Comparison of 80 and 120 kVp contrast-enhanced CT for attenuation correction in PET/CT, using quantitative analysis and reporter assessment of PET image quality.

AIM: To determine the effect of low tube voltage on positron-emission tomography (PET) image quality, quantitative analysis, and radiation dose in a combined PET/computed tomography (CT) study in patients with normal body mass index (BMI). MATERIALS AND METHODS: One hundred and twenty-nine examinations performed in 46 patients (mean age 57 years), who had at least two separate studies were retrospectively evaluated; at least one with 120 kVp and one with 80 kVp. Three independent readers reviewed all PET images and graded the image quality. PET signal and noise were recorded on the liver, spleen, fat, bone marrow, and aorta. CT dose index (CTDI) and the dose-length product (DLP) were used for CT radiation dose estimation. A mixed-effects model analysis was used for comparison of estimated radiation dose and PET data. RESULTS: There was a significant decrease of 15% in the radiation dose estimates between 80 and 120 kVp (DLP 946.2 ± 189 versus 1157.0 ± 236, respectively; p < 0.001). There was an increase of 12% in PET signal in the normal liver with 80 kVp. The average score of PET image quality obtained between 80 and 120 kVp was 4.85 ± 0.42 versus 4.90 ± 0.27, respectively (p = 0.47). CONCLUSION: PET/80 kVp CT has no statistically significant difference in the PET image quality and quantitative analysis compared to PET/120 kVp and may be used in selected patients to reduce the radiation dose.

[An atypical discipline: surgery in bullfighting. Two case reports]. / Une discipline atypique: la chirurgie taurine. A propos de deux observations.

Many bullfighters had been seriously injured, even sometimes killed during the fight in the bullring (around 300 deaths since the beginning of the 20th century). There is no comparison between bullfight's traumas and civil or war traumas, so only specialized medicine doctors and surgeons can be involved for practising. Surgery of bullfighting is a single speciality. The bullfight's surgeon in safekeeping will operate immediately in the bullfight place's infirmary and will aim at reducing the deep effect of horn injury. In this work, authors point out the bullfight pathology's complexity and its surgical treatment by presenting two original cases.

Computerized classification of congenital malformations using a modified Bayesian approach.

The diagnostic classification of children with dysmorphic features involves over 200 syndromes and 232 findings, with an average of about 15 findings per syndrome. A knowledge base expressed in terms of Boolean combinations of findings is impractical. The normal Bayesian method requires a very large incidence matrix with the vast majority of cells being zero. A modified Bayesian method is proposed in which each syndrome is described in terms of its associated findings, whose incidence P (S/D) are designated as essential (0.90), prevalent (0.90), occasional (0.70) or rare (0.15), whilst P(S/-D) ranged from (0.08) to (0.10). The Bayesian calculation determines the probability of the presence P(D/S) or the absence P(-D/S) of each syndrome. The differential diagnosis consisted of all syndromes whose presence has a probability greater than 0.85. One hundred and thirty-one cases from the Hanna Khoushi Developmental Pediatrics Center at Haifa's Rothschild Hospital were considered. Of the 42 cases for which the center's specialists reached a diagnosis, the system listed the correct diagnosis for 91%. The system reached a diagnosis in about half of the remaining 89 cases. The medical literature is arranged by syndrome whilst the computer allows a case by case approach, thereby avoiding the need for the physician to consider each syndrome to see if it fits his case. This study shows that our modified Bayesian analysis is a valid method for shortening the physician's search in an area of great diagnostic complexity.