Prevalence of burnout among German radiologists: a call to action.

OBJECTIVES: In the presence of escalating global concerns regarding physician burnout, this study aims to analyze the prevalence and associated factors of burnout among radiologists in Germany. METHODS: A comprehensive online survey, inclusive of 73 targeted questions including a German-modified version of the Maslach Burnout Inventory, was distributed among all members of the German Radiological Society and the German Interventional Radiological Society between May and August 2023. The survey encompassed aspects of employment, workload, well-being, and coping mechanisms. Data from 172 completed surveys were analyzed, with correlations explored via crosstabs and the Pearson-chi-square test. RESULTS: In total, 76.7% of participating radiologists were identified to be burnt out. The prevalence was significantly associated with increased workload, reduced sleep quality, suboptimal working conditions, reduced job satisfaction, and the negative interplay between work, family life, and health. Median work satisfaction was described as "satisfied" while median workload was assessed as "frequently overwhelming of work." A total of 41.9% of respondents noted facing daily time pressure. Radiologists' concerns about work interfering with private family life were voiced by approximately 70%, and 73.3% highlighted the perceived negative effects on their health. CONCLUSION: The pronounced prevalence of burnout among German radiologists demonstrates an urgent, unmet need for comprehensive interventions and systemic changes. Our findings act as a catalyst for initiating targeted, multifaceted strategies and dialogs, essential for fostering a resilient and effective healthcare ecosystem. Further large-scale systematic studies should follow to analyze the findings in broad. CLINICAL RELEVANCE STATEMENT: Consistent with other countries, there is a high prevalence of burnout among radiologists in Germany. A call for further investigation is recommended to help mitigate adverse outcomes associated with physician burnout. KEY POINTS: • The prevalence of burnout has yet not been evaluated for German radiologists. • German radiologists have a high prevalence of burnout. • Steps must be implemented to engage this problem to prevent worsening.

Waiting times between examinations with intravascularly administered contrast media: a review of contrast media pharmacokinetics and updated ESUR Contrast Media Safety Committee guidelines.

The pharmacokinetics of contrast media (CM) will determine how long safe waiting intervals between successive CT or MRI examinations should be. The Contrast Media Safety Committee has reviewed the data on pharmacokinetics of contrast media to suggest safe waiting intervals between successive contrast-enhanced imaging studies in relation to the renal function of the patient. CLINICAL RELEVANCE STATEMENT: Consider a waiting time between elective contrast-enhanced CT and (coronary) angiography with successive iodine-based contrast media administrations in patients with normal renal function (eGFR > 60 mL/min/1.73 m2) of optimally 12 h (near complete clearance of the previously administered iodine-based contrast media) and minimally 4 h (if clinical indication requires rapid follow-up). KEY POINTS: • Pharmacokinetics of contrast media will guide safe waiting times between successive administrations. • Safe waiting times increase with increasing renal insufficiency. • Iodine-based contrast media influence MRI signal intensities and gadolinium-based contrast agents influence CT attenuation.

Contrast media for hysterosalpingography: systematic search and review providing new guidelines by the Contrast Media Safety Committee of the European Society of Urogenital Radiology.

OBJECTIVES: Hysterosalpingography (HSG) is widely used for evaluating the fallopian tubes; however, controversies regarding the use of water- or oil-based iodine-based contrast media (CM) remain. The aim of this work was (1) to discuss reported pregnancy rates related to the CM type used, (2) to validate the used CM in published literature, (3) to discuss possible complications and side effects of CM in HSG, and (4) to develop guidelines on the use of oil-based CM in HSG. METHODS: A systematic literature search was conducted for original RCT studies or review/meta-analyses on using water-based and oil-based CM in HSG with fertility outcomes and complications. Nine randomized controlled trials (RCTs) and 10 reviews/meta-analyses were analyzed. Grading of the literature was performed based on the Oxford Centre for Evidence-Based Medicine (OCEBM) 2011 classification. RESULTS: An approximately 10% higher pregnancy rate is reported for oil-based CM. Side effects are rare, but oil-based CM have potentially more side effects on the maternal thyroid function and the peritoneum. CONCLUSIONS: 1. HSG with oil-based CM gives approximately 10% higher pregnancy rates. 2. External validity is limited, as in five of nine RCTs, the CM used is no longer on the market. 3. Oil-based CM have potentially more side effects on the maternal thyroid function and on the peritoneum. 4. Guideline: Maternal thyroid function should be tested before HSG with oil-based CM and monitored for 6 months after. CLINICAL RELEVANCE STATEMENT: Oil-based CM is associated with an approximately 10% higher chance of pregnancy compared to water-based CM after HSG. Although side effects are rare, higher iodine concentration and slower clearance of oil-based CM may induce maternal thyroid function disturbance and peritoneal inflammation and granuloma formation. KEY POINTS: • It is unknown which type of contrast medium, oil-based or water-based, is the optimal for HSG. • Oil-based contrast media give a 10% higher chance of pregnancy after HSG, compared to water-based contrast media. • From the safety perspective, oil-based CM can cause thyroid dysfunction and an intra-abdominal inflammatory response in the patient.

Analytical interference of intravascular contrast agents with clinical laboratory tests: a joint guideline by the ESUR Contrast Media Safety Committee and the Preanalytical Phase Working Group of the EFLM Science Committee.

The Contrast Media Safety Committee of the European Society of Urogenital Radiology has, together with the Preanalytical Phase Working Group of the EFLM Science Committee, reviewed the literature and updated its recommendations to increase awareness and provide insight into these interferences.

Differences in neonatal gastric tubes during insertion into a 3D model in relation to risk of potential perforation.

OBJECTIVES: Perforation of esophagus or stomach is a potential complication during and after insertion of a gastric tube in neonates. The aim of this study was to analyze different types of gastric tubes in a three-dimensional (3D) model of neonatal esophagus and stomach regarding potential perforations. METHODS: A 3D model of esophagus and stomach was created based on computed tomography data of a term neonate. Three types of gastric tubes were inserted into the 3D model, the localization was examined by radioscopy and the behavior, stiffness and manageability of each gastric tube was evaluated. RESULTS: Insertion of gastric tubes with higher stiffness was easier. The rates of correct localization differed significantly between the gastric tubes with the highest rate of correct localization in the softest tube (48.5%) and the lowest rate in the tube with the highest stiffness (21.2%). Additionally, the softest tube showed the lowest rate of localization of its tip at the stomach wall. CONCLUSIONS: The study illustrates differences between various types of gastric tubes regarding stiffness, behavior and resiliency. Softer gastric tubes may be beneficial. These differences may be relevant in neonatal care of very immature and very sick infants.

CT angiography of the lower limbs: combining small field of view with large matrix size and iterative reconstruction further improves image quality of below-the-knee arteries.

BACKGROUND: Image quality and diagnostic accuracy in computed tomography angiography (CTA) reach their limits in imaging of below-the-knee vessels. PURPOSE: To evaluate whether image quality in CTA of lower limbs is further improvable by combining side-separate reconstruction with a larger matrix size and whether resulting noise can be compromised with iterative reconstruction (IR). MATERIAL AND METHODS: From CTA of the lower extremities of 26 patients (5 women, 21 men; mean age = 68.5 ± 10.3 years), the lower legs were reconstructed side-separately with different reconstruction algorithms and matrix sizes including filtered back projection (FBP) with a 512 × 512 matrix, FBP with a 1024 × 1024 matrix, IR (SAFIRE) with a 512 × 512 matrix, and IR (SAFIRE) with a 1024 × 1024 matrix. A total of 208 CT series were evaluated. Subjective image quality was assessed by two readers using a 5-point Likert scale. Image noise was assessed by measuring signal-to-noise and contrast-to-noise ratios. RESULTS: Subjective image quality was rated significantly higher when using a 1024 × 1024 matrix (P < 0.001) and could further be increased with IR. Vessel sharpness was rated significantly better with a larger matrix (P < 0.001). Visible and measured image noise was significantly higher with a 1024 × 1024 matrix but could be reduced by using IR (P < 0.001), even to a level below FBP with a 512 × 512 matrix while reconstructing with a larger matrix (P < 0.001). CONCLUSION: Image quality, image noise, and vessel sharpness can be further improved in CTA of the lower extremities with side-separate reconstruction using a 1024 × 1024 matrix size and IR.

Medical students' general and radiology-specific motivation: Correlations, stability and associations with learning strategies and ability beliefs.

PURPOSE: This study investigated general and subject-specific motivational beliefs from the perspectives of self-determination theory (i.e. intrinsic, identified, introjected, and extrinsic motivation) and achievement goal theory (i.e. mastery, performance-approach, and -avoidance goal orientation including the respective classroom goal structures), their interrelations, their stability over time, and their associations with desirable outcomes (i.e. deep-level learning strategies, self-concept of ability). It was hypothesized that motivational beliefs are interrelated but demonstrate a distinct correlational pattern depending on whether they were assessed as general or subject-specific motivation. In addition, motivational beliefs were hypothesized to relate to learning strategies and ability beliefs. METHODS: Medical students (n = 146) participated in this longitudinal study with measurement points at the beginning and end of a semester. The questionnaire included established motivational scales to assess motivational beliefs and desirable outcomes. Measurement models were tested using confirmatory factor analyses; correlations of scale means were investigated to assess the nomological network of motivational beliefs. RESULTS: As expected, intrinsic and identified motivation were associated with mastery goal orientation and with desirable outcome variables, such as the use of deep-level learning strategies. General and subject-specific motivation exhibited distinct correlational patterns. Motivation was relatively stable over time. Results did not confirm the factor structure of classroom goal structure. CONCLUSIONS: The study emphasizes the benefit of a subject-specific conceptualization of motivation and the need for a careful adaptation of theoretical constructs from the secondary school context to make them fruitful for the promotion of medical students' motivation. Medical teachers can use established motivational interventions (e.g. using an individual frame of reference for feedback) to support students' adaptive motivational beliefs (e.g. self-determined motivation, mastery goals). Given the subject specificity of motivation, it seems beneficial to promote adaptive motivation in the respective medical specialty regardless of students' general motivational characteristics.

Safe use of contrast media in myasthenia gravis: systematic review and updated European Society of Urogenital Radiology Contrast Media Safety Committee guidelines.

OBJECTIVES: It is uncertain whether modern iodine-based or gadolinium-based contrast media (CM) administration can lead to increased symptoms in patients with myasthenia gravis. METHODS: A systematic search in Medline was conducted for studies describing the symptomatology of myasthenia gravis patients before and after receiving intravenous (IV) CM and having a matched control group of myasthenia gravis patients who did not receive IV CM. RESULTS: Three retrospective studies were selected with a total of 374 myasthenia gravis patients who received iodine-based CM and a total of 313 myasthenia gravis patients who underwent unenhanced CT and served as controls. Pooling of the data from the three retrospective studies showed that in 23 of 374 patients, increased symptoms after iodine-based CM administration were described (6.1%). Increased symptomatology also occurred in 11 of 313 patients after unenhanced CT (3.5%). When looking more deeply into the data of the three studies, conflicting results were found, as two articles did not find any relationship between CM and myasthenia gravis symptoms. The remaining study only found a significant increase in symptomatology within 1 day after CT scanning: seven patients (6.3%) in the contrast-enhanced CT group and one patient (0.6%) in the unenhanced CT group (p = 0.01). CONCLUSIONS: There is limited evidence on the relationship between CM and myasthenia gravis symptoms. In the vast majority of myasthenia gravis patients, CM are safe. Probably, in less than 5% of the patients, iodine-based CM administration may lead to increased severity of the symptoms within the first 24 h after administration. CLINICAL RELEVANCE STATEMENT: Be aware that intravenous administration of iodine-based contrast media can lead to an increase of symptoms in patients with myasthenia gravis within the first 24 h. This can probably happen in less than 5% of the patients. KEY POINTS: • It is unclear whether modern contrast media can lead to increased symptoms in myasthenia gravis patients after intravenous administration. • There seems to be a small risk of increased myasthenia gravis symptoms within 24 h after intravenous administration of iodine-based contrast media, probably in less than 5% of the administrations. • Gadolinium-based contrast media are safe for patients with myasthenia gravis.

Analytical interference of intravascular contrast agents with clinical laboratory tests: a joint guideline by the ESUR Contrast Media Safety Committee and the Preanalytical Phase Working Group of the EFLM Science Committee.

The Contrast Media Safety Committee of the European Society of Urogenital Radiology has, together with the Preanalytical Phase Working Group of the EFLM Science Committee, reviewed the literature and updated its recommendations to increase awareness and provide insight into these interferences. CLINICAL RELEVANCE STATEMENT: Contrast Media may interfere with clinical laboratory tests. Awareness of potential interference may prevent unwanted misdiagnosis. KEY POINTS: • Contrast Media may interfere with clinical laboratory tests; therefore awareness of potential interference may prevent unwanted misdiagnosis. • Clinical Laboratory tests should be performed prior to radiological imaging with contrast media or alternatively, blood or urine collection should be delayed, depending on kidney function.

The Subdiaphragmatic Angle Of The Gastric Tube In Neonates - A Potential Predictor For Perforations?

BACKGROUND: Traumatic subdiaphramatic perforation of esophagus or stomach in neonates represents a rare clinical complication following the insertion of a gastric tube and is associated with high morbidity and mortality. The aim of the present study was to evaluate whether the angle of the gastric tube depicted on a plain radiograph may serve as a diagnostic tool to predict subdiaphragmatic traumatic (or iatrogenic) perforation. PATIENTS AND METHODS: Thoraco-abdominal radiographs of 128 preterm and term neonates without perforation and 15 neonates with perforation of the esophagogastric junction or the stomach were retrospectively analysed. RESULTS: The angle of the gastric tube increases with postnatal age (p=0.0380). In the control group, the angle of the gastric tube varied between 13° and 48° (median: 31°), whereas the values ranged from -31° to 42° (median: 11°) in neonates with subdiaphragmatic perforation. Perforation should thus be suspected in cases with an angle of<20° (sensitivity: 93.3%; specificity: 91.4%). Moreover, an unusual localization of the tip beyond the gastric bubble is highly indicative of perforation. DISCUSSION: The present study emphasizes the importance of verifying the correct course of an inserted gastric tube. CONCLUSIONS: In daily clinical practice, an angle of<20° should be followed by thorough physical examination, abdominal ultrasound and if applicable contrast medium examinations to exclude perforation.

Focal Therapy for Renal Cancer: Comparative Trends in the USA and Germany from 2006 to 2020 and Analysis of the German Health Care Landscape.

INTRODUCTION: The aim of the study was to investigate trends of FT for in-patient treatment of renal RCC in the USA and Germany. METHODS: We analyzed the SEER database for the USA and the nationwide German hospital billing database each from 2006 to 2019 for a RCC diagnosis in combination with FT, radical nephrectomy, and partial nephrectomy. FT was defined as radiofrequency ablation (RFA) or cryotherapy. Linear regression analysis was performed to detect changes over time. RESULTS: For the USA, we included 7,318 FT cases. The share of FT increased from 2.4% in 2006 to 6.4% in 2019 (p < 0.001). For Germany, we identified 2,920 FT cases. The share of FT increased from 0.7% in 2006 to 2.0% in 2019 (p < 0.001). The number of RFAs in the USA steadily increased by 227% from a total of 93 in 2006 to 304 in 2019 while the number of cryotherapies in the USA steadily increased by 289% from a total of 127 in 2006 to 494 in 2019 (p < 0.001). The number of RFAs in Germany increased by 344% from a total of 59 in 2006 to 262 in 2019 (p < 0.001) while the number of cryotherapies steadily increased by 43% from a total of 54 in 2006 to 77 in 2019 (p < 0.001). In Germany, RFA is significantly more performed than cryotherapy while in the USA cryotherapy is more frequently applied. CONCLUSION: We observed a constant increase of FT in the USA and Germany for RCC in-patient treatment with a higher share in the USA.

Intravenous contrast medium extravasation: systematic review and updated ESUR Contrast Media Safety Committee Guidelines.

NEED FOR A REVIEW: Guidelines for management and prevention of contrast media extravasation have not been updated recently. In view of emerging research and changing working practices, this review aims to inform update on the current guidelines. AREAS COVERED: In this paper, we review the literature pertaining to the pathophysiology, diagnosis, risk factors and treatments of contrast media extravasation. A suggested protocol and guidelines are recommended based upon the available literature. KEY POINTS: • Risk of extravasation is dependent on scanning technique and patient risk factors. • Diagnosis is mostly clinical, and outcomes are mostly favourable. • Referral to surgery should be based on clinical severity rather than extravasated volume.

Digital Variance Angiography in Selective Lower Limb Interventions.

PURPOSE: To evaluate the potential benefits of digital variance angiography (DVA) in selective lower limb angiography and to compare the performance of 2 DVA algorithms (conventional DVA1 and the recently developed DVA2) to that of digital subtraction angiography (DSA). MATERIALS AND METHODS: From November 2019 to May 2020, 112 iodinated contrast media (ICM) and 40 carbon dioxide (CO2) angiograms were collected from 15 and 13 peripheral artery disease patients, respectively. The DVA files were retrospectively generated from the same unsubtracted source file as DSA. The objectively calculated contrast-to-noise ratio (CNR) and the subjective visual image quality of DSA, DVA1, and DVA2 images were statistically compared using the Wilcoxon signed-rank test. The images were evaluated by 6 radiologists (R.P.T., S.V., A.M.K., S.S.A., O.E., and J.S.) from 2 centers using a 5-grade Likert scale. RESULTS: Both DVA algorithms produced similar increase (at least 2-fold) in CNR values (P < .001) and significantly higher image quality scores than DSA, independent of the contrast agent used. The overall scores with ICM were 3.61 ± 0.05 for DSA, 4.30 ± 0.04 for DVA1, and 4.33 ± 0.04 for DVA2 (each P < .001 vs DSA). The scores for CO2 were 3.10 ± 0.14 for DSA, 3.63 ± 0.13 for DVA1 (P < .001 vs DSA), and 3.38 ± 0.13 for DVA2 (P < .05 vs DSA). CONCLUSIONS: DVA provides higher CNR and significantly better image quality in selective lower limb interventions irrespective of the contrast agent used. Between DVA algorithms, DVA1 is preferred because of its identical or better image quality than DVA2. DVA can potentially help the interventional decision process and its quality reserve might allow dose management (radiation/ICM reduction) in the future.

[Guideline-based thermal ablation of hepatocellular carcinoma]. / Leitliniengerechte Anwendung der Thermoablation beim hepatozellulären Karzinom.

BACKGROUND: Hepatocellular carcinoma (HCC) is fifth most common cancer worldwide. The German S3 guideline on the diagnosis and the treatment of hepatocellular and biliary carcinoma was recently revised. OBJECTIVE: Determination of the current status of thermal ablation in HCC according to the German S3 guideline. MATERIALS AND METHODS: Based on the current guideline and a selective literature search, the current status on indication and application of thermal ablation in HCC was revisited. RESULTS: Radiofrequency ablation (RFA) and microwave ablation (MWA) provide similar survival when compared with surgery. Accordingly, RFA und MWA are considered first-line treatments for HCCs ≤ 3 cm in cirrhotic livers. For HCCs with diameters of 3-5 cm, a combination of transarterial chemoembolization and thermal ablation is recommended. CONCLUSION: The current S3 guideline on diagnosis and treatment of HCC comprises relevant changes regarding thermal ablation in HCC. The overall role of interventional oncology procedures in the treatment of HCC was reinforced.

[Interdisciplinary management of extracranial vascular anomalies]. / Interdisziplinäres Management extrakranieller Gefäßanomalien.

BACKGROUND: A multitude of vascular anomalies exist and can lead to severe complications. Treatment can be complex. OBJECTIVE: This overview aims to provide important information for the management of vascular anomalies. MATERIALS AND METHODS: In addition to current literature, experiences from the interdisciplinary Vascular Anomalies Center in Marburg were included in this review. RESULTS: Hemangiomas at critical sites, arteriovenous malformations, and vascular anomalies of uncertain etiology require particular attention. CONCLUSION: Self-help and support groups, specialized interdisciplinary centers, scientific medical societies, and networks can provide help for the treatment of vascular anomalies.

Optimized 64-channel array configurations for accelerated simultaneous multislice acquisitions in 3T cardiac MRI.

PURPOSE: Three 64-channel cardiac coils with different detector array configurations were designed and constructed to evaluate acceleration capabilities in simultaneous multislice (SMS) imaging for 3T cardiac MRI. METHODS: Three 64-channel coil array configurations obtained from a simulation-guided design approach were constructed and systematically evaluated regarding their encoding capabilities for accelerated SMS cardiac acquisitions at 3T. Array configuration AUni-sized consists of uniformly distributed equally sized loops in an overlapped arrangement, BGapped uses a gapped array design with symmetrically distributed equally sized loops, and CDense has non-uniform loop density and size, where smaller elements were centered over the heart and larger elements were placed surrounding the target region. To isolate the anatomic variation from differences in the coil configurations, all three array coils were built with identical semi-adjustable housing segments. The arrays' performance was compared using bench-level measurements and imaging performance tests, including signal-to-noise ratio (SNR) maps, array element noise correlation, and SMS acceleration capabilities. Additionally, all cardiac array coils were evaluated on a healthy volunteer. RESULTS: The array configuration CDense with the non-uniformly distributed loop density showed the best overall cardiac imaging performance in both SNR and SMS encoding power, when compared to the other constructed arrays. The diffusion weighted cardiac acquisitions on a healthy volunteer support the favorable accelerated SNR performance of this array configuration. CONCLUSION: Our results indicate that optimized highly parallel cardiac arrays, such as the 64-channel coil with a non-uniform loop size and density improve highly accelerated SMS cardiac MRI in comparison to symmetrically distributed loop array designs.

Establishment of a new valid animal model for the evaluation of hyperthermic intraperitoneal chemotherapy (HIPEC) in pediatric rhabdomyosarcoma.

BACKGROUND: Cytoreductive surgery in combination with hyperthermic intraperitoneal chemotherapy has been established as a novel treatment approach for peritoneal sarcomatosis. Despite promising clinical reports, there is still a lack of knowledge regarding optimal drug usage and local effects. Therefore, we intended to establish a murine animal model for further evaluation. PROCEDURE: Alveolar rhabdomyosarcoma cells were xenotransplanted into NOD/LtSz-scid IL2Rγnullmice (n = 100). The mice received a continuous intraperitoneal lavage with isotonic saline solution as control or with cisplatin (30 or 60 mg/m2 ) as treatment group for 60 minutes at 37°C or 42°C (6 subgroups, each n = 16). Tumor spread was documented by an adapted peritoneal cancer index and MRI (n = 4). Tumor and tissue samples, harvested at the end of the perfusion, were evaluated regarding morphology, proliferation, and apoptosis (H&E-, Ki-67-, cleaved caspase 3-staining, TUNEL assay). RESULTS: Extensive peritoneal sarcomatosis in over 91% of the cases was observed. HIPEC was feasible without acute side effects. Ki-67 staining revealed concentration- or temperature-dependent effects of cisplatin-based HIPEC on the tumors. Although cleaved caspase-3 showed only sporadic apoptotic effects. TUNEL assay detected concentration- or temperature-dependent apoptotic effects at the outer tumor surface. MRI scans confirmed the observed tumor dissemination. CONCLUSION: This is the first animal model for evaluation of HIPEC in pediatric RMS in mice. Cisplatin-based HIPEC had early effects on the proliferation whereas circumscribed apoptotic effects could be detected at the tumor surface. This model allows further insights on the possible efficiency of HIPEC in RMS. Further studies using other drug combinations and treatment will follow.

[Interventional management of peripheral vascular injuries : From the exclusion indication to the procedure of first choice]. / Interventionelles Management peripherer Gefäßverletzungen : Von der Ausnahmeindikation zum Verfahren der 1. Wahl.

BACKGROUND: Approximately one third of all traumatic peripheral artery injuries affect the upper extremities, while two thirds involve the arteries of the lower extremities. Historically, these injuries were treated by open surgical repair. Nowadays, interventional treatment, such as embolization or stent grafting are increasingly used to treat peripheral artery injuries. OBJECTIVE: Determination of the current state of interventional treatment options for injuries of peripheral arteries. MATERIAL AND METHODS: Selective literature review on the current state of interventional management of peripheral artery injuries. RESULTS: Although scarce, the available data confirm the efficacy of interventional techniques for managing peripheral artery injuries; however, despite improvements in treatment techniques and interventional devices, not all patients are equally well suited for endovascular or open surgical treatment. Consequently, a multidisciplinary decision on the best treatment has to be made on a case by case basis. CONCLUSION: According to the promising clinical data, interventional treatment should be considered more often. Diagnostic algorithms need to be adapted accordingly.

Patient radiation dose in percutaneous biliary interventions: recommendations for DRLs on the basis of a multicentre study.

OBJECTIVE: Percutaneous biliary interventions (PBIs) can be associated with a high patient radiation dose, which can be reduced when national diagnostic reference levels (DRLs) are kept in mind. The aim of this multicentre study was to investigate patient radiation exposure in different percutaneous biliary interventions, in order to recommend national DRLs. METHODS: A questionnaire asking for the dose area product (DAP) and the fluoroscopy time (FT) in different PBIs with ultrasound- or fluoroscopy-guided bile duct punctures was sent to 200 advanced care hospitals. Recommended national DRLs are set at the 75th percentile of all DAPs. RESULTS: Twenty-three facilities (9 interventional radiology depts. and 14 gastroenterology depts.) returned the questionnaire (12%). Five hundred sixty-five PBIs with 19 different interventions were included in the analysis. DAPs (range 4-21,510 cGy·cm2) and FTs (range 0.07-180.33 min) varied substantially depending on the centre and type of PBI. The DAPs of initial PBIs were significantly (p < 0.0001) higher (median 2162 cGy·cm2) than those of follow-up PBIs (median 464 cGy·cm2). There was no significant difference between initial PBIs with ultrasound-guided bile duct puncture (2162 cGy·cm2) and initial PBIs with fluoroscopy-guided bile duct puncture (2132 cGy·cm2) (p = 0.85). FT varied substantially (0.07-180.33 min). CONCLUSIONS: DAPs and FTs in percutaneous biliary interventions showed substantial variations depending on the centre and the type of PBI. PBI with US-guided bile duct puncture did not reduce DAP, when compared to PBI with fluoroscopy-guided bile duct puncture. National DRLs of 4300 cGy·cm2 for initial PBIs and 1400 cGy·cm2 for follow-up PBIs are recommended. KEY POINTS: • DAPs and FTs in percutaneous biliary interventions showed substantial variations depending on the centre and the type of PBI. • PBI with US-guided bile duct puncture did not reduce DAP when compared to PBI with fluoroscopy-guided bile duct puncture. • DRLs of 4300 cGy·cm2for initial PBIs (establishing a transhepatic tract) and 1400 cGy·cm2for follow-up PBIs (transhepatic tract already established) are recommended.