Iodine-131 metaiodobenzylguanidine scintigraphy for localization of lesions in children with neuroblastoma: comparison with computed tomography and ultrasonography

Iodine-131 metaiodobenzylguanidine (MIBG) scintigraphy, computed tomography (CT) and ultrasonography (US) were used to localize tumour lesions in 28 children with histologically proven neuroblastoma. Overall, a total of 73 lesions were detected on imaging studies. MIBG scintigraphy, CT and US localized 63 (86%), 49 (67%) and 36 (49%) of these lesions, respectively. The findings of the three imaging techniques were concordant in respect of only 31 (42%) of the lesions. The best agreement among MIBG scintigraphy, CT and US was observed for abdominal lesions (the techniques were concordant for 22 of 23 lesions, i.e. 96%). MIBG scintigraphy detected nine out of ten (90%) liver metastases, but agreement with CT and US was observed in only six instances (60%). The imaging findings were concordant in respect of only two (33%) out of six lymph node metastases; the MIBG scan was normal in the other four cases. Imaging agreement was observed for a lesion located in the pelvis. MIBG and CT findings were concordant in four lesions located in the chest, but US was not performed. MIBG scintigraphy depicted the majority (96%) of the skeletal lesions (23/24); CT showed five of these, but, again, US was not performed. The imaging findings were not concordant as regards the remaining five lesions located in different anatomical sites. The results indicated that MIBG imaging is more sensitive that CT and US in localizing the majority of neuroblastoma lesions. Since the metastatic spread of neuroblastoma is unpredictable, we recommend MIBG scintigraphy as the initial imaging modality for staging of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-dimensional index distribution determination from near-field measurements in single-mode fibres

The refractive-index distribution of single-mode optical fibres can be obtained from transmitted near-field intensity measurements. The generalisation of the method from conventional fibres to noncircularly symmetric guides (e.g. polarisation-maintaining fibres) is discussed. Results obtained both on circular and on polarisation-maintaining fibres are presented.     

Two forms of persistence in visual information processing.

Iconic memory, once regarded as a unitary phenomenon, has been subdivided into several components. We examined the joint effects of 2 such components (visible persistence and the visual analog representation [VAR]) on performance in a partial report task. The display consisted of 15 letters arranged around the perimeter of an imaginary circle on the face of an oscilloscope. The observer named the character singled out by a bar-probe. Two factors were varied: exposure duration of the array (10, 50, 100, 150, 200, 300, 400, or 500 ms) and duration of blank period (interstimulus interval [ISI]) between the termination of the array and the onset of the probe (0, 50, 100, 150, or 200 ms). Performance was progressively impaired as exposure duration and ISI were increased. Results were explained in terms of a probabilistic combinatorial model in which the timecourses of visible persistence and of the VAR are regarded as time-locked to the onset and to the end of stimulation, respectively. The impairing effect of exposure duration was attributed to the relatively high spatial demands of the task that could be met optimally by information in visible persistence, but less adequately by information in the VAR. A second experiment, employing a task with lesser spatial demands, confirmed this interpretation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ENEA activities on seismic isolation of nuclear and non-nuclear structures

Work on seismic isolation of nuclear and non-nuclear structures was started by ENEA in cooperation with ISMES in 1988. The first activity consisted of a proposal for guidelines for seismically isolated nuclear plants using high-damping, steel-laminated elastomer bearings. This is being performed in the framework of an agreement with General Electric Company. Furthermore, research and development (R&D) work has been defined and recently initiated to support development of the seismic isolation guidelines as well as that of qualification procedures for seismic isolation systems in general. The present R&D work includes static and dynamic experiments on single bearings, shake table tests with multi-axial simultaneous excitations on reduced-scale mockups of isolated structures supported by multiple bearings, and dynamic tests on large-scale isolated structures with on-site test techniques. It also includes the development and validation of finite-element nonlinear models of the single bearings, as well as those of simplified design tools for the analysis of the isolated structures' dynamic behavior. Extension of this work is foreseen in a wider national frame.     

Querying medical databases in an environment offering logical data independence

Medical information systems are becoming popular. Furthermore, their use is expected to be expanded in future. In order to easily extract information from the underlying databases, easy to use man-machine interfaces are required. This paper concerns the doctor interface of the ARPIA medical information system based on a relational database management system. The whole system is currently used inside the Outpatient Pediatric Clinic of the Catholic University of Rome, Italy. The interface provides logical data independence towards the underlying relational database. The paper contains some background about this kind of interfaces, and also, it sketches the software architecture of the implemented prototype.