螺旋CT靶扫描对肺部小结节的诊断价值

目的　探讨肺部结节CT靶扫描的应用价值。材料与方法　筛选同时具有常规 10mm层厚和靶扫描的CT资料共 70例 ,诊断证实途径包括手术切除、经皮肺穿刺、痰脱落细胞学、抗炎治疗或随访 2年以上。结节大小为 0 .5～ 3 .0cm ,平均 2 .2cm。CT常规扫描采用 10mm层厚 ,靶扫描采用小FOV( 14～ 2 0cm) ,包括一侧肺和纵隔 ,层厚 2～ 5mm ,pitch =1～ 2 ,重建时重叠 40 %～ 67%。 3 6例作了三维重建 (表面遮盖显示法 ,SSD)。诊断依据可靠程度分为四等级 :明确诊断、可能性大、可能、无诊断倾向或未诊断 ,分别对常规扫描和靶扫描进行回顾性评价并对比。统计检验采用参照单位分析法和卡方检验。结果　 70例扫描中经靶扫描作出明确诊断者 3 6例 ( 5 1.4% ) ,可能性大者 2 7例 ( 3 8.6% ) ,可能者 4例 ( 5 .7% ) ;前三级诊断准确率为 95 .7% ( 67/ 70 ) ,显著高于常规扫描( 68.6% ,48/ 70 ;χ2 =8.64 ,P <0 .0 1) ;明确诊断比率为 5 1.4% ( 3 6/ 70 ) ,显著高于常规扫描 ( 8.6% ,6/ 70 ;χ2 =3 3 .77,P <0 .0 1)。靶扫描诊断可靠性明显优于常规扫描 (前者R值为 95 % ,可信区间为 0 .2 79～ 0 .417,后者为 0 .10 8～ 0 .2 46,两者无重叠 ,P <0 .0 5 )。结论　螺旋CT靶扫描有助于肺部结节的鉴别诊断 ,是肺部结节检查的有

The Value of Targeted Spiral CT Scan in the Diagnosis of Small Pulmonary Nodules

Objective　To evaluate targeted spiral CT (TSCT) scan in the diagnosis of small pulmonary nodules.　Materials and Methods　Seventy cases who had both conventional CT (CCT) and TSCT scan were selected. The diagnoses were confirmed by surgery, puncture biopsy, sputum examination, diagnostic inflammatory therapy or a follow-up observation over two years. The diameters of the nodules were 0.5～3cm (mean 2.2cm). For CCT scan 10mm slice thickness was used. For TSCT scan a small FOV (14～20cm, covering unilateral lung and mediastinum), 2～5mm slice thickness and 1～2 pitch with 40%～67% overlapping were adopted. Of 70 cases, surface shaded display was applied in 36. The reliability of diagnostic basis was graded in four levels: definite, probable, likely and indefinite. Retrospective evaluation of CCT and TSCT was made respectively.　Results　With TSCT scan definite diagnosis were obtained in 36 cases (51.4%), probable diagnosis in 27 (38.6%), likely diagnosis in 4 (5.7%). The accuracy of the first diagnosis (51.4%) and overall diagnosis (95.7%) with TSCT was significantly higher than that with CCT, which was 8.6% (χ2=33.77) and 68.6% (χ2=8.64), respectively, with P＜0.01.The confidence of diagnosis with TSCT (R values of 95% confidence interval being 0.279～0.417) was markedly higher than that with CCT (0.108～0.246), with P＜0.05. 　Conclusion　TSCT is an effective diagnostic means very helpful in differentiating pulmonary nodules.