Comparison of Acceptance and Knowledge Transfer in Patient Information Before an MRI Exam Administered by Humanoid Robot Versus a Tablet Computer: A Randomized Controlled Study

PURPOSE

 To investigate whether a humanoid robot in a clinical radiological setting is accepted as a source of information in conversations before MRI examinations of patients. In addition, the usability and the information transfer were compared with a tablet.

METHODS

 Patients were randomly assigned to a robot or tablet group with their consent prior to MRI. The usability of both devices was compared with the extended System Usability Scale (SUS) and the information transfer with a knowledge query. Reasons for refusal were collected by a non-responder questionnaire.

RESULTS

 At the University Hospital Halle 117 patients were included for participation. There was no statistically significant difference in gender and age. Of 18 non-responders, 4 refused to participate partly because of the robot; for another 3 the reason could not be clarified. The usability according to SUS score was different with statistical significance between the groups in the mean comparison and was one step higher for the tablet on the adjective scale. There was no statistically significant difference in knowledge transfer. On average, 8.41 of 9 questions were answered correctly.

CONCLUSION

 This study is the first application, in a clinical radiological setting, of a humanoid robot interacting with patients. Tablet and robot are suitable for information transfer in the context of MRI. In comparison to studies in which the willingness to interact with a robot in the health care sector was investigated, the willingness is significantly higher in the present study. This could be explained by the fact that it was a concrete use case that was understandable to the participants and not a hypothetical scenario. Thus, potentially high acceptance for further specific areas of application of robots in radiology can be assumed. The higher level of usability perceived in the tablet group can be explained by the fact that here the interface represents a form of operation that has been established for years in all population groups. More frequent exposure to robots could also improve the response in the future.

KEY POINTS

· patients accept humanoid robots in clinical radiologic situations. · at present they can only convey information as well as an inexpensive tablet. · future systems can relieve the burden on personnel..

CITATION FORMAT

· Stoevesandt D, Jahn P, Watzke S et al. Comparison of Acceptance and Knowledge Transfer in Patient Information Before an MRI Exam Administered by Humanoid Robot Versus a Tablet Computer: A Randomized Controlled Study. Fortschr Röntgenstr 2021; 193: 947 - 954.

Super selective percutaneous transhepatic coil embolization of intrahepatic pseudoaneurysm after pediatric liver transplantation: a case report

Background

Intrahepatic arterial pseudoaneurysms are a rare, life-threatening complication after pediatric liver transplantation. Treatment of choice represents interventional radiological management with endovascular embolization of the segmental artery proximal and distal to the aneurysm. However, this technique results in loss of arterial perfusion distal to the aneurysm with subsegment arterial ischemia.

Case presentation

We report a case of a 1-year-old girl with a pseudoaneurysm in the split-liver graft. Direct percutaneous, transhepatic access to the pseudoaneurysm was performed followed by super selective coil application into the aneurysm.

Conclusion

Super selective percutaneous, transhepatic coil application is feasible even in pediatric patients after liver transplantation and results in preservation of the entire course of the liver artery.

Fluoroscopy-guided endoscopic sclerotherapy: a novel hybrid approach for symptomatic rectosigmoidal venous malformation (with video)

BACKGROUND AND AIMS

Recommendations for the treatment of lower GI bleeding do not include bleeding from venous malformations (VMs). The aim of this study was to delineate the usefulness of a novel hybrid intervention (fluoroscopy-guided endoscopic sclerotherapy) for the treatment of symptomatic VMs in the rectosigmoidal colon with bleeding.

METHODS

The magnetic resonance images of 421 patients with VM, referred to multicenter vascular anomaly centers from 2009 to 2017, were analyzed retrospectively. Treatment was performed for all patients who experienced bleeding from rectosigmoidal VMs using fluoroscopy-guided endoscopic sclerotherapy with polidocanol foam as a novel approach.

RESULTS

A total of 27 patients displayed VM in the rectosigmoidal area. Eleven of these presented with acute or previous bleeding and received treatment. Active bleeding was observed in 8 patients (72.7%), whereas 3 patients (27.3%) had signs of previous bleeding. Six of the 11 patients had anemia (54.5%). There were no adverse events within 24 hours of the intervention. In a 2-year follow-up period, only 1 patient (9.1%) presented with recurrent bleeding after 13 months and was successfully treated again with fluoroscopy-guided endoscopic sclerotherapy.

CONCLUSIONS

Fluoroscopy-guided endoscopic sclerotherapy was shown to be a safe and effective treatment of symptomatic VMs of the rectosigmoidal area. Thus, fluoroscopy-guided endoscopic sclerotherapy should be considered for patients with bleeding from VMs of the rectosigmoid after a comprehensive workup and interdisciplinary case discussion.

Additive value of transarterial embolization to systemic sirolimus treatment in kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor in children, which can be accompanied by life-threatening thrombocytopenia, referred to as Kasabach-Merritt phenomenon (KMP). The mTOR inhibitor sirolimus is emerging as targeted therapy in KHE. As the sirolimus effect on KHE occurs only after several weeks, we aimed to evaluate whether additional transarterial embolization is of benefit for children with KHE and KMP. Seventeen patients with KHE and KMP acquired from 11 hospitals in Germany were retrospectively divided into two cohorts. Children being treated with adjunct transarterial embolization and systemic sirolimus, and those being treated with sirolimus without additional embolization. Bleeding grade as defined by WHO was determined for all patients. Response of the primary tumor at 6 and 12 months assessed by magnetic resonance imaging (MRI), time to response of KMP defined as thrombocyte increase >150 × 10³ /μL, as well as rebound rates of both after cessation of sirolimus were compared. N = 8 patients had undergone additive embolization to systemic sirolimus therapy, sirolimus in this group was started after a mean of 6.5 ± 3 days following embolization. N = 9 patients were identified who had received sirolimus without additional embolization. Adjunct embolization induced a more rapid resolution of KMP within a median of 7 days vs 3 months; however, tumor response as well as rebound rates were similar between both groups. Additive embolization may be of value for a more rapid rescue of consumptive coagulopathy in children with KHE and KMP compared to systemic sirolimus only.

3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo

PURPOSE

 To assess morphological and hemodynamic characteristics of peripheral vascular malformations on 3 T magnetic resonance imaging (MRI) including qualitative comparison of two fat-saturated sequences: short tau inversion recovery (STIR) and three-dimensional high-resolution volume interpolated gradient recalled echo (GRE).

MATERIALS AND METHODS

 During 9 months, 100 patients with suspected or known vascular malformations were prospectively assessed on a 3 T scanner using T2-weighted STIR and turbo spin echo (TSE), T1-weighted TSE, time-resolved contrast-enhanced magnetic resonance angiography (MRA) with interleaved stochastic trajectories (TWIST) and T1-weighted volume interpolated breath-hold examination (VIBE) after contrast enhancement. The analysis included signal behavior and morphologic and hemodynamic characteristics. Additionally, the image quality of the fat-saturated sequences was evaluated by 2 radiologists.

RESULTS

 86 patients (14 dropouts; 57 female, 29 male; mean age 26.8 years, age range 1-56) were analyzed. 22 had high-flow and 64 low-flow malformations, including 14 with a lymphatic component. In 21 of 22 patients with high-flow malformations, typical characteristics (flow voids, hyperdynamic arteriovenous fistula, dilated main/feeder-arteries and draining veins) were documented. Patients with low-flow malformations had phleboliths in 35 cases, fluid-fluid levels in 47 and dilated draining veins in 23. Lymphatic malformations showed peripheral contrast enhancement of cyst walls in the volume interpolated GRE. The comparison of fat-saturated sequences showed significantly better results of the volume interpolated GRE in all categories except the presence of artifacts which were significantly reduced in the STIR (p < 0.05).

CONCLUSION

 3 T MRI with MRA provides detailed morphological and hemodynamic information of different types of peripheral vascular malformations. Contrast-enhanced high-resolution volume interpolated GRE proved superior to STIR in differentiating morphologic features and to be diagnostic in the differentiation of lymphatic parts and joint involvement.

KEY POINTS

  · 3 T MRI with MRA offers detailed information about vascular malformations.. · Fat-saturated MRI provides especially information about morphological characteristics, extent and tissue involvement.. · Volume interpolated GRE proved superior in almost all categories compared to STIR.. · Volume interpolated GRE showed more artifacts.. · Volume interpolated GRE additionally allows differentiation of lymphatic parts and evaluation of joint involvement..

CITATION FORMAT

· Höhn F, Hammer S, Fellner C et al. 3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo. Fortschr Röntgenstr 2021; 193: 446 - 458.

Fast TWIST with iterative reconstruction improves diagnostic accuracy of AVM of the hand

Very high temporal and spatial resolution is mandatory for the diagnosis of arteriovenous malformations (AVM) of the hand. Until now, magnetic resonance imaging (MRI) has not fulfilled both requirements simultaneously. This study presents how the combination of a very fast TWIST MRI (time-resolved angiography with interleaved stochastic trajectories) sequence and iterative reconstructions optimizes temporal as well as spatial resolution. 11 patients were examined at a 3-T MRI scanner with two different TWIST protocols: the standard and the study protocol, acquiring a data set every 5.57 s and 1.44 s respectively. The study data was retrospectively iteratively reconstructed with different regularization factors (0.001, 0.002, 0.004, 0.008). Results were compared using the sign-test. P-values < 0.05 were regarded statistically significant. With a low amount of contrast medium, the temporal resolution of the study protocol enabled the differentiation of arteries from veins in all patients whereas the signal-to-noise ratio (SNR) deteriorated. Depending on the regularization factors, SNR, delineation of arterial feeders and non-involved hand and interdigital arteries, as well as artefact levels varied. Overall, iterative reconstruction with regularization factor 0.004 achieved the best results, consequently showing the ability of MRI as a reliable diagnostic method in AVMs of the hand.

Contrast-enhanced ultrasound with perfusion analysis in patients with venous malformations before and after percutaneous treatment with ethanol-gel

INTRODUCTION

Percutaneous sclerotherapy is a well-established treatment option for venous malformations (VM). A recently established sclerosing agent is ethanol-gel. Aim of this study was to identify, if contrast-enhanced ultrasound (CEUS) with an integrated perfusion analysis allows for differentiation between untreated VM, healthy tissue, and with gelified ethanol treated malformation tissue.

MATERIAL AND METHODS

In this institutional review board approved prospective study symptomatic VM patients underwent CEUS at exactly the same position before and after sclerotherapy with ethanol-gel. Two experienced sonographers performed all examinations after the bolus injection of microbubbles using a multi-frequency probe with 6 -9 MHz of a high-end ultrasound machine. An integrated perfusion analysis was applied in the center of the VM and in healthy, surrounding tissue. For both regions peak enhancement (peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT) were evaluated. Wilcoxon signed rank test was executed; p-values <0.05 were regarded statistically significant.

RESULTS

In 23 patients including children (mean age 25.3 years, 19 females) before treatment all identified parameters were significantly higher in the VM center compared to healthy tissue (peak: p < 0.01; TTP: p < 0.01; AUC: p < 0.01; MTT: p < 0.01). Comparing the VM center before and after treatment, TTP (p < 0.02) and MTT (p < 0.01) reduced significantly after sclerotherapy. In surrounding tissue only peak changed after treatment in comparison to pre-treatment results (p = 0.04). Comparing data in the VM center with surrounding tissue after sclerotherapy, results still differed significantly for peak (p < 0.01), TTP (p < 0.01), and AUC (p < 0.01), but assimilated for MTT (p = 0.07).

CONCLUSION

All with CEUS identified parameters seem to be excellent tools for differentiating between VM and healthy tissue. TTP and MTT could distinguish between with ethanol-gel sclerotized VM portions and untreated malformation parts and thereby might assist the monitoring of sclerotherapy with ethanol-gel.

Pelvines Stauungssyndrom: Wie wird die Diagnose gesichert, wer muss behandelt werden?

Unterleibsbeschwerden waren lange Zeit die Domäne von Gynäkologen, Internisten und Urologen. Die Erkenntnis, dass auch eine venöse Abstrombehinderung im kleinen Becken bzw. im Abdomen ähnliche Beschwerden hervorrufen kann, hat dazu geführt, dass in den letzten Jahren auch Gefäßmediziner in die Diagnostik und Behandlung einbezogen werden.

Das pelvine Stauungssyndrom kann eine Vielzahl von auch nichtspezifischen Beschwerden verursachen. Die differenzialdiagnostische Abgrenzung zu gynäkologischen, internistischen oder auch orthopädischen Störungen stellt damit eine Herausforderung dar. Die akribische Anamneseerhebung und Symptombeschreibung sind von übergeordneter Bedeutung. In der weiteren Diagnostik kommt der Sonografie die wichtigste Bedeutung zu, die durch radiologische Schichtbildverfahren ergänzt werden kann. Wird vor allem eine Varikose im Genitalbereich beklagt, ist zu klären, ob es sich um eine venöse Insuffizienz im Bereich der Vena iliaca interna bzw. der Vena ovarica handelt oder ob postthrombotische Veränderungen eine Rolle spielen. Bei pelvinen und abdominellen Schmerzzuständen müssen zusätzlich die Nierenvenen und die untere Hohlvene beurteilt werden.

Nur wenn die Störung differenzialdiagnostisch sicher abgegrenzt werden kann, ist eine invasive Behandlung durch Katheterverfahren und/oder Schaumsklerotherapie angezeigt.

Author Correction: Rectosigmoidal manifestations of venous malformations: MR imaging findings and interdisciplinary therapeutic modalities

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Interventional therapies of vascular malformations]

Vascular malformations can appear at any age and in every region of the body. Due to their rare appearance and differences in clinical manifestations the appropriate diagnosis and subsequent classification remains challenging. Once the diagnosis is established, various treatment options exist, requiring an interdisciplinary approach. This review provides an overview over state-of-the-art interventional therapies of vascular malformations.

Peripheral Vascular Anomalies – Essentials in Periinterventional Imaging

Background Peripheral vascular anomalies represent a rare disease with an underlying congenital mesenchymal and angiogenetic disorder. Vascular anomalies are subdivided into vascular tumors and vascular malformations. Both entities include characteristic features and flow dynamics. Symptoms can occur in infancy and adulthood. Vascular anomalies may be accompanied by characteristic clinical findings which facilitate disease classification. The role of periinterventional imaging is to confirm the clinically suspected diagnosis, taking into account the extent and location of the vascular anomaly for the purpose of treatment planning.

Method In accordance with the International Society for the Study of Vascular Anomalies (ISSVA), vascular anomalies are mainly categorized as slow-flow and fast-flow lesions. Based on the diagnosis and flow dynamics of the vascular anomaly, the recommended periinterventional imaging is described, ranging from ultrasonography and plain radiography to dedicated ultrafast CT and MRI protocols, percutaneous phlebography and transcatheter angiography. Each vascular anomaly requires dedicated imaging. Differentiation between slow-flow and fast-flow vascular anomalies facilitates selection of the appropriate imaging modality or a combination of diagnostic tools.

Results Slow-flow congenital vascular anomalies mainly include venous and lymphatic or combined malformations. Ultrasound and MRI and especially MR-venography are essential for periinterventional imaging. Arteriovenous malformations are fast-flow vascular anomalies. They should be imaged with dedicated MR protocols, especially when extensive. CT with 4D perfusion imaging as well as time-resolved 3D MR-A allow multiplanar perfusion-based assessment of the multiple arterial inflow and venous drainage vessels of arterio-venous malformations. These imaging tools should be subject to intervention planning, as they can reduce procedure time significantly. Fast-flow vascular tumors like hemangiomas should be worked up with ultrasound, including color-coded duplex sonography, MRI and transcatheter angiography in case of a therapeutic approach. In combined malformation syndromes, radiological imaging has to be adapted according to the dominant underlying vessels and their flow dynamics.

Conclusion Guide to evaluation of flow dynamics in peripheral vascular anomalies, involving vascular malformations and vascular tumors with the intention to facilitate selection of periinterventional imaging modalities and diagnostic and therapeutic approach to vascular anomalies.

Key Points: 

Citation Format

Mean muscle attenuation correlates with severe acute pancreatitis unlike visceral adipose tissue and subcutaneous adipose tissue

Background

Acute pancreatitis (AP) is a frequent disorder with considerable morbidity and mortality. Obesity has previously been reported to influence disease severity.

Objective

The aim of this study was to investigate the association of adipose and muscle parameters with the severity grade of AP.

Methods

In total 454 patients were recruited. The first contrast-enhanced computed tomography of each patient was reviewed for adipose and muscle tissue parameters at L3 level. Associations with disease severity were analysed through logistic regression analysis. The predictive capacity of the parameters was investigated using receiver operating characteristic (ROC) curves.

Results

No distinct variation was found between the AP severity groups in either adipose tissue parameters (visceral adipose tissue and subcutaneous adipose tissue) or visceral muscle ratio. However, muscle mass and mean muscle attenuation differed significantly with p-values of 0.037 and 0.003 respectively. In multivariate analysis, low muscle attenuation was associated with severe AP with an odds ratio of 4.09 (95% confidence intervals: 1.61-10.36, p-value 0.003). No body parameter presented sufficient predictive capability in ROC-curve analysis.

Conclusions

Our results demonstrate that a low muscle attenuation level is associated with an increased risk of severe AP. Future prospective studies will help identify the underlying mechanisms and characterise the influence of body composition parameters on AP.

[Diagnosis and management of vascular malformations : Interdisciplinary teamwork in demand]

Vascular anomalies are very rare, but can occur in children and adults in almost every region of the body. Due to the complexity of this disease, the path to a definitive diagnosis is often difficult. It requires interdisciplinary teamwork with close exchange of information between the individual treatment partners to reach the correct diagnosis and then to start the best therapy. This article provides an overview of the main types of vascular malformations from a clinical, imaging, and histological point of view, following the current classification of the International Society for the Study of Vascular Anomalies (ISSVA).

Vascular tumors in infants and adolescents

Malignant vascular tumors as part of the vascular anomalies spectrum are extremely rare in children and young adults. Instead, benign vascular neoplasias are frequently encountered in the pediatric patient population. While vascular malformations are congenital vascular lesions, originating from a mesenchymal stem cell defect, vascular tumors are neoplastic transformations of endothelial and other vascular cells. The appropriate differential diagnosis and nomenclature according to the classification of the International Society for the Study of Vascular Anomalies (ISSVA) is decisive to initiate correct therapy. While infantile hemangioma can be routinely diagnosed by clinical means and rarely require therapy, more rare vascular tumors are frequently difficult to diagnose, require dedicated cross-sectional imaging, and benefit from an interdisciplinary treatment approach. The focus of this review is to provide an overview over the spectrum of vascular tumors, typical imaging characteristics, and summarize treatment options including interventional radiology approaches.

Preoperative computed tomography angiography (CTA) of the body in vascular patients: prevalence and significance of unsuspected extravascular findings

PURPOSE

 Evaluation of the prevalence and significance of unsuspected extravascular findings on computed tomography angiography (CTA) of the body before endovascular or surgical treatment in vascular patients.

MATERIALS AND METHODS

 This study was approved by the local institutional review board. Radiology reports of 806 patients who underwent CTA of the body during January 2004 until December 2014 before endovascular or surgical treatment of vascular diseases were retrospectively reviewed. All unexpected extravascular abnormalities were classified as clinically non-significant (requiring no follow-up) or clinically significant (requiring further follow-up/immediate treatment). The course of patients with significant extravascular findings was retrospectively evaluated.

RESULTS

 Overall 806 patients were included in this study (592 men; mean age: 67 years). In 778 (96.5 %) of 806 patients 3293 incidental extravascular findings were diagnosed. There were 259 suspicious findings in 205 patients (25.4 %) that required further follow-up or immediate treatment. A previously unknown malignant tumor was diagnosed in 23 (2.9 %) patients. 10 patients (1.2 %) were diagnosed with lung cancer. Malignant tumors were detected more often in men than in women (3.5 % versus 0.9 %). Patients with an incidental tumor were significantly older than patients without a tumor (mean age: 72.3 vs. 67.5 years).

CONCLUSION

 Clinically significant unexpected extravascular findings are common in vascular patients. Especially noteworthy are malignant tumors of the lung.

KEY POINTS

  · Clinically relevant extravascular findings were detected in 25.4 % of the patients.. · The incidence of malignant tumors was 2.9 %.. · Lung cancer had the highest incidence among all malignancies (1.2 %)..

CITATION FORMAT

· Turowski LS, Dollinger M, Wohlgemuth WA et al. Preoperative computed tomography angiography (CTA) of the body in vascular patients: prevalence and significance of unsuspected extravascular findings. Fortschr Röntgenstr 2019; 191: 716 - 724.

Evaluation of dynamic effects of therapy-induced changes in microcirculation after percutaneous treatment of vascular malformations using contrast-enhanced ultrasound (CEUS) and time intensity curve (TIC) analyses

The aim of this follow-up study was to demonstrate the effect of percutaneous interventional treatment on local microcirculation of peripheral vascular malformations using CEUS and TIC analysis.

MATERIAL AND METHODS

Retrospective analysis of 197 patients (136 female; 61 male; 3-86 years) with 135 venous (VM), 39 arterio-venous (AVM), 8 lymphatic and 15 veno-lymphatic peripheral vascular malformations before and after the first percutaneous treatment.CEUS was performed after i.v. injection of 1-2.4 ml of sulfur hexafluoride microbubbles (SonoVue®) using a 6-9 MHz linear probe. Digitally stored cine loops (starting in the early arterial phase for 60 sec) were read by independent readers in consensus. Regions of interest (ROI) were defined in the center and at the margins of the malformation, as well as in the healthy surrounding tissue. TIC analyses with Time to Peak (TTP) and Area under the Curve (AUC) were calculated using integrated perfusion software.

RESULTS

After the treatment there was a significant decrease for median AUC in VM in the center from 297.8 (14.5-2167.6) rU down to 243.3 (0.1-1678.8) rU (p = 0.043) and in the surrounding tissue down to 107.7 (20.2-660.2) rU (p = 0.018). For the other malformations AUC decreased in the center and the margins as well. TTP rose, however these changes did not reach the level of significance.

CONCLUSION

Analyzing the capillary microcirculation TICs offer a possibility of monitoring therapy-induced capillary changes of vascular malformations.

Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies

BACKGROUND

 Vascular anomalies are a diagnostic and therapeutic challenge. They require dedicated interdisciplinary management. Optimal patient care relies on integral medical evaluation and a classification system established by experts in the field, to provide a better understanding of these complex vascular entities.

METHOD

 A dedicated classification system according to the International Society for the Study of Vascular Anomalies (ISSVA) and the German Interdisciplinary Society of Vascular Anomalies (DiGGefA) is presented. The vast spectrum of diagnostic modalities, ranging from ultrasound with color Doppler, conventional X-ray, CT with 4 D imaging and MRI as well as catheter angiography for appropriate assessment is discussed.

RESULTS

 Congenital vascular anomalies are comprised of vascular tumors, based on endothelial cell proliferation and vascular malformations with underlying mesenchymal and angiogenetic disorder. Vascular tumors tend to regress with patient's age, vascular malformations increase in size and are subdivided into capillary, venous, lymphatic, arterio-venous and combined malformations, depending on their dominant vasculature. According to their appearance, venous malformations are the most common representative of vascular anomalies (70 %), followed by lymphatic malformations (12 %), arterio-venous malformations (8 %), combined malformation syndromes (6 %) and capillary malformations (4 %).

CONCLUSION

 The aim is to provide an overview of the current classification system and diagnostic characterization of vascular anomalies in order to facilitate interdisciplinary management of vascular anomalies.

KEY POINTS

  · Vascular anomalies are comprised of vascular tumors and vascular malformations, both considered to be rare diseases.. · Appropriate treatment depends on correct classification and diagnosis of vascular anomalies, which is based on established national and international classification systems, recommendations and guidelines.. · In the classification, diagnosis and treatment of congenital vascular anomalies, radiology plays an integral part in patient management..

CITATION FORMAT

· Sadick M, Müller-Wille R, Wildgruber M et al. Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies. Fortschr Röntgenstr 2018; 190: 825 - 835.

Impact of low dose settings on radiation exposure during pediatric fluoroscopic guided interventions

PURPOSE

To evaluate the effects of lowering the detector entrance exposure in children undergoing interventional radiology procedures.

MATERIALS AND METHODS

The study retrospectively investigated radiation dose levels in pediatric patients aged 0-18 years before (n = 39) and after (n = 26) lowering detector entrance dose, undergoing embolization of peripheral Arteriovenous malformations, Portal Vein Interventions or Percutaneous Transhepatic Cholangio Drainage (PTCD) between 2014 and 2017. Patient characteristics, fluoroscopy time, protocols used as well as resulting Skin Dose and Dose Area Product (DAP) were compared in each cohort. Image quality was assessed by two independent readers.

RESULTS

The two patient cohorts did not differ in terms of patient demographics. Similarly, fluoroscopy time did not differ before and after implementation of the low dose settings. An overall reduction of skin dose of 75.1% for AVM embolizations, 80.5% for Portal Vein Interventions and 85.3% for PTCD placement was observed. The DAP decrease was 82.5% for AVM embolizations, 72.2% for Portal Vein Interventions and 79.8% for PTCD placement. Image quality was generally considered to be good with an insignificant difference between pre and post implementation of the low dose approach and good agreement between the two readers. Manual inroom-switching to higher dose levels was possible, however this was not performed more frequently after implementation of the low dose settings.

CONCLUSION

Lowering the detector entrance dose in pediatric interventional radiology procedures results in a significant decrease of the radiation dose burden.

Vascular Anomalies (Part II): Interventional Therapy of Peripheral Vascular Malformations

BACKGROUND

 The International Society for the Study of Vascular Anomalies (ISSVA) categorizes vascular anomalies into vascular tumors and vascular malformations. Vascular malformations are further divided into slow-flow (venous, lymphatic, and capillary malformation) and fast-flow malformations (arteriovenous malformation and arteriovenous fistula). This interdisciplinary classification has therapeutic implications.

METHODS

 The objective of this article is to provide concise information about the current terminology and treatment strategies of peripheral vascular malformations, based on the currently available literature, with a focus on interventional therapy of venous malformations (VM), lymphatic malformations (LM), arteriovenous malformations (AVM) and arteriovenous fistulae (AVF).

RESULTS AND CONCLUSION

 Accurate classification is crucial for appropriate therapy of peripheral vascular malformations. Modern imaging technologies and refined interventional treatment strategies are now central parts in the multidisciplinary management of these patients. Slow-flow and fast-flow vascular malformations can be treated successfully by percutaneous sclerotherapy and endovascular embolotherapy as first-line interventions.

KEY POINTS

  · The ISSVA classification is essential for the correct diagnosis of vascular malformations. · The Schobinger classification as well as the Cho classification should be used for description of arteriovenous malformations (AVM). · Sclerotherapy and embolotherapy are the primary treatments of choice for vascular malformations.

CITATION FORMAT

· Müller-Wille R, Wildgruber M, Sadick M et al. Vascular Anomalies (Part II): Interventional Therapy of Peripheral Vascular Malformations. Fortschr Röntgenstr 2018; DOI: 10.1055/s-0044-101266.