Semi-Supervised Deep Learning for Multi-Tissue Segmentation from Multi-Contrast MRI

Segmentation of thigh tissues (muscle, fat, inter-muscular adipose tissue (IMAT), bone, and bone marrow) from magnetic resonance imaging (MRI) scans is useful for clinical and research investigations in various conditions such as aging, diabetes mellitus, obesity, metabolic syndrome, and their associated comorbidities. Towards a fully automated, robust, and precise quantification of thigh tissues, herein we designed a novel semi-supervised segmentation algorithm based on deep network architectures. Built upon Tiramisu segmentation engine, our proposed deep networks use variational and specially designed targeted dropouts for faster and robust convergence, and utilize multi-contrast MRI scans as input data. In our experiments, we have used 150 scans from 50 distinct subjects from the Baltimore Longitudinal Study of Aging (BLSA). The proposed system made use of both labeled and unlabeled data with high efficacy for training, and outperformed the current state-of-the-art methods with dice scores of 97.52%, 94.61%, 80.14%, 95.93%, and 96.83% for muscle, fat, IMAT, bone, and bone marrow tissues, respectively. Our results indicate that the proposed system can be useful for clinical research studies where volumetric and distributional tissue quantification is pivotal and labeling is a significant issue. To the best of our knowledge, the proposed system is the first attempt at multi-tissue segmentation using a single end-to-end semi-supervised deep learning framework for multi-contrast thigh MRI scans.Comment: 20 pages, 9 figures, Journal of Signal Processing System

Joint Solution For Pet Image Segmentation, Denoising, And Partial Volume Correction

Segmentation, denoising, and partial volume correction (PVC) are three major processes in the quantification of uptake regions in post-reconstruction PET images. These problems are conventionally addressed by independent steps. In this study, we hypothesize that these three processes are dependent; therefore, jointly solving them can provide optimal support for quantification of the PET images. To achieve this, we utilize interactions among these processes when designing solutions for each challenge. We also demonstrate that segmentation can help in denoising and PVC by locally constraining the smoothness and correction criteria. For denoising, we adapt generalized Anscombe transformation to Gaussianize the multiplicative noise followed by a new adaptive smoothing algorithm called regional mean denoising. For PVC, we propose a volume consistency-based iterative voxel-based correction algorithm in which denoised and delineated PET images guide the correction process during each iteration precisely. For PET image segmentation, we use affinity propagation (AP)-based iterative clustering method that helps the integration of PVC and denoising algorithms into the delineation process. Qualitative and quantitative results, obtained from phantoms, clinical, and pre-clinical data, show that the proposed framework provides an improved and joint solution for segmentation, denoising, and partial volume correction

18F-Naf And 18F-Fdg Pet/Ct In Gorham-Stout Disease

Gorham-Stout disease (GSD) is an extremely rare skeletal disorder of unknown etiology characterized by benign proliferation of vascular or lymphatic channels, leading to progressive bone resorption. We report on a patient diagnosed with GSD affecting the right scapula and the right ribs, who underwent PET/CT scans using F-FDG and F-NaF. The remnant upper portion of the affected scapula did not show F-FDG uptake but demonstrated markedly increased F-NaF activity. Furthermore, intense F-NaF activity was seen on the right posterior ribs, which were actively being resorbed, suggesting the potential application of F-NaF-PET/CT imaging in GSD diagnosis and follow-up

Serum Igf-1, Igfbp-3 Levels And Circulating Tumor Cells (Ctcs) In Early Breast Cancer Patients

Objective Insulin-like growth factor (IGF)-axis is involved in human oncogenesis and metastasis development for various solid tumors including breast cancer. Aim of this study was to assess the association between IGF-1, IGF-binding protein-3 (IGFBP-3) serum levels and the presence of circulating tumor cells (CTCs) in the peripheral blood of women diagnosed with early breast cancer (EBC), before and after adjuvant chemotherapy. Design 171 patients with early-stage breast adenocarcinomas were retrospectively evaluated. Immunoradiometric (IRMA) assays were employed for the in-vitro determination of IGF-1 and IGFBP-3 serum levels in blood samples collected after surgical treatment and before initiation of adjuvant chemotherapy. CTCs’ presence was assessed through detection of cytokeratin-19 (CK-19) mRNA transcripts using quantitative real time reverse transcription polymerase chain reaction (RT-PCR). IGF-1, IGFBP-3 serum levels were correlated with CTCs’ presence before and after adjuvant chemotherapy as well as with tumor characteristics including tumor size, axillary lymph node status, oestrogen (ER)/progestorene (PR) and human epidermural growth factor receptor 2 (HER2) receptor status. Log-rank test was applied to investigate possible association between IGF-1, IGFBP-3 serum levels and disease-free interval (DFI) and overall survival (OS). Results Before initiation of adjuvant therapy IGF-1, IGFBP-3 serum levels were moderately associated (Spearman\u27s rho = 0.361, p \u3c 0.001) with each other, while presenting significant differences across age groups (all p values \u3c 0.05). IGF-1 serum levels did not correlate with the presence of CTCs before initiation (p = 0.558) or after completion (p = 0.474) of adjuvant chemotherapy. Similarly, IGFBP-3 serum levels did not show significant association with detectable CTCs either before (p = 0.487) or after (p = 0.134) completion of adjuvant chemotherapy. There was no statistically significant association between the clinical outcome of patients in terms of DFI, OS and IGF-1(DFI: p = 0.499; OS: p = 0.220) or IGFBP-3 (DFI: p = 0.900; OS: p = 0.406) serum levels. Conclusions IGF-1 and IGFBP-3 serum levels before initiation of adjuvant chemotherapy are not indicative of CTCs’ presence in the blood and do not correlate with clinical outcome of women with early-stage breast cancer

\u3csup\u3e18\u3c/sup\u3eF-Naf Pet/Ct In Extensive Melorheostosis Of The Axial And Appendicular Skeleton With Soft-Tissue Involvement

Melorheostosis is a rare, nonhereditary, benign, sclerotic bone dysplasia with no sex predilection, typically occurring in late childhood or early adulthood, which can lead to substantial functional morbidity, depending on the sites of involvement. We report on a patient with extensive melorheostosis in the axial and appendicular skeleton, as well as in the soft tissues, who was evaluated with whole-body 18F-NaF PET/CT scan. All melorheostotic lesions of the skeleton and of the ossified soft-tissue masses demonstrated intensely increased 18F-NaF activity, suggesting the application of this modality in assessing and monitoring the disease activity

Epididymal Cystadenomas In Von Hippel-Lindau Disease Showing Increased Activity On \u3csup\u3e68\u3c/sup\u3eGa Dotatate Pet/Ct

von Hippel-Lindau (VHL) disease is a familial cancer syndrome characterized by the development of a variety of malignant and benign tumors, including epididymal cystadenomas. We report a case of a VHL patient with bilateral epididymal cystadenomas who was evaluated with 68Ga DOTATATE PET/CT, showing intensely increased activity (SUVmax, 21.6) associated with the epididymal cystadenomas, indicating cell-surface overexpression of somatostatin receptors. The presented case supports the usefulness of somatostatin receptor imaging using 68Ga DOTA-conjugated peptides for detection and follow-up of VHL manifestations, as well as surveillance of asymptomatic gene carriers

Kidney Tumor In A Von Hippel-Lindau (Vhl) Patient With Intensely Increased Activity On 68Ga-Dota-Tate Pet/Ct

Renal and pancreatic cysts and tumors are the most common visceral manifestations of von Hippel-Lindau (VHL) disease, a heritable multisystem cancer syndrome characterized by development of a variety of malignant and benign tumors. We report a case of a VHL patient with multiple renal cystic and complex cystic/solid lesions. The patient underwent Ga-DOTA-TATE-PET/CT showing intensely increased activity by a solid lesion which demonstrated enhancement on both CT and MRI scans, raising high suspicion for malignancy. The presented case indicates application of SSTR-imaging using Ga-DOTA-conjugated peptides in VHL-patients and emphasizes the need for cautious interpretation of renal parenchyma Ga-DOTATATE activity