AJR. American journal of roentgenology
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The ability of high-resolution MR imaging (1.5 T) to detect invasion of the cavernous sinuses by pituitary adenoma was determined through a retrospective review of 74 patients. These patients were divided into three groups: 25 normal subjects, 24 subjects with invasive pituitary adenomas, and 25 subjects with noninvasive pituitary adenomas. A fourth group of 30 patients, who subsequently underwent surgery for pituitary adenoma, was evaluated prospectively by MR for the presence or absence of cavernous sinus invasion. ⋯ The prospective MR evaluation of 30 patients undergoing surgery for pituitary tumor revealed a sensitivity for predicting cavernous sinus invasion of 55%, a specificity of 85.7%, a positive predictive value of 62.5%, and a negative predictive value of 81.8%. No feature permitted certain distinction between invasive and noninvasive microadenomas, as the medial dural wall of the cavernous sinus could not be reliably identified. The most specific sign of cavernous sinus invasion was carotid artery encasement.
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AJR Am J Roentgenol · Oct 1988
Necrotizing enterocolitis: value of radiographic findings to predict outcome.
To investigate whether radiographic findings could be used to predict pan-necrosis (necrosis of 75% or more of the jejunum, ileum, and colon), we reviewed the serial abdominal radiographs and clinical records of 147 infants with necrotizing enterocolitis. Pan-necrosis occurred in 29 infants (20%) and was always fatal. The presence and degree of pneumatosis intestinalis, pneumoperitoneum and portal venous gas were studied. ⋯ Pan-necrosis was found most frequently in infants with severe pneumatosis intestinalis (56%), portal venous gas (61%), or the combination of severe pneumatosis intestinalis and portal venous gas (79%). The mortality rates in these three groups were 63%, 65%, and 86%, respectively. Thus, infants with the worst outcome (those who develop pan-necrosis) can be identified on plain films by detection of severe pneumatosis intestinalis and portal venous gas.
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AJR Am J Roentgenol · Sep 1988
ReviewThe Doppler signal: where does it come from and what does it mean?
Doppler sonographic measurement of blood velocity and associated physiologic parameters is a powerful diagnostic technique. State-of-the-art instrumentation incorporates velocity measurement with two-dimensional imaging capability; it uses intensity and color coding to display complex physiologic and anatomic data to the observer in an easily understood format. Although the concepts underlying Doppler sonography are not complex, mastery of the technique requires extra training and commitment. ⋯ Doppler sonographic measurements may be used to determine the presence of flow, determine the direction of flow, identify time-varying velocity characteristics, and detect velocity disturbances. Because flow and velocity are related, it is possible to estimate flow from velocity measurements with careful calibration and proper precautions. Velocity is related to flow, which, in turn, is related to both pressure and vascular resistance.(ABSTRACT TRUNCATED AT 400 WORDS)
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AJR Am J Roentgenol · Jun 1988
Comparative StudyComparison of oxygen and barium reduction of ileocolic intussusception.
Reports that gas reduction of ileocolic intussusception has a better success rate than traditional barium reduction prompted us to evaluate this technique and to compare the results with our previous experience with barium. Our method of intussusception reduction uses oxygen at a flow rate of 2 l/min and with a maximum pressure of 80 mm Hg. The results of 65 consecutive patients with 69 episodes of intussusception over a 9-month period were retrospectively reviewed. ⋯ No complications have occurred to date. We have had greater success with the use of oxygen than with that of barium, and have had no complications. Therefore, at our institution, oxygen has superseded barium for the therapeutic reduction of ileocolic intussusception.