Practical Application of Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-Squares Estimation (IDEAL) Imaging in Minimizing Metallic Artifacts

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter.

Craniopharyngiomas: Predictive Factors of Recurrence

OBJECTIVE: The authors present a retrospective analysis of the long-term recurrence rate for the 79 craniopharyngima patients surgically treated between Jan 1989 and Dec 1999. METHODS:Tumor recurrence rates were analysed with respect to age of patients, symptom duration, tumor size, localization of tumor, morphology of tumor, the extent of surgical resection, pathologic diagnosis and the other treatment modalities. RESULTS: For 79 patients, with a mean follow-up period of 5 years, the overall recurrence rate was 29%. Factors associated with decreased risk of recurrence was gross total tumor resection(p=0.01). Subtotal resection was associated with increased risk of tumor recurrence. The adjuvant radiation therapy was revealed efficient not in decreasing recurrence rate but in the delay of tumor recurrence time(p=0.05). There were no differences in recurrence rates for other factors. CONCLUSION: A rigorous evaluation of recurrence for craniopharyngima must consider the extent of resection, as judged by postoperative imaging. Adjuvant radiation therapy or Gamma knife surgery could be the effective treatment modalities.