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E Arana

Publications and source records attributed to E Arana.

At least 19 recordsLinked to original sources
PubMed2006

Low-high and high-low biphasic injection forms in computed tomography examinations of the upper abdomen.

PURPOSE: To analyze the influence of different biphasic and monophasic injection rate protocols in abdominal computed tomography (CT). MATERIAL AND METHODS: A randomized, consecutive, parallel group study was designed and conducted in 60 patients studied with the same CT helical protocol. Patients were randomly distributed into three groups: (A) monophasic (120 ml at 2.5 ml/s); (B) low-high biphasic (120 ml, first 60 ml at a rate of 2 ml/s, the other 60 ml at 2.5 ml/s); and (C) high-low biphasic (120 ml, first 60 ml at a rate of 2.5 ml/s, the other 60 ml at 2 ml/s). All patients were injected with 300 mg I/ml non-ionic contrast media at a fixed delay time of 55 s. Contrast enhancement efficacy was evaluated by attenuation coefficient measurements. RESULTS: Although non-significant, monophasic protocol enhancements were higher than biphasic protocol enhancements in all measurements except aortic bifurcation (p=0.003). At this level, biphasic protocols obtained an increased mean enhancement from 7.6% to 2.5% compared to monophasic protocols. CONCLUSION: Monophasic contrast agent injection in helical CT of the upper abdomen produces a higher enhancement of parenchymal and venous structures. No significant difference was observed between low-high and high-low biphasic protocols.

Adult↗
PubMed2005

Comparative study of muromonab-CD3 (OKT3) versus daclizumab (Zenapax) in cardiac transplantation at our center.

Recent studies support the addition of new immunosuppressive drugs as cytolytic induction therapy in cardiac transplantation. We carried out a comparative study comprising 52 patients who had undergone cardiac transplantation at our center. Thirty patients received muromonab-CD3 (OKT3, Janssen-Cilag, The Netherlands) as the induction therapy, whereas 22 patients received Daclizumab (Zenapax, Hoffman-La Roche, Nutley, NJ, USA) instead. All patients received cyclosporine or tacrolimus, mycophenolate, and steroids. Over an average follow-up period of 23.21 +/- 18 months, we analyzed retrospectively the incidence of grade > or = 3A biopsy-confirmed acute rejection episodes, the presence of infectious processes at 1 and 6 months, the occurrence of significant secondary effects, and the necessity to modify the immunosuppressive therapy during the follow-up. The results suggest that daclizumab is linked to a decreased incidence of grade > or = 3A biopsy-confirmed acute rejection and to a reduced necessity to modify the immunosuppressive therapy during the medium-term follow-up.

Antibodies, Monoclonal↗
PubMed2005

Magnetic resonance myelography evaluation of the lumbar spine end plates and intervertebral disks.

PURPOSE: To evaluate the value of magnetic resonance (MR) myelography in the evaluation of intervertebral disk and end-plate degenerative changes in the lumbar spine. MATERIAL AND METHODS: Conventional MR and MR myelography examinations were performed in 150 consecutive patients (69 F and 81 M, mean age 45+/-15 years, range 18 89). Sagittal T1 and T2-weighted TSE images were compared to MR myelography obtained with a multishot-TSE-T2-weighted sequence (4000/250/fat suppression). Coronal, sagittal, and both oblique MR myelography projections were obtained. Image analysis was carried out independently by two radiologists who categorized lumbar disks into normal, degenerated, or edematous; and vertebral end plates into normal, edematous, or with fatty changes. The proportions were statistically compared at every lumbar intervertebral level. RESULTS: There was good agreement in the classification of disk disease (Kappa: 0.8-0.9). MRI detected a larger number of disk degeneration and end-plate fatty metamorphosis, while the MR myelography technique depicted a larger number of edematous disks and end plates. CONCLUSION: MR myelography was of limited value in detecting the same vertebral end-plate changes observed in MRI, although with similar findings in disk disease. However, the higher detection of edema changes by MR myelography should be analyzed prospectively, as it could be more sensitive than conventional MR sequences.

Adolescent↗
PubMed2004

Dural enhancement with primary calvarial lesions.

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

Adolescent↗
PubMed2004

MR-myelography as an adjunct to the MR examination of the degenerative spine.

Our objective was to analyse the usefulness of single-slice MR-myelography images as a complementary test to conventional MR of the spine in patients with clinically suspected degenerative spine disease. A prospective analysis of 1022 consecutive patients studied with conventional MR and MR-myelography (four acquisitions: one coronal plane, one sagittal plane, and two oblique lateral, right and left planes) examinations was performed. Conventional MR and MR-myelography studies were classified as positive when morphological or structural alterations were noted. Positive MR-myelography information was also categorized as relevant if findings were considered important and radiologically significative to the final diagnosis (either by increasing the radiologists confidence in the diagnosis or because the findings were not observed in the conventional study). Other positive findings were considered non- relevant. There were 62% cases considered positive in the MR-myelography examination. Of them, 3% revealed no alterations on the conventional MR examination. Of the negative MR-myelography studies, 75% had a positive conventional MR examination. Considered as diagnostic techniques, their Kappa concordance was poor. However, MR-myelography complemented the information obtained with the conventional MR examination of the spine, this information being relevant to the final MR diagnosis in 22% of the total number of cases. The contribution of MR-myelography was not different in the three spinal levels. In conclusion, MR-myelography complements the information obtained with conventional MR in a large number of cases.

Aging↗
PubMed2004

Cognitive impairment: classification by 1H magnetic resonance spectroscopy.

1H magnetic resonance spectroscopy (MRS) allows accurate and non-invasive in vivo metabolic study, and is a useful tool for the diagnosis of different forms of dementias. Cognitive impairment pathologies have been almost exclusively studied with MRS by comparison with healthy without a global comparison amongst Alzheimer disease (AD), vascular dementia, mild cognitive impairment (MCI) and major depression patients with cognitive impairment. Whereas decrease of N-acetylaspartate (NAA) and increase myo-Inositol (mI) at different brain locations by 1H MRS are common features of AD, Choline (Cho) alterations have been inconclusive. In our study, 64 patients with cognitive impairment were evaluated by 1H MRS using two echo times (31 and 136 ms). There were statistical differences between dementia (AD and vascular dementia) and non-dementia (MCI and depression) spectra at posterior cingulate gyrus. Cho/Cr, mI/Cr and NAA/Cr have been valuables for the differentiation amongst the different cognitive impairment entities. NAA/mI provides the best area under the ROC curve with the highest sensitivity (82.5%) and specificity (72.7%) in diagnosing AD. NAA/mI and mI/Cr ratios differed amongst the four cognitive impairment degenerative pathologies. Metabolic MRS differences found amongst patients with cognitive impairment entities can be useful to differentiate between AD, vascular dementia, MCI and depression.

Aged↗
PubMed2003

[Diagnosis of calvarial lesions. Feature selection by neural network and logistic regression].

OBJECTIVES: To establish the minimun set of features needed in the diagnosis of calvarial lesions using computed tomography (CT) and to assess the accuracy of logistic regression (LR) and artificial neural networks (NN) for their diagnosis. MATERIAL AND METHODS: 167 patients with calvarial lesions as the only known disease were enrolled. The clinical and CT data were used for LR and NN models. Both models were tested with the jacknife method. The final results of each model were compared using the area under ROC curves (A 2 ). RESULTS: The lesions were 73.1 % benign and 26.9% malignant. There was no statistically significant difference between LR and NN in differentiating malignancy. In characterizing the histologic diagnoses, NN was statistically superior to LR. Important NN features needed for malignancy classification were age and edge definition, and for the histologic diagnoses matrix, marginal sclerosis and age. CONCLUSIONS: A minimum four features is needed to diagnose these lesions, not being important patients' symptoms. NNs offer wide possibilities over statistics for the calvarial lesions study besides a superior diagnostic performance.

Adolescent↗
PubMed2002

Long-term outcome of patients with asystole induced by head-up tilt test.

AIMS: To analyse the long-term outcome of the largest reported cohort of patients presenting asystole during head-up tilt test. METHODS AND RESULTS: Since 1990, 1322 patients with syncope of unknown origin have undergone tilt-table testing. Of those, 330 patients (24 X 9%) presented an abnormal response (syncope or pre-syncope). Furthermore, 58 of those patients (17 X 5%) suffered a period of asystole (> or = 3000 ms) during the test. Asystole (median (interquartile range)) lasted 10 (4, 19 X 2) s (range 3-90). Two different protocols (angles) of tilting (Westminster (60 degrees) n=1124; isoproterenol (80 degrees) n=198)) influenced the time to the syncopal episode (13 (6 X 5, 20 X 5) vs 2 (1, 6 X 5) min, P=0,0005) but not the duration of the asystole. During this period, therapy for asystole featured three different stages: first patients were treated with pacemakers; later drug therapy (metoprolol and/or etilefrine) was recommended; lastly (from 1995), no specific treatment was given. In a cohort age- and gender-matched study, those patients without were compared to those with asystole in a 2:1 basis. During 40 X 7 months of follow-up (17 X 7, 66 X 8), 12 patients (20 X 6%) with asystole had syncopal recurrences. Furthermore, 34 patients (28 X 8%) without asystole presented syncopal episodes during a follow-up of 51 X 6 months (29 X 3, 73 X 1) (P=ns). The Kaplan-Meier analysis in patients with and without asystole showed a mean time free of recurrence of 92 X 6 +/- 6 months vs 82 X 6 +/- 4 X 7 months (P=ns). The previous number of syncopes had a significant relationship with recurrences (P=0 X 002), but not therapy. There were no cardiac related deaths. CONCLUSIONS: (1) Asystole during head-up tilt test does not imply a malignant outcome and syncope recurrence is low; (2) pacemaker or drug therapy do not significantly influence outcome which correlates to the previous number of syncopal episodes but not to gender, age, asystole occurrence, asystole duration and timing to asystole during head-up tilt test; (3) tilting protocol (angle) might influence time to and incidence of asystole during head-up tilt test.

Adult↗
PubMed2000

[School-age smoking in the province of Seville. Epidemiology and influence of personal and social environment (smoking prevention campaign, 1998-1999)].

OBJECTIVE: To study the prevalence os smoking in school children in Sevilla and the influence of personal and social environment on smoking patterns. METHODS: This study was part of a preventative anti-smoking campaign in schools. Students filled in anonymous questionnaires based on the World Health Organization survey instrument for population attitudes and habits. RESULTS: We surveyed 3385 students between 10 and 19 years of age at 47 schools in Seville and 28 villages in the surrounding province. Current smoking was reported by 19.1% of the students; slightly more girls (19.8%) than boys (18.3%) smoked. Smoking was related to having an older brother or sister who smoked and particularly to having friends who smoked (OR 20.5). The adolescents reported that parents were less permissive than the rest of their environment. Smokers associated tobacco with values such as independence and freedom; they believed that smoking might have an impact on health, although their conviction was less strong than that of non-smokers, regular smokers had high expectations of continuing. CONCLUSIONS: We found a high proportion of smokers among students of both sexes. Starting and continuing to smoke during adolescence is considerably influenced by the social environment of peers and is possibly affected by messages of independence and freedom transmitted through tobacco industry advertising.

Adolescent↗
PubMed1999

Validation of logistic regression models in small samples: application to calvarial lesions diagnosis.

We have used the leave-one-out (LOO) method and the area under the receiver operating characteristic (ROC) curve to validate logistic models with a sample of 167 patients with calvarial lesions. Seven logistic regression models were developed from 12 clinical and radiological variables to predict the most common diagnoses separately. The LOO method was used to test the validity of the equations. The discriminant power of every model was assessed by means of the area under the ROC curve (Az). The model with the greatest discrimination ability for the whole data set was the osteoma equation (Az = 0.951). The discriminatory ability of the statistical models decreased significantly with the LOO procedure, having the malignancy model the highest value (Az = 0.931). The LOO method can obtain a high benefit from small samples in order to validate prediction rules. In studies with small samples, resampling techniques such as the LOO should be routinely used in predictive modeling. This method may improve the forecast of infrequent diseases, such as calvarial lesions.

Bone Neoplasms↗
PubMed1999

Validation procedures in radiologic diagnostic models. Neural network and logistic regression.

OBJECTIVE: To compare the performance of two predictive radiologic models, logistic regression (LR) and neural network (NN), with five different resampling methods. METHODS: One hundred sixty-seven patients with proven calvarial lesions as the only known disease were enrolled. Clinical and CT data were used for LR and NN models. Both models were developed with cross-validation, leave-one-out, and three different bootstrap algorithms. The final results of each model were compared with error rate and the area under receiver operating characteristic curves (Az). RESULTS: The NN obtained statistically higher Az values than LR with cross-validation. The remaining resampling validation methods did not reveal statistically significant differences between LR and NN rules. CONCLUSIONS: The NN classifier performs better than the one based on LR. This advantage is well detected by three-fold cross-validation but remains unnoticed when leave-one-out or bootstrap algorithms are used.

Adolescent↗
PubMed1998

Neurofibromatosis type 1 in children: MR imaging and follow-up studies of central nervous system findings.

PURPOSE: To determine the frequency, evolution and diagnostic impact of characteristic central nervous system MR imaging lesions in children with neurofibromatosis type 1 (NF1). SUBJECTS: We reviewed 89 children with established or clinically suspected disease. A final diagnosis of NF1 was made in 72 (age range, 10 months to 14 years). RESULTS: Hyperintense lesions on long TR images were detected in 78% of patients, principally involving the basal ganglia, cerebellum and brain stem. In 30% of the globus pallidus lesions, hyperintensity was seen on short TR images, being usually isointense on IR T1 weighted images. Globus pallidus lesions did not enhance. Eight patients presented atypical unenhanced lesions showing either edema, mass effect or hypointensity on short TR images; 2 of them were considered symptomatic brain stem gliomas. Six other children showed one or more growing enhanced cerebral lesions classified as tumors. Other child developed a growing enhanced lesion that markedly decreased in the follow-up studies. Twenty patients (28%) had optic gliomas. In two children, under 6 years old, this tumor appeared de novo. Forty-five children had several follow-up MR imaging studies (mean interval, 3 years). Regression of the basal ganglia lesions, both in size and/or intensity was noticed in 42% of cases, enlargement or new appearance of lesions in 24.5%, mixed increased/decreased in 7%, and stability in 26.5%. White matter lesions of the cerebellum and brain stem decreased in size in 40%, grew in 15.5%, showed a mixed increased/decreased pattern in 11%, and remained unchanged in 33.5% of cases. An involutional tendency of these lesions occurred in children older than 10 years, while progression was more frequent in younger children (P<0.05). CONCLUSIONS: Hyperintense lesions are highly prevalent and characteristic in patients with NF1. MR imaging contributed to a definitive diagnosis of NF1 in 53% of suspected cases. Follow-up studies are necessary in the evaluation of suspected NF1, even if the first examination is negative.

Adolescent↗
PubMed1998

Calvarial eosinophilic granuloma: diagnostic models and image feature selection with a neural network.

RATIONALE AND OBJECTIVES: The authors analyzed the accuracy of diagnostic features used by an artificial neural network compared with logistic-regression analysis in the diagnosis with computed tomography (CT) of calvarial eosinophilic granuloma. MATERIALS AND METHODS: Thirty-one of 167 patients with calvarial lesions were found to have eosinophilic granuloma. Clinical and CT data were used for logistic-regression and neural network models. Both models were tested by using the leave-one-out method. The final results of each model were compared by means of the area under the receiver operating characteristic curve (Az). RESULTS: Identification of eosinophilic granuloma was significantly more accurate with the neural network than with logistic regression (Az = 0.9846 +/- 0.0157 [standard deviation] vs 0.9117 +/- 0.0373) (P = .001). The most important diagnostic features identified with the neural network were patient age and marginal sclerosis. For logistic regression, the most important features were age, shape, and lobularity. CONCLUSION: The neural network is a useful tool for analyzing the features of calvarial eosinophilic granuloma. Age and marginal sclerosis are important diagnostic features.

Adolescent↗
PubMed1998

Focal calvarial bone lesions. Comparison of logistic regression and neural network models.

RATIONALE AND OBJECTIVES: To assess the accuracy of logistic regression (LR) and artificial neural networks (NN) in the diagnosis of calvarial lesions using computed tomography (CT) and to establish the importance of the different features needed for the diagnosis. METHODS: One hundred sixty-seven patients with calvarial lesions as the only known disease were enrolled. The clinical and CT data were used for LR and NN models. Both models were tested with the leave-one-out method. The final results of each model were compared using the area under receiver operating characteristic curves (Az). RESULTS: Of the lesions, 73.1%, were benign and 26.9% were malignant. There was no statistically significant difference between LR and NN in differentiating malignancy. In characterizing the histologic diagnoses, NN was statistically superior to LR. Important NN features needed for malignancy classification were age and edge definition, and for the histologic diagnoses matrix, marginal sclerosis, and age. CONCLUSION: NNs offer wide possibilities over statistics for the study of calvarial lesions other than their superior diagnostic performance.

Adolescent↗
PubMed1997

Eikenella corrodens skull infection: a case report with review of the literature.

BACKGROUND: Subgaleal abscesses and skull osteomyelitis are very uncommon since the introduction of antibiotics. Eikenella corrodens infection is extremely rare in childhood and has never been reported in calvarial osteomyelitis. METHODS: We present a previously healthy 9-year-old boy, with a history of frontal contusion without injury, who developed E corrodens osteomyelitis of the skull. The radiographic findings are reviewed, including skull films and computed tomographic scans. The patient underwent surgical debridement of the lesion, as well as systemic medical therapy with amoxicillin. We review the medical and surgical therapy for such lesions. The differential diagnosis of a posttraumatic scalp swelling is also reviewed. RESULTS: Good resolution after debridement and antibiotic therapy is reported. CONCLUSIONS: Surgical intervention is emphasized for the removal of bony sequestrum and nonviable bone while maintaining an intact dura.

Child↗
PubMed1996

Intradiploic epidermoid cysts.

We studied 37 intradiploic epidermoid cysts, reviewing typical and atypical radiological features and the differential diagnosis. The most common clinical feature was a long standing lump in the scalp, occurring in 25 patients (67.7%). Plain films were the most cost-effective radiological technique in diagnosis. The typical finding was a well-defined lytic lesion with sclerotic border, seen in 29 cases (78%). Atypical lesions were those larger than 5 cm and/or with an ill-defined edge, being observed in 8 cases (22%). CT and MRI were the best methods for assessing atypical ones. In all cases with typical radiological findings a preoperative diagnosis of intradiploic epidermoid cyst was suggested.

Adolescent↗
PubMed1996

Primary intraosseous meningiomas.

PURPOSE: A retrospective study was performed to evaluate the clinical, radiological and histological findings of 14 intraosseous meningiomas. MATERIAL AND METHODS: 14 histologically proved intraosseous meningiomas were studied with plain skull film and CT. Pathological records were reviewed. RESULTS: We found 9 calvarial cases and 5 spheno-orbital ones. The most common symptom in the calvarial cases was a lump in the scalp, and in the spheno-orbital lesions it was exophtalmos. Hyperostosis was present in all 5 spheno-orbital cases and in 3 out of the 9 calvarial ones; in the other 6 cases it had a mixed pattern. Enhanced dura was present in 3 calvarial cases and in 2 sphenoidal ones. Dura was involved in 5 cases: 2 with inflammatory changes, 2 with a minimal intradural tumour and one with a subdural tumour. CONCLUSION: CT better detected both the bony reaction and the intraosseous extension of the tumour. The dural changes were not specific of tumoural involvement. The differential diagnosis comprises: fibrous dysplasia, osteoma, blastic metastasis and mainly meningioma en plaque (MEP). Comparing our findings with other series, we noticed that in some cases the term MEP was used for similar cases. As the name MEP is merely descriptive and both entities share a larger number of similarities than differences, we believe that a differentiation between hyperostotic en plaque meningioma and intraosseous meningioma can hardly be made.

Adult↗