摘要:
目的:探讨腹部能谱CT血管成像双低扫描方案的可行性和应用价值。方法:前瞻性收集疑腹部病变需行全腹血管CT成像BMI≤25的患者367例。首先按照首诊时间分实验组和对照组,再根据体质指数(BMI)分成两个亚组,BMI≤22为实验1组或对照1组,22<BMI≤25为实验2组或对照2组。扫描参数:实验1组(80kVp、50%ASIR、270mgI/mL),实验2组(100kVp、50%ASIR、270mgI/mL),对照1组(120kVp、FBP、350mgI/mL),对照2组(120kVp、FBP、350mgI/mL)。对比各组腹主动脉CT值,CNR,FOM,CTDI<sub<vol</sub<,对比剂碘含量及肾动脉图像质量评分。结果:腹主动脉CT值:实验1组、实验2组分别为(601.75±67.11)HU和(459.87±49.17)HU,对照1组、对照2组分别为(436.55±84.12)HU和(432.15±87.68)HU,实验1组<对照1组,差异具有统计学意义(<i<P</i<值<0.05)。CNR:实验1组、实验2组分别为(19.01±2.66)和(15.24±2.52),对照1组、对照2组分别为(12.42±2.68)和(10.24±2.22),实验1组<对照1组,实验2组<对照2组,差异均有统计学意义(<i<P</i<<0.05)。FOM:实验1组、实验2组分别为(69.72±29.75)和(33.44±8.87),对照1组、对照2组分别为(20.08±8.05)和(15.21±10.12),实验1组<对照1组,实验2组<对照2组,差异均有统计学意义(<i<P</i<值<0.05)。CTDI<sub<vol</sub<:实验1组、实验2组为(5.41±1.38)mGy和(6.98±1.49)mGy,对照1组、对照2组为(9.87±2.97)mGy和(12.02±5.21)mGy,实验1组较对照1组降低45.19%(4.46/9.87)、实验2组较对照2组降低41.93%(5.04/12.02)。实验组、对照组的碘对比剂浓度分别为270mgI/mL和350mgI/mL,实验组降低22.86%(80/350)。肾动脉血管评分:实验1组、实验2组分别为(4.61±0.47)和(4.22±0.59),对照1组、对照2组分别为(3.73±0.72)和(3.93±0.66),实验1组<对照1组,差异具有统计学意义(<i<P</i<<0.05);实验2组与对照2组间差异无统计学意义(<i<P</i<值<0.05)。结论:针对中小体质指数患者,双低扫描方案腹部能谱CT血管成像在保证图像质量的同时可以大幅度地降低辐射剂量和碘对比剂含量,适于推广临床应用。
Abstract:
Purpose: To explore the feasibility and application value of abdominal spectral CT angiography imaging with double low scan protocol. Methods: Total of 367 patients with the BMI ≤ 25 kg/m<sup<2</sup< who were suspected abdominal disease was performed abdominal CT angiography imaging prospectively. Firstly, these patients were divided into experience group and control group according to the first time of treatment and then were divided into two subgroups according to the BMI: Experience 1 group or control 1 group(BMI ≤ 22) and experience 2 group or control 2 group(22 BMI ≤ 25). The scan protocols as follows: Experience 1 group(80 kVp, 50% ASIR, 270 mgI/mL), experience 2 group(100 kVp, 50% ASIR, 270 mgI/mL), control 1 group(120 kVp, FBP, 350 mgI/mL), control 2 group(120 kVp, FBP, 350 mgI/mL). To compare the CT values of aorta abdominalis, CNR, FOM, CDIvol, iodine content of contrast agent and imaging quality score of renal arteries. Results: The CT values of aorta abdominalis of group experience 1, experience 2, control 1, control 2were(601.75 ±67.11) HU,(459.87 ±49.17) HU,(436.55 ±84.12) HU,(432.15 ±87.68), respectively and CT values of groups experience were higher than that of groups control(<i<P</i<<0.05). The CNR of group experience 1, experience 2, control 1, control 2 were(19.01 ±2.66),(15.24 ±2.52),(12.42 ±2.68),(10.24 ±2.22), respectively and CNR of groups experience were higher than that of groups control(<i<P</i<<0.05). The FOM of group experience 1, experience 2, control 1, control 2 were(69.72 ±29.75),(33.44 ±8.87),(20.08 ±8.05),(15.21 ±10.12), respectively and FOM of groups experience were higher than that of groups control(<i<P</i<<0.05). The CTDI<sub<vol</sub< of group experience 1, experience 2, control 1, control 2 were(5.41 ±1.38) mGy,(6.98 ±1.49) mGy,(9.87 ±2.97) mGy,(12.02 ±5.21) mGy, respectively and CTDI<sub<vol</sub< of group experience 1 was reduced by 45.19%(4.46/9.87) than that of control 1 and experience 2 was reduced by 41.93%(5.04/12.02) than that of control 2. The iodine Concentration of group experience and group control was 270 mgI/mL and 350 mgI/mL respectively. The iodine Concentration of group experience was reduced by 22.86%(80/350). The scores of renal arteries of group experience 1, experience 2, control 1, control 2 were(4.61 ±0.47),(4.22 ±0.59),(3.73 ±0.72),(3.93 ±0.66), respectively. The score of group experience 1 was higher than that of group control 1(<i<P</i<<0.05) and there was no statistical significance between group experience 2 and group control 2. Conclusion: The abdominal spectral CT angiography imaging with double low scan protocol can reduce radiation dose and iodine content sharply for the patients with small BMI, and which will be applied to clinic.
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