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    ABSTRACT: The thyroid scintigraphs of 207 patients were examined with a view to investigate the anatomical origin of the pyramidal lobe (PL) and in order to determine the incidence of its scintigraphic detection. The PL was visualized in 41% of the cases studied with a greater incidence among the females as compared to the males. It was established that the likelihood of the PL arising from the isthmus of the thyroid or its lobes was about the same. Further, it was observed that the isthmal PL was usually located in the mid-line rather than laterally, in which case it was more often deviated to the left than to the right. The scintigraphic visualization of the PL was seen to increase with the size of the gland but in large goitres it was difficult to detect. It evolves that although at times, there might be a discrepancy between the apparent and the actual location of the PL due to the presence of overlying tissue, in a majority of cases, the scintigraphic appearances do in fact reflect the true picture.
    Nuclear Medicine Communications 10/1989; 10(9):685-93. · 1.37 Impact Factor
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    ABSTRACT: A novel neural network based image watermarking algorithm in wavelet domain is described. We firstly select some wavelet coefficients in zerotrees from subimages of different resolutions according to different 2×2 pixel blocks, and then establish the relational model among these coefficients by using the neural network. Finally a bit of the watermark is embedded by adjusting the polarity between a high frequency coefficient and the output value of the model. In the proposed method, the filter banks are regarded as the key to take overall control of the embedding process, and so the algorithm is public while keeping high security. The experimental results show that the watermark can not only discriminate between malicious and incidental tamper but also exactly locate the malicious modifications.
    Machine Learning and Cybernetics, 2004. Proceedings of 2004 International Conference on; 09/2004
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    ABSTRACT: Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia without alteration of consciousness or personal identity. Interestingly, recent studies have reported a high frequency of small high-signal abnormalities in the hippocampus with diffusion-weighted (DW) imaging, and ischemia has been proposed as an etiology of TGA. We hypothesized that TGA lesions occur preferentially in the CA1 region of the hippocampus, known to be susceptible to ischemia. Over a 30-month period 34 patients with TGA underwent MRI including DW imaging within 4 days of symptom onset. Patients with high-signal abnormalities in the hippocampus on the initial DW images underwent subsequent DW and T2-weighted imaging in the coronal plane to identify the precise lesion locations. Fourteen patients had small (1-3 mm) high-signal abnormalities in the hippocampus unilaterally on DW images. One of these patients had two lesions in one hippocampus and therefore in total 15 lesions were identified: four in the hippocampal head, and 11 in the body. Eleven lesions in ten patients with available coronal images were clearly demonstrated on both coronal DW and T2-weighted images and were localized to the lateral portion of the hippocampus, corresponding to the CA1 region. Lesions associated with TGA were localized exclusively to the lateral portion of the hippocampus corresponding to the CA1 region. This finding supports the ischemic etiology of TGA; however, the pathophysiological mechanism involved requires further study.
    Neuroradiology 07/2007; 49(6):481-7. DOI:10.1007/s00234-007-0213-5 · 2.37 Impact Factor
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