Journal of X-Ray Science and Technology - Volume 27, issue 4

Authors: Kong, Que | Lu, Fengqi | Gao, Yu | Qiao, Peng | Shao, Min | Xie, Min

Article Type: Research Article

Abstract: BACKGROUND: Computed tomography (CT) is considered a standard modality for imaging the paranasal sinus (PS), but increasingly radiation dose is of concern, especially in children. Objective: This study aims to investigate the feasibility of using a 320-detector CT scanner with a 16 cm wide-detector combined with iterative reconstruction (IR) algorithm to further reduce radiation dose when scanning the PS. METHODS: A total of 90 children who underwent CT of the PS were randomly allocated into three groups namely, (1) the experimental group using low-dose wide-detector scan (n = 30, 9±4 years); (2) low-dose helical group …(n = 30, 9±4 years); and (3) pediatric conventional group (n = 30, 8±4 years). Statistical software SPSS 19.0 was used for one-way ANOVA analysis of the general data (age, BMI), image quality, and radiation dose. Multiple comparisons of data without homogeneity of variance were analyzed by Bonferroni test and Tamhane’s test. RESULTS: All patients underwent successful CT examinations. No significant differences in the general data and image quality evaluation were detected between three groups (all P values > 0.05). CTDIvol and DLP were 2.87 mGy and 32.58 mGy·cm in the experimental group, 4.92 mGy and 70.84 mGy·cm in the low-dose helical group, and 9.95 mGy and 131.83 mGy·cm in the conventional group, respectively, which were significantly different among these three groups as indicated by multiple comparisons (all P values < 0.05). In the experimental group, the effective radiation dose was 0.07 mSv, which was reduced by 76% and 56% comparing to the conventional group and the low-dose helical group, respectively. CONCLUSIONS: The 320-detector CT scanner equipped with the wide-detector combined with IR can further reduce radiation dose, while maintaining good image quality comparing to the low-dose helical or pediatric modes. Show more

Keywords: 320-detector computed tomography (CT), wide-detector, iterative reconstruction, pediatric, paranasal sinus, low dose

DOI: 10.3233/XST-180487

Citation: Journal of X-Ray Science and Technology, vol. 27, no. 4, pp. 731-738, 2019

Authors: Li, Kuai | Sang, Ziru | Zhang, Xuezhu | Zhang, Mengxi | Jiang, Changhui | Zhang, Qiyang | Ge, Yongshuai | Liang, Dong | Yang, Yongfeng | Liu, Xin | Zheng, Hairong | Hu, Zhanli

Article Type: Research Article

Abstract: X-ray radiation is harmful to human health. Thus, obtaining a better reconstructed image with few projection view constraints is a major challenge in the computed tomography (CT) field to reduce radiation dose. In this study, we proposed and tested a new algorithm that combines penalized weighted least-squares using total generalized variation (PWLS-TGV) and dictionary learning (DL), named PWLS-TGV-DL to address this challenge. We first presented and tested this new algorithm and evaluated it through both data simulation and physical experiments. We then analyzed experimental data in terms of image qualitative and quantitative measures, such as the structural similarity index (SSIM) …and the root mean square error (RMSE). The experiments and data analysis indicated that applying the new algorithm to CT data recovered images more efficiently and yielded better results than the traditional CT image reconstruction approaches. Show more

Keywords: Dictionary learning, total generalized variation, regularization, CT image reconstruction, few-view

DOI: 10.3233/XST-190506

Citation: Journal of X-Ray Science and Technology, vol. 27, no. 4, pp. 739-753, 2019

Authors: Tao, Wei | Xue, Boxin | Sun, Chuanyang | Yang, Dongrong | Zhang, Yuanyuan | Shan, Yuxi

Article Type: Research Article

Abstract: OBJECTIVE: To evaluate safety, efficacy, and long-term outcomes of photoselective vaporization of prostate using 120-W HPS GreenLight KTP laser and compare the results with those obtained with 2-micrometer continuous-wave (2 um CW) laser for treatment of patients with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: One group of 216 patients diagnosed with BPH underwent 120-W KTP laser vaporization of the prostate, while another group of 198 BPH patients underwent 2 um CW laser vaporization. The relevant pre-, peri-, and post-operative parameters were compared between the two therapy groups. Functional results in terms of improvement of International Prostate Symptom Score (IPSS), …maximum flow rate (Qmax), and post-void residual (PVR) urine were assessed at 3, 6, 12, and 24 months. RESULTS: BPH was successfully treated with 120-W HPS KTP laser and 2 um CW laser in all patients. There were no significant difference between two patient groups in the baseline characteristics (such as PSA, IPSS, QoL, and Qmax). No major complications occurred intraoperatively (capsule perforation and TUR syndrome) or postoperatively (electric unbalance), and no blood transfusions were required in both groups. Average catheterization time was 1.9±1.3 days for the 120-W PVP and 2.2±1.9 days for the 2 um CW laser treatment. In addition, the hospitalization times were 3.8±1.2days (120-W PVP) and 4.8±1.5 days (2 um CW laser), respectively. The incidence of dysuria and urge incontinence was higher in the 2 um CW laser group (35/198, 24/198) than in the 120 W PVP group (15/216, 10/216). Dramatic improvement was observed in Qmax, IPSS, Qol, and PVR as compared with the respective pre-operative values. The degree of improvement during the follow-up period was comparable in both groups. No significant differences were observed in terms of re-operation rates, bladder neck stricture, and urethral stricture. CONCLUSIONS: Both 120-W HPS laser and 2 um CW laser vaporization present effective treatment options in patients with BPH, but 120-W PVP provides safer therapy with less post-operative complications within the 2-year follow-up period. Show more

Keywords: Benign prostatic hyperplasia (BPH) treatment, laser surgery, vaporization outcomes

DOI: 10.3233/XST-190507

Citation: Journal of X-Ray Science and Technology, vol. 27, no. 4, pp. 755-764, 2019

Authors: Li, Shuang | Khan, Alick | Chen, Jing | Tan, Jun

Article Type: Research Article

Abstract: We report the case of a 19-year old man who presented to our institution with a history of pain of one week in the ulnar side of the left wrist and continuous pressing sensation in the palm. According to patient, there was no history of acute hand trauma. The conventional roentgenograms did not show the fracture and computerized tomographic (CT) scanning demonstrated a complete fracture of the hook of the hamate. The patient was given a surgical intervention and the hamate bone was reduced through a palmar skin incision. After surgery, the operated hand was immobilized in a wrist brace …and the patient was put on a rehabilitation protocol. At the last follow-up, the patient was able to return to normal living activities without any symptoms. We reviewed the latest articles of the past 18 years and compared the research studies related to the diagnosis and treatment of the hamate hook fracture. Our conclusion is that CT scan is the most effective diagnostic tool for detecting the hamate hook fracture. Three-dimensionally (3D) reconstructed images based of CT could provide more accurate and insight illustration for better evaluation in surgical planning. Show more

Keywords: Hamate hook fracture, open reduction and internal fixation, computed tomography, 3D reconstruction

DOI: 10.3233/XST-190497

Citation: Journal of X-Ray Science and Technology, vol. 27, no. 4, pp. 765-772, 2019