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41.
A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern. 相似文献
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The effects of section separation on image contrast and calculated T1 relaxation times were investigated in healthy volunteers and a phantom using an early commercial version magnetic resonance imaging system. The effects are explained qualitatively on the basis of side lobes of excitation occurring outside the selected section resulting in reduction of the time permitted for T1 relaxation. The options for dealing with imperfect section selection, including separation of the sections (i.e., leaving gaps) and nonsequential excitation, are illustrated and the trade-offs involved in each explained. 相似文献
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High-resolution MR imaging with local coils 总被引:4,自引:0,他引:4
We propose the following rules to govern the choice of local coils by the practicing radiologist: 1. Smaller coils permit smaller FOVs and better resolution. The coil should be as small as possible. 2. Match the ROS of the coil to the FOV, which will be determined by the anatomic region of interest. 3. For the case of a choice between surface coils or between a surface and a whole- or partial-volume coil, the anatomic region should lie on the high side of the crossover point. For the case of a choice among whole-volume coils, the smallest coil that surrounds the region of interest should be chosen. 4. Considerations in regard to the anatomic shape or the need to vary the position of the structure may alter the choice of coil from that obtained by S/N considerations alone. 相似文献
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ANDERSON G; COLES ET; CRANE M; DOUGLAS AC; GIBBS AR; GEDDES DM; PEEL ET; WOOD JB 《QJM : monthly journal of the Association of Physicians》1992,83(3):427-438
In order to describe the British experience of Wegener's granuiomatosisHospital Activity Analysis was used to collect cases diagnosedin England, Wales and Scotland between 1975 and 1985. Wherepossible clinical details, histological material and chest radiographswere obtained. Two hundred and sixty five patients were consideredto have Wegener's granuiomatosis. In 109 a single pathologistconfirmed the diagnosis by finding both granulomas and vasculitisin biopsy material. The diagnosis was made on clinical groundsor clinical grounds together with histological diagnosis inthe local hospital in 156 patients. Wegener's granuiomatosiswas confined to the lung or upper respiratory tract in 22 percent of patients and renal disease occurred in 58 per cent.Laboratory tests showed a pattern of mild anaemia, polymorphleucocytosis, eosinophilia and an elevated ESR and hypergammaglobulinaemia,with no specific pattern of changes. Histological confirmation was most frequently obtained by examinationof nasal biopsy specimens, but multiple biopsies were oftenrequired. Renal biopsies showed focal proliferative glomerulonephritisbut granulomatous glomerulonephritis was uncommon. Of availablechest radiographs 61 per cent were abnormal, large opacitiesbeing most common. Small irregular opacities were found lessoften and other abnormalities were uncommon. Treatment varied widely and 10 per cent of patients receivedno drug therapy. This large series illustrates that even withoutspecific treatment, patients with Wegener's granuiomatosis cansurvive for several years and with modern treatment survivalfor more than a decade is possible. Conclusions about the effectivenessof the various therapies cannot be drawn from this restrospectivestudy. Renal failure and disseminated vasculities were the commonestcauses of death; death was considered to result from complicationsof treatment with cytotoxic drugs or prednisolone in 6 per centof patients. 相似文献
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EM Keane MRCGP DOM H Wilson MPS D McGrane MB BCh D Coakley MD JB Walsh FRCP 《International journal of clinical practice》1995,49(2):71-72
SUMMARY In this test a course of 4 drops twice a day for 5 days of ear wax solvents, a cerumenolytic, sodium bicarbonate, or sterile water significantly increased the clearance of wax from ears by natural expulsion and eliminated the requirement for ear syringing in 50% of cases. 相似文献