Monte Carlo simulations to assess the effects of tube current modulation on breast dose for multidetector CT.
Monte Carlo simulations to assess the effects of tube current modulation on breast dose for multidetector CT.
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DOI：
10.1088/0031-9155/54/3/003
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发表时间：
2009-02-07
影响因子：
3.5
通讯作者：
McNitt-Gray MF
中科院分区：
文献类型：
--
作者：
Angel E;Yaghmai N;Jude CM;Demarco JJ;Cagnon CH;Goldin JG;Primak AN;Stevens DM;Cody DD;McCollough CH;McNitt-Gray MF
管电流调制旨在降低CT成像中的辐射剂量，同时保持整体图像质量。本研究的目的是开发一种方法来评估管电流调制（TCM）对器官剂量的实际病人解剖CT检查的影响。通过在30个体素化患者模型上模拟TCM和固定管电流胸部CT检查并估计每个患者腺体乳腺组织的辐射剂量，验证了该方法。将这种估算器官剂量的新方法与其他传统的剂量减少估算方法进行了比较。基于先前接受过临床指示CT扫描（包括胸部区域）的女性患者的图像数据，创建了患者解剖结构的30个详细体素化模型。作为患者尺寸的指标，使用半自动技术在包含至少一个乳头的图像上测量患者的周长。放射科医生在每张图像上绘制乳房轮廓，并从该区域半自动分割腺体组织。先前验证的Monte Carlo模型的两个多探测器CT扫描仪，考虑到有关的源光谱，过滤，准直和扫描仪的几何形状的细节。从每个患者的临床扫描中获得TCM数据，并将其纳入模型以模拟TCM的效果。对于每个患者模型，模拟两次检查：固定管电流胸部CT和管电流调制胸部CT。通过体素化患者模型的解剖结构传输X射线光子，并在腺体乳腺组织中记录辐射剂量。将管电流调制模拟得到的剂量与使用固定mA值进行模拟得到的结果进行比较。所有患者模型的固定管电流扫描对乳腺腺体组织的平均辐射剂量为19 mGy。使用管电流调制扫描的乳房剂量平均减少17%。结果取决于尺寸，较小的患者获得更好的剂量减少（减少高达64%），较大的患者获得较小的减少，在某些情况下，当使用管电流调制时，剂量实际上增加（增加高达41%）。结果表明，使用管电流调制CT采集时，乳腺腺体组织的辐射剂量通常会降低，但患者体型（在某些情况下，患者定位）可能会影响剂量降低。
Tube current modulation was designed to reduce radiation dose in CT imaging while maintaining overall image quality. This study aims to develop a method for evaluating the effects of tube current modulation (TCM) on organ dose in CT exams of actual patient anatomy. This method was validated by simulating a TCM and a fixed tube current chest CT exam on 30 voxelized patient models and estimating the radiation dose to each patient’s glandular breast tissue. This new method for estimating organ dose was compared with other conventional estimates of dose reduction. Thirty detailed voxelized models of patient anatomy were created based on image data from female patients who had previously undergone clinically indicated CT scans including the chest area. As an indicator of patient size, the perimeter of the patient was measured on the image containing at least one nipple using a semi-automated technique. The breasts were contoured on each image set by a radiologist and glandular tissue was semi-automatically segmented from this region. Previously validated Monte Carlo models of two multidetector CT scanners were used, taking into account details about the source spectra, filtration, collimation and geometry of the scanner. TCM data were obtained from each patient’s clinical scan and factored into the model to simulate the effects of TCM. For each patient model, two exams were simulated: a fixed tube current chest CT and a tube current modulated chest CT. X-ray photons were transported through the anatomy of the voxelized patient models, and radiation dose was tallied in the glandular breast tissue. The resulting doses from the tube current modulated simulations were compared to the results obtained from simulations performed using a fixed mA value. The average radiation dose to the glandular breast tissue from a fixed tube current scan across all patient models was 19 mGy. The average reduction in breast dose using the tube current modulated scan was 17%. Results were size dependent with smaller patients getting better dose reduction (up to 64% reduction) and larger patients getting a smaller reduction, and in some cases the dose actually increased when using tube current modulation (up to 41% increase). The results indicate that radiation dose to glandular breast tissue generally decreases with the use of tube current modulated CT acquisition, but that patient size (and in some cases patient positioning) may affect dose reduction.
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影响因子：
19.7
作者：
BOICE, JD;LAND, CE;TOKUNAGA, M
通讯作者：
TOKUNAGA, M
影响因子：
5.9
作者：
Kalender, WA;Wolf, H;Bautz, WA
通讯作者：
Bautz, WA
影响因子：
2.3
作者：
Hill, DA;Preston-Martin, S;Bernstein, L
通讯作者：
Bernstein, L
影响因子：
3.8
作者：
DeMarco, JJ;Solberg, TD;Smathers, JB
通讯作者：
Smathers, JB
影响因子：
3.5
作者：
DeMarco, JJ;Cagnon, CH;McNitt-Gray, MF
通讯作者：
McNitt-Gray, MF