Original Research of Technological Improvement of Low Dose Spiral Computed Tomography in Lumbar Vertebra and Lumbar Intervertebral Disc Diseases

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Amy Poole
7 years ago
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1 127 CT * ATCM CT CT 50 5 BMI 5 CT mas 120 kv 2 ~ 5 NI 21 HU 25 HU 25 HU 25 HU 100 ~ 710 mas 100 ~ 710 mas 40 ~ 300 mas 40 ~ 300 mas 120 kv 120 kv 120 kv 100 kv CT CTDIvol DLP VR batch IQS L 3 ~ 4 L 4 ~ 5 L 5 ~ S 1 SD BMI CTDIvol P CTDIvol % % DLP P DLP % % VR batch VR 1 ~ 4 5 batch L 3 ~ 4 L 4 ~ 5 L 5 ~ S 1 SD 1 ~ 4 5 NI 25 HU 40 ~ 300 mas 120 kv % CT Original Research of Technological Improvement of Low Dose Spiral Computed Tomography in Lumbar Vertebra and Lumbar Intervertebral Disc Diseases TAN Wenli ZHAN Songhua ZHAO Xi et al. Radiology Department of Shuguang Hospital Affiliated to Traditional Chinese Medical University P. R. China Abstract Objective To explore the value of radiation dose reduction for lumbar vertebra volume CT examinations with automatic tube current modulation ATCM and its different parameters. Materials and Methods 50 patients who underwent lumbar multislice CT examination were prospectively collected whose body mass index BMI were recorded. They were randomly divided into 5 groups undergoing different scan parameters. Group 1 received CT scan with fixed tube current 405mAs and tube voltage 120 kv /Group 2 group 3 group 4 group 5 were examined with SmartmA whose noise index NI was respectively 21 HU 25 HU 25 HU 25 HU range of tube current was respectively mas mas mas mas and tube voltage was respectively 120 kv 120 kv 120 kv 100 kv. The CT dose index of volume CTDIvol and the dose length product DLP were recorded. VR and batch reconstruction imaging were evaluated by the image quality score IQS. The image standard deviation SD of psoas major was measured at the middle level of L 3-4 L 4-5 L 5 - S 1 lumbar disc in different groups. The statistical analysis was performed. Results There was not statistical difference in BMI between different groups. The CTDIvol of different groups existed significant statistical difference P The CTDIvol of group 4 group 5 was % % of group 1. There was significant statistical difference in DLP among different groups P The DLP of group 4 group 5 was respectively % % of group 1. IQS of VR and batch imaging showed statistical difference and IQS of group 1-4 showed statistical difference with group 5. There was significant difference in IQS of batch imaging between group 1 and 5 group 2 and ZXY *

2 128 There was statistical difference in SD index of psoas major muscle. SD index of group 1-4 showed statistical difference with group 5. Conclusion The correct application of ATCM could reduce the dose of examinee and ensure the quality of imaging. ATCM with NI equal to 25 range of tube current mas tube voltage 120 kv could decrease % radiation dose. Key words Automatic tube current modulation ATCM Multi-slice spiral CT Dose of radiation Lumbar vertebra CT / 3 mm /3 mm / 350 HU /40 CT HU VR batch 1 image quality score IQS 5 automatic tube current modulation ATCM CT standard deviation SD ~ batch L 3 ~ ± kg L 4 ~ 5 L 5 ~ S 1 m body mass index BMI 2 90 ± 10 mm 2 = / BMI SD SD GE Light Speed 64 VCT 5 CT CTDIvol DLP mas 120 kv 2 SPSS noise index NI 21 BMI CTDIvol DLP SD One-way Anova 100 ~ 710 mas 120 kv 3 LSD VR batch NI ~ 710 mas Kruskal-Wallis 120 kv 4 NI 25 Mann-Whitney 40 ~ 300 mas 120 kv 5 P NI ~ 300 mas 100 kv / = mm / mm BMI CTDIvol DLP VR 0. 8 s / 40 mm / T 12 batch SD 1 ± S 1 BMI CTDIvol DLP GE AW CTDIvol VR F P batch L 3 ~ 4 L 4 ~ 5 L 5 ~ S 1 5

3 F /chi-square P BMI kg /m ± ± ± ± ± CTDIvol mgy ± ± ± ± ± DLP mgy cm ± ± ± ± ± VR 4. 9 ± ± ± ± ± Batch 5 ± ± ± ± ± L 3 ~ 4 SD HU ± ± ± ± ± L 4 ~ 5 SD HU ± ± ± ± ± L 5 ~ S 1 SD HU ± ± ± ± ± CTDIvol % % 5 CTDIvol % % 5 DLP F P DLP % % 5 DLP % % 2. 2 VR batch 5 VR ATCM ~ 10 X Z 5 batch ~ 15 ATCM 2. 3 batch SD 5 L 3 ~ 4 L 4 ~ 5 L 5 ~ S 1 26% Rizzo 6 SD L 3 ~ 4 ATCM Z ATCM CT % ~ 42% ATCM L 4 ~ 5 L 5 ~ S SD 37% ATCM 10% ATCM 3 ATCM ATCM Z ATCM 3 ATCM ATCM 360 X-Y 4 Z ATCM Kalra 5 Z ATCM CT Mulkens 2 ATCM Z ATCM 2 CT CT automatic exposure control AEC X vol DLP L 3 ~ 4 NI CTDI- SD L 4 ~ 5 L 5 ~ S 1 2 SD ATCM

4 mas CTDIvol % Greess 7 3 NI NI L 3 ~ 4 SD NI

5 131 4 mas kv NI CTDIvol % Mulkens 2 5 ATCM CTDIvol % 1 Aaron S Pieter F Baeyens et al. Recurrent CT cumulative radiation 1 2 exposure and associated radiation-induced cancer risks from CT of 5 VR batch adults. Radiology SD 1 ~ 4 SD NI SD 4 NI 5 NI SD NI SD 6 Rizzo S Kalra M Schmidt B 8 7 Greess H Lutze J Nomayr A SD NI ATCM 4 2 Mulkens TH Bellinck P Baeyaert M et al. Use of an automatic exposure control mechanism for dose optimization in multi-detector row CT examinations clinical evaluation. Radiology Lee CH Goo JM Ye HJ et al. Radiation dose modulation techniques in the multidetector CT era from basics to practice. RadioGraphics Kalra MK Maher MM Toth TL et al. Techniques and applications of automatic tube current modulation for CT. Radiology Kalra MK Rizzo S Maher MM et al. Chest CT performed with z-axis modulation scanning protocol and radiation dose. Radiology et al. Comparison of angular and combined automatic tube current modulation techniques with constant tube current CT of the abdomen and pelvis. AJR et al. Dose reduction in subsecond multislice helical CT examination of children by online tube current modulation. Eur Radiol Kalra MK Maher MM Kamath RS et al. Sixteen-detector row CT of abdomen and pelvis study for optimization of Z-axis modulation technique performed in 153 patients. Radiology % %

Chest CT protocols. Mannudeep K. Kalra, MD, DNB. Dianna D. Cody, PhD. Massachusetts General Hospital Harvard Medical School

Chest CT protocols. Mannudeep K. Kalra, MD, DNB. Dianna D. Cody, PhD. Massachusetts General Hospital Harvard Medical School Chest CT protocols Mannudeep K. Kalra, MD, DNB Dianna D. Cody, PhD Massachusetts General Hospital Harvard Medical School M.D. Anderson Cancer Center Specific principles Routine chest CT Lung nodule follow