目的 探讨纵横比(A/T)在CT鉴别甲状腺结节良恶性的临床价值.方法 选取甲状腺结节患者152例,术前均行甲状腺CT检查,共183个不同性质结节.按照病理结果将其分为良性和恶性2组.由2名有10年以上工作经验放射科医生测量各甲状腺结节前后径、左右径、A/T.应用Kruskal-Wallis检验对比3个指标在良、恶性甲状腺结节之间的统计学差异,绘制A/T鉴别甲状腺良恶性结节的受试者工作特征(ROC)曲线,计算曲线下面积(AUC).通过计算约登指数选择合适的诊断临界值.结果 甲状腺良、恶性结节的前后径、左右径及A/T均有统计学差异.良性结节前后径为(18.0±9.7)mm,恶性结节前后径为(14.0±8.1)mm(P=0.032);良性结节左右径为(17.0±9.9)mm,恶性结节左右径为(11.4±6.6)mm(P=0.001);良性结节的A/T为1.0±0.2,恶性结节的A/T为1.3±0.3(P=0.000).A/T诊断甲状腺结节良恶性的AUC为0.742.当参照超声标准,选择1.0为诊断临界值时,约登指数为0.30,敏感性为79.4％,特异性为51.0％.最佳诊断临界值为1.2,约登指数为0.46,敏感性为61.8％,特异性为84.6％.结论 在甲状腺结节CT检查中,应用A/T判断甲状腺良恶性结节具有较高的诊断效能及临床意义.CT诊断甲状腺结节良恶性的A/T临界值应选择1.2,即当结节的A/T≥1.2时,结节多为恶性.

目的 评估MR多模态成像对乳腺良恶性病变的诊断价值.方法 170例患者(181个病灶)进行MR扫描.除了MR常规序列平扫,还依次行DWI、T1加权动态增强扫描(DCE-T1 WI)、灌注加权成像(PWI).各序列诊断结果与病理结果对照分析,最后MR多模态成像联合应用进行综合分析.结果 ADC值、洗进图、洗出图、阳性强化积分图(PEI)及结合图灌注参数值在乳腺良恶性病变的组间差异均有统计学意义(P＜0.05),AUC分别为0.883、0.671、0.853、0.588、0.684,洗出图灌注参数值与ADC值的AUC无统计学差异(P=0.442).ADC值、TIC、洗出图灌注参数值及MR多模态成像联合应用综合诊断的灵敏度分别为80.3％、85.7％、76.3％、96.2％,特异度为93.3％、82.9％、89.5％、88.2％,约登指数为73.6％、68.6％、65.8％、84.4％.结论 ADC值、TIC、PWI对乳腺良恶性病变的诊断及鉴别诊断具有较高价值.ADC值与洗出图灌注参数值具有较高的诊断预测性.洗出图灌注参数值可作为诊断依据之一.MR多模态成像联合应用能够提高乳腺疾病诊断的灵敏度和约登指数.

Objective: To evaluate and compare the value of high resolution computed tomography(HRCT) and magnetic resonance imaging(MRI) in the diagnosis of middle ear cholesteatoma. Methods: Retrospectively analyzed 55 patients(63 ears) with clinically suspected middle ear cholesteatoma who received both 16-slice HRCT and 1.5T MR scanning within 5 days before operation.HRCT and MRI were compared based on pathology and performed statistical analysis. Sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) of HRCT and MRI were calculated and the inter-observer agreement between both was assessed with the kappa value. Results: Among 63 ears, 40 ears were diagnosed as middle ear cholesteatoma by pathology. By HRCT, 30 ears having middle ear cholesteatoma were identified correctly. The false positive was 11 and the false negative was 10. The sensitivity,specificity, PPV and NPV of HRCT were 75%, 52.17%, 73.17% and 54.55%, respectively. In contrast, 37 ears having middle ear cholesteatoma were identified correctly by MRI. Both the false positive and the false negative were 3. The sensitivity, specificity, PPV and NPV of MRI were 92.5%, 86.96%, 75% and 86.96%. The inter-observer agreement between HRCT and MRI was poor, Kappa=0.274(P0.05). Removing 10 post-operative ears, only for the 53 non-operated ears, the inter-observer agreement between HRCT and MRI raised, Kappa=0.462(P0.05). Conclusion: The total positive rate of MRI was higher than HRCT, especially for post-operative recurrence. The combination of HRCT and MRI had a complementary role in diagnosis of middle ear cholesteatoma.