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1.
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
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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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Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
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Between January 1981 and December 1990, 79 liver resections were performed for hepatic metastases in 73 patients. Eight of these patients had a repeat resection (2 patients had their first resection performed before 1981). This figure represented 35% of 228 liver resections performed during this period. Mean age was 56.5 years (23 to 81 years). There were 38 men and 35 women. Fifty-four resections were performed for colorectal metastases and 25 resections for secondaries of other origins. There were 45 major hepatectomies (57%), defined by the resection of at least 3 Couinaud segments, and 34 minor resections (less than three segments). In 12 patients, liver resection was associated with excision of the primary tumor. Complications were observed in 25 patients (32%), pulmonary complications being the most frequent. Five re-explorations were necessary: 3 for postoperative bleeding, one for an abdominal abscess and one for intestinal obstruction. Mean postoperative stay was 18 days. There was no mortality for the first liver resections in 71 patients. One death was encountered among the second resections in 8 patients, with a global mortality of 1.3%. Follow-up was obtained for all patients but one (lost to follow-up at 5 years). Actuarial survival for the 50 patients operated on for colorectal secondaries was 98% at 6 months, 83% at 1 year, 46% at 2 years, 24% at 3 years and 15% at 5 years. In non-colorectal secondaries, the survival depended on the nature of the primary tumor but was very different from one patient to another.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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