The Evaluation of Optimal Image Quality for Bone Scintigraphy

• Main Authors: Cheng-Kai Huang, 黃政凱
• Other Authors: Kai-=Yuan Cheng
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/24284570970007737102

碩士 === 中臺科技大學 === 放射科學研究所 === 95 === ABSTRACT Objective: This study has assessed an optimal protocol and parameters for bone scintigraphy. Four image-quality parameters were considered clinically: patient hydration, time interval between injection and bone scanning, injection activity of 99mTc-methylene diphosphonate (Tc-99m MDP), and scan speed of the gamma camera. The main purpose of this study is to introduce a new insight using Taguchi-Methodology in medical image field to assess which factor and a combination of angiographic level are of importance in bone scintigraphy of nuclear medicine. Materials and methods: Forty-five volunteer female patients without clinical evidence of renal disease were enrolled in this study. A Taguchi’s L9 array was used to generate nine different designs of angiographic levels. Four controllable factors were selected for this study, and three levels for each as the following combinations: (A) three hydration (500ml, 1000ml, 1500ml), (B) three time interval (2 hr,3 hr, 4 hr), (C) three injection activity (15 mCi, 20 mCi, 25 mCi), and (D) three scan speed (12 cm /min, 14 cm /min, 16 cm /min). A statistical analysis, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to estimate the optimum level of each controllable factor and to analyze the effect of these factors respectively. Results: The optimal levels combination obtained by the S/N ratio to get the highest image quality for bone scintigraphy is at level ‘1’ of hydration, level ‘3’ of time interval, level ‘3’ of injection dose, and level ‘3’ of scan speed. The analytical results also indicated that dominant parameters were injection activity of Tc-99m MDP and time interval. Notably, time interval was the most dominant variable. Strong cross interaction can be detected between hydration and time interval, No obvious cross interaction can be detected between injection dose and time interval, and strong cross interaction can be detected between scan speed and time interval. Conclusions: The setting of 4 hr (delayed time) and 25 mCi (injection activity) obtains the best image quality for bone scintigraphy. In addition, this study was also showed a revised technique coupled with Taguchi-Methodology in medical image field and enabled us to analyze influences of the various factors and to find the optimal combination of essential parameters.