Objective The aim of the study was to calculate the effective dose during fluoroscopy-guided pediatric interventional procedures of the liver in a phantom model before and after adjustment of preset parameters. Methods Organ doses were measured in three anthropomorphic Rando-Alderson phantoms representing children at various age and body weight (newborn 3.5kg, toddler 10kg, child 19kg). Collimation was performed focusing on the upper abdomen representing mock interventional radiology procedures such as percutaneous transhepatic cholangiography and drainage placement (PTCD). Fluoroscopy and digital subtraction angiography (DSA) acquisitions were performed in a posterior-anterior geometry using a state of the art flat-panel detector. Effective dose was directly measured from multiple incorporated thermoluminescent dosimeters (TLDs) using two different parameter settings. Results Effective dose values for each pediatric phantom were below 0.1mSv per minute fluoroscopy, and below 1mSv for a 1 minute DSA acquisition with a frame rate of 2 f/s. Lowering the values for the detector entrance dose enabled a reduction of the applied effective dose from 12 to 27% for fluoroscopy and 22 to 63% for DSA acquisitions. Similarly, organ doses of radiosensitive organs could be reduced by over 50%, especially when close to the primary x-ray beam. Conclusion Modification of preset parameter settings enabled to decrease the effective dose for pediatric interventional procedures, as determined by effective dose calculations using dedicated pediatric Rando-Alderson phantoms.
Purpose
To evaluate risk factors associated with alterations in venous structures adjacent to an ablation zone after percutaneous irreversible electroporation (IRE) of hepatic malignancies at subacute follow-up (1 to 3 days after IRE) and to describe evolution of these alterations at mid-term follow-up.
Materials and Methods
43 patients (men/women, 32/11; mean age, 60.3 years) were identified in whom venous structures were located within a perimeter of 1.0 cm of the ablation zone at subacute follow-up after IRE of 84 hepatic lesions (primary/secondary hepatic tumors, 31/53). These vessels were retrospectively evaluated by means of pre-interventional and post-interventional contrast-enhanced magnetic resonance imaging or computed tomography or both. Any vascular changes in flow, patency, and diameter were documented. Correlations between vascular change (yes/no) and characteristics of patients, lesions, and ablation procedures were assessed by generalized linear models.
Results
191 venous structures were located within a perimeter of 1.0 cm of the ablation zone: 55 (29%) were encased by the ablation zone, 78 (41%) abutted the ablation zone, and 58 (30%) were located between 0.1 and 1.0 cm from the border of the ablation zone. At subacute follow-up, vascular changes were found in 19 of the 191 vessels (9.9%), with partial portal vein thrombosis in 2, complete portal vein thrombosis in 3, and lumen narrowing in 14 of 19. At follow-up of patients with subacute vessel alterations (mean, 5.7 months; range, 0 to 14 months) thrombosis had resolved in 2 of 5 cases; vessel narrowing had completely resolved in 8 of 14 cases, and partly resolved in 1 of 14 cases. The encasement of a vessel by ablation zone (OR = 6.36, p<0.001), ablation zone being adjacent to a portal vein (OR = 8.94, p<0.001), and the usage of more than 3 IRE probes (OR = 3.60, p = 0.035) were independently associated with post-IRE vessel alterations.
Conclusion
Venous structures located in close proximity to an IRE ablation zone remain largely unaffected by this procedure, and thrombosis is rare.
Evaluation of the efficacy and safety of Gelfoam for the closure of transhepatic or transsplenic parenchymal puncture tracts with large-bore sheaths in pediatric patients.Between January 2012 and May 2013, 8 percutaneous transhepatic accesses and 3 percutaneous transsplenic accesses were closed using percutaneous Gelfoam in pediatric patients. The primary study endpoints to determine treatment efficacy and safety were patient survival, technical success defined as successful closure of the puncture tract without signs of bleeding, and complication rates. The secondary study endpoints were the occurrence of local and systemic inflammation.Overall survival was 100 % with a median follow-up of 256 days. The procedure was technically successful in 10 of 11 procedures. One patient suffered from bleeding, which was successfully managed by a single blood transfusion. No re-bleeding was detected during follow-up and no surgical interventions were necessary. No signs of local or systemic infections related to the Gelfoam application occurred.Percutaneous Gelfoam application is an effective and safe technique for the closure of transhepatic or transsplenic accesses in pediatric patients.Interventional closure of large transhepatic and transsplenic parenchymal accesses in children after interventional treatment is recommended to avoid bleeding. Gelfoam application does not cause artifacts in magnetic resonance imaging and does not increase the risk of local or systemic inflammation in comparison to permanent embolic agents. Thus, especially children under immunosuppressive therapy can benefit from the application of Gelfoam.
Thrombotische Ablagerungen auf der Gasaustauschoberfläche von Geräten zur Extrakorporalen Membranoxygenierung (ECMO) stellen eine ernstzunehmende klinische Komplikation dar. Neben einem Funktionsverlust des Gerätes mit der Notwendigkeit des Geräteaustausches, können thrombotische Ablagerungen die Gerinnungskaskade im Patienten aktivieren und lebensbedrohliche Blutungen verursachen. In dieser Studie beschreiben wir mithilfe der Multidetektor-Computertomografie (MDCT) die Häufigkeit, das Volumen und das Verteilungsmuster von thrombotischen Ablagerungen in ECMO-Geräten.
Arteriovenöse Fisteln (AV-Fistel) sind eine sehr seltene und unerwartete Komplikation nach Bandscheibenoperationen. Anfängliche Symptome wie beidseitige Beinschwellung und Dyspnoe werden zunächst oft als tiefe Beinvenenthrombose und Lungenembolie gedeutet. Der Links-rechts-Shunt führt aufgrund der enormen Volumenbelastung zu einer hyperzirkulatorischen Herzinsuffizienz (high-output heart failure). Wir berichten über eine 58-jährige Patientin, welche sich 2 Monate nach einer Bandscheibenoperation mit einer symptomatischen arteriovenösen Fistel zwischen der rechten A. iliaca communis und der linken V. iliaca communis in unserer Klinik vorstellte. Zur Vermeidung einer dauerhaften unphysiologischen Volumenbelastung des Herzens wurde die AV-Fistel durch die Platzierung eines gecoverten Stents in die rechte A. iliaca communis interventionell erfolgreich verschlossen.
To evaluate a newly introduced high resolution linear transducer for vascularization and mural perfusion assessment using contrast harmonic imaging (CHI) with quantitative time intensity curve analysis (TIC) in patients with active Crohn's disease (CD).We prospectively evaluated 14 consecutive patients (7 women, 7 males, age range 19-42 years, median 28 years) with histologically proven CD having an acute episode of the disease applying contrast enhanced MRI and high resolution ultrasound. For the ultrasound we used a newly introduced high resolution linear multi-frequency transducer (6-9 MHz, Logiq 9, GE). Ultrasound was performed by an experienced radiologist applying color coded Doppler sonography (CCDS), power Doppler (PD) and contrast enhanced CHI using the 'true agent detection mode'. Additionally, 5 healthy volunteers were examined by ultrasound applying CCDS, PD and CHI. After the injection of 2.4 ml ultrasound contrast agent (SonoVue) the dynamic CHI cine sequences were recorded as digital raw data for 60 seconds. Therefore we were able to perform a quantitative perfusion analysis using TIC retrospectively. CCDS, PD and CHI with TIC were compared and analyzed.In all 14 patients MRI showed inflammatory changes in the terminal or pre-terminal ileum. Using PD and CCDS enlarged vessels surrounding the bowel wall were visualized in all patients. PD as well as CCDS diagnosed just in 9 of 14 patients augmented mural vessels. Having CHI with TIC increased mural contrast enhancement was diagnosed in all 14 patients. Patients with CD showed a maximum enhancement 36 s after injection with 9 dB (range 5.9-13.2 dB), while healthy volunteers reached the maximum level of 2.8 dB (range 2-3.8 dB) after 23 s (p<0.05).Using high resolution linear transducer mural perfusion changes in active Crohn's disease can be appreciated applying CHI with TIC. This technique could be an effective dynamic imaging modality for diagnosis and especially follow-up examination to monitor treatment in CD.
Ziel dieser Studie ist es, den technischen und klinischen Erfolg der Bronchialarterienembolisation (BAE) mittels des Flüssigembolisat Ethylen-Vinylalkohol-Copolymer bei Patienten mit akuten Hämoptysen zu evaluieren.
Background Splenic vein thrombosis is a known complication of acute or chronic pancreatitis (PISVT–pancreatitis-induced splenic vein thrombosis). It can lead to increased blood flow through splenoportal, gastroepiploic or mesenteric collaterals. This may result in the development of esophageal, gastric or colonic varices with a high risk of severe gastrointestinal bleeding. Hepatic venous pressure gradient (HVPG) is generally normal in these patients. While clear guidelines for treatment are lacking, splenectomy or splenic artery embolization are used to prevent bleeding.
