A novel method for the optimization of positron emission tomography scanners imaging performance.

Objective: The aim of the present study was to propose a comprehensive method for positron emission tomography (PET) scanners image quality assessment, by simulation of a thin layer chromatography (TLC) flood source with a previously validated Monte Carlo model.

Methods And Materials: We used the GATE Monte Carlo package (GEANT4 application for tomographic emission) and the reconstructed images were obtained using the software for tomographic image reconstruction (STIR), with cluster computing. The PET scanner used in this simulation study was the General Electric Discovery-ST (USA).

A novel easy-to-use phantom for the determination of MTF in SPECT scanners.

Purpose: To evaluate modulation transfer function (MTF) in single photon emission computed tomography (SPECT) systems using the line spread function (LSF) method and a novel flood source which can be easily fabricated with materials accessible in hospital facilities.

Methods: A Tc-99m-based flood source (E(γ) = 140 keV) consisting of a radiopharmaceutical bound to the grains of a radiographic film was prepared in laboratory. Various films and radiopharmaceuticals were examined, in order to obtain a thin homogenous and reproducible flood source.

[Cutaneous melanoma; diagnostic procedures and their evaluation in diagnosing and mapping sentinel nodes. Part 2].

The second part of this review describes the advantages, and evaluates the radionuclide-guided methods for sentinel lymph node localization and also evaluates the intraoperative application of the blue dye technique in melanoma. By combining the two techniques, the detection rate rises to 96%-98%. The presence of cancer cells in the sentinel node is histopathologically shown by using hematoxylin-eosin and by using sensitive techniques for the detection of micrometastases.

[Cutaneous malignant melanoma; diagnostic procedures and their evaluation in diagnosing and mapping sentinel nodes].

Cutaneous malignant melanoma represents 4% of all the malignant neoplasms. Nevertheless, 79% of the fatal malignant skin diseases are attributed to melanoma. In melanoma patients, the most important prognostic factor is the regional lymph node invasion.