odds of CSCR were alcohol use (odds ratio, OR: 3.4; 95% confidence interval: 1.36-8.53), sleep disturbance (OR: 5.44; 1.76-16.8), gastroesophageal reflux (OR: 9.34; 1.15-75.50), psychological disorder (OR: 5.78; 1.24-26.97), tuberculosis history (OR: 8.2; 1.0-67.10), serum albumin: globulin ratio (AGR) > 2 (OR: 10.43; 2.33-46.57), and serum hemoglobin (per unit increase; OR: 1.35; 1.14-1.61). Although the mean blood pressure was significantly higher in cases, the distribution among various hypertension categories was not significantly different. Exogenous steroid use and morning 8 am serum cortisol levels were not significantly different between the groups. On multivariable analysis, alcohol use (OR: 4.72; 1.33-16.76), sleep disturbances (OR: 5.04; 1.36-18.70), dysthyroid state (OR: 3.02; 1.04-8.74), serum AGR > 2 (OR: 14.28; 2.33-87.28), and serum hemoglobin (per unit increase; OR: 1.43; 1.13-1.81) were significant independent associations. CONCLUSION: Other than the previously described associations of CSCR like alcohol use and sleep disturbances, this study reports possible association with deranged serum protein and thyroid hormone profile. Further large-scale prospective studies need to validate these results.


Subject(s)
Central Serous Chorioretinopathy , Retinal Detachment , Adult , Case-Control Studies , Central Serous Chorioretinopathy/diagnosis , Humans , Prospective Studies , Risk Factors
19.
Indian J Ophthalmol ; 68(9): 1990-1993, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32823453

ABSTRACT

A 30-year-old female patient presented with bilateral anterior nodular sclerokeratitis and multiple erythematous skin lesions involving the face, trunk, arms, and legs. The patient had a history of temporary relief with steroids, however the lesions recurred. A dermatology consultation was sought and the patient was diagnosed to have syphilis, consequent to which she was started on benzathine penicillin and showed a dramatic improvement in both skin and ocular lesions. A high index of suspicion for syphilis should be kept in mind for patients presenting with nodular scleritis to initiate timely and appropriate management with penicillin.


Subject(s)
Keratitis , Scleritis , Syphilis , Adult , Female , Humans , Keratitis/diagnosis , Keratitis/drug therapy , Keratitis/etiology , Neoplasm Recurrence, Local , Scleritis/diagnosis , Scleritis/drug therapy , Scleritis/etiology , Skin , Syphilis/complications , Syphilis/diagnosis , Syphilis/drug therapy
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