Dynamic X-ray Flux Modulation of Inverse-Geometry CT

被引：0

作者：

Shen, Liuxing ^{[1
]}

Windsor, Haydon ^{[1
]}

Zhou, Shuang ^{[2
]}

Jiang, Hao ^{[1
]}

Zhang, Tiezhi ^{[1
,2
]}

机构：

[1] Tetraimaging LLC, Maryland Hts, MO 63043 USA

[2] Washington Univ, Dept Radiat Oncol, St Louis, MO 63110 USA

来源：

MEDICAL IMAGING 2024: PHYSICS OF MEDICAL IMAGING, PT 1 | 2024年 / 12925卷

关键词：

Distributed x-ray source; Inverse-geometry CT; CT dose reduction;

D O I：

10.1117/12.3006916

中图分类号：

TP18 [人工智能理论];

学科分类号：

081104 ; 0812 ; 0835 ; 1405 ;

摘要：

A novel inverse-geometry CT based on multi-pixel thermionic emission x-ray (MPTEX) sources is under development. Inverse-geometry CT is capable of modulating x-ray flux based on region of interest (ROI) location and thus minimizing x-ray exposure to the patients. The variations of emission currents of the MPTEX source at each projection angle are predetermined based on ROI position and realized by varying filament heating powers. To power and control filament electron emissions, a 50-channel prototype MPTEX control unit was developed based on GaN switching power technology. The filament heating powers of electron sources are controlled individually by a microprocessor while electron emission is turned on and off by switching the bias voltages during inverse-geometry CT scans. The emission current was measured as a function of filament heating voltage. The result shows that magnitude of emission current can be controlled dynamically by varying filament heating voltages. Compared with pulse width modulation, this approach can effectively prolong the lifetime of the filaments by minimizing their working temperature. A simulation of electron emission current sinogram was conducted as well. This work is supoorted by NIH grant R42EB026401.

引用

页数：4