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.

Early goal-directed management after out-of-hospital cardiac arrest: lessons from a certified cardiac Arrest centre.

BACKGROUND: Despite continuous advances in post-resuscitation management, outcome after out-of-hospital cardiac arrest (OHCA) is limited. To improve the outcome, interdisciplinary Cardiac Arrest Centers (CACs) have been established in recent years, but survival remains low and treatment strategies vary considerably in clinical and geographical aspects. Here we analyzed a strategy of in-hospital post-resuscitation management while evaluating the outcome. METHODS: A broad spectrum of pre- and in-hospital parameters of 545 resuscitated patients, admitted to the Cardiac Arrest Center of the University Hospital of Marburg (MCAC) between 01/2018 and 12/2022 were retrospectively analyzed. Inclusion criteria were ≥ 18 years, resuscitation by emergency medical services, and non-traumatic cause of OHCA. RESULTS: In the overall patient cohort, the survival rate to hospital discharge was 39.8% (n = 217/545), which is 50.7% higher than in the EuReCa-TWO registry. 77.2% of the survivors had CPC status 1 or 2 (favorable neurological outcome) before and after therapy. A standardized 'therapy bundle' for in-hospital post-resuscitation management was applied to 445 patients who survived the initial treatment in the emergency department. In addition to basic care (standardized antimicrobial therapy, adequate anticoagulation, targeted sedation, early enteral and parenteral nutrition), it includes early whole-body CT (n = 391; 87.9%), invasive coronary diagnostics (n = 322; 72.4%), targeted temperature management (n = 293; 65.8%) and if indicated, mechanical circulatory support (n = 145; 32.6%) and appropriate neurological diagnostics. CONCLUSIONS: Early goal-directed post-resuscitation management in a well-established and highly frequented CAC leads to significantly higher survival rates. However, our results underline the need for a broader standardization in post-resuscitation management to ultimately improve the outcome.

ChatGPT: Evaluating answers on contrast media related questions and finetuning by providing the model with the ESUR guideline on contrast agents.

OBJECTIVE: This study aimed to assess the feasibility of GPT-4 for answering questions related to contrast media with and without the context of the European Society of Urogenital Radiology (ESUR) guideline on contrast agents. The overarching goal was to determine whether contextual enrichment by providing guideline information improves answers of GPT-4 for clinical decision-making in radiology. METHODS: A set of 64 questions, based on the ESUR guideline on contrast agents mirroring pertinent sections, was developed and posed to GPT-4 both directly and after providing the guideline using a plugin. Responses were graded by experienced radiologists for quality of information and accuracy in pinpointing information from the guideline as well as by radiology residents for utility, using Likert-scales. RESULTS: GPT-4's performance improved significantly with the guideline. Without the guideline, average quality rating was 3.98, which increased to 4.33 with the guideline (p = 0036). In terms of accuracy, 82.3% of answers matched the information from the guideline. Utility scores also reflected a significant improvement with the guideline, with average scores of 4.1 (without) and 4.4 (with) (p = 0.008) with a Fleiss´ Kappa of 0.44. CONCLUSION: GPT-4, when contextually enriched with a guideline, demonstrates enhanced capability in providing guideline-backed recommendations. This approach holds promise for real-time clinical decision-support, making guidelines more actionable. However, further refinements are necessary to maximize the potential of large language models (LLMs). Inherent limitations need to be addressed.

Feasibility of GPT-3 and GPT-4 for in-Depth Patient Education Prior to Interventional Radiological Procedures: A Comparative Analysis.

PURPOSE: This study explores the utility of the large language models, GPT-3 and GPT-4, for in-depth patient education prior to interventional radiology procedures. Further, differences in answer accuracy between the models were assessed. MATERIALS AND METHODS: A total of 133 questions related to three specific interventional radiology procedures (Port implantation, PTA and TACE) covering general information as well as preparation details, risks and complications and post procedural aftercare were compiled. Responses of GPT-3 and GPT-4 were assessed for their accuracy by two board-certified radiologists using a 5-point Likert scale. The performance difference between GPT-3 and GPT-4 was analyzed. RESULTS: Both GPT-3 and GPT-4 responded with (5) "completely correct" (4) "very good" answers for the majority of questions ((5) 30.8% + (4) 48.1% for GPT-3 and (5) 35.3% + (4) 47.4% for GPT-4). GPT-3 and GPT-4 provided (3) "acceptable" responses 15.8% and 15.0% of the time, respectively. GPT-3 provided (2) "mostly incorrect" responses in 5.3% of instances, while GPT-4 had a lower rate of such occurrences, at just 2.3%. No response was identified as potentially harmful. GPT-4 was found to give significantly more accurate responses than GPT-3 (p = 0.043). CONCLUSION: GPT-3 and GPT-4 emerge as relatively safe and accurate tools for patient education in interventional radiology. GPT-4 showed a slightly better performance. The feasibility and accuracy of these models suggest their promising role in revolutionizing patient care. Still, users need to be aware of possible limitations.

pTEVAR of an aorto-esophageal fistula in esophageal cancer: Case report and review of the literature.

An aorto-esophageal fistula (AEF) is a rare and life-threatening situation, associated with aneurysms, foreign bodies, infiltrating tumors, and radiotherapy. The ideal management is unclear. Open surgery of AEF has a high mortality and morbidity. Thoracic endovascular aortic repair (TEVAR) of an AEF is an effective and safe emergency treatment for these patients. We describe a case of AEF due to esophageal cancer successfully treated the first time by total percutaneous TEVAR (pTEVAR). A 70-year-old male patient presented with massive hematemesis at the emergency department. The patient had a known history of esophageal cancer previously treated by radiochemotherapy which was completed 3 days before. Emergency upper gastrointestinal endoscopy failed to stop the bleeding. Subsequent contrast-enhanced computed tomography revealed an aorto-esophageal fistula and emergency pTEVAR was performed. The bleeding stopped directly after stent graft placement and the patient was discharged after 10 days later. He died 3 months after pTEVAR from cancer progression. pTEVAR is an effective and safe treatment option for AEF. It can be applied as a first-line treatment and offers the potential to improve survival in the emergency setting.

Physical strain while wearing personal radiation protection systems in interventional radiology.

OBJECTIVES: Multiple studies show orthopedic health problems for medical staff due to wearing radiation protection aprons. The aim of this study was to evaluate the weight pressure on the shoulder as a marker of physical strain caused by different radiation-protection devices. METHODS: For the weight pressure measurement, a pressure sensor (OMD-30-SE-100N, OptoForce, Budapest, Hungary) placed on the left and right shoulder was used. Wearing different radiation protection systems the force measurement system was used to quantify the weight pressure. Measurements were acquired in still standing position and during various movements. RESULTS: A mean significant decreasing weight pressure on the shoulder between 74% and 84% (p<0.001) was measured, when the free-hanging radiation protection system was used in comparison to one-piece and two-piece radiation protection aprons and coats. Using two-piece radiation protection aprons, the weight pressure was significantly lower than that of one-piece radiation protection coats. If a belt was used for the one-piece radiation protection coat, the weight pressure on the shoulder was reduced by 32.5% (p = 0.003). For a two-piece radiation protection apron and a one-piece radiation protection coat (with and without belt) a significant different weight pressure distribution between the right and left shoulder could be measured. CONCLUSIONS: The free-hanging radiation protection system showed a significant lower weight pressure in comparison to the other radiation protection devices. Apart from this, use of a two-piece radiation protection apron or addition of a belt to a radiation protection coat proved to be further effective options to reduce weight pressure.

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.

[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.

Feasibility and safety of automated CO2 angiography in peripheral arterial interventions.

ABSTRACT: Carbon dioxide (CO2) gas is an established alternative to iodine contrast during angiography in patients with risk of postcontrast acute kidney injury and in those with history of iodine contrast allergy. Different CO2 delivery systems during angiography are reported in literature, with automated delivery system being the latest. The aim of this study is to evaluate the safety, efficacy, and learning curve of an automated CO2 injection system with controlled pressures in peripheral arterial interventions and also to study the patients' tolerance to the system.From January 2018 to October 2019 peripheral arterial interventions were performed in 40 patients (median age-78 years, interquartile range: 69-84 years) using an automated CO2 injection system with customized protocols, with conventional iodine contrast agent used only as a bailout option. The pain and tolerance during the CO2 angiography were evaluated with a visual analog scale at the end of each procedure. The amount of CO2, iodine contrast used, and radiation dose area product for the interventions were also systematically recorded for all procedures. These values were statistically compared in 2 groups, viz first 20 patients where a learning curve was expected vs the rest 20 patients.All procedures were successfully completed without complications. All patients tolerated the CO2 angiography with a median total pain score of 3 (interquartile range: 3-4), with no statistical difference between the groups (P = .529). The 2 groups were statistically comparable in terms of comorbidities and the type of procedures performed (P = .807). The amount of iodine contrast agent used (24.60 ±â€Š6.44 ml vs 32.70 ±â€Š8.70 ml, P = .006) and the radiation dose area product associated were significantly lower in the second group (2160.74 ±â€Š1181.52 µGym2 vs 1531.62 ±â€Š536.47 µGym2, P = .043).Automated CO2 angiography is technically feasible and safe for peripheral arterial interventions and is well tolerated by the patients. With the interventionalist becoming familiar with the technique, better diagnostic accuracy could be obtained using lower volumes of conventional iodine contrast agents and reduction of the radiation dose involved.

Update Regarding Imaging of Neuroendocrine Neoplasms. / Update Bildgebung neuroendokrine Neoplasien.

BACKGROUND: Neuroendocrine neoplasms (NEN) are a heterogeneous group of tumors characterized by the expression of typical proteins. A wide range of morphological and functional imaging methods is required in order to adequately assess the course of the disease and to optimally treat the patient. The spectrum of indications ranges from the detection of small primary tumors to the documentation of the metastasis pattern and the assessment of the suitability for certain invasive or noninvasive therapy methods. The exact recording and quantification of findings is indispensable. METHODS: This article is based on a comprehensive literature search on the different aspects of neuroendocrine neoplasm imaging. RESULTS: This article is intended to provide an overview of the available imaging procedures with their respective advantages and disadvantages for diagnostics and their value for the follow-up of neuroendocrine neoplasms. Recommendations for examination protocols, typical image findings, and an outlook regarding future developments are presented. KEY POINTS: · Neuroendocrine neoplasms are relatively rare and represent a complex and multiform disease group. Even in metastatic disease, long-term progression-free survival is not uncommon.. · Diagnostics in neuroendocrine neoplasms use a wide range of complementary morphological and functional imaging methods.. · Adequate selection of the imaging method, examination planning and preparation of the patient are essential for exact staging and reliable follow-up.. CITATION FORMAT: · Figiel JH, Viniol SG, Görlach J et al. Update Regarding Imaging of Neuroendocrine Neoplasms. Fortschr Röntgenstr 2020; 192: 171 - 182.

Diagnosis, Treatment, and Outcome of Arterioureteral Fistula: The Urologist's Perspective.

INTRODUCTION: Arterioureteral fistula (AUF) is a rare but potentially life-threatening disease that primarily arises as a long-term complication in oncological patients who have permanent ureteral stenting. The incidence is rising. The objective of this study was to outline the risk factors for management and outcome of AUF in a large individual case series. PATIENTS AND METHODS: Twenty-six AUF cases in 24 patients from six German tertiary referral centers occurring between 2008 and 2016 were identified retrospectively and entered into a dedicated database by using patient notes and out-patient visits. RESULTS: Of 24 patients, 23 had a history of abdominopelvic surgery for oncological disease, 21/24 had undergone radiotherapy, and 23/24 had long-term ureteral stenting. All cases presented with visible hematuria, 11/26 at the time of a stent exchange. Blood transfusions were required in 92.3%, and intravenous inotropes were needed in 46.2%. Of 26 patients, 11 had flank pain. CT angiogram was positive in 35.7%. Angiography and endovascular fistula repair was performed in 88.5%, and the rest received open surgical repair. Mortality was 7.7%. Endovascular treatment was technically successful in 91.3%, and open surgery was successful in 3/4 cases. Recurrent AUF developed in 3/24 patients. Stent-related complications occurred in 15%. Vascular complications were common. Long-term survival was limited due to progression of the underlying malignant disease. CONCLUSION: AUF results in major hemorrhage and warrants time-efficient diagnosis and treatment. Awareness is key. When AUF is considered, interventional angiography should promptly be performed. Fistula detection can be improved by guidewire manipulation. Pre-interventional CT angiogram may be omitted due to low sensitivity. Endovascular repair with stenting and/or coiling is effective and safe.