Image quality and radiation dose of CT venography with double dose reduction using model based iterative reconstruction: comparison with conventional CT venography using filtered back projection

2017 ◽  
Vol 59 (5) ◽  
pp. 546-552 ◽  
Author(s):  
Yeo-Jin Jeong ◽  
Ki Seok Choo ◽  
Kyung Jin Nam ◽  
Ji Won Lee ◽  
Jin You Kim ◽  
...  

Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B ( P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups ( P > 0.05). In addition, radiation dose in group A was significantly lower than in group B ( P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP.

2020 ◽  
pp. 028418512091762
Author(s):  
Ting Liang ◽  
Yonghao Du ◽  
Chenguang Guo ◽  
Yuan Wang ◽  
Jin Shang ◽  
...  

Background Computed tomography (CT)-guided percutaneous lung biopsy is usually performed by helical scanning. However, there are no studies on radiation dose, diagnostic accuracy, image quality, and complications based on axial scan mode. Purpose To determine radiation dose, accuracy, image quality, and complication rate following an ultra-low-dose (ULD) protocol for CT-guided lung biopsy in clinic. Material and Methods A total of 105 patients were enrolled to receive CT-guided lung biopsy. The use of an ULD protocol (axial scan) for CT-guided biopsy was initiated. Patients were randomly assigned to axial mode (Group A) and conventional helical mode (Group B) CT groups. 64-slice CT was performed for CT-guided pulmonary biopsy with an 18-G coaxial cutting biopsy needle. The radiation dose, accuracy, image quality, and complication rate were measured. Results Ninety-seven patients were selected for the final phase of the study. There was no significant difference between the two groups for pulmonary nodule characteristics ( P > 0.05). The mean effective dose in group A (0.077 ± 0.010 mSv) was significantly reduced relative to group B (0.653 ± 0.177 mSv, P < 0.001). There was no significant difference in accuracy, image quality, and complication rate ( P > 0.050) between the two modes. Conclusion An ULD protocol for CT-guided lung nodule biopsy yields a reduction in the radiation dose without significant change in the accuracy, image quality, and complication rate relative to the conventional helical mode scan.


2019 ◽  
Vol 61 (1) ◽  
pp. 28-36
Author(s):  
Zlatan Alagic ◽  
Haris Alagic ◽  
Robert Bujila ◽  
Subhash Srivastava ◽  
Saif Jasim ◽  
...  

Background The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% ( P<0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively ( P < 0.001). The success rate in group A was 91.2% and 87.9% in group B ( P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.


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