Effects of combining multiple dose reduction techniques on coronary computed tomography angiography

BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.AIM To explore the value of multiple dose reduction techniques for CCTA.METHODS Consecutive normal and overweight patients were prospectively divided into two groups:Group A1,patients who received multiple dose reduction scans(n=82);and group A2,patients who received conventional scans(n=39).The scan parameters for group A1 were as follows:Isocentric scan,tube voltage=80 kV,and tube current control using 80%smart milliampere.The scan parameters for group A2 were as follows:Normal position,tube voltage=100 kV,and smart milliampere.RESULTS The average effective doses(EDs)for groups A1 and A2 were 1.13±0.35 and 3.36±1.30 mSv,respectively.There was a statistically significant difference in ED between the two groups(P<0.01).Furthermore,noise was significantly lower,and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1(P<0.01).Moreover,the subjective image quality(IQ)scores were excellent in both groups,in which there was no significant difference in subjective IQ score between the two groups(P=0.12).CONCLUSION Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.

Influence of quality assurance on patients dose reduction in some hospitals

The radiation dose received by patients undergoing chest radiography was included. 200 patients who attended these investigations in 10 hospitals in Iran were randomly selected from all ages groups and both female and male. Critically ill patients were excluded. This paper presents the work, which was implemented on 200 patients and evaluated using the entrance skin dose （ESD） in the posterior anterior （PA） chest projection measured directly at the center of the X-ray field. In addition, the machine room, and dark room .parameters, as well as work practices and repeat rates were studied. The quality control （QC） parameters and the ESD before and after QC were evaluated utilizing an anthropomorphic phantom to define the optimal exposure condition at all hospitals. This research shows that after using the QC parameters and after optimization of the exposure conditions, the ESD was decreased by 42% on average. Also the qua/ity of the radiographs generally increased. The reported method is easily implemented in any clinical situation where optimization of chest radiography is needed.

Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors

Background：Contrast dose and radiation dose reduction in computerized tomography （CT） scan for adult has been explored successfully,but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations.This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction （ASiR） for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors.Methods：Forty-five patients with solid tumors who had initial CT （Group B） and follow-up CT （Group A） after chemotherapy were enrolled.The initial diagnostic CT scan （Group B） was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast,and the follow-up scan （Group A） was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode.Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A.In addition,filtered back-projection （FBP） reconstruction was used for monochromatic images 〈60 keV in Group A.The total radiation dose,total iodine load,contrast injection speed,and maximum injection pressure were compared between the two groups.The 40 keV and 60 keV spectral CT images of Group A were compared with the images of Group B to evaluate overall image quality.Results：The total radiation dose,total iodine load,injection speed,and maximum injection pressure for Group A were decreased by 19%,15%,34.4%,and 18.3%,respectively.The optimal energy level in spectral CT for displaying the abdominal vessels was 40 keV.At this level,the CT values in the abdominal aorta and its three branches,the portal vein and its two branches,and the inferior vena cava were all greater than 340 hounsfield unit （HU）.The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement （t =0.36 and-1.716 for liver,0.153 and-1.546 for pancreas,and 2.427 and 0.866 for renal cortex,all P 〉 0.05）.Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B （t =-8.11 for liver,-7.83 for pancreas,and-5.38 for renal cortex,all P 〈 0.05）.However,the subjective scores for the 40 keV （FBP） and 60 keV （40% ASiR） spectral CT images determined by two radiologists were all 〉3,indicating clinically acceptable image quality.Conclusions：Single-phase,dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

Computed tomography pulmonary angiography using a 20% reduction in contrast medium dose delivered in a multiphasic injection

AIM To evaluate the feasibility of reducing the dose of iodinated contrast agent in computed tomography pulmonary angiography(CTPA). METHODS One hundred and twenty-seven patients clinically suspected of having pulmonary embolism underwent spiral CTPA, out of whom fifty-seven received 75 mL and the remaining seventy a lower dose of 60 mL of contrast agent. Both doses were administered in a multiphasic injection. A minimum opacification threshold of 250 Hounsfield units(HU) in the main pulmonary artery is used for assessing the technical adequacy of the scans. RESULTS Mean opacification was found to be positively correlated to patient age(Pearson's correlation 0.4255, P < 0.0001) and independent of gender(male:female, 425.6 vs 450.4,P = 0.34). When age is accounted for, the study and control groups did not differ significantly in their mean opacification in the main(436.8 vs 437.9, P = 0.48),left(416.6 vs 419.8, P = 0.45) or the right pulmonary arteries(417.3 vs 423.5, P = 0.40). The number of sub-optimally opacified scans(the mean opacification in the main pulmonary artery < 250 HU) did not differ significantly between the study and control groups(7 vs 10).CONCLUSION A lower dose of iodine contrast at 60 mL can be feasibly used in CTPA without resulting in a higher number of sub-optimally opacified scans.

Semaglutide for the management of diabesity:The real-world experience

BACKGROUND Diabesity(diabetes as a consequence of obesity)has emerged as a huge healthcare challenge across the globe due to the obesity pandemic.Judicious use of antidiabetic medications including semaglutide is important for optimal management of diabesity as proven by multiple randomized controlled trials.However,more real-world data is needed to further improve the clinical practice.AIM To study the real-world benefits and side effects of using semaglutide to manage patients with diabesity.METHODS We evaluated the efficacy and safety of semaglutide use in managing patients with diabesity in a large academic hospital in the United States.Several parameters were analyzed including demographic information,the data on improvement of glycated hemoglobin(HbA1c),body weight reduction and insulin dose adjustments at 6 and 12 months,as well as at the latest follow up period.The data was obtained from the electronic patient records between January 2019 to May 2023.RESULTS 106 patients(56 males)with type 2 diabetes mellitus(T2DM),mean age 60.8±11.2 years,mean durations of T2DM 12.4±7.2 years and mean semaglutide treatment for 2.6±1.1 years were included.Semaglutide treatment was associated with significant improvement in diabesity outcomes such as mean weight reductions from baseline 110.4±24.6 kg to 99.9±24.9 kg at 12 months and 96.8±22.9 kg at latest follow up and HbA1c improvement from baseline of 82±21 mmol/mol to 67±20 at 12 months and 71±23 mmol/mol at the latest follow up.An insulin dose reduction from mean baseline of 95±74 units to 76.5±56.2 units was also observed at the latest follow up.Side effects were mild and mainly gastrointestinal like bloating and nausea improving with prolonged use of semaglutide.CONCLUSION Semaglutide treatment is associated with significant improvement in diabesity outcomes such as reduction in body weight,HbA1c and insulin doses without major adverse effects.Reviews of largescale real-world data are expected to inform better clinical practice decision making to improve the care of patients with diabesity.

Occupational Eye Lens Radiation Dose While Performing Interventional Procedures over 18 Months Using a Face-Shield Equipped Suspended Radiation Protection System

Background: Numerous studies have demonstrated increasing evidence for cataractogenesis at lower levels of ionizing radiation than previously believed, with some suggesting possible absence of a threshold. Genetic differences between individuals also result in increased susceptibility in some operators, who might not be aware. European occupational exposure limits have been reduced and operators are seeking protective measures. Objective: To evaluate the protective effect of a face-shield equipped suspended protection system (Zero-Gravity®, TIDI Products, Neenah, WI) along with adherence to safety practices against radiation dose to the eye lens for an interventional radiologist performing a wide variety of procedures. Materials and Methods: In this institutional review board-approved single-institution study, one interventional radiologist wore a highly sensitive personnel monitoring dosimeter badge on the cap near the left eye while performing 299 procedures (3690 fluoroscopy minutes) over 18 consecutive months while utilizing the suspended protection system along with adherence to other generally recommended safety practices and movement away from the field during angiographic power injections. Dosimetry reports and procedural information were retrospectively reviewed. Results: Total lens dose equivalent to the left eye over 18 months was 0.11 mSv (annualized dose = 0.073 mSv, or 7.3 mRem). The patient-dose-area product standardized dose of 0.00576 μSv/Gy⋅cm2 is well below reports of conventional lead aprons, shields, and protective eyewear. Conclusion: Eye exposures were kept to near-background levels using the materials and methods of this study while performing a wide variety of complex procedures from all positions around the patient.

Continuation,reduction,or withdrawal of tofacitinib in patients with rheumatoid arthritis achieving sustained disease control:a multicenter,open-label,randomized controlled trial

Background:Rheumatoid arthritis(RA),a chronic systemic autoimmune disease,is characterized by synovitis and progressive damage to the bone and cartilage of the joints,leading to disability and reduced quality of life.This study was a randomized clinical trial comparing the outcomes between withdrawal and dose reduction of tofacitinib in patients with RA who achieved sustained disease control.Methods:The study was designed as a multicenter,open-label,randomized controlled trial.Eligible patients who were taking tofacitinib(5 mg twice daily)and had achieved sustained RA remission or low disease activity(disease activity score in 28 joints[DAS28]≤3.2)for at least 3 months were enrolled at six centers in Shanghai,China.Patients were randomly assigned(1:1:1)to one of three treatment groups:continuation of tofacitinib(5 mg twice daily);reduction in tofacitinib dose(5 mg daily);and withdrawal of tofacitinib.Efficacy and safety were assessed up to 6 months.Results:Overall,122 eligible patients were enrolled,with 41 in the continuation group,42 in the dose-reduction group,and 39 in the withdrawal group.After 6 months,the percentage of patients with a DAS28-erythrocyte sedimentation rate(ESR)of<3.2 was significantly lower in the withdrawal group than that in the reduction and continuation groups(20.5%,64.3%,and 95.1%,respectively;P<0.0001 for both comparisons).The average flare-free time was 5.8 months for the continuation group,4.7 months for the dose reduction group,and 2.4 months for the withdrawal group.Conclusion:Withdrawal of tofacitinib in patients with RA with stable disease control resulted in a rapid and significant loss of efficacy,while standard or reduced doses of tofacitinib maintained a favorable state.Trial Registration:Chictr.org,ChiCTR2000039799.

Dynamic Flow Control Strategies of Vehicle SCR Urea Dosing System

Selective Catalyst Reduction（SCR）Urea Dosing System（UDS）directly affects the system accuracy and the dynamic response performance of a vehicle.However,the UDS dynamic response is hard to keep up with the changes of the engine＇s operating conditions.That will lead to low NO_χconversion efficiency or NH_3 slip.In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions,an advanced control strategy based on an air-assisted volumetric UDS is presented.It covers the methods of flow compensation and switching working conditions.The strategy is authenticated on an UDS and tested in different dynamic conditions.The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS.The inject deviation range is improved from being between-8%and 10%to-4%and 2%and became more stable than before,and the dynamic response time was shortened from 200 ms to 150 ms.The ETC cycle result shows that after using the new strategy the NH_3 emission is reduced by 60%,and the NO_χemission remains almost unchanged.The trade-off between NO_χconversion efficiency and NH_3 slip is mitigated.The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine＇s operating conditions quickly.

Cases for acupoint embedding of epilepsy

In this report,acupoint embedding method was used for a 25-year-old female patient with epilepsy.The patient suffered from repeated paroxysmal unconsciousness combined with convulsions of four limbs for13 years,and exacerbation for 2 months.She was orally administered with antiepileptic drugs which showed poor control.Using the treatment principles of regulating the mind,opening the orifices,extinguishing wind,and relieving epilepsy,suture-embedded acupoints include Dàzhuī(大椎GV14),Bǎihuì(百会GV20),Xuánlú(悬颅GB5),Yāoqí(腰奇EX-B9),Gānshū(肝俞BL18),Jiūwěi(鸠尾CV15),Jiānshǐ(间使PC5),and Fēnglóng(丰隆ST40),and the patient was treated once a month(qw).After treatment for 6 times,the patient had occasionally a seizure that lasted for several seconds,and the patient’s condition was improved obviously.Acupoint embedding method can control the frequency of epileptic seizures effectively,and reduce the dose of antiepileptic drugs,and deserves further research.