Morton Ryan P, Reynolds Renee M, Ramakrishna Rohan, Levitt Michael R, Hopper Richard A, Lee Amy, Browd Samuel R
Division of Neurosurgery, Seattle Children's Hospital, Seattle, Washington.
J Neurosurg Pediatr. 2013 Oct;12(4):406-10. doi: 10.3171/2013.7.PEDS12631. Epub 2013 Aug 23.
In this study, the authors describe their experience with a low-dose head CT protocol for a preselected neurosurgical population at a dedicated pediatric hospital (Seattle Children's Hospital), the largest number of patients with this protocol reported to date.
All low-dose head CT scans between October 2011 and November 2012 were reviewed. Two different low-dose radiation dosages were used, at one-half or one-quarter the dose of a standard head CT scan, based on patient characteristics agreed upon by the neurosurgery and radiology departments. Patient information was also recorded, including diagnosis and indication for CT scan.
Six hundred twenty-four low-dose head CT procedures were performed within the 12-month study period. Although indications for the CT scans varied, the most common reason was to evaluate the ventricles and catheter placement in hydrocephalic patients with shunts (70%), followed by postoperative craniosynostosis imaging (12%). These scans provided adequate diagnostic imaging, and no patient required a follow-up full-dose CT scan as a result of poor image quality on a low-dose CT scan. Overall physician comfort and satisfaction with interpretation of the images was high. An additional 2150 full-dose head CT scans were performed during the same 12-month time period, making the total number of CT scans 2774. This value compares to 3730 full-dose head CT scans obtained during the year prior to the study when low-dose CT and rapid-sequence MRI was not a reliable option at Seattle Children's Hospital. Thus, over a 1-year period, 22% of the total CT scans were able to be converted to low-dose scans, and full-dose CT scans were able to be reduced by 42%.
The implementation of a low-dose head CT protocol substantially reduced the amount of ionizing radiation exposure in a preselected population of pediatric neurosurgical patients. Image quality and diagnostic utility were not significantly compromised.
在本研究中，作者描述了他们在一家专门的儿科医院（西雅图儿童医院）对预先选定的神经外科患者群体采用低剂量头部CT方案的经验，这是迄今为止报告使用该方案患者数量最多的情况。
回顾了2011年10月至2012年11月期间所有的低剂量头部CT扫描。根据神经外科和放射科商定的患者特征，使用了两种不同的低剂量辐射剂量，分别为标准头部CT扫描剂量的二分之一或四分之一。还记录了患者信息，包括CT扫描的诊断和指征。
在为期12个月的研究期间共进行了624例低剂量头部CT检查。尽管CT扫描的指征各不相同，但最常见的原因是评估脑积水患者分流术后的脑室和导管位置（70%），其次是术后颅骨缝早闭成像（12%）。这些扫描提供了足够的诊断成像，没有患者因低剂量CT扫描图像质量差而需要进行后续的全剂量CT扫描。总体而言，医生对图像解读的舒适度和满意度较高。在同一12个月期间还进行了另外2150例全剂量头部CT扫描，使CT扫描总数达到2774例。该数值与研究前一年获得的3730例全剂量头部CT扫描相比，当时在西雅图儿童医院低剂量CT和快速序列MRI不是可靠的选择。因此，在1年的时间里，总CT扫描中有22%能够转换为低剂量扫描，全剂量CT扫描减少了42%。
低剂量头部CT方案的实施显著降低了预先选定的儿科神经外科患者群体的电离辐射暴露量。图像质量和诊断效用没有受到显著影响。
