Department of Radiology, Massachusetts General Hospital, 55 Fruit St., White 270, Boston, MA 02114, USA.
AJR Am J Roentgenol. 2011 Jan;196(1):146-51. doi: 10.2214/AJR.10.4271.
The objective of our study was to analyze body CT utilization trends, indications, fetal radiation doses, and scanning parameters associated with high fetal radiation doses (defined as > 30 mGy).
A retrospective review of all chest and abdominopelvic CT examinations performed between 1998 and 2005 of patients known to be pregnant was conducted. Demographics, gestational age, examination indication, and scan parameters were recorded. Fetal radiation dose was calculated for those abdominopelvic examinations with direct fetal irradiation.
From a database of more than 170,000 chest and more than 180,000 abdominopelvic CT examinations, 74 chest and 86 abdominopelvic examinations of pregnant patients were identified. Chest CT use increased on average 75%/y/1,000 deliveries in pregnancy versus 19%/y increase in all patients (p = 0.2700). Abdominopelvic CT utilization increase was on average 22%/y/1,000 deliveries in pregnant patients versus 13%/y increase in all patients (p = 0.1865). The most common indication for chest CT during pregnancy was suspected pulmonary embolism (85%, 63/74) and for abdominopelvic CT, suspected appendicitis (58%, 50/86). The average fetal dose from abdominopelvic CT was 24.8 mGy (range, 6.7-56 mGy); one examination exceeded the 50-mGy threshold for increased risk of childhood cancer. Scanning parameters associated with a dose of more than 30 mGy were a pitch of less than 1 (p = 0.0080) and more than one series acquisition (p = 0.0136).
Growth of CT during pregnancy reflects the trend of increased CT utilization in the general population. Avoiding use of CT in pregnant patients with suspected appendicitis would significantly decrease fetal radiation exposure. Abdominopelvic CT during pregnancy should be carefully planned and monitored so as not to exceed the fetal radiation dose for negligible risk.
本研究旨在分析身体 CT 利用趋势、适应证、胎儿辐射剂量以及与高胎儿辐射剂量（定义为>30mGy）相关的扫描参数。
对 1998 年至 2005 年期间已知妊娠的所有胸部和腹部盆腔 CT 检查进行了回顾性分析。记录了人口统计学、孕龄、检查适应证和扫描参数。对有直接胎儿照射的腹部盆腔检查计算了胎儿辐射剂量。
从超过 170,000 次胸部 CT 和超过 180,000 次腹部盆腔 CT 检查的数据库中，确定了 74 次胸部和 86 次腹部盆腔妊娠患者 CT 检查。与所有患者相比，妊娠期间胸部 CT 的使用平均每年增加 75%/1,000 例分娩（p=0.2700），而腹部盆腔 CT 的使用增加了 22%/1,000 例分娩（p=0.1865）。妊娠期间胸部 CT 最常见的适应证是疑似肺栓塞（85%，63/74），腹部盆腔 CT 最常见的适应证是疑似阑尾炎（58%，50/86）。腹部盆腔 CT 的胎儿平均剂量为 24.8mGy（范围 6.7-56mGy）；一次检查超过了 50mGy 的阈值，增加了儿童癌症的风险。剂量超过 30mGy 的扫描参数为小于 1 的螺距（p=0.0080）和一次以上系列采集（p=0.0136）。
妊娠期间 CT 的增长反映了一般人群中 CT 利用率的增长趋势。避免对疑似阑尾炎的妊娠患者使用 CT 将显著降低胎儿辐射暴露。妊娠期间的腹部盆腔 CT 应仔细规划和监测，以免超过可忽略风险的胎儿辐射剂量。
