Open-Source Image-Based Tool to Experimentally Evaluate Blood Residence Time in Clinical Devices.

This article introduces an open-source tool to experimentally compare blood residence time in biomedical devices using an image-based method. The experimental setup and the postprocessing workflow are comprehensively elucidated in a detailed report that conducts a thorough comparison of the residence times of a blood analog within three distinct blood oxygenator prototypes. To enable widespread accessibility and ease of use, the user-friendly MATLAB App developed for the analysis is available on the Mathworks repository: https://www.mathworks.com/matlabcentral/fileexchange/135156 .

Feasibility of Ultra-Low Volume Contrast-Saline Mixture Injection With Dual-Flow Technique in a Pre-TAVI Computed Tomography Angiography.

BACKGROUND: To explore the feasibility and image quality of ultra-low volume contrast-saline mixture injection with dual-flow injection technique in a computed tomography angiography (CTA) protocol in patients scheduled for transcatheter aortic valve implantation (TAVI). METHODS: Forty (40) TAVI candidates underwent investigation with CTA using a third-generation dual-source CT scanner between September and November 2020. Different volumes of a monophasic contrast-saline mixture at an 80:20 ratio were administered at an infusion rate of 3 mL/s in 20 patients (group A). The injected volume was based on patient body mass index (BMI): 50 mL if BMI <29 kg/m2 and 63 mL if BMI >29 kg/m2. The other 20 patients (group B)-the control cases-received a total of 65 mL of contrast medium (CM), in multiphasic injections at different flow rates, followed by 10 mL of saline. The images that were obtained were prospectively evaluated for image quality, vessel attenuation (HU), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and estimated radiation dose. RESULTS: Image quality of the aortic root and ilio-femoral vessels was diagnostic in all patients. Vascular attenuation was >200 HU and CNR >3 at any vessel level. CONCLUSIONS: Data from this study suggest that a monophasic ultra-low volume contrast-saline mixture injection with a dual-flow technique can provide clear visualisation of the aortic root and ilio-femoral vessels in pre-TAVI CTA, which is comparable with a standard multiphasic volume injection protocol.

COVID-19 safety measures at the Radiology Unit of a Transplant Institute: the non-COVID-19 patient's confidence with safety procedures.

PURPOSE: To support the wellbeing of both patients and their families, our aim was to investigate the satisfaction of non-COVID in- and out-patients regarding safety measures implemented at our radiology unit of a transplant institute against COVID infection. MATERIALS AND METHODS: Over a five-month period, adult patients' feedback was obtained by a questionnaire on the fear of contracting COVID-19 during a radiology examination, the perceived delay in treatment, and the following safety measures implemented: modified schedules to limit the number of patients in the waiting area and to maximize social distancing; assistance by staff when visitors were not admitted; cleaning and disinfection of machines; mask wearing and hand hygiene of staff; and staff advice on hand hygiene and infection control precautions. RESULTS: Over a five-month period, our preliminary results (387 patients) showed general patient satisfaction (99.1%) with safety measures applied at our radiology unit. Patients were satisfied with distancing and assistance by staff (100%), cleaning and disinfection (91%), mask wearing and hand hygiene of the staff (97%), and staff advice (94%). There was some criticism of the perceived delay in treatment (7.3%) and in the scheduling of the waiting list (5.4%), with 5.4% fearing contracting the virus. Patients' awareness of safety measures and confidence in the hospital preparedness policy was perceived by all interviewers, and 100% appreciated being questioned. CONCLUSION: The feedback given by the non-COVID patient helps to measure the quality in health care, to improve the quality service, and to protect and satisfy more vulnerable patients, also during the COVID-19 pandemic.

Occupational burnout among radiation therapy technologists in Italy before and during COVID-19 pandemic.

INTRODUCTION: Radiation therapy technologists (RTTs) are exposed to high stress levels which may lead to burnout, which could be further increased by the current pandemic. The aim of our study was to assess burnout and stress among Italian RTTs before and during the pandemic. METHODS: The Italian Association of Radiation Therapy and Medical Physics Technologists (AITRO) and the Italian Federation of Scientific Radiographers Societies (FASTeR) proposed a national online survey, including the Maslach Burnout Inventory assessing emotional exhaustion (EE), depersonalisation (DP), and personal accomplishment (PA) to RTTs before and during the pandemic. Multivariate regression analyses and χ2 tests were used for data analysis. RESULTS: We obtained 367 answers, 246 before and 121 during the pandemic. RTTs before and during the pandemic showed high EE and DP, intermediate PA. Median EE was 37 (interquartile range [IQR] 31-46] before and 37 (IQR 30-43) during the pandemic, median DP was 16 (IQR 13-21) and 15 (IQR 12-20), respectively. PA was 31 (IQR 28-34) and 32 (IQR 28-34), respectively. Through multivariate analysis, being female and having children led to higher EE scores before and during the pandemic (p≤0.026). Only the presence of workplace stress management courses was related to lower DP before and being female was related to higher DP during the pandemic (p<0.001). Being female, having children, and working with paediatric patients were related to lower PA before and during the pandemic (p≤0.015). CONCLUSION: Our study highlighted high burnout levels for RTTs regardless of the pandemic. Future interventions aimed at preventing burnout should be implemented in their work environment, independently of the impact of exceptional events.

Patient Perceptions and Knowledge of Ionizing Radiation From Medical Imaging.

Importance: Although imaging has become a standard tool of modern medicine, its widespread use has been paralleled by an increasing cumulative radiation dose to patients despite technological advancements and campaigns calling for better awareness and minimization of unnecessary exposures. Objective: To assess patients' knowledge about medical radiation and related risks. Design, Setting, and Participants: A survey study of hospitals in Italy was conducted; all patients in waiting rooms for medical imaging procedures before undergoing imaging examinations at 16 teaching and nonteaching hospitals were approached to take the survey. The survey was performed from June 1, 2019, to May 31, 2020. Main Outcomes and Measures: Survey respondents' basic knowledge of ionizing radiation levels and health risks, earlier imaging tests performed, and information and communication about radiation protection issues. Results: Among 3039 patients invited to participate, the response rate was 94.3% (n = 2866). Participants included 1531 women (53.4%); mean (SD) age was 44.9 (17.3) years. Of the 2866 participants, 1529 (53.3%) were aware of the existence of natural sources of ionizing radiation. Mammography (1101 [38.4%]) and magnetic resonance imaging (1231 [43.0%]) were categorized as radiation-based imaging modalities. More than half of the 2866 patients (1579 [55.1%]; P = .03) did not know that chest computed tomography delivers a larger dose of radiation than chest radiography, and only 1499 (52.3%) knew that radiation can be emitted after nuclear medicine examinations (P = .004). A total of 667 patients (23.3%) believed that radiation risks were unrelated to age, 1273 (44.4%) deemed their knowledge about radiation risks inadequate, and 2305 (80.4%) preferred to be informed about radiation risks by medical staff. A better knowledge of radiation issues was associated with receiving information from health care professionals (odds ratio [OR], 1.71; 95% CI, 1.43-2.03; P < .001) and having a higher educational level (intermediate vs low: OR, 1.48; 95% CI, 1.17-1.88; P < .001; high vs low: OR, 2.68; 95% CI, 2.09-3.43; P < .001). Conclusions and Relevance: The results of this survey suggest that patients undergoing medical imaging procedures have overall limited knowledge about medical radiation. Intervention to achieve better patient awareness of radiation risks related to medical exposures may be beneficial.

A critical appraisal of the quality of guidelines for radiation protection in interventional radiology using the AGREE II tool: A EuroAIM initiative.

PURPOSE: To systematically review and assess the methodological quality of guidelines for radiation protection in interventional radiology. MATERIALS AND METHODS: On April 15th, 2021, a systematic search for guidelines on radiation protection in interventional radiology was performed using MEDLINE, EMBASE, National Guideline Clearinghouse, and National Institute for Health and Clinical Excellence databases. Among retrieved guidelines, we then excluded those not primarily focused on radiation protection or on interventional radiology. Authors' professional role and year of publication were recorded for each included guideline. Guideline quality evaluation was performed independently by three authors using the six-domain tool "AGREE II", with an overall guideline quality score divided into three classes: low (<60%), acceptable (60-80%), and good quality (>80%). RESULTS: Our literature search identified 106 citations: after applying exclusion criteria, 11 guidelines published between 2009 and 2018 were included, most of their authors being interventional radiologists (168/224, 75%). Overall quality of included guidelines was acceptable (median 72%, interquartile range 64-83%), with only one guideline (9%) with overall low quality and four guidelines (36%) with overall good quality. Among AGREE II domains, "Scope and Purpose", "Clarity of Presentations", and "Editorial Independence" had the best results (87%, 76%, and 75% respectively), while "Applicability", "Rigor of Development", and "Stakeholder Involvement" the worst (46%, 49%, and 52% respectively). CONCLUSION: Considering all guidelines, the overall methodological quality was acceptable with one third of them reaching the highest score class. The "Applicability" domain had the lowest median score, highlighting a practical implementation gap to be addressed by future guidelines.

Feasibility of combined ECG-Gated and Helical acquisition mode in a pre-TAVI computed tomography angiography protocol using a fixed low-volume contrast medium injection.

BACKGROUND: To investigate the feasibility, image quality, and clinical implications of a combined ECG-gated and helical acquisition mode in a computed tomography angiography (CTA) protocol in patients scheduled for transcatheter aortic valve implantation (TAVI) using a fixed, low-volume, contrast medium injection. METHODS: Between July and October 2019, 43 TAVI candidates underwent investigation with CTA using a 64-slice CT scanner. Images obtained were prospectively evaluated. 65 mL of low iodine dose contrast medium (CM), followed by 25 mL of saline, were administered using a fixed multiphasic injection protocol in all patients. Patients were divided into three groups based on BMI: Group 1 (n = 9) with BMI < 22 kg/m2; Group 2 (n = 22) with BMI 22-29 kg/m2; Group 3 (n = 12) with BMI > 29 kg/m2. Images were evaluated for image quality, vessel attenuation (HU), Signal-to-Noise Ratio (SNR), Contrast-to-Noise Ratio (CNR) and estimated radiation dose. Image quality of the aortic root and iliac-femoral vessels was diagnostic in all patients. RESULTS: Vascular attenuation was > 200 HU and CNR > 3 at all vessel levels. CONCLUSION: Data from our study suggest that it is possible to image the aortic annulus and aorto-iliac anatomy and obtain high image quality in all patients by using a combined ECG-gated and helical acquisition mode in a computed tomography angiography (CTA) protocol with a fixed low-volume contrast medium injection (65 mL). This allows for accurate CT measurements of the aortic annulus, recruitment of patients for TAVI and facilitates pre-procedural planning in these high surgical risk patients.

Radiation exposure during transjugular intrahepatic portosystemic shunt creation in patients with complete portal vein thrombosis or portal cavernoma.

BACKGROUND: This study aims to evaluate radiation exposure in patients with complete portal vein thrombosis (CPVT) or portal cavernoma (PC) undergoing transjugular intrahepatic portosystemic shunt (TIPS) creation using real-time ultrasound guidance for portal vein targeting. MATERIALS AND METHODS: This is a single institution retrospective analysis. Between August 2009 and September 2018, TIPS was attempted in 49 patients with CPVT or PC. Radiation exposure (dose area product [DAP], air KERMA (AK) and fluoroscopy time [FT]), technical success, clinical success, complications and survival were analyzed. RESULTS: In total, 29 patients had CPVT and 20 patients had PC. 41/49 patients had cirrhosis. TIPS indications were refractory ascites (n = 25), variceal bleeding (n = 16) and other (n = 8). TIPS was successfully placed in 94% (46/49) of patients via a transjugular approach alone (n = 40), a transjugular/transhepatic approach (n = 5) and a transjugular/transsplenic approach (n = 1). Median DAP was 261 Gy * cm2 (range 29-950), median AK was 0.2 Gy (range 0.05-0.5), and median FT was 28.2 min (range 7.7-93.7). Mean portosystemic pressure gradient decreased from 16.8  ±  5.1 mmHg to 7.5  ±  3.3 mmHg (P <  0.01). There were no major procedural complications. Overall clinical success was achieved in 77% of patients (mean follow-up of 21.1 months). Encephalopathy was observed in 16 patients (34%), grade II-III encephalopathy in 7 patients (15%). TIPS revision was performed in 15 patients (32%). Overall survival rate was 75%. CONCLUSION: In our experience, the use of real-time ultrasound guidance allowed the majority of the TIPS to be performed via a transjugular approach alone with a reasonably low radiation exposure considering the high technical difficulties of the selected cohort of patients with CVPT or PC.

OCCUPATIONAL RADIATION DOSE PERFORMING HEPATOBILIARY MINIMALLY INVASIVE PROCEDURES IN CHILDREN WEIGHING LESS THAN 20 kg.

Our objective is to retrospectively evaluate the effective dose (E) of operators performing pediatric Hepatobiliary Minimally Invasive Procedures (HMIP). Between October 2015 and December 2017, 58 consecutive HMIP were performed on 26 children weighing less than 20 kg (mean 12.3 kg, median 13 kg, range 2.4-20 kg). About 31 vascular procedures (n = 9 hepatic venograms with/without stenting; n = 9 retrograde wedge portography; n = 8 transhepatic portography with angioplasty and/or stenting and n = 5 hepatic arteriography/embolization) and 27 non-vascular procedures (n = 6 percutaneous transhepatic biliary drainage (PTBD); n = 3 bilioplasty; n = 15 biliary catheter change and n = 3 cholangiogram) were performed. Electronic personal dosimeters were used to measure radiation doses to the interventional radiologist, radiographer and anesthesia nurse. The results shows the highest mean effective dose: interventional radiologist's in PTBD (1.18 µSv); radiographer's in hepatic veins phlebography with/without stenting (0.25 µSv) and nurse's in hepatic arteriography/embolization (0.26 µSv). Operators' E can vary depending on the complexity of procedure performed and the position of the operators within the angiosuite.

Erratum: Endoscopist's occupational dose evaluation related to correct wearing of dosimeter during X-ray-guided procedures.

[This corrects the article DOI: 10.1055/a-0841-3350.].

Radiation Doses to Operators in Hepatobiliary Interventional Procedures.

PURPOSE: The primary aim of this study is to provide a summary of operators' radiation doses during hepatobiliary fluoroscopic guided procedures. In addition, patient dose in these procedures was also documented. MATERIALS AND METHODS: A total of 283 transarterial chemoembolisation (TACE) and 302 biliary procedures, including 52 percutaneous transhepatic cholangiogram (PTC), 36 bilioplasty and 214 biliary catheter changes (BCC) performed over 14 months, were included. Electronic personal dosimeters were used to measure operator radiation doses. Effective dose (E) was calculated using modified Niklason algorithm. Patient dose was measured as dose area product (DAP) and fluoroscopy time (FT). RESULTS: For TACE, E for radiologist ranged between 0 and 9.96 µSv, for radiographer 0-0.99 µSv and for nurse 0-4.65 µSv. The patient DAP and FT ranged between 1.5 and 421.9 Gy cm2 and 1.91-67.25 min. For PTC, E for the radiologist ranged between 0.33 and 55.89 µSv, for radiographer 0-38.61 µSv and for nurse 0-3.18 µSv. Patient DAP and FT ranged between 1.7 and 218.4 Gy cm2 and 2.07-71.53 min. For bilioplasty, E ranged between 0.09 and 9.24 µSv for radiologist, 0-0.84 µSv for radiographer and 0-1.38 µSv for nurse. The patients' DAP and FT ranged from 0.7 to 52.54 Gy cm2 and 1.13-24.47 min. For BCC, E ranged from 0 to 12.78 µSv for radiologist, 0-8.43 µSv for radiographer and 0-4.05 µSv for nurse. Patient DAP and FT ranged between 0.12 and 117.3 Gy cm2 and 0.57-15.83 min. CONCLUSIONS: This study shows that doses to all operators performing hepatobiliary interventional procedures can be very low.

Radiation doses to operators performing transjugular intrahepatic portosystemic shunt using a flat-panel detector-based system and ultrasound guidance for portal vein targeting.

OBJECTIVES: The aim of this study was to prospectively evaluate effective dose (E) of operators performing transjugular intrahepatic portosystemic shunts (TIPS) in a single centre. Patients' radiation exposure was also collected. METHODS: Between 8/2015 and 6/2016, 45 consecutive TIPS were performed in adult patients using a flat-panel detector-based system (FPDS) and real-time ultrasound guidance (USG) for portal vein targeting. Electronic personal dosimeters were used to measure radiation doses to the primary and assistant operators, anaesthesia nurse and radiographer. Patients' radiation exposure was measured with dose area product (DAP); fluoroscopy time (FT) was also collected. RESULTS: Mean E for the primary operator was 1.40 µSv (SD 2.68, median 0.42, range 0.12 - 12.18), for the assistant operator was 1.29 µSv (SD 1.79, median 0.40, range 0.10 - 4.89), for the anaesthesia nurse was 0.21 µSv (SD 0.67, median 0.10, range 0.03 - 3.99), for the radiographer was 0.42 µSv (SD 0.71, median 0.25, range 0.03 - 2.67). Mean patient DAP was 59.31 GyCm2 (SD 56.91, median 31.58, range 7.66 - 281.40); mean FT was 10.20 min (SD 7.40, median 10.40, range 3.8 - 31.8). CONCLUSION: The use of FPDS and USG for portal vein targeting allows a reasonably low E to operators performing TIPS. KEY POINTS: • The operators' E vary according to the complexity of the procedure. • FPDS and USG allow a reasonably low E to TIPS operators. • FPDS and USG have an important role in reducing the occupational exposure.

Digital subtraction angiography during transjugular intrahepatic portosystemic shunt creation or revision: data on radiation exposure and image quality obtained using a standard and a low-dose acquisition protocol in a flat-panel detector-based system.

PURPOSE: To determine whether the use of a low-dose acquisition protocol (LDP) in digital subtraction angiography during transjugular intrahepatic portosystemic shunt (TIPS) creation/revision results in significant reduction of patient radiation exposure and adequate image quality, as compared to a default reference standard-dose acquisition protocol (SDP). METHODS: Two angiographic runs were performed during TIPS creation/revision: the first following catheterization of the portal venous system and the second after stent deployment/angioplasty. Constant field of view, object to image-detector distance, and source to image-receptor distance were maintained in each patient during the two angiographic runs. 17 consecutive adult patients who underwent TIPS creation (n = 11) or TIPS revision (n = 6) from December 2013 to March 2014 were considered eligible for this single centre prospective study. In each patient, the LDP and the SDP were used in a random order for the two runs, with each patient serving as his/her own control. The dose-area product (DAP) was calculated for each image and compared. Image quality was graded by two interventional radiologists other than the operator. RESULTS: In all runs acquired with the LDP, image quality was considered adequate for a successful procedural outcome. The DAP per image of the LDP was numerically inferior as compared to the DAP per image of the SDP in all patients. The mean reduction in DAP per image was 75.24% ± 5.7% (p < 0. 001). CONCLUSION: Radiation exposure during TIPS creation/revision was significantly reduced by selecting a LDP in our flat-panel detector-based system, while maintaining adequate image quality.

Comparison between radiation exposure levels using an image intensifier and a flat-panel detector-based system in image-guided central venous catheter placement in children weighing less than 10 kg.

BACKGROUND: Ultrasound-guided central venous puncture and fluoroscopic guidance during central venous catheter (CVC) positioning optimizes technical success and lowers the complication rates in children, and is therefore considered standard practice. OBJECTIVE: The purpose of this study was to compare the radiation exposure levels recorded during CVC placement in children weighing less than 10 kg in procedures performed using an image intensifier-based angiographic system (IIDS) to those performed in a flat-panel detector-based interventional suite (FPDS). MATERIALS AND METHODS: A retrospective review of 96 image-guided CVC placements, between January 2008 and October 2013, in 49 children weighing less than 10 kg was performed. Mean age was 8.2 ± 4.4 months (range: 1-22 months). Mean weight was 7.1 ± 2.7 kg (range: 2.5-9.8 kg). The procedures were classified into two categories: non-tunneled and tunneled CVC placement. RESULTS: Thirty-five procedures were performed with the IIDS (21 non-tunneled CVC, 14 tunneled CVC); 61 procedures were performed with the FPDS (47 non-tunneled CVC, 14 tunneled CVC). For non-tunneled CVC, mean DAP was 113.5 ± 126.7 cGy cm(2) with the IIDS and 15.9 ± 44.6 cGy · cm(2) with the FPDS (P < 0.001). For tunneled CVC, mean DAP was 84.6 ± 81.2 cGy · cm(2) with the IIDS and 37.1 ± 33.5 cGy cm(2) with the FPDS (P = 0.02). CONCLUSION: The use of flat-panel angiographic equipment reduces radiation exposure in small children undergoing image-guided CVC placement.

Removal of the antiscatter grid during routine biliary interventional procedures performed in a flat-panel interventional suite: preliminary data on image quality and patient radiation exposure.

PURPOSE: To determine whether grid removal during routine biliary interventional procedures performed in a flat-panel interventional suite results in adequate image quality and a significant decrease of patient radiation exposure. MATERIALS AND METHODS: Routine biliary interventional procedures were defined as those in which absence of fine image detail during fluoroscopy carries no procedural impact, including substitution of internal-external biliary drains (n = 25) or bilioplasty of benign biliary anastomotic strictures (n = 5). All patients had undergone a previous procedure in which the grid was used. Constant object-to-detector and source-to-image distance were maintained in each patient during the grid/no-grid procedures. The same fluoroscopy protocol was used for all examinations. The dose area product (DAP [cGy.cm(2)]) and procedure fluoroscopy time (seconds) were recorded for each procedure. DAP was normalized per unit of fluoroscopy time (nDAP [cGy.cm(2)/s]). RESULTS: In all procedures, image quality was considered adequate by two different interventional radiologists, and all procedures were successfully completed without significant changes in fluoroscopy time between the two groups (p = 0.13). In every procedure without the grid, nDAP was inferior compared with nDAP in procedures performed using the grid. The mean decrease in dose was 39.2 ± 23.5 % (p = 0.000001). CONCLUSION: Our preliminary data show that removal of the grid during routine biliary procedures is feasible and results in a significant decrease of patient radiation exposure. This seems of particular relevance because most of these patients require frequent reintervention. Larger studies with more procedures are warranted to confirm these data.