Computer graphics in medicine: a survey.

Increased interest is presently given to three-dimensional (3-D) medical applications due to simultaneous emergence of high-resolution imaging systems and computer graphics techniques. This paper intends to present a survey of this field together with discussion and prospective views. The general framework is composed of six parts: data acquisition and preprocessing, polygonal object representation, voxel description, system architecture, medical applications, and prospects. Data base acquisition includes characterization of imaging modalities and medical specificity. Preprocessing schemes are directed to improvements (filtering), windowing, and spatial anisotropy (linear or spline interpolation). The two following sections are devoted to descriptions of the main object representations. Particular emphasis is given to optimal contour approximation, surface triangulation, mathematical surfaces on one hand, and cuberille and voxel representations on the other. Display capabilities--hidden surface removal, surface normal shading, structure enhancement--and data base structuration--hierarchical and nonhierarchical (graph and tree encoding)--are, respectively, described. An overview of 3-D systems is further given (Section V), and features of medical applications are reviewed and gathered in basic functionalities, surgery, and radiotherapy specifications (Section VI). The last section provides some prospective views on reconstruction from a few projections, model-guided labeling, multimodality image overlay, and local image network. Some of these issues are illustrated by examples of 3-D images.

Intraoral juvenile xanthogranuloma. A case report and literature review.

Juvenile xanthogranuloma rarely occurs in the oral cavity and has received little attention. A case of histologically documented juvenile xanthogranuloma of the oral cavity is described. This is the first intraoral case reported in the Oriental race and in the vestibule. Pertinent literature regarding intraoral lesions of this condition is also reviewed.

Menstrual cycle worsening of epileptic seizures in women with symptomatic focal epilepsy

INTRODUCTION: Hormonal fluctuation is responsible for worsening of epileptic seizures during the menstrual cycle. OBJECTIVE: To identify irregularities in the menstrual cycles of women with mesial temporal lobe epilepsy (MTLE) and extratemporal focal epilepsy (ETFE) and correlate the frequency of seizures during the menstrual cycles. METHOD: We evaluated prospectively women in the menacme with MTLE and ETFE. Calendars were provided for these patients, and they were asked to mark their seizure frequency according to the menses. Calendars were reviewed in each routine medical appointment. RESULTS: Thirty-nine patients with MTLE and 14 with ETFE were evaluated. We registered 211 cycles in the patients with MTLE and 49 in those with ETFE. Irregular menstrual cycles were found in 28 (28/39, 71.7%) patients with MTLE and 6 (6/14, 42.8%) with ETFE (p=0.052). Premenstrual seizure worsening was observed in 46 (21.8%) patients with MTLE and 9 (18.3%) with ETFE (p=0.596). Menstrual worsening was observed in 47 (22.2%) patients with MTLE and 15 (30.6%) with ETFE (p=0.217). Ovulatory worsening was observed in 36 (17%) patients with MTLE and 13 (26.5%) with ETFE (p=0,126). Catamenial worsening was observed in 58 (27.4%) of the patients with MTLE and in 17 (34.7%) of the patients with ETFE (p=0.315). CONCLUSION: There was no difference between the group of patients with MTLE and ETFE regarding the frequency of irregular cycles and seizure worsening during the premenstrual, menstrual, catamenial or ovulatory periods.

INTRODUÇÃO: Admite-se que a flutuação hormonal seja a responsável para a piora de crises epilépticas no período catamenial. OBJETIVO: Identificar irregularidades nos ciclos menstruais de mulheres com epilepsia de lobo temporal mesial (ELTM) e epilepsia focal extratemporal (EFET); e relacionar a frequencia de crises durante o ciclo menstrual. MÉTODO: Avaliamos mulheres na menacme, que apresentem quadro clínico laboratorial compatível com ELTM e EFET. Foram fornecidos calendários para estas pacientes e instruídas para preenchimento correto da menstruação e das crises epilépticas e serão revistos em cada consulta médica rotineira. RESULTADOS: Foram avaliadas 39 pacientes com ELTM e 14 com EFET. Registramos 211 ciclos nas pacientes com ELTM e 49 nas com EFET. Ciclos menstruais irregulares foram apresentados por 28 (71,7%) pacientes com ELTM e 14 (42,8%) com EFEP (p=0,052). Piora pré-menstrual foi observada em 46 (21,8%) pacientes com ELTM e 9 (18,3%) com EFET (p=0,596). Piora menstrual foi observada em 47 (22,2%) pacientes com ELTM e 15 (30,6%) com EFET (p=0,217). Piora ovulatória foi observada em 36 (17%) pacientes com ELTM e 13 (26,5%) com EFET (p=0,126). Piora catamenial foi observada em 58 (27,4%) das pacientes com ELTM e em 17 (34,7%) das pacientes com EFET (p=0,315). CONCLUSÃO: Não houve diferença entre os grupos de pacientes com ELTM e EFET quanto à freqüência de ciclos irregulares e piora das crises nos períodos pré-menstrual, menstrual, catamenial ou ovulatório.