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.

LOCAL DIAGNOSTIC REFERENCE LEVELS FOR PEDIATRIC RETROGRADE WEDGE PORTOGRAPHY INTERVENTIONAL PROCEDURES USING A DOSE MONITORING SOFTWARE AT A TRANSPLANTATION INSTITUTE

The aim of this work was to establish local diagnostic reference levels (DRLs) for retrograde wedge portography (RWP) performed on pediatric patients assessing the usefulness of radiation dose monitoring software in the establishing process. Between September 2016 and April 2020, 66 consecutive RWP were performed at a transplantation institute and were included in our study. Patients were divided in three groups according to age: n = 25 infants, n = 20 middle childhood and n = 21 early adolescence. The third quartile of both Air Kerma at the reference point (Ka,r) and air kerma-area product (PKA) were evaluated to establish local DRLs (lDRLs). In addition, to control high Ka,r levels during procedures, the software notified to operators if Ka,r exceeded the dose 'alert' threshold set at 2 Gy. lDRLs were established for all three groups using PKA and Ka,r: infant group: 5.6 Gy.cm 2 and 0.034 Gy; middle childhood: 6.4 Gy.cm2 and 0.018 Gy and early adolescence: 12.8 Gy.cm2 and 0.059 Gy. The dose threshold 'alert' was never encountered (alert quota: 0%). The dose monitoring system supports the feasibility of accurate and easier lDRLs' establishment.

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 15^th, 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.

FLUOROSCOPY-GUIDED BILIARY PROCEDURES IN A PREGNANT, LIVER TRANSPLANT PATIENT: FETUS RADIATION PROTECTION

We report three cases of clinically necessary, fluoroscopy-guided, percutaneous biliary procedures performed safely in a pregnant, liver transplant recipient using three different angiography suites. The uterine cumulative equivalent dose was 0.25 mSv, a value obtained by adding the doses of the three procedures described above, and which is relatively low when compared with the naturally occurring background radiation exposure for a 9-month pregnancy (~0.5-1 mSv). Our experience shows that staff knowledge, awareness and liaison promote the application of all dose reduction strategies possible while still achieving the clinical aim despite using different angiographic equipment.

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.

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.

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

Background Since endoscopists performing procedures in the endoscopy suite can change their position by turning their back, side or front toward the X-ray source, this study aimed to establish whether dosimeter position affects the correct evaluation of an endoscopist’s personal radiation exposure during X-ray-guided procedures.

Materials and methods Between January and February 2018, two dosimeters specularly placed outside the lead apron (anterior one on the chest and posterior one on the back) measured endoscopists’ personal dose equivalent (Hp) during 62 X-ray-guided procedures on adult and pediatric patients. Procedures were divided into three groups considering the position taken by the endoscopist with respect to the radiation source. For each group, the difference between mean Hp from the anterior and posterior dosimeters was calculated.

Results A statistically significant difference in mean Hp was recorded for the endoscopists’ frontal and back positions (P = 0.014, and P < 0.00001, respectively). No significant difference was found in mean Hp for the side position (P = 0.489).

Conclusions The position of personal dosimeters affects the correct evaluation of endoscopists’ radiation exposure during X-ray-guided procedures when frontal and back positions were recorded. To correctly evaluate radiation doses, the whole-body dosimeter should be worn according to the position of the endoscopist with respect to the radiation source; otherwise, it results in an incorrect personal dose evaluation, which may lead to substantial underestimation of staff exposure.

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.