Percutaneous Transsplenic Balloon-Assisted Transjugular Intrahepatic Portosystemic Shunt Placement in Patients with Portal Vein Obliteration for Portal Vein Recanalization: Feasibility, Safety and Effectiveness

Purpose To assess the feasibility, safety and effectiveness of portal vein recanalization (PVR)–transjugular portosystemic shunt (TIPS) placement via splenic access using a balloon puncture technique. Materials and Methods In a single-center retrospective study from March 2017 to February 2021, 14 consecutive patients with portal hypertension, chronic liver disease and portal vein occlusion or near-complete (> 95%) occlusion were referred for PVR–TIPS placement. Feasibility, safety and effectiveness including procedural characteristics such as technical success, complication profile and splenic access time (SAT), balloon positioning time (BPT), conventional portal vein entry time (CPVET), overall procedure time (OPT), fluoroscopy time (FT), dose–area product (DAP) and air kerma (AK) were evaluated. Results Transsplenic PVR–TIPS using balloon puncture technique was technically feasible in 12 of 14 patients (8 men, 49 ± 13 years). In two patients without detectable intrahepatic portal vein branches, TIPS placement was not feasible and both patients were referred for further treatment with nonselective beta blockers and endoscopic variceal ligation. No complications grade > 3 of the Cardiovascular and Interventional Radiological Society of Europe classification system occurred. The SAT was 25 ± 21 min, CPVET was 33 ± 26 min, the OPT was 158 ± 54 min, the FT was 42 ± 22 min, the DAP was 167.84 ± 129.23 Gy*cm2 and the AK was 1150.70 ± 910.73 mGy. Conclusions Transsplenic PVR–TIPS using a balloon puncture technique is feasible and appears to be safe in our series of patients with obliteration of the portal vein. It expands the interventional options in patients with chronic PVT.

Radiation Dose and Fluoroscopy Time of Diagnostic Angiography in Patients with Spinal Dural Arteriovenous Fistula

Purpose Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs. Methods Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm2) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th percentile of the DAP distribution was used to define the local DRL. Results A total of 62 spinal angiographies were performed in 25 patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p < 0.01). The local DRL was 329.41 Gy cm2 for a nonspecific (n = 62), 395.59 Gy cm2 for a preoperative and 138.6 Gy cm2 for a postoperative spinal angiography. Preoperative angiography of uncommonly located SDAVFs yielded a significantly longer fluoroscopy time (p = 0.02). The MRA-based fistula detection had no significant impact on dosimetrics (p > 0.05). A low-dose protocol yielded a 61% reduction of DAP. Conclusion The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures.

Predictors of radiation dose for uterine artery embolisation are angiography system-dependent

This study sought to achieve radiation dose reductions for patients receiving uterine artery embolisation (UAE) by evaluating radiation dose measurements for the preceding generation (Allura) and upgraded (Azurion) angiography system. Previous UAE regression models in the literature could not be applied to this centre’s practice due to being based on different angiography systems and radiation dose predictor variables. The aims of this study were to establish whether radiation dose is reduced with the upgraded angiography system and to develop a regression model to determine predictors of radiation dose specific to the upgraded angiography system. A comparison between Group I (Allura, n = 95) and Group II (Azurion, n = 95) demonstrated a significant reduction in KAP (kerma-area product) and Ka, r (reference air kerma) by 63% (143.2 Gy·cm2 vs 52.9 Gy·cm2; P < 0.001, d = 0.8) and 67% (0.6 Gy vs 0.2 Gy; P < 0.001, d = 0.8), respectively. The multivariable linear regression (MLR) model identified the UAE radiation dose predictors for KAP on the upgraded angiography system as total fluoroscopy dose, Ka, r, and total uterus volume. The predictive accuracy of the MLR model was assessed using a Bland-Altman plot. The mean difference was 0.39 Gy·cm2 and the limits of agreement (LoA) were +28.49 and -27.71 Gy·cm2, and thus illustrated no proportional bias. Our findings validated the upgraded angiography system and its advance capabilities to significantly reduce radiation dose for our patients. Interventional radiologist and interventional radiographer familiarisation of the system’s features and the implementation of the newly established MLR model would further facilitate dose optimisation for all centres performing UAE procedures using the upgraded angiography system.

Intraoral and dental panoramic imaging: A diagnostic reference level study comparing radiation dose using two dosimeters in Saudi Arabia

The purpose of this study was to determine local diagnostic reference levels (DRLs) for patients undergoing intraoral and panoramic dental examinations at the intraoral radiology units of the public hospitals in Najran, Saudi Arabia. DRLs were determined based on measurements of dose area product (DAP) at intraoral and dental panoramic radiology units. This study has covered over 47% of the public hospitals in Najran with the intention to establish the local DRLs for all the possible intraoral and panoramic X-ray examinations for children and adults. For intraoral, the values for the estimated DAP ranged from 6 to 70 mGy.cm2 (average: 27.6, 29.8, 39.9 and 39.6 mGy.cm2 for incisive, both premolar and canine, molar upper and lower jaw, respectively). For panoramic, the mean value of DAP is 61.5 and 89.8 mGy.cm2 for paediatric and adult patients, respectively. DRLs were established at the 3rd quartile for incisive, both premolar and canine, molar upper and lower jaw protocols are 29.2, 37.1, 50.2 and 50.1 mGy.cm2, respectively. Furthermore, DRLs for panoramic radiography for paediatric and adult patients are 72.7 and 92.3 mGy.cm2, respectively. The proposed DRLs were comparable to those previously reported in other countries, such as UK and India.

Meat Analogues in the Perspective of Recent Scientific Research: A Review

There are many reasons why consumers and food producers are looking for alternatives to meat and meat products, which includes the following: health, environmental or ethical aspects. This study reviews recent scientific reports on meat analogues. The scope of the review includes the following: formulation and nutritional value; health safety and legal regulations; manufacturing and processing technologies including the latest developments in this area; product availability on the food market; and consumer attitudes towards meat analogues. The analysis of the literature data identified technological challenges, particularly in improving consumer acceptability of meat analogues. Among the risks and limitations associated with the production of meat analogues, the following were identified: contamination from raw materials and the risk of harmful by-products due to intensive processing; legal issues of product nomenclature; and consumer attitudes towards substituting meat with plant-based alternatives. The need for further research in this area, particularly on the nutritional value and food safety of meat analogues, was demonstrated.

Review on the Traditional and Integrated Passives: State-of-the-Art Design and Technologies

With the increased necessity of a high power density and efficient system in aerospace and marine industries, integrated motor drives provide an excellent solution in the modern era. Therefore, a close structural and functional integration of passive components has become a prerequisite task to make a compact overall system. This article reviews the existing motor drives system with integrated passive technologies. To start, the design aspect of the traditional and integrated filter inductors, using the area product approach, is discussed. Subsequently, layouts of traditional and integrated inductors are presented. The available capacitor technologies, suitable for integration, are also discussed with pros and cons of each capacitor type.

Combined Echo and Fluoroscopy-Guided Pulmonary Valvuloplasty in Neonates and Infants: Efficacy and Safety

Percutaneous balloon pulmonary valvuloplasty (PBPV) is the treatment of choice for isolated pulmonary valve stenosis. While this procedure is highly efficacious and has an excellent safety profile, as currently practiced, patients are obligatorily exposed to the secondary risks of ionizing radiation and contrast media. To mitigate these risks, we developed a protocol which utilized echo guidance for portions of the procedure which typically require fluoroscopy and/or angiography. Ten cases of echo-guided pulmonary valvuloplasty (EG-PBPV) for isolated pulmonary stenosis in children less than a year of age were compared to a historical cohort of nineteen standard cases using fluoroscopy/angiography alone, which demonstrated equivalent procedural outcomes and safety, while achieving a median reduction in radiation (total dose area product) and contrast load of 80% and 84%, respectively. Our early experience demonstrates that EG-PBPV in neonates and infants has results equivalent to standard valvuloplasty but with less radiation and contrast.

Radiation exposure in 101 non-coronary fluoroscopically guided interventional procedures: reference levels of air kerma at the reference point and air kerma-area product

Objectives: To present the median value and 75th percentile of air kerma at the reference point (Ka,r), air kerma-area product (KAP), and fluoroscopic time for a large number of fluoroscopically-guided interventional (FGI) procedures. Methods: This retrospective study included the consecutive non-coronary FGI procedures from a Radiology department between May 2016 and October 2018 at a large tertiary care hospital in the U.S. An in-house developed, semi-automated software, integrated with a dictation system, was used to record patient examination information, including Ka,r, KAP and fluoroscopic time. The included patient procedures were categorized into procedure types. A software package R (version 3.5.1, R Foundation) was used to calculate procedure-specific quartiles of radiation exposure. Results: Based on analysis of 24,911 FGI cases, median value and 75th percentile are presented for each of Ka,r, KAP and fluoroscopic time for 101 procedures that can act as benchmark for comparison for dose optimization studies. Conclusion: This study provides reference levels (50th and 75th percentiles) for a comprehensive list of FGI procedures, reflecting an overall picture of the latest FGI studies for diagnosis, targeted minimally invasive intervention, and therapeutic treatment. Advances in knowledge: This study provides reference levels (50th and 75th percentiles) for the largest number of fluoroscopically-guided interventional procedures reported to-date (101 procedures), in terms of air kerma at the reference point, air kerma-area product, and fluoroscopic time, among which these quartiles for ≥50 procedures are presented for the first time.