MRI spectroscopy in screening of prostate cancer.

BACKGROUND: The purpose of this study was to evaluate the suitability of MR Spectroscopy in screening for prostate cancer in comparison to T2-weighted MR imaging. MATERIALS AND METHODS: Forty-six patients with biopsy confirmed prostate cancer underwent combined endorectal-body-phased-array MRI at 1.5T (Tesla). Twelve patients were additionally examined with 3D-spectroscopy sequence. The results of the spectroscopy were compared with the findings of T2-weighted MR imaging and the histological examination of radical prostatectomy specimens. RESULTS: With 3D-spectroscopy, a choline+creatine/citrate-ratio of 0.45 for healthy tissue and a ratio of 1.90 for tumor tissue were found and a significant difference between the groups was demonstrated. In 6 cases diagnosis of tumor localization was improved with spectroscopy in comparison with T2-weighted imaging alone. CONCLUSION: 3D-spectroscopy is a suitable technique for improving MR imaging of prostate cancer. This method can improve the diagnostic accuracy of T2-weighted imaging alone. At present, 3D-CSI spectroscopy alone can not be recommended with sufficient validity.

The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations.

The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community.