Jadhav Siddharth P, Golriz Farahnaz, Atweh Lamya A, Zhang Wei, Krishnamurthy Rajesh
1 EB Singleton Department of Pediatric Radiology, Texas Children's Hospital, 6621 Fannin St, Houston, TX 77030.
AJR Am J Roentgenol. 2015 Feb;204(2):W184-91. doi: 10.2214/AJR.14.12846.
OBJECTIVE. The purpose of this study was to evaluate the radiation dose and image quality of target mode prospectively ECG-gated volumetric CT angiography (CTA) performed with a 320-MDCT scanner compared with the radiation dose and image quality of ungated helical CTA performed with a 64-MDCT scanner. MATERIALS AND METHODS. An experience with CTA for cardiovascular indications in neonates and infants 0-6 months old was retrospectively assessed. Radiation doses and quantitative and qualitative image quality scores of 28 CTA examinations performed with a 320-MDCT scanner and volumetric target mode prospective ECG gating plus iterative reconstruction (target mode) were compared with the doses and scores of 28 CTA examinations performed with a 64-MDCT scanner and ungated helical scanning plus filtered back projection reconstruction (ungated mode). All target mode studies were performed during free breathing. Seven ungated CTA examinations (25%) were performed with general endotracheal anesthesia. The findings of 17 preoperative CTA examinations performed in target mode were also compared with surgical reports for evaluation of diagnostic accuracy. RESULTS. All studies performed with target mode technique were diagnostic for the main clinical indication. Effective doses were significantly lower in the target mode group (0.51 ± 0.19 mSv) compared with the ungated mode group (4.8 ± 1.4 mSv) (p < 0.0001). Quantitative analysis revealed no statistically significant difference between the two groups with respect to signal-to-noise ratio (of pulmonary artery and aorta) and contrast-to-noise ratio. Subjective image quality was significantly better with target mode than with ungated mode (p < 0.0001). CONCLUSION. Target mode prospectively ECG-gated volumetric scanning with iterative reconstruction performed with a 320-MDCT scanner has several benefits in cardiovascular imaging of neonates and infants, including low radiation dose, improved image quality, high diagnostic accuracy, and ability to perform free-breathing studies.
目的。本研究的目的是评估使用320层MDCT扫描仪进行的目标模式前瞻性心电门控容积CT血管造影（CTA）的辐射剂量和图像质量，并与使用64层MDCT扫描仪进行的非门控螺旋CTA的辐射剂量和图像质量进行比较。材料与方法。回顾性评估了对0至6个月大的新生儿和婴儿进行心血管疾病CTA检查的经验。将使用320层MDCT扫描仪和容积目标模式前瞻性心电门控加迭代重建（目标模式）进行的28次CTA检查的辐射剂量、定量和定性图像质量评分，与使用64层MDCT扫描仪和非门控螺旋扫描加滤波反投影重建（非门控模式）进行的28次CTA检查的剂量和评分进行比较。所有目标模式研究均在自由呼吸状态下进行。7次非门控CTA检查（25%）在全身气管内麻醉下进行。还将以目标模式进行的17次术前CTA检查结果与手术报告进行比较，以评估诊断准确性。结果。所有采用目标模式技术进行的研究对于主要临床指征均具有诊断价值。目标模式组的有效剂量（0.51±0.19 mSv）显著低于非门控模式组（4.8±1.4 mSv）（p<0.0001）。定量分析显示，两组在（肺动脉和主动脉的）信噪比和对比噪声比方面无统计学显著差异。目标模式的主观图像质量明显优于非门控模式（p<0.0001）。结论。使用320层MDCT扫描仪进行的目标模式前瞻性心电门控容积扫描及迭代重建在新生儿和婴儿心血管成像中具有多项优势，包括低辐射剂量、改善的图像质量、高诊断准确性以及能够进行自由呼吸状态下的研究。
