The status of academic interventional radiologists in Germany with focus on gender disparity: how can we do better?

PURPOSE: The aim was to characterize the framework conditions in academic interventional radiology (IR) in Germany with focus on differences between genders. MATERIALS AND METHODS: After IRB approval, all members of The German Society for Interventional Radiology and Minimally Invasive Therapy (n = 1,632) were invited to an online survey on work and research. Statistical comparisons were undertaken with the Fisher's exact test, Wilcoxon rank sum test or Pearson's Chi-squared test. RESULTS: From 267 available questionnaires (general response rate 16.4%), 200 were fully completed. 40% of these (78/200) were involved in research (71% men vs. 29% women, p < 0.01) and eligible for further analysis. Of these, 6% worked part-time (2% vs. 17%, p < 0.05). 90% of the respondents spent less than 25% of their research during their paid working hours, and 41% performed more than 75% of their research during. leisure time. 28% received exemption for research. 88% were (rather) satisfied with their career. One in two participants successfully applied for funding, with higher success rates among male applicants (90% vs. 75%) and respondents with protected research time (93% vs. 80%). Compared to men, women rated their entrance in research as harder (p < 0.05), their research career as more important (p < 0.05), felt less noticed at congresses (93% vs. 53%, p < 0.01), less confident (98% vs. 71%, p < 0.01), and not well connected (77% vs. 36%, p < 0.01).  CONCLUSION: Women and men did research under the same circumstances; however, women were underrepresented. Future programs should generally focus on protected research time and gather female mentors to advance academic IR in Germany.

Endovascular treatment of renal artery stenosis in Germany: a retrospective analysis of the DEGIR registry 2018-2021.

PURPOSE: To provide an overview of endovascular treatment of renal artery stenosis (RAS) using the data of the Deutsche Gesellschaft für interventionelle Radiologie (DeGIR) quality management system. MATERIALS AND METHODS: A retrospective analysis was performed. Pre-, peri- and postprocedural data, technical success rates, complication rates, and clinical success rates at dismissal were examined. RESULTS: Between 2018 and 2021, 2134 angiography examinations of the renal arteries were performed: diagnostic angiography in 70 patients (3 %), balloon angioplasty in 795 (37 %), stent implantation in 1166 (55 %) and miscellaneous procedures in 103 (5 %). The lesion length was less than or equal to 5 mm in 1837 patients (87 %), between 5 and 10 mm in 197 (9 %), and between 10 and 20 mm in 62 (3 %). The degree of stenosis was less than 50 % in 156 patients (7 %), greater than 50 % in 239 (11 %), and greater than 70 % in 1472 (70 %). Occlusion was treated in 235 patients (11 %). Symptoms at discharge resolved in 600 patients (29 %), improved in 1012 (49 %), were unchanged in 77 (4 %), and worsened in 5 (0.2 %). Complications were reported in 51 patients (2.5 %) and the mortality rate was 0.15 %. CONCLUSION: A substantial number of patients with RAS and occlusions were treated by radiologists in Germany, with high technical success rates and low complication rates. The indication should be determined carefully as the current European guidelines for the treatment of RAS suggest that only carefully selected groups of patients will benefit from recanalizing treatment. KEY POINTS: · Carefully selected patient groups may benefit from endovascular treatment of renal artery stenosis.. · Analysis of the DEGIR quality management database shows that treatment of renal artery stenosis was performed by radiologists in Germany with high technical success rates and low complication rates.. · Recanalization even led to symptom improvement in a large proportion of patients with occlusions..

Machine learning based prediction of length of stay in acute ischaemic stroke of the anterior circulation in patients treated with thrombectomy.

BACKGROUND: Length of stay is an important factor for managing the limited resources of a hospital. The early, accurate prediction of hospital length of stay leads to the optimized disposition of resources particularly in complex stroke treatment. OBJECTIVE: In the present study we evaluated different machine learning techniques in their ability to predict the length of stay of patients with stroke of the anterior circulation who were treated with thrombectomy. MATERIAL AND METHODS: This retrospective study evaluated four algorithms (support vector machine, generalized linear model, K-nearest neighbour and Random Forest) to predict the length of hospitalization of 113 patients with acute stroke who were treated with thrombectomy. Input variables encompassed baseline data at admission, as well as periprocedural and imaging data. Ten-fold cross-validation was used to estimate accuracy. The accuracy of the algorithms was checked with a test dataset. In addition to regression analysis, we performed a binary classification analysis to identify patients that stayed longer than the mean length of stay. RESULTS: Mean length of stay was 10.7 days (median 10, interquartile range 6-15). The sensitivity of the best-performing Random Forest model was 0.8, the specificity was 0.68 and the area under the curve was 0.73 in the classification analysis. The mean absolute error of the best-performing Random Forest Model was 4.6 days in the test dataset in the regression analysis. CONCLUSION: Machine learning has potential use to estimate the length of stay of patients with acute ischaemic stroke that were treated with thrombectomy.

Thrombectomy in ischemic stroke patients with alberta stroke program early computed tomography score 4-5 and 0-3: Factors associated with favorable outcome.

OBJECTIVES: Recently published results of the ANGEL-ASPECT and SELECT2 trials suggest that stroke patients presenting with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) benefit from mechanical thrombectomy. Purpose of this retrospective study was to identify factors that are associated with a favorable outcome in patients with low ASPECTS of 4-5 and 0-3 undergoing mechanical thrombectomy. MATERIAL AND METHODS: All patients reported in the quality registry of the German Society for Neuroradiology that were treated between 2018 and 2020 were analyzed. Favorable outcome was defined as a National Institute of Health Stroke Scale (NIHSS) score of less than 9 at dismissal. Successful recanalization was defined as Thrombolysis in Cerebral Infarction (mTICI) ≥ 2b. Multivariable logistic regression analyses were performed to assess the association of baseline and treatment variables with favorable outcome. RESULTS: 621 patients were included in the analysis, thereof 495 with ASPECTS 4-5 and 126 with ASPECTS 0-3. In patients with ASPECTS 4-5patients with favorable outcome had less severe neurological symptoms at admission with median NIHSS of 15 vs. 18 (p<0.001), had less often wake-up strokes (44% vs. 81%, p<0.001), received more often iv-lysis (37% vs. 30%, p<0.001), had more often conscious sedation (29% vs. 16%, p<0.001), had a higher rate of successful recanalization (94% vs. 66% and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.89-0.91) and successful recanalization (aOR 3.96, CI 2-8.56) were associated with favorable outcome. For ASPECTS 0-3, patients with favorable outcome had lower median NIHSS at admission (16 vs. 18 (p<0.001), lower number of passes (1 vs. 3, p=0.003) and a higher rate of successful recanalization (94% vs. 66%, p<0.001) and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.81-0.94) and successful recanalization, (aOR 11.19, CI 3.19-55.53), were associated with favorable outcome. CONCLUSION: Full recanalization with low groin punction to recanalization times and low number of passes were associated with favorable outcome in patients with low ASPECTS.

Outcome prediction prior to thrombectomy of the posterior circulation with machine learning.

PURPOSE: Various studies have identified prognostic factors for a favorable outcome of endovascular treatment in posterior circulation. We evaluated various machine learning algorithms in their ability to classify between patients with favorable (defined as 0-2 points on the modified Rankin scale [mRS]), unfavorable (mRS 3-6), poor (mRS 5-6), and nonpoor (mRS 0-4) outcomes at dismissal. METHODS: We retrospectively analyzed data from 415 patients that were treated between 2018 and 2021 from the multicentric DGNR registry. Five models (random forest, support vector machine, k-nearest neighbor, neural network [NN], and generalized linear model [GLM]) were trained with clinical input variables and evaluated with a test dataset of 82 patients. The model with the highest accuracy on the training dataset was defined as the best model. RESULTS: A total of 132 patients showed poor and 162 patients showed favorable outcome. All baseline variables except sex were highly significantly different between patients with favorable and unfavorable outcomes. The variables NIHSS, the presence of wake-up stroke, the administration of IV-thrombolysis and mRS pretreatment were significantly different between patients with poor and nonpoor outcomes. The best-performing NN achieved a sensitivity of 0.56, a specificity of 0.86 and an area under the curve (AUC) of 0.77 on the test dataset in the classification analysis between favorable and unfavorable outcomes. The best-performing GLM achieved a sensitivity of 0.65, a specificity of 0.91 and an AUC of 0.81 in the classification analysis between poor and nonpoor outcomes. CONCLUSION: Short-term favorable and poor outcomes in patients with acute ischemic stroke of the posterior circulation can be predicted prior to thrombectomy with moderate sensitivity and high specificity with machine learning models.

Feasibility of Network-Based, Online Endovascular Simulator Training in Real Time: Results from a Pilot Study.

PURPOSE: To test the feasibility of an online, simulator-based comprehensive interventional radiology (IR) training curriculum in times of COVID-19-induced travel restrictions. MATERIALS AND METHODS: A network of six VIST simulators (Mentice, Gothenburg, Sweden) was installed in six geographically different radiology departments. Two courses with six sessions each took place. 43 participants were recruited on a voluntary basis among local residents. The training sessions were conducted in real time with interconnected simulation devices and were led by experts in the field of IR on a rotational basis. The participants attitude toward various topics was quantified before and after training on a seven-point Likert scale (1 = "not at all", 7 = "to the highest degree"). In addition, post-course surveys were conducted. RESULTS: The courses led to an improvement for all items compared with baseline: interest in IR (pre: 5.5, post: 6.1), knowledge of endovascular procedures (pre: 4.1, post: 4.6), likelihood of choosing IR as a subspecialty (pre: 5.7, post: 5.9). Experience with endovascular procedures (pre: 3.7, post: 4.6) improved significantly (p = 0.016). In the post-course surveys high satisfaction rates with the pedagogical approach (mean 6), the teaching content (mean 6.4), and the duration and frequency of the course (mean 6.1) were observed. CONCLUSION: The implementation of a simultaneous endovascular online training curriculum in different geographic locations is feasible. The curriculum has the potential to meet the demand for training in IR in times of COVID-19-associated travel restrictions and can complement future training in the context of radiologic congresses. KEY POINTS: · The implementation of a simultaneous endovascular online training curriculum in different geographic locations is feasible. For interested residents, the presented online curriculum can offer a low-threshold and comprehensive entry into the world of interventional radiology at the site of their training..

Thrombectomy of Mild Stroke : An Analysis of the Nationwide Registry of the German Society for Neuroradiology.

PURPOSE: Whether patients presenting with mild stroke (NIHSS at admission < 6) should be treated with mechanical thrombectomy (MT) is the subject of an ongoing debate. This retrospective study based on large-scale clinical data aims to identify factors associated with favorable outcome (FO) in patients with mild stroke. METHODS: A total of 761 patients with mild stroke enrolled between 1 January 2020 and 31 December 2020 in the Quality Registry of the German Society for Neuroradiology were analyzed. The FO was defined as stable or improved NIHSS at discharge vs. admission. Descriptive statistics and multivariable logistic regression analyses were performed to identify factors associated with FO. Furthermore, a subgroup analysis of mild stroke based on distal vessel occlusion was conducted. RESULTS: In this study 610 patients had FO with a median NIHSS at discharge of 1 (interquartile range, IQR, 0-2) and 151 had an unfavorable outcome (UO) with median NIHSS at discharge of 10 (IQR 13). Patients with FO had a slightly higher NIHSS at admission (4 vs. 3, p < 0.001), lower mTICI 0 (2.7% vs. 14.2%, p < 0.001), higher mTICI 3 (61.3% vs. 34.5%, p < 0.001) and a lower number of passes (1 vs. 2, p < 0.001). No statistically significant difference was observed for MT-related adverse events. Multivariable logistic regression suggested that NIHSS at admission (adjusted odds ratio (aOR) = 1.28, 95% confidence interval (CI) = 1.10-1.48), mTICI 2b (aOR = 5.44, CI = 2.06-15.03), mTICI 2c (aOR = 10.81, CI = 3.65-34.07) and mTICI 3 (aOR = 11.56, CI = 4.49-31.10) as well as number of passes (aOR 0.76, CI = 0.66-0.88) were significantly associated with FO. No MT-related adverse events were observed for distal vessel occlusions. CONCLUSION: The FO in patients with mild stroke undergoing MT was associated with successful recanalization. No significant differences between patients with FO and UO were found for MT-related adverse events, suggesting that MT complications have no significant effects on the outcome of these patients. MT might improve the prognosis also in patients with mild stroke based on distal vessel occlusions without significantly increasing the risk of adverse events.

How to Treat Type B Aortic Dissections in the Presence of an Aberrant Right Subclavian Artery: A Systematic Review.

An aberrant right subclavian artery (ARSA) is the most common congenital variant of the aortic arch. Usually, this variation is largely asymptomatic, but sometimes it may be involved in aortic dissection (AD). Surgical management of this condition is challenging. The therapeutic options have been enriched in recent decades by establishing individualized endovascular or hybrid procedures. Whether these less invasive approaches bear advantages, and how they have changed the treatment of this rare pathology, is still unclear. Therefore, we conducted a systematic review. We performed a review of literature from the past 20 years (from January 2000 until February 2021) complying with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All reported patients treated for Type B AD in the presence of an ARSA were identified and classified into three groups according to the received therapy (open, hybrid, and total endovascular). Patient characteristics, as well as in-hospital mortality, and major and minor complications were determined and statistically analyzed. We identified 32 relevant publications comprising 85 patients. Open arch repair has been offered to younger patients, but significantly less often in symptomatic patients needing urgent repair. Therefore, the maximum aortic diameter was also significantly larger in the open repair group compared with that in the hybrid or total endovascular repair group. Regarding the endpoints, we did not find significant differences. The literature review revealed that open surgical therapies are preferred in patients presenting with chronic dissections and larger aortic diameters, most likely because they are unsuitable for endovascular aortic repair. Hybrid and total endovascular approaches are more often applied in emergency situations, where aortic diameters remain smaller. All therapies demonstrated good, early, and midterm outcomes. But, these therapies carry potential risks in the long term. Therefore, long-term follow-up data are urgently needed to validate that these therapies are sustainable.

Increased aortic repair in Germany correlates with reduction of death caused by aortic aneurysms but not aortic dissections.

INTRODUCTION: We asked if there is a significant correlation between the increasing trend in aortic repair (AR) and decreasing aortic aneurysm (AA) and aortic dissection (AD) mortality? Therefore, we retrospectively analyzed all aortic repairs in patients with AA and AD and its correlation with disease-specific death rates and hospitalizations for ruptured AA and AD in Germany. METHODS: We retrieved the number of cases hospitalized for AA and AD as well as the procedures in these cases from the Federal Bureau of Statistics (DRG statistics) and death rates from the national mortality statistic published by the Federal Statistical Office in Germany for the years 2006-2017. RESULTS: From 2006 to 2017, the total number of hospitalized cases admitted with principal diagnosis of AA increased by 25.8% and that of AD by 56.7%. That of cases with the principal diagnosis of ruptured AA (rAA) remained unchanged (-2.5%) and that with rAD increased by 54.6%. The number of (open and endovascular) procedures in cases hospitalized for AA increased by 39.4% and for AD by 126.4%. The age-adjusted death rates in Germany for AA decreased from 4.0 to 2.9 per 100,000 inhabitants and that for AD increased from 1.0 to 1.4. The decrease in death attributed to AA cases can be described by linear regression as y = -0.0003*y + 6.7076 (p < 0.0001). Accepting this association between increased elective procedures and reduced AA mortality, each/all 1000 procedures save 0.3 lives per 100,000 inhabitants. CONCLUSION: Despite increasing numbers of AR for AA and AD, only the mortality rate for all AAs decreased, while we did not observe a decrease in overall mortality of AD in Germany.

Machine learning based outcome prediction of large vessel occlusion of the anterior circulation prior to thrombectomy in patients with wake-up stroke.

PURPOSE: Outcome prediction of large vessel occlusion of the anterior circulation in patients with wake-up stroke is important to identify patients that will benefit from thrombectomy. Currently, mismatch concepts that require MRI or CT-Perfusion (CTP) are recommended to identify these patients. We evaluated machine learning algorithms in their ability to discriminate between patients with favorable (defined as a modified Rankin Scale (mRS) score of 0-2) and unfavorable (mRS 3-6) outcome and between patients with poor (mRS5-6) and non-poor (mRS 0-4) outcome. METHODS: Data of 8395 patients that were treated between 2018 and 2020 from the nationwide registry of the German Society for Neuroradiology was retrospectively analyzed. Five models were trained with clinical variables and Alberta Stroke Program Early CT Score (ASPECTS). The model with the highest accuracy was validated with a test dataset with known stroke onset and with a test dataset that consisted only of wake-up strokes. RESULTS: 2419 patients showed poor and 3310 patients showed favorable outcome. The best performing Random Forest model achieved a sensitivity of 0.65, a specificity of 0.81 and an AUC of 0.79 on the test dataset of patients with wake-up stroke in the classification analysis between favorable and unfavorable outcome and a sensitivity of 0.42, a specificity of 0.83 and an AUC of 0.72 in the classification analysis between poor and non-poor outcome. CONCLUSION: Machine learning algorithms have the potential to aid in the decision making for thrombectomy in patients with wake-up stroke especially in hospitals, where emergency CTP or MRI imaging is not available.

Work and Training Conditions of German Residents and Young Radiologists in Interventional Radiology - A Nationwide Survey.

With the increasing need for minimally invasive procedures based on lower complication rates, higher patient acceptance, and technical developments, there is a growing focus on the sound interventional training of young radiologists. This survey aimed to analyze the current situation in interventional radiology (IR) training in Germany to detect shortcomings and identify areas for improvement.From November 1-30, 2020, an online questionnaire was distributed to representative radiological associations and societies with the request to forward it to radiology residents and radiologists < 40 years. The 44 questions covered six distinct areas from personal working conditions to the characterization of the IR department, training conditions, role of women in IR, and attendance at congresses/external training.A total of 330 participants completed the questionnaire. 77 % of participants expressed a high interest in IR, and 47 % could even imagine subspecializing in interventional radiology. Most institutions provided the necessary learning conditions and infrastructure. The rate of overall satisfaction with IR training conditions was 45 % (vs. a dissatisfaction rate of 39 %). However, females showed a lower satisfaction rate with their training environment than male participants (28 % vs. 51 %; P = 0.06). Positive correlations with work satisfaction were found for the presence and duration of the IR rotation, the number of partly independently/mentored performed interventions, and structured feedback. Moreover, the need for a structured training curriculum was expressed by 67 % of participants.Radiological residents and young radiologists expressed a high interest in interventional radiology, and they rate the infrastructure of German hospitals regarding IR as sufficient. However, they expressed the need for consistent IR rotations and better-structured resident and postgraduate education (curricula & interviews).Interest in interventional radiology among radiological residents and young radiologists in Germany is high, but satisfaction with interventional radiology training leaves room for improvement. The most frequently mentioned aspects that can improve IR training were · organized rotations of at least 6 months. · structured curriculums with face-to-face feedback. · structured guidance by senior interventionists during procedures. CITATION FORMAT: · Sieren M, Katoh M, Mahnken AH et al. Work and Training Conditions of German Residents and Young Radiologists in Interventional Radiology - A Nationwide Survey. Fortschr Röntgenstr 2022; 194: 1346 - 1357.

Thin Slice Unenhanced Brain CT Can Detect Aneurysms Larger than 7 mm.

Purpose: To evaluate the detection rate of intracranial aneurysms on reconstructed thin slice non enhanced CT (NECT) scans. Methods: NECT scans from 34 patients with 35 aneurysms and 35 individuals without aneurysms were collected. Thin slice maximum intensity projections of the NECT scans were reconstructed. One observer evaluated the native images twice with a time interval of six month between both passes with respect to the prevalence and location of an aneurysm. The size and location of the aneurysms were evaluated in corresponding CT-Angiography and Time of flight datasets. A logit regression analysis was performed with size and location as dependent variables. 2 × 2 tables were constructed. The sensitivity and false negative rate were calculated for aneurysms with 0-6.9 mm, 7-9.9 mm and 10-20 mm and the under the curve (AUC) was calculated. Results: The overall detection rate of the aneurysms was 63% for the first pass and 66% for the second pass in the reconstructed NECT scans. The detection rate of aneurysms is size dependent. The sensitivity to detect aneurysms with a size of 0-6.9 mm was 0.09 and 0.03, for aneurysms with a size of 7-9.9. mm was 0.8 and 0.7 and for aneurysms with a size of 10-20 mm was 0.92 for both passes.The AUC was 0.77 for the first pass and 0.78 for the second pass. Conclusions: NECT scans can be used to detect a significant proportion of intracranial aneurysms larger than 7 mm if properly displayed and reconstructed. These patients should receive further vascular imaging to prevent future aneurysm related subarachnoid hemorrhage.

Nationwide Provision of Radiologically-guided Interventional Measures for the Supportive Treatment of Tumor Diseases in Germany - An Analysis of the DeGIR Registry Data. / Flächendeckende Versorgung mit radiologisch-interventionellen supportiven Maßnahmen bei Tumorerkrankungen und anderen Erkrankungen (DeGIR-Modul C) in Deutschland ­ Eine Analyse der DeGIR-Registerdaten.

PURPOSE: In addition to direct oncologic therapy, interventional radiology plays an important supportive role in oncologic therapy primarily guided by other disciplines. These supporting measures include diagnostic punctures, drainages, biliary interventions, central venous access including port implantations, osteoplasties, pain therapies etc.). This study investigated the extent to which these radiologically guided supportive measures are available in Germany. MATERIAL AND METHODS: All interventional procedures documented in the DeGIR-registry (excluding transhepatic portosystemic shunts) of the years 2018 and 2019 were recorded (DeGIR-module C). A breakdown of the documented interventions was performed based on federal states as well as 40 individual regions (administrative districts and former administrative districts). RESULTS: A total of 136,328 procedures were recorded at 216 centers in DeGIR Module C in 2018 and 2019. On average, 389 cases were documented per hospital in 2018 and 394 cases in 2019; the increase per hospital from 2019 is not statistically significant but is relevant in the aggregate when new participating centers are included, with an overall increase of 10 % (6,554 more cases than the previous year). Normalized to one million inhabitants, an average of 781 procedures took place across Germany in 2018 and 860 in 2019. Districts with no registered procedures are not found for Module C.Indications for Module C interventions were mostly interdisciplinary in 2018 and 2019. In this context, the quality of outcome was very high; for the procedures drain placement, marking and biopsy the technical success was 99 %, while the complication rate was lower than 1 %. CONCLUSION: The structural analysis of this work concludes that in Germany there is good nationwide availability of radiologically guided supportive measures in oncological therapy. Accordingly, the training situation for prospective interventional radiologists is good, as the distribution to centers with high experience is excellent. In addition, the overall outcome quality of radiology-guided interventions is very high. KEY POINTS: · In Germany, there is good nationwide coverage of radiologically guided supportive interventions in oncological therapy.. · The training situation for prospective interventional radiologists is good, as the distribution to centers with high experience is excellent.. · The overall outcome quality of radiology-guided interventions is very high.. CITATION FORMAT: · Nadjiri J, Schachtner B, Bücker A et al. Nationwide Provision of Radiologically-guided Interventional Measures for the Supportive Treatment of Tumor Diseases in Germany - An Analysis of the DeGIR Registry Data. Fortschr Röntgenstr 2022; 194: 993 - 1002.

Quantification of periaortic adipose tissue in contrast-enhanced CT angiography: technical feasibility and methodological considerations.

To examine the feasibility of the quantification of abdominal periaortic fat tissue (PaFT) (tissue within - 45 to - 195 HU) in enhanced CT-angiographies compared to unenhanced CT-scans and identify methodological issues affecting its clinical implementation. Using OsirixMD, PaFT volume and mean HU value were retrospectively measured within a 5 mm periaortic ring in paired unenhanced and enhanced abdominal aortic CT-scans. The correlation between PaFT values was examined in a derivation cohort (n = 101) and linear regression analysis produced correction factors to convert values from enhanced into values from unenhanced CTs. The conversion factors were then applied to enhanced CTs in a different validation cohort (n = 47) and agreement of corrected enhanced values with values from unenhanced scans was evaluated. Correlation between PaFT Volume und Mean HU from enhanced and unenhanced scans was very high (r > 0.99 and r = 0.95, respectively, p < 0.0001 for both). The correction factors for PaFT Volume and Mean HU were 1.1057 and 1.0011. Potential confounding factors (CT-kilovoltage, slice thickness, mean intraluminal contrast density, aortic wall calcification, longitudinal variation of intraluminal contrast density, aortic diameter) showed no significant effect in a multivariate regression analysis (p > 0.05). Bland-Altman analysis of corrected enhanced and unenhanced values showed excellent agreement and Passing-Bablok regression confirmed minimal/no residual bias. PaFT can be quantified in enhanced CT-angiographies very reliably. PaFT Volume scores are very consistently slightly underestimated in enhanced scans by about 10%, while the PaFT Mean HU value remains practically constant and offers distinct methodological advantages. However, a number of methodological issues remain to be addressed.

Availability of Interventional Oncology in Germany in the Years 2018 and 2019 - Results from a Nationwide Database (DeGIR Registry Data). / Flächendeckende Versorgung mit radiologisch durchgeführten Verfahren zur interventionell-onkologischen Tumortherapie in Deutschland in den Jahren 2018 und 2019 dargestellt anhand der DeGIR-Registerdaten.

OBJECTIVE: Over the past few decades, radiology has established itself in tumor therapy through interventional oncology including innovative and efficient procedures for minimalinvasive treatment of various tumor entities besides the "classic" therapeutic options such as surgery, chemotherapy and radiotherapy.Aim of this study was to evaluate the extent to which interventional oncology can provide nationwide care using the data from the register of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR registry), which records radiological interventions as part of quality assurance. METHODS: The numbers of interventions of participating clinics, which were recorded as part of module D (oncological procedures including TACE or other tumor-specific embolization, ablation, percutaneous tumor therapy) and identified by the DeGIR registry between 2018 and 2019, were analyzed retrospectively. The collected intervention data were evaluated regarding federal states and 40 smaller regions (administrative districts and former administrative districts). RESULTS: In 2018, 11 653 oncological interventions in 187 clinics were recorded by the DeGIR registry. In 2019, the number of participating clinics rose to 216 and the number of oncological interventions increased by 6 % to 12 323. The average number of oncological interventions per clinic decreased slightly from 62.5 (2018) to 57.1 (2019). The DeGIR requirement for being certified as a training center was met by 116 clinics in 2018 including 31 clinics with more than 100 interventions and 129 clinics in 2019 including 36 with more than 100 interventions. Oncological interventions have been performed in each of the 40 regions. An average of 599 interventions per region (standard deviation of 414) was recorded in the period between 2018 and 2019. CONCLUSION: Based on the distribution of the documented oncological interventions at federal state level as well as the district level, the supply of interventional tumor therapy depends on the geographical location. Therefore, the demand of oncological interventions might not be sufficiently covered in some regions. KEY POINTS: · Interventional-oncological tumor therapies are performed throughout Germany. · Looking at the notable geographical differences, the need for interventional oncological procedures does not seem to be sufficiently met.. · In order to improve the comprehensive provision of oncological interventions, the training of interventional radiologists should be promoted further.. CITATION FORMAT: · Radosa CG, Nadjiri J, Mahnken AH et al. Availability of Interventional Oncology in Germany in the Years 2018 and 2019 - Results from a Nationwide Database (DeGIR Registry Data). Fortschr Röntgenstr 2022; 194: 755 - 761.

Value of machine learning to predict functional outcome of endovascular treatment for acute ischaemic stroke of the posterior circulation.

PURPOSE: Clinical outcomes vary considerably among individuals with vessel occlusion of the posterior circulation. In the present study we evaluated machine learning algorithms in their ability to discriminate between favourable and unfavourable outcomes in patients with endovascular treatment of acute ischaemic stroke of the posterior circulation. METHODS: This retrospective study evaluated three algorithms (generalised linear model, K-nearest neighbour and random forest) to predict functional outcomes at dismissal of 30 patients with acute occlusion of the basilar artery who were treated with thrombectomy. Input variables encompassed baseline as well as peri and postprocedural data. Favourable outcome was defined as a modified Rankin scale score of 0-2 and unfavourable outcome was defined as a modified Rankin scale score of 3-6. The performance of the algorithms was assessed with the area under the receiver operating curve and with confusion matrixes. RESULTS: Successful reperfusion was achieved in 83%, with 30% of the patients having a favourable outcome. The area under the curve was 0.93 for the random forest model, 0.86 for the K-nearest neighbour model and 0.78 for the generalised linear model. The accuracy was 0.69 for the generalised linear model and 0.84 for the random forest and the K nearest neighbour models. CONCLUSION: Favourable and unfavourable outcomes at dismissal of patients with acute ischaemic stroke of the posterior circulation can be predicted immediately after the follow-up non-enhanced computed tomography using machine learning.

Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19. / Versorgungslage mit interventionell-radiologischer Gefäßrevaskularisation in Deutschland ­ eine Analyse der DEGIR-Registerdaten 2018/19.

PURPOSE: Peripheral artery disease (PAD) is a common condition with high socio-economic relevance. Therefore, qualified nationwide provision of interventional treatments of PAD is important for maintaining a high quality medical service in Germany. MATERIALS AND METHODS: All data on revascularization procedures from the quality management system of the German interventional radiological society (DeGIR) for the years 2018 and 2019 were retrospectively analysed. Number and distribution of DeGIR certified endovascular specialists and treatment centres was mapped. Documented procedures were broken down to the level of administrative districts. Absolute number of revascularization procedures and normalized number per one million inhabitants were computed. RESULTS: In 2019 there were 57 732 revascularization procedures from 228 participating centres performed by DeGIR certified interventional radiologists. A median of 62 recanalization procedures were documented per centre. 36 centres were considered to be high volume centres, with more than 500 procedures each. On a regional level in the years 2018 and 2019 combined a median (range) of 2324 (323-12 518) revascularization procedures per administrative district were performed by DeGIR certified interventional radiologist. CONCLUSION: There is a comprehensive nationwide high quality interventional-radiology service for the provision of revascularization procedures available in Germany. KEY POINTS: · In Germany there is a nationwide comprehensive infratsructure for the interventional-radiological treatment of PAD. · The volume of interventional-radiological treatments for PAD is growing. · There is a sufficient number of training and treatment centres for the delivery of interventional radiology procedures. CITATION FORMAT: · Mahnken AH, Nadjiri J, Schachtner B et al. Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19. Fortschr Röntgenstr 2022; 194: 160 - 168.

Embolization of Hemorrhoidal Arteries: A Novel Endovascular Therapy Option for the Treatment of Hemorrhoidal Disease. / Hämorrhoidenembolisation: Eine neue minimalinvasive endovaskuläre Therapieoption bei Hämorrhoidalleiden.

BACKGROUND: Hemorrhoids are a widespread disease. Treatment options range from dietary measures to open surgery. A novel treatment approach is the embolization of the hemorrhoidal arteries. METHOD: A review was performed based on a selective literature search in PubMed representing the current state of research. The keywords "hemorrhoid" and "embolization" and "emborrhoid" were used. In addition, technical details of the hemorrhoidal embolization procedure are explained. RESULTS AND CONCLUSION: Embolization of hemorrhoidal arteries is a safe treatment, which allows efficient symptom control even in patients with contraindications for open surgery. KEY POINTS: · Embolization of hemorrhoidal arteries is a new approach to the treatment of hemorrhoids.. · Embolization of hemorrhoidal arteries is feasible in patients with contraindications for open surgery such as hypercoaguable states and contraindications for general anesthesia.. · The endovascular approach causes no rectal and anal trauma and associated complications can be avoided.. · The treatment of bleeding hemorrhoids seems to be particularly effective.. · No ischemic complications have been reported so far when coils as well as particles were used.. CITATION FORMAT: · Feyen L, Freyhardt P, Schott P et al. Hämorrhoidenembolisation: Eine neue minimalinvasive endovaskuläre Therapieoption bei Hämorrhoidalleiden. Fortschr Röntgenstr 2022; 194: 266 - 271.

Completion of Target Vessel Stenting After FEVAR via Snare Technique in a Patient with Tortuous Right Renal Artery.

Target vessel catheterization remains challenging in patients with complex anatomies. Fenestrated endovascular aneurysm repair (FEVAR) is an established technique to treat aortic aneurysms. In this case report, we treated a juxtarenal aneurysm using FEVAR. Initial attempts to complete the target vessel stenting were unsuccessful because of an unfavorable orifice and tortuosity of the right renal artery. The completion of FEVAR was achieved with a bifemoral approach using a snare system, which aligned the tip of a steerable sheath at the level of the fenestration for the right renal artery to create a stable condition. Control angiography and computed tomography confirmed a successful stenting of the target vessel and the sealing of the fenestration without an endoleak.