Are Gadolinium-Enhanced MR Sequences Needed in Simultaneous 18F-FDG-PET/MRI for Tumor Delineation in Head and Neck Cancer?

BACKGROUND AND PURPOSE: PET/MRI with 18F-FDG has demonstrated the advantages of simultaneous PET and MR imaging in head and neck cancer imaging, MRI allowing excellent soft-tissue contrast, while PET provides metabolic information. The aim of this study was to evaluate the added value of gadolinium contrast-enhanced sequences in the tumor delineation of head and neck cancers on 18F-FDG-PET/MR imaging. MATERIALS AND METHODS: Consecutive patients who underwent simultaneous head and neck 18F-FDG-PET/MR imaging staging or restaging followed by surgery were retrospectively included. Local tumor invasion and lymph node extension were assessed in 45 head and neck anatomic regions using 18F-FDG-PET/MR imaging by 2 rater groups (each one including a radiologist and a nuclear medicine physician). Two reading sessions were performed, one without contrast-enhanced sequences (using only T1WI, T2WI, and PET images) and a second with additional T1WI postcontrast sequences. The results were compared with the detailed histopathologic analysis, used as reference standard. The κ concordance coefficient between the reading sessions and sensitivity and specificity for each region were calculated. RESULTS: Thirty patients were included. There was excellent agreement between the contrast-free and postgadolinium reading sessions in delineating precise tumor extension in the 45 anatomic regions studied (Cohen κ = 0.96, 95% CI = [0.94-0.97], P < .001). The diagnostic accuracy did not differ between contrast-free and postgadolinium reading sessions, being 0.97 for both groups and both reading sessions. For the 2 rater groups, there was good sensitivity for both contrast-free (0.83 and 0.85) and postgadolinium reading sessions (0.88 and 0.90, respectively). Moreover, there was excellent specificity (0.98) for both groups and reading sessions. CONCLUSIONS: Gadolinium chelate contrast administration showed no added value for accurate characterization of head and neck primary tumor extension and could possibly be avoided in the PET/MR imaging head and neck workflow.

Use of the lapidus bunionectomy in first ray insufficiency.

Surgical management of first ray insufficiency in HAV or hallux limitus is crucial to long-term success. Although technically demanding, the Lapidus fusion serves to address the deformity at its apex and restores normal weight bearing to the foot. This arthrodesis offers predictable, durable results in addressing various first ray deformities and occupies an important place in the foot and ankle surgeon's armamentarium. The authors' technique is described herein for the interest of and evaluation by surgeons performing this procedure. As clinicians recognize the importance of addressing proximal components of the HAV deformity, the Lapidus and other procedures will likely see increased use in the surgical management of first ray deformities.

Lesser metatarsal stress fractures.

Stress fractures continue to be a fact of military life. With appropriate attention to training issues, shoe gear, and physical training activities, however, their effect can be minimized.

Genealogy, natural history, and phenotype of Alström syndrome in a large Acadian kindred and three additional families.

We describe a large Acadian kindred including 8 Alstrom Syndrome (AS) patients, with an age range of 4 to 26 at the time of clinical assessment. The affected subjects come from 5 nuclear families within this kindred. The phenotype includes early childhood retinopathy, progressive sensorineural hearing loss, truncal obesity, and acanthosis nigricans. In addition, hyperinsulinemia and hypertriglyceridemia with normal cholesterol levels were observed in most affected individuals tested. Non-insulin dependent diabetes mellitus and growth retardation appear to be age-related manifestations that occur post-adolescence. Younger affected children are not overtly hyperglycemic and are normal or above average height for age. Although the AS patients in kindred 1 presumably carry the same mutation, many manifestations of the disease are variable. For example, of the 8 children in the Acadian kindred, 4 have scoliosis, 2 have had infantile cardiomyopathy, 2 are hypothyroid, 1 has had hepatic dysfunction and is hypertensive, and 4 have developed asthma. Seven subjects described in this kindred exhibit developmental delay. One additional manifestation not described widely in the literature, advanced bone age, was observed in all subjects tested. The clinical data from this large Acadian kindred, together with information obtained from 4 additional AS patients in 3 unrelated kindreds, confirm and extend clinical observations previously described. In addition, the Acadian kindred with multiple affected individuals, probably arising from a common founder, should allow for identification of the chromosomal localization of a gene causing AS.

[Malaria epidemic during a military-humanitarian mission in Africa]. / Epidémie de paludisme au cours d'une intervention militaro-humanitaire en Afrique.

A malaria epidemic broke out among French servicemen during a humanitarian military mission carried out in Central Africa in 1996. The purpose of this study was to determine compliance with drug prophylaxis for malaria by measuring blood levels of antimalarial drugs (combination treatment using chloroquine-proguanil or treatment with doxycycline) as well as to assess the conditions of vector control. The incidence density rate of malaria over a 60-day period was 3.1 cases per month per 100 men. Only reinforcement troops were affected. The risk of developing malaria was 5 times higher among new arrivals than in servicemen who had been in the zone for several months (95% CI relative risk = [2.9-7.8]). Type of prophylactic treatment had no effect on the incidence density rate. Study data showed that 40.2% of those treated for malaria were not in compliance with prophylactic treatment at the time of the malarial attack and that those who were in compliance with prophylaxis, i.e. the remaining 59.8%, presented a strain of plasmodium that was resistant to the prophylactic drugs at doses used. Findings also indicated the epidemic occurred mainly because operating conditions prevented implementation of proper vectorial control. The risk of epidemic could probably have been reduced by improving compliance with prophylactic treatment and changing standard vectorial control techniques, e.g. by using insecticide-treated uniforms.

[Current status of dengue virus infections. Epidemiologic and pathogenetic aspects]. / Actualités des infections à virus dengue. Aspects épidémiologiques et pathogéniques.

The epidemiology of dengue fever is changing dramatically. The worldwide incidence is rising and clinical symptoms are worsening. Reports describing forms associated with hemorrhage or shock syndrome involving both children and adults are increasingly frequent in regions beyond Southeast Asia where the first cases were observed. Many mechanisms could be implicated in these changes including modifications of the virus, host, vector, or socioeconomic factors. Since no current model allows laboratory analysis of these mechanisms, observation of epidemics is still a major source of data. The findings of well conducted epidemiological studies allow not only assessment of morbidity and mortality in endemic areas and early detection of epidemic outbreaks but also evaluation of socioeconomic impact and effectiveness of control measures. Surveillance techniques must be chosen in function of prevailing local conditions. To ensure reliable results studies should be carried out in collaboration with an international network and a simple and accurate method of disease identification should be used.

[Control of an epidemic of meningococcal meningitis in Central Africa]. / Contrôle d'une épidémie de méningite à méningocoque en Afrique centrale.

A severe epidemic of group A meningococcal disease occurred in the northwest part of the Central African Republic from January to March 1992. The outbreak affected a large and densely populated area, with a poor road network, located 400 kilometers south of the classical meningitis belt. An initial selective vaccination campaign was carried out by the national health care service. As the epidemic was continuing, the national authorities asked for international assistance. The French participated by sending Bioforce, a medical task force designed by the Ministry of Defense, with the financial support of the Ministry of Cooperation. Neisseria meningitidis strains were isolated and identified within 36 hours by the Bioforce field laboratory. Strains from 24 patients were sent to the Pasteur Institute in Paris (Neisseria Unit) for serotyping, testing of antibiotic susceptibility, and multilocus enzyme electrophoresis. With one exception, all strains had formula A:4:P1.9. By an initial rapid assessment, the limits of the affected area and populations were determined. The weekly incidence rates observed in different areas varied within a range of 3 to 10 cases per 1,000, with fatality rates from 20 to 30 cases per 100. The spread of the epidemic was stopped by a mass vaccination campaign, which targeted the entire population (200,000 immunizations) of the affected area. The case fatality rate could not be reduced below 15%, despite antimicrobial treatments implemented as soon as possible. The optimal treatment was the standard single intramuscular injection of oily chloramphenicol. The predictive values of clinical symptoms were calculated. The efficacy of vaccination was estimated by comparison of the percentage of people immunized and the proportion of those vaccinated people who developed meningitis identified during the 3 weeks following the mass vaccination campaign. The efficacy varied between 93 to 95% according to the place. The typical weekly incidence rate of 1 case per 1,000 is not a relevant threshold to sufficiently and immediately detect a meningitis outbreak and needs to be reconsidered.

The electroretinographic diagnosis of the incomplete form of congenital stationary night blindness.

Fifteen patients with the incomplete form of congenital stationary night blindness (iCSNB) were reviewed to better characterize their electroretinographic (ERG) findings in view of differential diagnosis with other retinal conditions also presenting with negative bright-flash ERG responses. In all 15 patients, in dark-adapted conditions, the bright-flash ERG response had a normal a-wave followed by a subnormal b-wave. Oscillatory potentials (OPs) observed on the ascending limb of the b-wave, although delayed in implicit time, were of large amplitude. The response to a long-wavelength stimulus showed cone-related components and some well-delineated OPs. On the other hand, the photopically elicited cone responses were strongly abnormal, with a subnormal a-wave followed by a barely recordable b-wave. No OPs could be elicited under photopic conditions. The cone related components and the OP characteristics clearly distinguish iCSNB from the complete form of CSNB and other retinal conditions presenting with minimal fundus abnormalities but with negative bright-flash ERG responses, such as found in Duchenne muscular dystrophy and Aland Island eye disease. The severely abnormal post-synaptic components in the photopic recordings contrast with the well-differentiated cone activity evoked in scotopic conditions. We propose a cone system that does not respond optimally under the normal operating range (photopic) but rather under mesopic or scotopic conditions. In spite of the severe cone-ERG deficits, visual acuity was only slightly reduced. We propose that the defect, which interferes marginally with the neuronal flow of information, lies in the structures responsible for the building of the b-wave.

[Drinking water for troops in the field]. / Alimentation en eau des troupes en campagne.

To provide for Armed Forces' water wants, drinking water is only used. Its production is not an easy thing in military operations. Armed Forces must use their own production means. Four new individual and collective field purification systems adapted to manpower, will been soon in use in the French Army. Filtration or distillation processes always with chlorine addition are used. The results give satisfaction in bacterial epuration; nevertheless chemical and nuclear risks are not controlled except in case of distillation mechanism associated with ion resins exchanging and charcoal filtration.