Osteonecrosis of the Upper Extremity: MRI-Based Zonal Patterns and Differential Diagnosis

2019 ◽  
Vol 23 (05) ◽  
pp. 523-533
Author(s):  
Rainer Schmitt ◽  
K.H. Kalb ◽  
G. Christopoulos ◽  
J.P. Grunz

AbstractRegarding the upper extremity, osteonecrosis can relate to the humeral head and to any carpal bone, most commonly the lunate (Kienböck's disease), scaphoid (Preiser's disease and nonunion), and capitate bone (osteonecrosis of the capitate head). In children and adolescents, osteochondrosis is an important differential diagnosis at the epiphyses. Appropriate imaging of osteonecrosis depends on knowledge about blood supply, biomechanical load, and bone repair mechanisms. Contrast-enhanced MRI (ceMRI) enables the differentiation of up to three mostly band-shaped zones: necrotic tissue (proximal), hypervascular repair tissue (intermediate), and viable bone (distal). To distinguish between necrotic and repair zones, intravenous gadolinium is recommended in MRI. Osteosclerosis and insufficiency fractures in early and intermediate stages as well as osteoarthritis in advanced stages are best depicted using high-resolution CT (HRCT). The combination of HRCT and ceMRI allows for exact classification of osteonecrosis regarding morphology and viability.

2019 ◽  
Vol 70 (6) ◽  
pp. 1983-1987
Author(s):  
Cristian Trambitas ◽  
Anca Maria Pop ◽  
Alina Dia Trambitas Miron ◽  
Dorin Constantin Dorobantu ◽  
Flaviu Tabaran ◽  
...  

Large bone defects are a medical concern as these are often unable to heal spontaneously, based on the host bone repair mechanisms. In their treatment, bone tissue engineering techniques represent a promising approach by providing a guide for osseous regeneration. As bioactive glasses proved to have osteoconductive and osteoinductive properties, the aim of our study was to evaluate by histologic examination, the differences in the healing of critical-sized calvarial bone defects filled with bioactive glass combined with adipose-derived mesenchymal stem cells, compared to negative controls. We used 16 male Wistar rats subjected to a specific protocol based on which 2 calvarial bone defects were created in each animal, one was filled with Bon Alive S53P4 bioactive glass and adipose-derived stem cells and the other one was considered control. At intervals of one week during the following month, the animals were euthanized and the specimens from bone defects were histologically examined and compared. The results showed that this biomaterial was biocompatible and the first signs of osseous healing appeared in the third week. Bone Alive S53P4 bioactive glass could be an excellent bone substitute, reducing the need of bone grafts.


2021 ◽  
pp. 1-11
Author(s):  
Yaning Liu ◽  
Lin Han ◽  
Hexiang Wang ◽  
Bo Yin

Papillary thyroid carcinoma (PTC) is a common carcinoma in thyroid. As many benign thyroid nodules have the papillary structure which could easily be confused with PTC in morphology. Thus, pathologists have to take a lot of time on differential diagnosis of PTC besides personal diagnostic experience and there is no doubt that it is subjective and difficult to obtain consistency among observers. To address this issue, we applied deep learning to the differential diagnosis of PTC and proposed a histological image classification method for PTC based on the Inception Residual convolutional neural network (IRCNN) and support vector machine (SVM). First, in order to expand the dataset and solve the problem of histological image color inconsistency, a pre-processing module was constructed that included color transfer and mirror transform. Then, to alleviate overfitting of the deep learning model, we optimized the convolution neural network by combining Inception Network and Residual Network to extract image features. Finally, the SVM was trained via image features extracted by IRCNN to perform the classification task. Experimental results show effectiveness of the proposed method in the classification of PTC histological images.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahana Perveen ◽  
Karmaine A. Millington ◽  
Suchitra Acharya ◽  
Amit Grag ◽  
Vita Boyar

AbstractObjectivesTo describe challenges in diagnosis and treatment of congenital neonatal gangrene lesions associated with history of maternal coronavirus disease 2019 (COVID-19) infection.Case presentationA preterm neonate was born with upper extremity necrotic lesions and a history of active maternal COVID-19 infection. The etiology of his injury was challenging to deduce, despite extensive hypercoagulability work-up and biopsy of the lesion. Management, including partial forearm salvage and hand amputation is described.ConclusionsNeonatal gangrene has various etiologies, including compartment syndrome and intrauterine thromboembolic phenomena. Maternal COVID-19 can cause intrauterine thrombotic events and need to be considered in a differential diagnosis.


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