低剂量MSCT乳腺扫描临床应用

Clinical Application of Low Dosage Multislice Spiral CT on Mammary Gland Scan

目的探讨乳腺MSCT扫描时降低mA值,乳腺接受的射线剂量及其对图像质量的影响。方法对30例乳腺钼靶X线检查发现的35个肿块病灶分别行120 kV,160 mA、50 mA的MSCT扫描,由2位有15年以上影像工作经验的医师在不了解扫描、重建参数的情况下双盲法阅片,分别就乳腺内病灶的密度、形态、边缘,以及有无毛刺、钙化等征象进行逐一判定。结果当mA值由160减至50时乳腺所接受的射线剂量由8.7 mGy降至2.72 mGy,下降幅度达68%以上,2者差异有统计学意义。而图像质量无明显下降,2者差异无统计学意义。结论在降低mA值的条件下,受检者所接受的射线剂量明显减少,虽然图像噪声有所增加,但所获得的影像信息和图像质量可以满足诊断要求。

Objective To study the radio dosage accepted by mammary gland and its effect on the picture quality when mA value was decreased in Muhislice Spiral CT （MSCT） scanning. Methods 35 focuses among 30 cases checked by molybdenum target were scanned by MSCT at 120 KV, 160 mA,50 mA separately. The pictures were double blind diagnosed by two doctors with work experience over 15years. The density,shape and edge of the focus with or without bur and calcification were assessed. Results The radio dosage accepted by mammary gland decreased from 8.7 mGy to 2.72 mGy when the value of mA was decreased from 160 to 50,the declining amplitude was over 68% and there was obvious statistics significance. There was no decline on the picture quality. Conclusions The dosage accepted by subjects decreased obviously under the condition of decline mA. The picture message and picture quality can meet the diagnosis needs although the noise augments.