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Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
3.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
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In this study, the word retrieval, phonological awareness, sentence completion, and narrative discourse processing skills of 93 reading-disabled and 93 normally achieving subjects from 8 to 14 years of age were compared. The subjects were matched for age, sex, and neighborhood. Results revealed that the two groups differed significantly on the time and accuracy of word retrieval, their ability to produce a syntactically appropriate structure in a sentence completion task, their retelling of stories that had been read to them, their answers to questions about the stories, and their inferences. Further analysis revealed that the variance in the younger reading-disabled children's reading comprehension scores was best accounted for by their performance on the sentence completion and word retrieval measures; the inferencing skills of the older reading-disabled children best accounted for the variance in their reading comprehension. By contrast, the younger normally achieving children's reading comprehension scores were best accounted for by their sentence completion, the proportion of the stories that they retold, and word retrieval scores. The proportion of stories retold and the phonological awareness score of the older normally achieving children best accounted for the variance in their reading scores. These findings suggest that the oral language skills of normally achieving and reading-disabled children may relate differently to their reading comprehension at different age levels. 相似文献
6.
Spontaneous uterine rupture during subsequent pregnancy following non-excision of an interstitial ectopic gestation 总被引:2,自引:1,他引:1
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Oral glucocorticoids are widely used to treat exacerbations of asthma and COPD. A role for their use in treating exacerbations in Cystic Fibrosis (CF) is not proven. We describe the current practice, amongst UK adult CF physicians, of oral glucocorticoid use as an adjuvant to intravenous (IV) antibiotic treatment during CF pulmonary exacerbation (P EX). The survey also examined whether physicians thought a randomised controlled trial (RCT) was necessary and their willingness to participate patients in such a trial. Eighty one percent of physicians replied. All of them used corticosteroids with P EX. Most physicians supported the need for a RCT and would be willing to enroll consenting patients in the trial. This survey highlighted the need for a RCT which would examine the role of adjuvant corticosteroids to IV antibiotics in CF P EX. 相似文献
8.
OBJECTIVE: The indications for pre-operative radiotherapy in rectal cancer are still unclear with the exception of T4 tumours. The aim of this study was to assess local and overall recurrence in patients with T1-T3 rectal cancers undergoing total mesorectal excision (TME). METHODS: Prospective data was collected from 150 patients with rectal cancer treated in one surgical centre between July 1997 and July 2002. One hundred and twenty-nine primary resections were carried of which 102 were with curative intent. Seventy-nine patients with T1-T3 tumours were included in the analysis. Nine had local resections and 70 underwent TME; 19 of the 70 patients were node positive and 51 were node negative. RESULTS: At a median follow-up of 37 months (range 19-79 months) there were 3 (4.3%) isolated local recurrences. One node positive patient developed isolated local recurrence compared with 2 node negative patients. The node positive patient died from a myocardial infarction while the two node negative patients died as a consequence of local recurrence. Three (4.3%) of 70 patients developed systemic relapse all of whom were node positive. The cancer specific mortality rate over the same follow-up period was 3/19 for node positive patients and 2/51 for node negative patients. Of 9 patients who had local resections, none developed local recurrence or systemic relapse. CONCLUSIONS: With TME the rate of local recurrence in T1-T3 tumours is low. Our results do not support the use of pre-operative radiotherapy for these patients. 相似文献
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