Alignment of volume MR images and high resolution [18F]fluorodeoxyglucose PET images for the evaluation of patients with brain tumors.

PURPOSE: The goal of the study was to investigate the use of automated registration techniques for interpretation of volume MR and high resolution FDG-PET images that were obtained from patients with brain tumors. METHOD: Twenty-one patients with brain tumors were studied on one or more occasions using MRI and high resolution FDG-PET. The data were aligned using automated volume- and surface-matching algorithms. Composite images comprising the resliced pre- and postgadolinium spoiled GRE, T2-weighted SE, and PET data were constructed to correlate intensities of regions on the PET images with regions that corresponded to normal gray matter, white matter, and gadolinium enhancement. RESULTS: The accuracy of registration between the MR and PET images was estimated to be within 1-2 mm based upon the distance between surfaces of the outside of the head. In 12 of the 24 examinations, there were diagnoses of recurrent tumor, with only 5 of these exhibiting regions of higher FDG uptake than normal gray matter. For 19 of the 24 studies, the anatomic context provided by the registered MR images was found to be important in distinguishing recurrent tumor from necrosis based upon FDG uptake. CONCLUSION: The automated alignment was found to be an important factor in interpreting the high resolution PET images. This was particularly true for small lesions close to the cortex and for situations where FDG uptake had been reduced by prior treatment with radiation therapy.

[Influence of adenoidal vegetation on rhinopharyngeal obstruction: cephalometric study]. / Influenza delle vegetazioni adenoidee sulla pervietà rinofaringea: studio cefalometrico.

In this paper, the Authors propose a new method of cephalometric visualization of adhaenoids, in order to verify the amount of them as cause of an obstructive pathology. In this evaluation, related to a group of 100 individuals, was found an inversely proportional relation between adhaenoid's volume and angolar value of FHBoPA angle.

[Incidence of enamel fissures in a group of orthodontic patients. In vivo study]. / Incidenza di fessure dello smalto in un campione di popolazione sottoposta a terapia ortodontica: studio in vivo.

In this paper, the Authors researched the frequence of enamel fissures in a group of 75 individuals. Particular attention was dedicated to the search of such anomalies on teeth treated with multibracket orthodontic appliances, in order to prove a causal nexus between the fissures and the appliances used. After a long term experience, it was found that enamel fissures are a frequent found in almost 60% of the sample examined; moreover, the Authors cannot prove an increment of cracks in subjects treated with multibracket appliances. It was concluded that the whole of the fissures founded, would be considered as preexistent to the positioning of the brackets, even if it cannot be excluded that an excessive torque, or an inadequate debonding technique couldn't produce a mechanical stress on the enamel surface capable to enhance such cracks.