Browsing by Subject "Magnetic resonance image"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Fully Automated 3D Segmentation of MR-Imaged Calf Muscle Compartments: Neighborhood Relationship Enhanced Fully Convolutional Network
    (Elsevier, 2021) Guo, Zhihui; Zhang, Honghai; Chen, Zhi; van der Plas, Ellen; Gutmann, Laurie; Thedens, Daniel; Nopoulos, Peggy; Sonka, Milan; Neurology, School of Medicine
    Automated segmentation of individual calf muscle compartments from 3D magnetic resonance (MR) images is essential for developing quantitative biomarkers for muscular disease progression and its prediction. Achieving clinically acceptable results is a challenging task due to large variations in muscle shape and MR appearance. In this paper, we present a novel fully convolutional network (FCN) that utilizes contextual information in a large neighborhood and embeds edge-aware constraints for individual calf muscle compartment segmentations. An encoder-decoder architecture is used to systematically enlarge convolution receptive field and preserve information at all resolutions. Edge positions derived from the FCN output muscle probability maps are explicitly regularized using kernel-based edge detection in an end-to-end optimization framework. Our method was evaluated on 40 T1-weighted MR images of 10 healthy and 30 diseased subjects by fourfold cross-validation. Mean DICE coefficients of 88.00-91.29% and mean absolute surface positioning errors of 1.04-1.66 mm were achieved for the five 3D muscle compartments.
  • Thumbnail Image
    Item
    Pathologic fracture and hardware failure in Streptococcus anginosus femoral osteomyelitis: Case report
    (Elsevier, 2021-06-09) Stillson, John E.; Bunch, Connor M.; Thomas, Anthony V.; Mjaess, Nicolas; Dynako, Joseph A.; Piscoya, Andres S.; Post, Joel M.; Ratigan, Brian L.; Goldstein, Zachary H.; Walsha, Mark M.; Orthopaedic Surgery, School of Medicine
    Introduction: Pathologic fracture of the femur due to Streptococcus anginosus osteomyelitis has rarely been described. With limited evidence for treating S. anginosus osteomyelitis, the orthopaedic surgeon is presented with a difficult treatment decision at index presentation. Presented here is a case of failed conservative management, diagnostic dilemma, failed hardware stabilization, and definitive surgical treatment resulting in good clinical outcome. Case presentation: A 69-year-old male experienced acute right thigh pain, edema, and erythema after dental treatment 17 days prior. He was diagnosed with right femoral diaphyseal osteomyelitis and Brodie's abscess. Blood cultures grew S. anginosus, but all site-specific tissue cultures resulted negative. Initial management consisted of intravenous antibiotic therapy and percutaneous abscess drainage. Months later, the patient sustained a displaced pathologic fracture of the diaphyseal femur and there was concern for neoplasm, but biopsies were negative. Stabilization was attempted with a lateral plate and screws. This hardware catastrophically failed in the setting of an oligotrophic femoral nonunion. Ultimately, the patient was successfully treated with an intramedullary nail coated with antibiotic-impregnated cement. Twelve months later, the patient achieved clinical and radiographic healing with no evidence of relapse of his osteomyelitis. Clinical discussion: Conservative management of S. anginosus femoral osteomyelitis was inadequate and corroborates the existing literature. S. anginosus osteomyelitis and pyomyositis may be most optimally treated aggressively with early surgical intervention. Conclusion: Early surgical debridement and stabilization of the compromised bone with an antibiotic coated intramedullary nail following medullary reaming may prevent pathologic fracture, eradicate infection, and achieve predictable outcomes.