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741.
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743.
WE Berdon TL Slovis JB Campbell DH Baker JO Haller 《Canadian Metallurgical Quarterly》1977,125(2):457-462
Neonatal small left colon syndrome is a cause of functional colon obstruction in newborn infants, with a high association of maternal diabetes. There has been much confusion regarding its relationship to meconium plug syndrome and aganglionosis. Six cases of aganglionosis (2 in infants of diabetic mothers) were encountered in which the radiographic findings were identical to small left colon syndrome, indicating the need for caution in dismissing aganglionosis solely on the basis of a small left colon seen radiographically in a newborn infant with colon obstruction. Small left colon and meconium plug syndrome are overlapping entities in the total spectrum of functional intestinal obstruction in newborn infants. 相似文献
744.
PG Boysen AJ Block GN Olsen PV Moulder JO Harris RE Rawitscher 《Canadian Metallurgical Quarterly》1977,72(4):422-425
We evaluated 33 high-risk patients before pneumonectomy, all of whom had a forced expiratory volume in one second (FEV1) of less than 2.0 L before surgery. A quantitative perfusion lung scan was used to assess the right-left distribution of blood flow. A predicted postoperative FEV1 was calculated from the information on the lung scan and the preoperative FEV1. If this calculated value exceeded 800 ml, the patient was physiologically cleared for surgery up to and including a pneumonectomy. Surgery was otherwise believed to be contraindicated in the absence of studies using balloon occlusion. Perioperative mortality (less than or equal to 30 days after surgery) was found to be 15 percent (5/33). In surgery of this magnitude, we find this to be an acceptable percentage of mortality and have continued to use these simple physiologic criteria to determine whether a patient can tolerate pneumonectomy. 相似文献
745.
JO Westgard T Groth T Aronsson H Falk CH de Verdier 《Canadian Metallurgical Quarterly》1977,23(10):1857-1867
When assessing the performance of an internal quality control system, it is useful to determine the probability for false rejections (pfr) and the probability for error detection (ped). These performance characteristics are estimated here by use of a computer stimulation procedure. The control rules studied include those commonly employed with Shewhart-type control charts, a cumulative sum rule, and rules applicable when a series of control measurements are treated as a single control observation. The error situations studied include an increase in random error, a systematic shift, a systematic drift, and mixtures of these. The probability for error detection is very dependent on the number of control observations and the choice of control rules. No one rule is best for detecting all errors, thus combinations of rules are desirable. Some appropriate combinations are suggested and their performance characteristics are presented. 相似文献
746.
The depth of penetration of heavy charged-particle therapy beams is sensitive to the density of tissues traversed. Maximum depth of dose contours will vary appreciably as the beam passes through bone, muscle, lung, and air or gas. Calculations suggest that beam activation of the short-lived positron-emitting isotope 15O in vivo will permit localization of proton therapy beams with resonable detected-event density and dose. Preliminary tests of this method indicate that the beam can be located at depth with a typical dose of 15 rad, using a large field-of-view positron camera on-ling. This technique is also applicable to other heavy charged-particle beams, negative pions, and heavy ions. 相似文献
747.
Measurement of cerebral blood flow (CBF) using a 133Xe inhalation technique requires monitoring the clearance rate of the radioisotope from the head using externally situated detectors and also from arterial blood using a detector to monitor the expired air activity. The end-tidal concentration function is assumed to be proportional to the arterial concentration function and this has to be deconvoluted from the clearance functions obtained from the head to enable CBF to be calculated. A digital computer is generally considered to be essential for this. In this paper a procedure using three-dimensional nomograms is derived and tested. It is shown that results obtained using the nomograms do not differ significantly from results obtained using a full deconvolution procedure, and so it is not essential to use a computer to calculate CBF by the inhalation technique. 相似文献
748.
749.
TL Levin WE Berdon JO Haller C Ruzal-Shapiro A Hurlet-Jenson 《Canadian Metallurgical Quarterly》1996,26(9):646-649
PURPOSE: We studied six patients with sickle cell disease (SSD), five homozygous for sickle cell anemia and one with sickle beta-thalassemia, in whom rounded intrasplenic masses proved to be preserved functioning splenic tissue. MATERIALS AND METHODS: Available images including computed tomography, ultrasonography, bone scans (Tc-99m MDP), liver spleen scans (Tc-99m sulfur colloid), and MRI were evaluated. RESULTS: The masses were low density on CT (in an otherwise calcified spleen), hypoechoic relative to the echogenic spleen on US, and had the imaging characteristics of normal spleen on MRI. They failed to accumulate Tc-99m MDP but did demonstrate uptake of Tc-99m sulfur colloid. CONCLUSION: In a patient with SSD and intrasplenic masses, proper correlation of multiple imaging modalities will establish the diagnosis of functioning splenic tissue and avoid mistaken diagnosis of splenic abscess or infarction. 相似文献