214 research outputs found
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MR-guided focused ultrasound (MRgFUS) is effective for the distinct pattern of uterine fibroids seen in African-American women: data from phase III/IV, non-randomized, multicenter clinical trials
Background: Uterine fibroids are common among women at the reproductive age. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a novel and a conservative treatment for symptomatic cases. The aim of the study was to evaluate the efficacy of MRgFUS in African-American (AA) women compared with that in non-African-Americans (non-AA). Methods: A single-armed phase IV study was conducted to establish the efficacy of treatment in AA women. Comparison of patient, fibroid, and treatment characteristics from this trial was compared with that of the previously published phase III trial. Both studies were approved by the IRB of each medical center. Results: Sixty-three AA and 59 non-AA women were treated with MRgFUS. Although AA women had a different pattern of disease, outcomes were similar in both groups. AA patients had a significant higher total number of fibroids compared with non-AA (median 6.0, interquartile range (IQR) 3.0–10.0 vs. 2.0, IQR 1.0–4.0, respectively, p < 0.001), although their total fibroid volume was significantly smaller (median 196.9 cm3, IQR 112.8–415.3 cm3 vs. 394.8 cm3, IQR 189.8–674.4 cm3, respectively, p < 0.001). AA women were younger compared with non-AA (mean ± SD 43.4 ± 5.1 vs. 46.3 ± 4.1 years of age, respectively, p = 0.001) when they presented for treatment. The rate of alternative treatments as well as fibroid-associated symptoms at follow-up time points (3, 6, 12, 24, and 36 months, period following MRgFUS treatment) did not differ according to race (p ≥ 0.62). Conclusion: Despite differences in the pattern of fibroid disease, MRgFUS for uterine fibroids has a similar efficacy for AA women compared with non-AA women
Transfer Learning for Domain Adaptation in MRI: Application in Brain Lesion Segmentation
Magnetic Resonance Imaging (MRI) is widely used in routine clinical diagnosis
and treatment. However, variations in MRI acquisition protocols result in
different appearances of normal and diseased tissue in the images.
Convolutional neural networks (CNNs), which have shown to be successful in many
medical image analysis tasks, are typically sensitive to the variations in
imaging protocols. Therefore, in many cases, networks trained on data acquired
with one MRI protocol, do not perform satisfactorily on data acquired with
different protocols. This limits the use of models trained with large annotated
legacy datasets on a new dataset with a different domain which is often a
recurring situation in clinical settings. In this study, we aim to answer the
following central questions regarding domain adaptation in medical image
analysis: Given a fitted legacy model, 1) How much data from the new domain is
required for a decent adaptation of the original network?; and, 2) What portion
of the pre-trained model parameters should be retrained given a certain number
of the new domain training samples? To address these questions, we conducted
extensive experiments in white matter hyperintensity segmentation task. We
trained a CNN on legacy MR images of brain and evaluated the performance of the
domain-adapted network on the same task with images from a different domain. We
then compared the performance of the model to the surrogate scenarios where
either the same trained network is used or a new network is trained from
scratch on the new dataset.The domain-adapted network tuned only by two
training examples achieved a Dice score of 0.63 substantially outperforming a
similar network trained on the same set of examples from scratch.Comment: 8 pages, 3 figure
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Potential of minimally invasive procedures in the treatment of uterine fibroids: a focus on magnetic resonance-guided focused ultrasound therapy
Minimally invasive treatment options are an important part of the uterine fibroid-treatment arsenal, especially among younger patients and in those who plan future pregnancies. This article provides an overview of the currently available minimally invasive therapy options, with a special emphasis on a completely noninvasive option: magnetic resonance-guided focused ultrasound (MRgFUS). In this review, we describe the background of MRgFUS, the patient-selection criteria for MRgFUS, and how the procedure is performed. We summarize the published clinical trial results, and review the literature on pregnancy post-MRgFUS and on the cost-effectiveness of MRgFUS
Epistatic interactions between mutations of TACI (TNFRSF13B) and TCF3 result in a severe primary immunodeficiency disorder and systemic lupus erythematosus
Common variable immunodeficiency disorders (CVID) are a group of primary immunodeficiencies where monogenetic causes account for only a fraction of cases. On this evidence, CVID is potentially polygenic and epistatic although there are, as yet, no examples to support this hypothesis. We have identified a non-consanguineous family, who carry the C104R (c.310T>C) mutation of the Transmembrane Activator Calcium-modulator and cyclophilin ligand Interactor (TACI, TNFRSF13B) gene. Variants in TNFRSF13B/TACI are identified in up to 10% of CVID patients, and are associated with, but not solely causative of CVID. The proband is heterozygous for the TNFRSF13B/TACI C104R mutation and meets the Ameratunga et al. diagnostic criteria for CVID and the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). Her son has type 1 diabetes, arthritis, reduced IgG levels and IgA deficiency, but has not inherited the TNFRSF13B/TACI mutation. Her brother, homozygous for the TNFRSF13B/TACI mutation, is in good health despite profound hypogammaglobulinemia and mild cytopenias. We hypothesised that a second unidentified mutation contributed to the symptomatic phenotype of the proband and her son. Whole-exome sequencing of the family revealed a de novo nonsense mutation (T168fsX191) in the Transcription Factor 3 (TCF3) gene encoding the E2A transcription factors, present only in the proband and her son. We demonstrate mutations of TNFRSF13B/TACI impair immunoglobulin isotype switching and antibody production predominantly via T-cell-independent signalling, while mutations of TCF3 impair both T-cell-dependent and -independent pathways of B-cell activation and differentiation. We conclude that epistatic interactions between mutations of the TNFRSF13B/TACI and TCF3 signalling networks lead to the severe CVID-like disorder and SLE in the proband.We thank AMRF, A+ Trust, IDFNZ,
ASCIA and the Australian National Health and Medical Research Council
(NHMRC, Program Grant 1054925, Project Grant 1127198 and Independent
Research Institutes Infrastructure Support Scheme Grant 361646) for grant
support. We also received support from Bloody Long Way (BLW) the Victorian
State Government Operational Infrastructure scheme and Walter and Eliza Hall
Institute (WEHI) Innovation Grant. CAS is supported by NHMRC
postgraduate scholarship 1075666
Artificial intelligence in cancer imaging: Clinical challenges and applications
Judgement, as one of the core tenets of medicine, relies upon the integration of multilayered data with nuanced decision making. Cancer offers a unique context for medical decisions given not only its variegated forms with evolution of disease but also the need to take into account the individual condition of patients, their ability to receive treatment, and their responses to treatment. Challenges remain in the accurate detection, characterization, and monitoring of cancers despite improved technologies. Radiographic assessment of disease most commonly relies upon visual evaluations, the interpretations of which may be augmented by advanced computational analyses. In particular, artificial intelligence (AI) promises to make great strides in the qualitative interpretation of cancer imaging by expert clinicians, including volumetric delineation of tumors over time, extrapolation of the tumor genotype and biological course from its radiographic phenotype, prediction of clinical outcome, and assessment of the impact of disease and treatment on adjacent organs. AI may automate processes in the initial interpretation of images and shift the clinical workflow of radiographic detection, management decisions on whether or not to administer an intervention, and subsequent observation to a yet to be envisioned paradigm. Here, the authors review the current state of AI as applied to medical imaging of cancer and describe advances in 4 tumor types (lung, brain, breast, and prostate) to illustrate how common clinical problems are being addressed. Although most studies evaluating AI applications in oncology to date have not been vigorously validated for reproducibility and generalizability, the results do highlight increasingly concerted efforts in pushing AI technology to clinical use and to impact future directions in cancer care
Treatment of esophageal tumors using high intensity intraluminal ultrasound: first clinical results
<p>Abstract</p> <p>Background</p> <p>Esophageal tumors generally bear a poor prognosis. Radical surgery is generally the only curative method available but is not feasible in the majority of patients; palliative therapy with stent placement is generally performed. It has been demonstrated that High Intensity Ultrasound can induce rapid, complete and well-defined coagulation necrosis. Thus, for the treatment of esophageal tumors, we have designed an ultrasound applicator that uses an intraluminal approach to fill up this therapeutic gap.</p> <p>Methods</p> <p>Thermal ablation is performed with water-cooled ultrasound transducers operating at a frequency of 10 MHz. Single lesions extend from the transducer surface up to 10 mm in depth when applying an intensity of 14 W/cm<sup>2 </sup>for 10s. A lumen inside the therapy applicator provides path for an endoscopic ultrasound imaging probe operating at a frequency of 12 MHz. The mechanical rotation of the applicator around its axis enables treatment of sectorial or cylindrical volumes. This method is thus particularly suitable for esophageal tumors that may develop only on a portion of the esophageal circumference. Previous experiments were conducted from bench to <it>in vivo </it>studies on pig esophagi.</p> <p>Results</p> <p>Here we report clinical results obtained on four patients included in a pilot study. The treatment of esophageal tumors was performed under fluoroscopic guidance and ultrasound imaging. Objective tumor response was obtained in all cases and a complete necrosis of a tumor was obtained in one case. All patients recovered uneventfully and dysphagia improved significantly within 15 days, allowing for resuming a solid diet in three cases.</p> <p>Conclusion</p> <p>This clinical work demonstrated the efficacy of intraluminal high intensity ultrasound therapy for local tumor destruction in the esophagus.</p
A Perfect Script? Manchester United's Class of ‘92
The Class of ’92 is a documentary film featuring six Manchester United F.C. players who recount their time during a pivotal period for the club, English football and English society. The documentary claims to offer a commentary on Britain in the 1990s, but appears, without acknowledging the fact, to be a promotional vehicle to establish the six men as a brand labeled the Class of ’92 (CO92). Creating this brand necessarily involved presenting a selective account of their time and places with the film being little more than an advertisement, masquerading as an observational documentary. The film draws freely upon the symbolic capital held by the club and the city of Manchester and uses the Busby Babes/Munich chapter and the more recent “Madchester scene” to forge the Class of ’92 brand by editing out those elements that did not accord with this project. The article argues that a more complete representation of ’90s Britain, while disrupting the intended narrative, would acknowledge the significant structural and commercial changes experienced by the club, the sport, and the city in the last decade of the 20th century. We suggest that the Class of ’92 invites the viewer to consider how the documentary film genre can contribute to brand development and promotion
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Variability in MRI vs. ultrasound measures of prostate volume and its impact on treatment recommendations for favorable-risk prostate cancer patients: a case series
Background: Prostate volume can affect whether patients qualify for brachytherapy (desired size ≥20 mL and ≤60 mL) and/or active surveillance (desired PSA density ≤0.15 for very low risk disease). This study examines variability in prostate volume measurements depending on imaging modality used (ultrasound versus MRI) and volume calculation technique (contouring versus ellipsoid) and quantifies the impact of this variability on treatment recommendations for men with favorable-risk prostate cancer. Methods: We examined 70 patients who presented consecutively for consideration of brachytherapy for favorable-risk prostate cancer who had volume estimates by three methods: contoured axial ultrasound slices, ultrasound ellipsoid (height × width × length × 0.523) calculation, and endorectal coil MRI (erMRI) ellipsoid calculation. Results: Average gland size by the contoured ultrasound, ellipsoid ultrasound, and erMRI methods were 33.99, 37.16, and 39.62 mLs, respectively. All pairwise comparisons between methods were statistically significant (all p < 0.015). Of the 66 patients who volumetrically qualified for brachytherapy on ellipsoid ultrasound measures, 22 (33.33%) did not qualify on ellipsoid erMRI or contoured ultrasound measures. 38 patients (54.28%) had PSA density ≤0.15 ng/dl as calculated using ellipsoid ultrasound volumes, compared to 34 (48.57%) and 38 patients (54.28%) using contoured ultrasound and ellipsoid erMRI volumes, respectively. Conclusions: The ultrasound ellipsoid and erMRI ellipsoid methods appeared to overestimate ultrasound contoured volume by an average of 9.34% and 16.57% respectively. 33.33% of those who qualified for brachytherapy based on ellipsoid ultrasound volume would be disqualified based on ultrasound contoured and/or erMRI ellipsoid volume. As treatment recommendations increasingly rely on estimates of prostate size, clinicians must consider method of volume estimation
Ultrasound-Guided Radiofrequency Thermal Ablation of Uterine Fibroids: Medium-Term Follow-Up
Previous studies have shown that radiofrequency thermal ablation (RFA) of uterine fibroids through a percutaneous ultrasound (US)-guided procedure is an effective and safe minimally invasive treatment, with encouraging short-term results. The aim of this study was to assess the results in terms of volume reduction and clinical symptoms improvement in the midterm follow-up of fibroids with a diameter of up to 8 cm. Eleven premenopausal females affected by symptomatic fibroids underwent percutaneous US-guided RFA. Symptom severity and reduction in volume were evaluated at 1, 3, 6, 9, and 12 months. The mean symptom score (SSS) before the procedure was 50.30 (range 31.8–67.30), and the average quality of life (QOL) score value was 62 (range 37.20–86.00). The mean basal diameter was 5.5 cm (range 4.4–8) and the mean volume was 101.5 cm3 (range 44.58–278 cm3). The mean follow-up was 9 months (range 3–12 months). The mean SSS value at the end of the follow-up was 13.38 (range 0–67.1) and the QOL 90.4 (range 43.8–100). At follow-up the mean diameter was 3.0 cm (range 1.20–4.5 cm), and the mean volume was 18 cm3 (range 0.90–47.6 cm3). In 10 of 11 patients we obtained total or partial regression of symptoms. In one case the clinical manifestations persisted and it was thus considered unsuccessful. In conclusion, US-guided percutaneous RFA is a safe and effective treatment even for fibroids up to 8 cm
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