Jejunum and ileum blunt trauma: what has changed with the implementation of multislice computed tomography?

OBJECTIVE: to evaluate the impact of the new technology of multidetector computed tomography (MDCT) in improving the accuracy and early diagnosis of BSBI.METHODS: patients with blunt small bowel injuries (BSBI) grade> I were identified retrospectively and their CT scans reviewed by an experienced radiologist. Clinical and tomographic findings were analyzed and patients grouped as "pre-MDCT" and "post-MDCT", according to the time of implementation of a 64-slice MDCT.RESULTS: of the 26 patients with BSBI 16 had CT scans. Motor vehicle collision (62.5%) was the most frequent mechanism of injury. In the pre-MDCT period, five of the 13 patients (38.5%) had abdominal CT, and in the post-MDCT, 11 of 13 patients (84.6%) had the exam. During pre-MDCT, all CT scans were abnormal with findings of pneumoperitoneum (60%), free fluid (40%) and bowel wall enhancement (20%). In the post-MDCT group, all exams but one were abnormal and the most frequent findings were free fluid (90.9%), bowel wall enhancement (72.7%), and pneumoperitoneum (54.5%). However, the rate of delayed laparotomy did not change. The mortality rate in both groups were similar, with 20% during pre-MDCT and 18.2% during post-MDCT.CONCLUSION: the use of MDCT in abdominal trauma in our service has increased the sensibility of the diagnosis, but has had no impact on outcome so far.

Computed tomography image of the mediastinal and axillary lymph nodes in clinically sound Rottweilers

Trough computed tomography (CT), it is possible to evaluate lymph nodes in detail and to detect changes in these structures earlier than with radiographs and ultrasound. Lack of information in the veterinary literature directed the focus of this report to normal aspects of the axillary and mediastinal lymph nodes of adult dogs on CT imaging. A CT scan of 15 normal adult male and female Rottweilers was done. To define them as clinically sound, anamnesis, physical examination, complete blood count, renal and hepatic biochemistry, ECG, and thoracic radiographs were performed. After the intravenous injection of hydrosoluble ionic iodine contrast medium contiguous 10mm in thickness thoracic transverse images were obtained with an axial scanner. In the obtained images mediastinal and axillary lymph nodes were sought and when found measured in their smallest diameter and their attenuation was compared to musculature. Mean and standard deviation of: age, weight, body length and the smallest diameter of the axillary and mediastinal lymph nodes were determined. Mean and standard deviation of parameters: age 3.87±2.03 years, weight 41.13±5.12, and body length 89.61±2.63cm. Axillary lymph nodes were seen in 60% of the animals, mean of the smallest diameter was 3.58mm with a standard deviation of 2.02 and a minimum value of 1mm and a maximum value of 7mm. From 13 observed lymph nodes 61.53% were hypopodense when compared with musculature, and 30.77% were isodense. Mediastinal lymph nodes were identified in 73.33% of the dogs; mean measure of the smallest diameter was 4.71mm with a standard deviation of 2.61mm and a minimum value of 1mm, and a maximum value of 8mm. From 14 observed lymph nodes 85.71% were isodense when compared with musculature and 14.28% were hypodense. The results show that it is possible to visualize axillary and mediastinal lymph nodes in adult clinically sound Rottweilers with CT using a slice thickness and interval of 10mm. The smallest diameter of the axillary and mediastinal lymph nodes not surpassed 7mm and 8mm respectively. Their attenuations were equal or smaller than that of musculature in the post contrast scan.

Geostatistics for constrained variables: positive data, compositions and probabilities. Applications to environmental hazard monitoring

Aquesta tesi estudia com estimar la distribució de les variables regionalitzades l'espai mostral i l'escala de les quals admeten una estructura d'espai Euclidià. Apliquem el principi del treball en coordenades: triem una base ortonormal, fem estadística sobre les coordenades de les dades, i apliquem els output a la base per tal de recuperar un resultat en el mateix espai original. Aplicant-ho a les variables regionalitzades, obtenim una aproximació única consistent, que generalitza les conegudes propietats de les tècniques de kriging a diversos espais mostrals: dades reals, positives o composicionals (vectors de components positives amb suma constant) són tractades com casos particulars. D'aquesta manera, es generalitza la geostadística lineal, i s'ofereix solucions a coneguts problemes de la no-lineal, tot adaptant la mesura i els criteris de representativitat (i.e., mitjanes) a les dades tractades. L'estimador per a dades positives coincideix amb una mitjana geomètrica ponderada, equivalent a l'estimació de la mediana, sense cap dels problemes del clàssic kriging lognormal. El cas composicional ofereix solucions equivalents, però a més permet estimar vectors de probabilitat multinomial. Amb una aproximació bayesiana preliminar, el kriging de composicions esdevé també una alternativa consistent al kriging indicador. Aquesta tècnica s'empra per estimar funcions de probabilitat de variables qualsevol, malgrat que sovint ofereix estimacions negatives, cosa que s'evita amb l'alternativa proposada. La utilitat d'aquest conjunt de tècniques es comprova estudiant la contaminació per amoníac a una estació de control automàtic de la qualitat de l'aigua de la conca de la Tordera, i es conclou que només fent servir les tècniques proposades hom pot detectar en quins instants l'amoni es transforma en amoníac en una concentració superior a la legalment permesa.

Aging is associated with positive responding to neutral information but reduced recovery from negative information

Studies on aging and emotion suggest an increase in reported positive affect, a processing bias of positive over negative information, as well as increasingly adaptive regulation in response to negative events with advancing age. These findings imply that older individuals evaluate information differently, resulting in lowered reactivity to, and/or faster recovery from, negative information, while maintaining more positive responding to positive information. We examined this hypothesis in an ongoing study on Midlife in the US (MIDUS II) where emotional reactivity and recovery were assessed in a large number of respondents (N = 159) from a wide age range (36–84 years). We recorded eye-blink startle magnitudes and corrugator activity during and after the presentation of positive, neutral and negative pictures. The most robust age effect was found in response to neutral stimuli, where increasing age is associated with a decreased corrugator and eyeblink startle response to neutral stimuli. These data suggest that an age-related positivity effect does not essentially alter the response to emotion-laden information, but is reflected in a more positive interpretation of affectively ambiguous information. Furthermore, older women showed reduced corrugator recovery from negative pictures relative to the younger women and men, suggesting that an age-related prioritization of well-being is not necessarily reflected in adaptive regulation of negative affect.

Cone-beam computerized tomographic, radiographic, and histologic evaluation of periapical repair in dogs` post-endodontic treatment

Objective. To evaluate the periapical repair after root canal treatment in the teeth of dogs using CT and conventional radiography and to compare these findings with the gold standard microscopic evaluation. Study design. The animals were divided into three groups according to endodontic treatment performed: Group 1, single-visit endodontic treatment in teeth without apical periodontitis; Group 2, single-visit endodontic treatment in teeth with apical periodontitis; and Group 3, endodontic treatment in teeth with apical periodontitis using calcium hydroxide as a root canal dressing. Group 4 consisted of teeth with apical periodontitis not submitted to root canal treatment and Group 5 consisted of healthy teeth without periapical disease. Radiographic, tomographic, and microscopic evaluations were performed by blind examiners. At 180 days experimental time, CT and radiographic measurements of periapical disease were compared with the gold standard microscopic measurement using intraclass correlation coefficient. Intergroup comparisons considering different methods of periapical lesions measurement or different clinical protocols of root canal treatment were performed by Kruskal Wallis test followed by Dunn. Integrity of lamina dura, presence of radiolucent areas, and presence of root resorption were analyzed by Fisher`s exact test. Results. There was discontinuity of the lamina dura and CPD in all teeth from Groups 2, 3, and 4 evaluated by tomography and radiography 45 days after CPD induction. Radiographically, 180 days after root canal treatment, there was no periapical lesion in teeth from Groups 1 and 3, different from groups 2 and 4 (p < .05). The highest reduction in the CPD size was observed on Group 3 (p < .05). According to the tomographic results, there was decrease of the size of the CPD on Group 3 but not on Groups 2 or 4. However, in all groups the periapical lesions presented larger mesio-distal extension if compared with radiography, both 45 days after CPD induction and 180 days after root canal treatment. At 180 days, CT measurements were closely related to microscopic results (ICC = 0.95) differently from radiographic evaluation (ICC = 0.86). Conclusion. CT Scan evaluation of periapical repair following root canal treatment provided similar information than that obtained by microscopic analysis, whereas radiographic evaluation underestimated the size do periapical lesion. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108:796-805)

Immunohistochemical, tomographic and histological study on onlay bone graft remodeling. Part II: calvarial bone

Objectives Little information is available on the molecular events that occur during graft incorporation over time. The calvarial bone (Cb) grafts have been reported to produce greater responses compared with other donor regions in maxillofacial reconstructions, but the scientific evidences for this are still lacking. The objectives of this study are (1) to study the morphological pattern of Cb onlay bone grafts and compare them with the biological events through immunohistochemical responses and (2) to establish the effects of perforations in maintaining the volume and bone density of the receptor bed. Material and methods Sixty New Zealand White rabbits were submitted to Cb onlay bone grafts on the mandible. In 30 rabbits, the receptor bed was perforated (perforated group), while for the remaining animals the bed was kept intact (non-perforated group). Six animals from each group were sacrificed at 5, 7, 10, 20 and 60 days after surgery. Histological sections from the grafted area were prepared for immunohistochemical and histological analyses. Immuno-labeling was found for proteins Osteoprotegerin (OPG), receptor activator of nuclear factor-kappa beta ligand (RANKL), alkaline phosphatase (ALP), osteopontin (OPN), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase (TRAP), Type I collagen (COL I) and osteocalcin (OC). The tomography examination [computerized tomography (CT) scan] was conducted just after surgery and at the sacrifice. Results The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the graft incorporation process. The results of the CT scan showed lower resorption for the perforated group (P < 0.05), and both groups showed high bone density rates at 60 days. This set of evidences is corroborated by the immunohistochemical outcomes indicating that proteins associated with revascularization and osteogenesis (VEGF, OPN, TRAP and ALP) were found in higher levels in the perforated group. Conclusions These findings indicate that the bone volume of calvarial grafts is better maintained when the receptor bed is perforated, probably resulting from more effective graft revascularization and greater bone deposition. The process of bone resorption peaked between 20 and 60 days post-operatively in both groups although significantly less in the perforated group. To cite this article:Pedrosa Jr WF, Okamoto R, Faria PEP, Arnez MFM, Xavier SP, Salata LA. Immunohistochemical, tomographic and histological study on onlay bone grafts remodeling. Part II: calvarial bone.Clin. Oral Impl. Res. 20, 2009; 1254-1264.doi: 10.1111/j.1600-0501.2009.01747.x.

Immunohistochemical, tomographic and histological study on onlay iliac grafts remodeling

The information concerning the molecular events taking place in onlay bone grafts are still incipient. The objective of the present study is to correlate the effects of perforation of resident bone bed on (1) the timing of onlay autogenous graft revascularization; (2) the maintenance of volume/density of the graft (assessed through tomography); and (3) the occurrence of bone remodeling proteins (using immunohistochemistry technique) delivered in the graft. Thirty-six New Zealand White rabbits were subjected to iliac crest onlay bone grafting on both sides of the mandible. The bone bed was drill-perforated on one side aiming at accelerating revascularization, whereas on the other side it was kept intact. After grafts fixation and flaps suture all animals were submitted to tomography on both mandible sites. Six animals were sacrificed, respectively, at 3, 5, 7, 10, 20 and 60 days after surgery. A second tomography was taken just before sacrifice. Histological slides were prepared from each grafted site for both immunohistochemistry analysis [osteopontin, osteocalcin, type I collagen and vascular endothelial growth factor (VEGF) anti-bodies] and histometric analysis. The values on bone volume measured on tomography showed no statistic significance (P >= 0.05) between perforated and intact sites. Grafts placed on perforated beds showed higher bone density values compared with non-perforated ones at 3 days (P <= 0.05). This correlation was inverted at 60 days postoperatively. The findings from VEGF labeling revealed a tendency for earlier revascularization in the perforated group. The early revascularization of bone grafts accelerated the bone remodeling process (osteocalcin, type I collagen and osteopontin) that led to an increased bone deposition at 10 days. The extended osteoblast differentiation process at intermediate stages in the perforated group cooperated for a denser bone at 60 days.

Performance Improvement of Tomographic Image Reconstruction Based on DSP Processors

This paper presents the use of a multiprocessor architecture for the performance improvement of tomographic image reconstruction. Image reconstruction in computed tomography (CT) is an intensive task for single-processor systems. We investigate the filtered image reconstruction suitability based on DSPs organized for parallel processing and its comparison with the Message Passing Interface (MPI) library. The experimental results show that the speedups observed for both platforms were increased in the same direction of the image resolution. In addition, the execution time to communication time ratios (Rt/Rc) as a function of the sample size have shown a narrow variation for the DSP platform in comparison with the MPI platform, which indicates its better performance for parallel image reconstruction.

Detection of periapical lesion development by conventional radiography or computed tomography

Objective. The aim of this study was to detect the development of experimentally induced periapical lesions using conventional radiography and computed tomography.Study design. The root canals of dogs' teeth were exposed to the oral environment for 7 days for contamination and then sealed for 7 days (GI), 15 days (GII), 30 days (GIII), and 60 days (GIV). Immediately after each experimental period, radiographs and tomograms were taken in order to detect the occurrence of periapical bone resorption. The periapical radiographs were digitized and areas of bone resorption were measured using the VIXWIN 2000 software. Scores were assigned to the tomograms based on the progression of periapical bone resorption. The specimens were evaluated by calibrated examiners who were blinded to the groups. The radiographic results were analyzed by ANOVA and Tukey's test (P <.05) and the tomographic results were analyzed by Kruskal-Wallis and Dunn's tests (P <.05).Results. The radiographic evaluation did not reveal periapical lesions at the 7-day control. Lesions were radiographically visible at 15 and 30 days (47.4% and 77.8% of the cases, respectively) and presented similar dimensions (P <.05). At 60 days, lesions were detected in all specimens, presenting larger dimensions than those of the earlier evaluation periods (P <.05). The tomographic evaluation detected lesions at 7 and 15 days (32.5% and 83.3% of the cases, respectively). Lesions were detected in all specimens at the 30- and 60-day periods, when the greatest values of bone resorption were observed (P <.05).Conclusions. Tomography was able to detect periapical lesion development in its initial stages, even when the lesions were undetectable radiographically.

Fresh-frozen human bone allograft in vertical ridge augmentation: clinical and tomographic evaluation of bone formation and resorption

The aim of the current study is to evaluate fresh-frozen human bone allografts (FHBAs) used in vertical ridge augmentation clinically and by computed tomography, and to analyze the resulting bone formation and graft resorption. Sixteen FHBAs were grafted in the maxillae and mandibles of 9 patients. The FHBAs, which were provided by the Musculoskeletal Tissue Bank of Marilia Hospital (Unioss), were frozen at -80A degrees C. After 7 months, dental implants were placed and bone parameters were evaluated. Vertical bone formation was measured by computerized tomography before (T0) and at 7 months (T1) after the surgical procedure. Bone graft resorption was measured clinically from a landmark screw head using a periodontal probe. The results were analyzed by Student's t-test. Significant differences existed in the bone formation values at T0 and T1, with an average change of 4.03 +/- A 1.69 mm. Bone graft resorption values were 1.0 +/- A 0.82 mm (20%). Implants were placed with varying insertion torque values (35-45 Ncm), and achieved primary stability. This study demonstrates that FHBAs promote satisfactory vertical bone formation with a low resorption rates, good density, and primary implant stability.

Immunohistochemical, tomographic and histological study on onlay iliac grafts remodeling

The information concerning the molecular events taking place in onlay bone grafts are still incipient. The objective of the present study is to correlate the effects of perforation of resident bone bed on (1) the timing of onlay autogenous graft revascularization; (2) the maintenance of volume/density of the graft (assessed through tomography); and (3) the occurrence of bone remodeling proteins (using immunohistochemistry technique) delivered in the graft. Thirty-six New Zealand White rabbits were subjected to iliac crest onlay bone grafting on both sides of the mandible. The bone bed was drill-perforated on one side aiming at accelerating revascularization, whereas on the other side it was kept intact. After grafts fixation and flaps suture all animals were submitted to tomography on both mandible sites. Six animals were sacrificed, respectively, at 3, 5, 7, 10, 20 and 60 days after surgery. A second tomography was taken just before sacrifice. Histological slides were prepared from each grafted site for both immunohistochemistry analysis [osteopontin, osteocalcin, type I collagen and vascular endothelial growth factor (VEGF) anti-bodies] and histometric analysis. The values on bone volume measured on tomography showed no statistic significance (P≥0.05) between perforated and intact sites. Grafts placed on perforated beds showed higher bone density values compared with non-perforated ones at 3 days (P≤0.05). This correlation was inverted at 60 days postoperatively. The findings from VEGF labeling revealed a tendency for earlier revascularization in the perforated group. The early revascularization of bone grafts accelerated the bone remodeling process (osteocalcin, type I collagen and osteopontin) that led to an increased bone deposition at 10 days. The extended osteoblast differentiation process at intermediate stages in the perforated group cooperated for a denser bone at 60 days. © 2008 Blackwell Munksgaard.

Peri-orbital bone dimensional analysis using computed tomography for placement of osseointegrated implants

Craniofacial osseointegrated implants enabled producing implant-retained facial prosthesis, namely the orbital prosthesis. Aim: To evaluate the length and width of the bone structure of the peri-orbital region and to present the method validation. Methods: Computed tomography scans of 30 dry human skulls were obtained in order to register linear length and width measurements of the periorbital region. Two examiners made the measurements twice with intervals of at least 7 days between them. Data were analyzed by descriptive statistics and the paired Student's t-test was used as inferential technique (SAS, α =0.05). Results: In most cases, the intra- and inter-examiner variations were not significant (p>0.05). Therefore, the method proposed was considered as precise and valid for the measurement of the peri-orbital region. The measured points correspond to the hours of a clock. The major lengths were observed at 1 h (18.32 mm) for the left peri-orbital bone and at 11h (19.28 mm) for the right peri-orbital bone, followed by the points situated at 2h (13.05 mm) and 12h (11.37 mm) for the left side and at 10 h (12.34 mm) and 12 h (11.56 mm) for the right side. It was verified that the three points with lowest values followed the same anatomical sequence in the supraorbital rim for the right and left orbits, showing compatibility with the insertion of the intraoral osseointegrated implants. The medial wall of both orbits did not present sufficient length to allow the insertion of intraoral or craniofacial implants. Conclusions: The largest width points were observed in the supraorbital rim and in the infralateral region of both orbits and those of smallest width were found in the supralateral region of both orbits.

Estudo dacriocistográfico e tomográfico da via lacrimal excretora de cães portadores de epífora

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Neurocriptococose pediátrica no Estado do Pará: espectro de achados tomográficos na infecção por Cryptococcus neoformans var. gattii

Este estudo mostra o espectro de lesões cerebrais, através de tomografia computadorizada, na neurocriptococose da infância, por Cryptococcus neoformans var. gattii, no Estado do Pará. Analisamos os achados tomográficos de onze crianças (menores de 13 anos de idade), com infecção comprovada do sistema nervoso central por Cryptococcus neoformans var. gattii, internados no Hospital Universitário João de Barros Barreto, Belém PA, entre janeiro de 1992 a dezembro de 2000. A neurocriptococose foi definida pela identificação de leveduras encapsuladas ao exame microscópico, isolamento de Cryptococcus neoformans do líquor e identificação positiva da variedade gattii, através do meio composto de canavanina, glicina e azul-de-bromotimol com, pelo menos, o estudo tomográfico no momento do diagnóstico. A idade das crianças estudadas variou entre 6 a 12 anos, com média de 8,8 anos. Cincos eram meninos e seis meninas. Os principais achados clínicos foram cefaléia, febre e rigidez de nuca (n=11), náuseas e vômitos (n=10). O tempo médio entre o início dos sintomas e o diagnóstico foi de 4,2 semanas (variando de 2 a 8 semanas). Todas as tomografias de crânio foram anormais. Em todos os pacientes foram observados nódulos hipodensos. As demais anormalidades tomográficas observadas foram: 6 pacientes com hidrocefalia, 9 com atrofia difusa e 5 com associação de hidrocefalia e atrofia difusa. Descreve-se, pela primeira vez, achados tomográficos em série de casos de neurocriptococose por Cryptococcus neoformans var. gattii em crianças imunocompetentes. Este estudo mostra que esta infecção desenvolve múltiplos nódulos hipodensos, especialmente na região dos gânglios da base e na substância branca cerebral. As lesões, aparentemente progridem para importante atrofia da substância branca, com dilatação ventricular e proeminência de sulcos cerebrais, provavelmente, conseqüência de hidrocefalia compensatória. Em geral, estes pacientes apresentaram alterações leves do córtex cerebral.

Dengue-4 false negative results by Panbio (R) Dengue Early ELISA assay in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)