CACTUSS: Common Anatomical CT-US Space for US examinations.

PURPOSE: The detection and treatment of abdominal aortic aneurysm (AAA), a vascular disorder with life-threatening consequences, is challenging due to its lack of symptoms until it reaches a critical size. Abdominal ultrasound (US) is utilized for diagnosis; however, its inherent low image quality and reliance on operator expertise make computed tomography (CT) the preferred choice for monitoring and treatment. Moreover, CT datasets have been effectively used for training deep neural networks for aorta segmentation. In this work, we demonstrate how leveraging CT labels can be used to improve segmentation in ultrasound and hence save manual annotations. METHODS: We introduce CACTUSS: a common anatomical CT-US space that inherits properties from both CT and ultrasound modalities to produce an image in intermediate representation (IR) space. CACTUSS acts as a virtual third modality between CT and US to address the scarcity of annotated ultrasound training data. The generation of IR images is facilitated by re-parametrizing a physics-based US simulator. In CACTUSS we use IR images as training data for ultrasound segmentation, eliminating the need for manual labeling. In addition, an image-to-image translation network is employed for the model's application on real B-modes. RESULTS: The model's performance is evaluated quantitatively for the task of aorta segmentation by comparison against a fully supervised method in terms of Dice Score and diagnostic metrics. CACTUSS outperforms the fully supervised network in segmentation and meets clinical requirements for AAA screening and diagnosis. CONCLUSION: CACTUSS provides a promising approach to improve US segmentation accuracy by leveraging CT labels, reducing the need for manual annotations. We generate IRs that inherit properties from both modalities while preserving the anatomical structure and are optimized for the task of aorta segmentation. Future work involves integrating CACTUSS into robotic ultrasound platforms for automated screening and conducting clinical feasibility studies.

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..

Simultaneous quantification of Gadoxetic acid and Cisplatin in hepatocellular carcinomas using laser ablation-inductively coupled plasma-mass spectrometry.

The gadolinium-based contrast agent Gadoxetic acid and the platinum-based antitumor agent Cisplatin were quantitatively imaged in liver and liver cancer (hepatocellular carcinoma, HCC) tissue of rats by means of laser ablation-inductively coupled plasma-mass spectrometry. HCC bearing rats simultaneously received a tail vein injection of the hepatocyte-specific magnetic resonance imaging contrast agent Gadoxetic acid and a transarterial injection of Cisplatin 15 min before sacrifice and liver removal. Resecting HCC with adjacent liver tissue allows the comparison of Gd, Pt, and endogenous elements like Fe, Cu, and Zn in the various tissue types. Region of interest analysis reveals lower concentrations of Gd in HCC and higher Gd content in the adjacent liver, fitting the selective uptake of Gadoxetic acid into hepatocytes. Furthermore, two malignancy grades and their possible impact on the Gadoxetic acid and Cisplatin uptake are compared. For this, four high grade (G3) and two moderate grade (G2) HCCs were analysed, including a control sample each. Gd concentrations were lower in HCC irrespective of the grade of dedifferentiation (G2, G3) compared to adjacent liver. Despite local arterial Cisplatin injection, concentrations of Pt were similar or also reduced in HCC compared to liver tissue. In addition, endogenous Fe, Cu, and Zn were quantified. While Zn was homogenously distributed, higher Fe concentrations were determined in liver tissue compared to HCC. Hotspots of Cu suggest a deregulated copper homeostasis in certain liver lesions. The Gd and Fe distributions are compared in detail with cellular alterations examined by hematoxylin and eosin staining.

Transjugular intrahepatic portosystemic shunt creation (TIPS) in the angio-CT-a hybrid intervention with image fusion.

OBJECTIVE: For transjugular intrahepatic portosystemic shunt (TIPS) creation, ultrasound guidance for portal vein puncture is strongly recommended. However, outside regular hours of service, a skilled sonographer might be lacking. Hybrid intervention suites combine CT imaging with conventional angiography allowing to project 3D information into the conventional 2D imaging and further CT-fluoroscopic puncture of the portal vein. The purpose of this study was to assess whether TIPS using angio-CT facilitates the procedure for a single interventional radiologist. METHODS: All TIPS procedures from 2021 and 2022 which took place outside regular working hours were included (n = 20). Ten TIPS procedures were performed with just fluoroscopy guidance and ten procedures using angio-CT. For the angio-CT TIPS, a contrast-enhanced CT was performed on the angiography table. From the CT, a 3D volume was created using virtual rendering technique (VRT). The VRT was blended with the conventional angiography image onto the live monitor and used as guidance for the TIPS needle. Fluoroscopy time, area dose product, and interventional time were assessed. RESULTS: Hybrid intervention with angio-CT did lead to a significantly shorter fluoroscopy time and interventional time (p = 0.034 for both). Mean radiation exposure was significantly reduced, too (p = 0.04). Furthermore, the mortality rate was lower in patients who underwent the hybrid TIPS (0% vs 33%). CONCLUSION: TIPS procedure in angio-CT performed by only one interventional radiologist is quicker and reduces radiation exposure for the interventionalist compared to mere fluoroscopy guidance. The results further indicate increased safety using angio-CT. CLINICAL RELEVANCE STATEMENT: This study aimed to evaluate the feasibility of using angio-CT in TIPS procedures during non-standard working hours. Results indicated that the use of angio-CT significantly reduced fluoroscopy time, interventional time, and radiation exposure, while also leading to improved patient outcomes. KEY POINTS: • Image guiding such as ultrasound is recommended for transjugular intrahepatic portosystemic shunt creation but might be not available for emergency cases outside of regular working hours. • Transjugular intrahepatic portosystemic shunt creation using an angio-CT with image fusion is feasible for only one physician under emergency settings and results in lower radiation exposure and faster procedures. • Transjugular intrahepatic portosystemic shunt creation using an angio-CT with image fusion seems to be safer than using mere fluoroscopy guidance.

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..

Impact of the COVID-19 Pandemic on Interventional Radiology in Germany. / Auswirkung der COVID-19-Pandemie auf die Interventionelle Radiologie in Deutschland.

PURPOSE: To investigate the effect of the ongoing COVID-19 pandemic on interventional radiology (IR) in Germany in 2020 and 2021. MATERIALS UND METHODS: This retrospective study is based on the nationwide interventional radiology procedures documented in the quality register of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR-QS-Register). The nationwide volume of interventions in the pandemic years 2020 and 2021 was compared with the pre-pandemic period (Poisson-test, Mann-Whitney test). The aggregated data were additionally evaluated by intervention type with differentiated consideration of the temporal epidemiological infection occurrence. RESULTS: During the two pandemic years 2020 and 2021, the number of interventional procedures increased by appr. 4 % compared to the same period of the previous year (n = 190 454 and 189 447 vs. n = 183 123, respectively, p < 0.001). Only the first pandemic wave in spring 2020 (weeks 12-16) showed a significant temporary drop in the number of interventional procedures by 26 % (n = 4799, p < 0.05). This primarily involved interventions that were not immediately medically urgent, such as pain treatments or elective arterial revascularization. In contrast, interventions in the field of interventional oncology, such as port catheter implantations and local tumor ablations, remained unaffected. The decline of the first wave of infection was accompanied by a rapid recovery and a significant, partly compensatory, 14 % increase in procedure numbers in the second half of 2020 compared to the same period of the previous year (n = 77 151 vs. 67 852, p < 0.001). Subsequent pandemic waves had no effect on intervention numbers. CONCLUSION: The COVID-19 pandemic in Germany led to a significant short-term decrease in interventional radiology procedures in the initial phase. A compensatory increase in the number of procedures was observed in the subsequent period. This reflects the adaptability and robustness of IR and the high demand for minimally invasive radiological procedures in medical care. KEY POINTS: · The study shows the nationwide pandemic-related effects on interventional radiology in Germany.. · In quantitative terms, the ongoing pandemic caused a significant, temporary decline in intervention cases only in the initial phase.. · Subsequent waves of infections had no effect on the scope of services provided by interventional radiology.. · Short-term deficits, especially in elective interventions, could be partially compensated.. CITATION FORMAT: · Schmidbauer M, Busjahn A, Paprottka P et al. Impact of the COVID-19 Pandemic on Interventional Radiology in Germany. Fortschr Röntgenstr 2023; 195: 597 - 604.

Safety of sheathless vascular access using braided 4 F selective catheters for common body interventions - a retrospective study.

BACKGROUND: Besides other factors, complication rate of transarterial interventions depends on the size of the vascular access. Therefore, the vascular access is mostly chosen as small as possible while still allowing all planned parts of the intervention. This retrospective analysis is to evaluate the safety and feasibility of sheathless arterial interventions for a broad spectrum of interventions in daily practice. METHODS: All sheathless interventions using a 4 F main catheter between May 2018 and September 2021 were included in the evaluation. Additionally, intervention parameters such as type of catheter, use of microcatheter and required change of main catheters were assessed. Information about the use about sheathless approach and catheters were obtained from the material registration system. All catheters were braided. RESULTS: 503 sheathless interventions with 4 F catheters from the groin were documented. The spectrum comprised bleeding embolization, diagnostic angiographies, arterial DOTA-TATE-therapy, uterine fibroid embolization, transarterial chemotherapy, transarterial radioembolization and others. In 31 cases (6 %) a change of the main catheter was required. In 381 cases (76 %) a microcatheter was utilized. No clinically relevant adverse events were observed (grade 2 or higher [CIRSE AE-classification]). None of the cases later required conversion to a sheath-based intervention. CONCLUSIONS: Sheathless interventions with a 4 F braided catheter from the groin are safe and feasible. It allows for a broad spectrum of interventions in daily practice.

Efficacy of ultrasound assisted catheter-directed thrombolysis compared to catheter-directed thrombolysis in vitro.

BACKGROUND: Catheter-directed thrombolysis (CDT) is an effective and safe endovascular method used in critical limb ischemia and many other thromboembolic events. Ultrasound-assisted catheter-directed thrombolysis (US-CDT) is an emerging technique considered to accelerate thrombolysis and therefore is supposed to improve outcome. PURPOSE: To evaluate the efficacy of US-CDT in comparison to standard CDT in vitro. MATERIAL AND METHODS: A total of 69 sets of human venous blood were evaluated, each comprising a tube just treated with CDT, a tube treated with US-CDT, and a control tube. All tubes were kept under physiological conditions. Except for the controls, in all tubes 5 mg of tissue-type plasminogen activator was administered over the predetermined treatment interval. Thrombus mass was weighted at the end of the lysis intervals at 6 h or 24 h, respectively. RESULTS: CDT led to a mean thrombus reduction of 32% and ultrasound-assisted lysis led to a mean thrombus reduction of 41% (P < 0.001 for both). Thrombus reduction was significantly higher after US-CDT compared to CDT (P = 0.001). The better efficacy of US-CDT was mostly already apparent at early phases during thrombolysis and did further mildly increase over time (r = 0.24; P = 0.047). CONCLUSION: In vitro US-CDT is significantly superior to standard CDT; this effect is apparent at an early timepoint of lysis and slightly further increases over time.

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.

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.

softALPPS - A novel, individual procedure for patients with advanced liver tumors.

BACKGROUND: The first-line therapy for liver malignancies is a radical extended liver resection. This high-risk operation has a high incidence of post-hepatectomy liver failure (PHLF) due to a small future liver remnant (FLR). One of the procedures to increase the FLR is the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) which is still associated with high morbidity and mortality. Here, we present a new, less invasive ALPPS variant that may be associated with lower morbidity. METHODS: SoftALPPS is characterized by reduced trauma to the liver tissue and individual adaptation to the patient's health constitution. In softALPPS, portal vein embolization (PVE) is performed instead of portal vein ligation (PVL) after complete recovery of liver function. In addition, a non-absorbable foil was avoided in order to be able to extend the interval to step two or skip step two when required. RESULTS: Four patients successfully underwent softALPPS. Two of these patients have been followed-up for over a year (one patient with Klatskin tumor, one patient with extensive HCC). Both patients show no evidence of recurrence after 12 months and are in good medical condition. The other two patients who recently had surgery are also doing well. CONCLUSION: SoftALPPS offers the chance to curatively resect patients with high tumor burden of the liver even when the FLR is inadequate. This individual therapy method can give patients the possibility of complete tumor resection and can help to reduce perioperative morbidity.

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.

[Imaging of intrahepatic cholangiocarcinoma : Reliable diagnosis according to the new S3 guideline]. / Bildgebung beim intrahepatischen Cholangiokarzinom : Richtige Diagnostik nach der neuen S3-Leitlinie.

The S3 guideline on hepatocellular carcinoma has been expanded to include malignant biliary carcinoma (synonym cholangiocarcinoma [CCA]). Magnetic resonance imaging (MRI) with additional magnetic resonance cholangiopancreatography (MRCP) is the imaging modality of choice to evaluate local findings. Use of gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-based contrast agent increases its diagnostic value. Histologic confirmation is always required when diagnosing intrahepatic CCA (iCCA) because using imaging alone there is a risk of confusion with HCC subtypes.