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Andrew J Montgomery Kris Thielemans Mitul A Mehta Federico Turkheimer Sanida Mustafovic Paul M Grasby 《Journal of nuclear medicine》2006,47(12):1936-1944
Head movement presents a continuing problem in PET studies. Head restraint minimizes movement but is unreliable, resulting in the need to develop alternative strategies. These include frame-by-frame (FBF) realignment or use of motion tracking (MT) during the scan to realign PET acquisition data. Here we present a comparative analysis of these 2 methods of motion correction. METHODS: Eight volunteers were examined at rest using (11)C-raclopride PET with the radioligand administered as a bolus followed by constant infusion to achieve steady state. Binding potential (BP) was estimated using the ratio method during 2 periods of the scan at steady state. Head movement was compensated by using coregistration between frames (FBF) and 3 methods using MT measurements of head position acquired with a commercially available optical tracking system. RESULTS: All methods of realignment improved test-retest reliability and noise characteristics of the raw data, with important consequences for the power to detect small changes in radiotracer binding, and the potential to reduce false-positive and false-negative results. MT methods were superior to FBF realignment using coregistration on some indices. CONCLUSION: Such methods have considerable potential to improve the reliability of PET data with important implications for the numbers of volunteers required to test hypotheses. 相似文献
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PC Chamyal A Mehta SL Ojha JR Bhardwaj 《Indian journal of otolaryngology and head and neck surgery》1991,43(1):26-27
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed. 相似文献
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National Programme of Research in Human Reproduction S.K. Banerjee R. Baveja R.V. Bhatt A. Chatterjee S.D. Choudhury B. Coyaji A.D. Engineer M.P. Gogoi V. Hingorani K. Lal M. Kochhar U. Krishna P. Misra F.S. Philips R. Rajan P.C. Sen Gupta K. Zaveri S. Datey S. Gupta S. Mehta N.C. Saxena B.N. Saxena 《Contraception》1986,34(6):573-582
The return of fertility following discontinuation of norethisterone oenanthate (NET EN) 200 mg injectable contraceptive after use for a minimum period of six months or more was studied in 69 women who discontinued the method for planning pregnancy. Former users of copper intra-uterine device (CuT 200) were enrolled as a control group. Another 161 women who had discontinued NET EN due to other reasons (e.g. amenorrhoea, excessive bleeding or personal reasons) were also studied for return of fertility after ensuring that they were not using any other method of contraception and were exposed to the risk of pregnancy. The subjects from both groups were followed for a period of one year. The cumulative conception rates at one year were 72.5 and 83.6 per 100 subjects for ex-NET EN and ex-CuT 200 users who had discontinued the method for planning pregnancy and this difference was not statistically significant (P > 0.05). The median time for conception for ex-NET EN users was 7.8 months as compared to 3.7 months in ex-CuT 200 users but the cumulative conception rates at the end of one year show that future return of fertility in NET EN users does not appear to be adversely affected.
In 51 subjects who had discontinued NET EN due to amenorrhoea, the return of fertility was predictably slower and less. The return of fertility in subjects who discontinued NET EN for other reasons (e.g. excessive bleeding and other personal reasons) was similar to ex-NET EN and ex-CuT 200 users. 相似文献
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Background
Pulmonary dysfunction following cardiac surgery is believed to be caused, at least in part, by a lung vascular injury and/or atelectasis following cardiopulmonary bypass (CPB) perfusion and collapse of non-ventilated lungs. 相似文献8.
Carel Bron Michel Wensing Jo LM Franssen Rob AB Oostendorp 《BMC musculoskeletal disorders》2007,8(1):107
Background
Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders. 相似文献9.
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B. S. Sharma Sumit Sinha V. S. Mehta A. Suri Aditya Gupta A. K. Mahapatra 《Child's nervous system》2007,23(3):327-333
Object Intracranial aneurysms are rare in children and have different epidemiological, clinical, and morphological characteristics
and outcome from those in adults.
Materials and methods We analyzed demographic, clinical, radiologic features, treatment, and outcome in 55 patients <18 years of age, treated from
Jan 1995 through December 2005.
Results Intracranial aneurysms in children below 18 years constituted 4% of all intracranial aneurysms. Internal Carotid artery (ICA)
bifurcation was the commonest location. About half of the aneurysms were complex. Three-fourth of the patients required surgical
treatment. Two patients died, constituting 5% mortality. Two patients (5%) had poor outcome, whereas the majority (90%) had
a favorable outcome.
Conclusions Pediatric aneurysms have male predominance, higher incidence of clinical features of mass effect or seizures, high incidence
of large, traumatic/mycotic aneurysms, associated illnesses and ICH/IVH and hydrocephalus, better Hunt and Hess grades at
presentation, ICA bifurcation as the commonest site, and better outcome than their adult counterparts. 相似文献