RESUMO
BACKGROUND: No gold standard exists for renal volumetry in vivo. PURPOSE: To devise and evaluate segmentation methods on magnetic resonance imaging (MRI) datasets. MATERIAL AND METHODS: Five combinations of MRI pulse sequences and measuring methods were used to measure the renal volumes of five men aged 54-72 years scanned before autologous renal stem cell transplantation and three, six, and 12 months post transplantation. RESULTS: Renal volume did not change after stem cell transplantation. The results varied considerably: the reproducibility (coefficient of variation) was 4.0-6.0% and measurements took 1-13 min per kidney. Manual segmentation of images from the volumetric interpolated breath-hold examination (VIBE) without fat saturation sequence provided best reproducibility but was time-consuming. Use of the ellipsoid formula from half Fourier acquisition single shot turbo spin echo (HASTE) provided the fastest measurement, but resulted in lower reproducibility. CONCLUSION: Renal volumetry based on images from the pulse sequence VIBE without fat saturation acquired using an out-of-phase TE may be investigated further, possibly in combination with the quick ellipsoid formula.
RESUMO
BACKGROUND: An understanding of the relationships among allelic variability and clinical outcomes will be critical if HIV-infected patients are to benefit from the explosion in knowledge in human genomics. Human DNA banks must allow future analyses while addressing confidentiality, ethical, and regulatory issues. METHOD: A multidisciplinary group of clinical investigators, ethicists, data managers, regulatory specialists, and community representatives developed Adult AIDS Clinical Trials Group (AACTG) Protocol A5128. Participants in past or present AACTG clinical trials may contribute DNA. Extraction from whole blood is performed at a central laboratory, where participants' unique identifiers are replaced by randomly assigned identifiers prior to DNA storage. To identify genotype-phenotype relationships, genetic assay results can be temporarily linked to clinical trials data. RESULTS: Institutional review boards in 21 states and Puerto Rico have approved Protocol A5128, and accrual is ongoing. Of the first 4,247 enrollees, 82% are male, 56% are white, 26% are African American, and 15% are Hispanic. Because participants may participate in multiple AACTG protocols, these represent 11,424 cases in 324 different AACTG studies and substudies, with at least 100 participants from 24 different studies. Studies exploring specific genotype-phenotype relationships are underway. CONCLUSION: The AACTG DNA bank will be an important resource for genomic discovery relevant to HIV therapy.
