共 25 条
Optimizing contrast enhancement during helical CT of the liver: A comparison of two bolus tracking techniques
被引:23
作者:
Schweiger, GD
[1
]
Chang, PJ
[1
]
Brown, BP
[1
]
机构:
[1] Univ Iowa Hosp & Clin, Dept Radiol, Iowa City, IA 52242 USA
关键词:
D O I:
10.2214/ajr.171.6.9843287
中图分类号:
R8 [特种医学];
R445 [影像诊断学];
学科分类号:
1002 ;
100207 ;
1009 ;
摘要:
OBJECTIVE. The purpose of this study was to evaluate a recently developed hardware and software system for CT scanning that generates images in real time and switches to helical CT scanning by either a visual cue or a region of interest (ROI) amplitude threshold. SUBJECTS AND METHODS. We randomly and prospectively divided 120 abdominal CT examinations into three groups. Two groups received 75 ml of contrast agent at 1.5 ml/sec. Helical CT scanning began after visualization of the contrast bolus arrival in the hepatic veins (visual cue triggering) (39 patients) or after reaching an ROI threshold (automated ROI threshold triggering) (39 patients). A third group served as a control group (42 patients) and received 150 ml of contrast agent at 1 ml/sec. Quality of hepatic enhancement was assessed objectively and subjectively. Comparisons were made after stratifying each group into three weight classes. RESULTS. Errors occurred in 12 (31%) of 39 examinations in the group with automated ROI threshold triggering. In that group, we found a significantly (p <.04) lower mean hepatic enhancement in two of three weight categories, and a significantly (p <.04) lower mean subjective scan quality in one of three weight categories, than we found in the group with visual cue triggering. CONCLUSION. Optimizing portal venous phase helical CT of the liver after a low-volume bolus of contrast agent and an injection rate of 1.5 ml/sec is best achieved by initiating helical CT scanning after visualizing the contrast bolus arrival within the liver rather than after reaching a preset attenuation threshold.
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页码:1551 / 1558
页数:8
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