Background: Bolus timing monitoring scans used for computed tomography angiography (CTA) repetitively expose the same region of the body to radiation with a view to determining the appropriate threshold attenuation level of the contrast material (CM). Therefore, for an effective CT scan, it is necessary to minimize repetitive radiation exposures from bolus timing. Objectives: This study aims to effectively identify and reduce the radiation dose needed for repetitive monitoring scans utilized in CT involving the bolus timing method. Patients and Methods: To investigate the currently employed protocols and the number of monitoring scans in bolus timing CT studies, 983 patients (581 males and 402 females; mean age 62. 7) were retrospectively analyzed from October 1, 2013 to March 31, 2014. To identify the appropriate kVp and mA change in the hounsfield unit (HU) and measure the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) in the bolus timing method, a 2 mL syringe containing CM diluted with saline at a ratio of 1 to 300 was inserted into cavities of a CT dose index (CTDI) head phantom and scanned with a 64-section multi-detector row CT system. The dose variation was analyzed using results from the ionization chamber and CTDI. Results: This retrospective analysis of bolus-timing CT studies found that patients underwent an average of 4. 5 to 5. 4 monitoring scans. Furthermore, while theHUvalue of the mixedCMsyringe in the central CTDI head phantom cavity was inversely proportional tomA, the decrease in theHUvaluebecameweaker at a value of 50mAwith 100kVpandat30mAwith 120kVp. Here, theCNR(Pearson correlation r = 0. 983, Kendall’ s t = 0. 978, P < 0. 000) became slightly higher with an increase in mA at 100 kVp compared to 120 kVp, whereas the SNR (Pearson correlation r = 0. 997, Kendall’ s t = 1. 0, P < 0. 000) became similar to 100 kVp. Conclusion: It is recommended that minimum level of radiation (100 kVp, 50 mA; 120 kVp, 30 mA) at which the HU value at the trigger threshold is not significantly different from that of the actual helical scans should be used to minimize the radiation dose caused by repetitive monitoring scans in the bolus timing method.

Background: To explore the clinical value of Test Bolus (TB) scanning technology and Bolus Tracking (BT) technology in the preoperative TNM staging of gastric cancer (GC) patients and the enhanced display of perigastric arteries. Materials and Methods: A retrospective analysis was conducted on the clinical information of 107 gastric cancer patients with complete imaging and pathological diagnostic data (TB group: 30 cases, BT group: 77 cases). Chi-square tests and t-tests were used to compare baseline information between the TB and BT groups. The consistency between the diagnostic results of the TB and BT groups and pathological examination results was analyzed using Kappa tests. Results: There were no statistically significant differences between the TB and BT groups in terms of gender (P=0.499), age (P=0.419), family history of tumors (P=0.979), smoking history (P=0.269), and pain symptoms (P=0.464), while there was a statistically significant difference in alcohol consumption history (P=0.016). The imaging differences between the BT and TB groups were not statistically significant (P>0.05). Except for T staging (P=0.029), there were no statistically significant pathological differences between the BT and TB groups (P>0.05). The consistency of the TB group with pathological results was superior to that of the BT group (Kappa-T: 0.468 vs. 0.439; Kappa-N: 0.301 vs. 0.247; Kappa-M: 0.651 vs. 0.551). Conclusion: TB scanning technology can improve the staging accuracy of GC, achieving better diagnostic performance, but it cannot enhance the display of perigastric arteries.

Background: We investigated the efficacy of a mobile-based bolus advisor app in comparison with the usual multiple daily injections(MDIs) in diabetic patients. Materials and Methods: In a nonrandomized, controlled clinical trial, 62 diabetic patients wereselected to receive a 12-week intensive glycemic control by either a mobile-based bolus advisor (app) or MDI in the usual manner.We compared mean blood glucose (BG) and HbA1c before and just after the treatment program. The data were analyzed usingpaired sample t-test and analysis of variance (ANOVA).Results: Fifty-six patients (30 cases and 26 controls) completed the study.The mean [standard deviation (SD)] of BG was 220.57 (43.7) and 231.5 (55) in the app group and control group, respectively. MeanBG decreased 38 mg/dL in the app and 16 mg/dL in the control group (P=0.001 and 0.049 respectively). Changes of mean BG weredifferent between the two groups significantly (P=0.039). HbA1c decreased from 8.4% to 7.6% in the case and from 8.4% to 8% inthe control group (P=0.001 and 0.06, respectively). Changes of HbA1c were not different between the two groups (P=0.141). Themean episodes of hypoglycemia were not different between the groups significantly (P=0.108).Conclusion: In conclusion, this studyrevealed that mobile-based bolus advisors can reduce mean BG better in patients who are planned to have a tight glycemic controlas a feasible and available method and may improve HbA1c in the long term.

Introduction: In radiotherapy, the bolus is often used while treating the tumor under the uneven surfaces of the patients for correcting the anatomical irregularities and increasing skin dose. Wet cotton and wet gauze are still used in developing countries, since the use of wet cotton and wet gauze has certain disadvantages, there is a need for transparent bolus which should be similar to a universally accepted bolus in terms of properties with a lower cost (50% less expensive). Material and Methods: The present study was conducted to investigate the characteristics of transparent bolus (Senflab) material, such as transmission factor, percentage depth dose (PDD), stability over time and high dose, homogeneity and transparency using 6 and 15 MV photons beam and 12, 15, and 18 MeV electrons beam. Moreover, the new bolus material was compared with those of the commercially available Superflab and RW3 slab. Results: The percentage difference in the transmission factor of Senflab was less than ± 1. 9%, compared with Superflab and RW3. For PDD, the percentage difference was ± 2. 88% and ± 1. 26% for photons and electron beams, respectively. The performance of bolus remained constant both physically and dosimetrically after higher dose exposure. The percentage standard deviation was 0. 0002% for a period of one month, and 0. 0003% for the homogeneity. The transparency of the bolus material was good enough to display the set radiation treatment field. Conclusion: This study shows the suitability of the new bolus for routine use in radiotherapy.