[Diagnostic evaluation of the breast using PET: optimization of data acquisition and postprocessing].

Purpose: Development and evaluation of an optimized protocol for PET examinations of the female breast with 2-F-18-fluoro-2-deoxyglucose (F-18-FDG).

Methods: All PET measurements were performed with a whole-body PET system (ECAT EXACT HR+). In order to examine the women with the breasts freely pendant, a special extension for the patient table made of carbon layer composite was designed.

[Reduction of radiation exposure in PET examinations by data acquisition in the 3D mode].

Aim: Modern volume PET systems offer the possibility to measure without the shadowing effect of interplane septa (2D mode) and thus to detect coincident events between detectors on distant rings (3D mode). It was the aim of the present paper to characterize the count rate behaviour of a latest-generation whole-body PET system in the 2D and 3D mode as well as to discuss the consequences for the radiation hygiene of PET examinations with 2-[F-18]-fluoro-2-deoxyglucose (18-F-FDG).

Methods: All experiments were performed with the PET system ECAT EXACT HR+.

Noninvasive determination of the arterial input function of an anticancer drug from dynamic PET scans using the population approach.

For the application of a kinetic model to PET data, it is generally necessary to obtain the arterial input function (AIF). It was the aim of the present study to introduce a method suitable for the determination of the AIF of a substance that undergoes biochemical transformation from noisy PET data: the population approach. F-18 labeled 5-fluorouracil (5-[18F]FU) was administered i.

[Clinical experiences with direct magnification mammography with the DIMA Plus M11].

Objective: The evaluation of mammographies carried out by conventional technique (standard imaging and focal imaging with 1.9x magnification) should be compared with a direct magnification image (standard imaging with 1.7x magnification, focal imaging with 4x magnification and preparation imaging with 7x magnification) provided by the mammographic device DIMA Plus M11 of the company feinfocus Medizintechnik.

[Investigation of the signal-to-noise ratio on a state-of-the-art PET system: measurements with the EEC whole-body phantom].

Aim: The spatial resolution of PET scanners can be improved by using smaller detector elements. This approach, however, results in poorer counting statistics of the reconstructed images. Therefore, the aim of this study was to investigate the influence of different acquisition parameters on the signal-to-noise ratio (SNR) and thus to optimize PET image quality.

[Optimization of PET image quality by means of 3D data acquisition and iterative image reconstruction].

Purpose: In the recent past, several algorithms have been developed in order to transform 3D sinograms acquired at volume PET systems into 2D data sets. These methods offer the possibility to combine the high sensitivity of the 3D measurement with the advantages of iterative 2D image reconstruction. The purpose of our study was the assessment of this approach by using phantom measurements and patient examinations.

Performance evaluation of a whole-body PET scanner using the NEMA protocol. National Electrical Manufacturers Association.

Unlabelled: This study evaluates the performance of the newly developed high-resolution whole-body PET scanner ECAT EXACT HR+.

Methods: The scanner consists of four rings of 72 bismuth germanate block detectors each, covering an axial field of view of 15.5 cm with a patient port of 56.

[Quality assurance in roentgen mammography. Comparison of recommended EUREF guidelines with relevant German regulations].

The Program "Europe against Cancer" published the 2nd edition of quality assurance guidelines for breast cancer screening in June 1996. For the enforcement of these guidelines, a European network of reference centres (EUREF) is being established. Although the EUREF protocol contains guidelines for all disciplines involved in breast cancer screening, this article concentrates on the physical and technical aspect.

Automatic identification of gray matter structures from MRI to improve the segmentation of white matter lesions.

The segmentation of MRI scans of patients with white matter lesions (WML) is difficult because the MRI characteristics of WML are similar to those of gray matter. Intensity-based statistical classification techniques misclassify some WML as gray matter and some gray matter as WML. We developed a fast elastic matching algorithm that warps a reference data set containing information about the location of the gray matter into the approximate shape of the patient's brain.