目的 观察临床基线资料无统计学差异的格雷夫斯病（Graves’ disease，GD）患者首次131I治疗时采用甲状腺CT估算重量法与甲状腺静态ECT核素显象估算法的区别，并比较两种不同方法短期疗效的差异。方法 根据年龄、病程、甲状腺大小、甲状腺吸碘率、有效半减期、每克甲状腺计划131I治疗量等标准化条件筛选解放军307医院2007年1月至2008年12月之间首次采用131I治疗的GD患者，采用CT估算甲状腺重量者纳入试验组，采用ECT核素显象估算甲状腺重量者纳入对照组。入组患者同时行甲状腺超声估重为参照，比较甲状腺CT与ECT估重结果的差异。两组采用相同131I计算公式及给药方式，治疗3月后根据临床症状、甲状腺功能检查结果判定疗效（无效、部分缓解、完全缓解、甲状腺功能减退），比较两组间疗效差异。结果 112例患者最终符合入组条件，试验组60例，观察组52例，两组间临床基线资料无统计学差异。试验组甲状腺CT估重大于B超估重（70.28±18.39g vs 50.21±13.82g，P＜0.05）且直线正相关（r=0.903，P＜0.05）；对照组甲状腺ECT估重大于B超估重（79.26±24.57g vs 42.22±13.02g，P＜0.05）且直线正相关（r=0.880，P＜0.05）。ECT与B超估重的差值大于CT与B超的差值（37.03±14.50g vs 20.06±8.31g，P＜0.05）。随访3月后观察疗效，2组治疗无效率无统计学差异（3/60 vs 1/52，P＞0.05）。试验组完全缓解率36.6%（对照组53.9%），部分缓解率51.7%（对照组25.0%），甲状腺功能减退发生率6.7%（对照组19.2%）,2组疗效差别有统计学意义（P＜0.05）。结论 甲状腺CT估重值大于B超值，小于ECT估重值。131I治疗GD时采用CT估重法总体有效率与ECT估重法相当，多数表现为好转，虽然治愈率低于ECT估重，但甲状腺功能减退发生率也低。

Objective To explore the difference between the mass of the thyroid determined by Computed Tomography (CT) and Emission Computed Tomography (ECT) scan in Graves’ disease (GD) patients with equivalent baseline clinical characteristics before they get their first 131I treatment, and to compare the short-term treatment effects between the patients whose thyroid gland masses were estimated by the two different ways. Methods Graves’ disease patients who were treated with 131I for the first time between Jan.2007 and Dec.2008 in PLA 307 hospital were included, whose age, length of disease course, thyroid size, thyroid iodine uptake rate, 131I effective half-life and planed 131I dosage per kilogram thyroid mass all met the inclusion criteria of this trial listed in the article below. Then patients were evaluated with CT (test group) and ECT (control group) to calculate their thyroid mass value. The ultrasound test was performed to estimate their thyroid weight which was used as a reference parameter to be compared with the CT and ECT results. The same formula was used to calculate the 131I treatment dosage and the same drug delivery method in both test and control group. 3 months later, and the patients’ therapeutic effects (invalid, improved, cured and hypothyroid) were evaluated in accordance with their clinical symptoms and thyroid function test results, and made comparisons between test and control group patients. Results In total, 112 patients were included in this study (60 in test group, 52 in control group, none statistically significant difference in baseline between two groups). CT determined thyroid mass value was higher than ultrasound result (average 70.28±18.39 vs 50.21±13.82，P＜0.05; linearly dependent, r=0.903，P＜0.05 ), ECT determined mass value was also higher than ultrasound result (average 79.26±24.57g vs 42.22±13.02g，P＜0.05; linearly dependent, r=0.880，P＜0.05 ).The average mass in ECT group was more heavier than that of in CT group (mean deviation from ultrasound result, 37.03±14.50g vs 20.06±8.31g，P＜0.05 ). After 3 months follow-up, there was no difference in invalid patient rate between the two groups (3/60 vs 1/52，P＞0.05), and there was more improved (51.7% vs 25.0%) but less cured (36.6% vs 53.9%) and hypothyroid (6.7% vs 19.2%) patients in test group (P＞0.05). Conclusion The mass of the thyroid gland determined by CT is heavier than that determined by ultrasound but lighter than the ECT test result. Compared to ECT evaluation, using CT scan to evaluate thyroid weight, more patients with GD treated by 131I get improved but less be cured and converted to hypothyroidism, though the valid rate (improved, cured and hypothyroid in all) is similar in two groups