Adrenal Vein Sampling: Tips and Tricks.

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Impact of equipment technology on reference levels in fluoroscopy-guided gastrointestinal procedures.

OBJECTIVES: To evaluate the effect of equipment technology on reference point air kerma (Ka,r), air kerma-area product (PKA), and fluoroscopic time for fluoroscopically-guided gastrointestinal endoscopic procedures and establish benchmark levels. METHODS: This retrospective study included the consecutive patients who underwent fluoroscopically-guided gastrointestinal endoscopic procedures from May 2016 to August 2023 at a tertiary care hospital in the U.S. Fluoroscopic systems included (a) Omega CS-50 e-View, (b) GE Precision 500D, and (c) Siemens Cios Alpha. Radiation dose was analyzed for four procedure types of endoscopic retrograde biliary, pancreas, biliary and pancreas combined, and other guidance. Median and 75th percentile values were computed using software package R (version 4.0.5, R Foundation). RESULTS: This large study analyzed 9,459 gastrointestinal endoscopic procedures. Among four procedure types, median Ka,r was 108.8-433.2 mGy (a), 70-272 mGy (b), and 22-55.1 mGy (c). Median PKA was 20.9-49.5 Gy∙cm2 (a), 13.4-39.7 Gy∙cm2 (b), and 8.91-20.9 Gy∙cm2 (c). Median fluoroscopic time was 2.8-8.1 min (a), 3.6-9.2 min (b), and 2.9-9.4 min (c). Their median value ratio (a:b:c) was 8.5:4.8:1 (Ka,r), 2.7:2.1:1 (PKA), and 1.0:1.1:1 (fluoroscopic time). Median value and 75th percentile are presented for Ka,r, PKA, and fluoroscopic time for each procedure type, which can function as benchmark for comparison for dose optimization studies. CONCLUSION: This study shows manifold variation in doses (Ka,r and PKA) among three fluoroscopic equipment types and provides local reference levels (50th and 75th percentiles) for four gastrointestinal endoscopic procedure types. Besides procedure type, imaging technology should be considered for establishing diagnostic reference level. SUMMARY: With manifold (2 to 12 times) variation in doses observed in this study among 3 machines, we recommend development of technology-based diagnostic reference levels for gastrointestinal endoscopic procedures.

Establishment of Diagnostic Reference Levels in Portuguese Interventional Radiology departments.

PURPOSE: To establish Portuguese Diagnostic Reference Levels (DRLs), for six body fluoroscopy guided interventional procedures (FGIP). METHOD: A retrospective study was conducted in five interventional departments most representative of Interventional Radiology (IR) practice. Dose values, in terms of air kerma area product (PKA in Gy.cm2), air kerma at the patient entrance reference point (Ka,r in mGy), and exposure parameters (fluoroscopy time (FT) and number of cine runs) were collected. Examinations were selected per procedure (at least 20), according to the antero-posterior and lateral diameter mean value (±5 cm), measured on previous Computed Tomography (CT) examinations. RESULTS: Data of 489 body FGIP show a large variation on dose values per procedure and per department. National DRLs in terms of PKA were 20.2 Gy.cm2 for Percutaneous transhepatic biliary drainage (PTBD), 98.2 Gy.cm2 for Bronchial artery embolisation (BAE), 247.7 Gy.cm2 for Transarterial chemoembolisation (TACE), 331.6 Gy.cm2 for Inferior epigastric arteries embolisation (IEAE), 312.0 Gy.cm2 for Transjugular intrahepatic portosystemic shunt (TIPS) and 19.3 Gy.cm2 for Endovascular treatment of femoral popliteal arteries (ETFPA). CONCLUSIONS: This is the first study reporting Interventional Radiology DRLs in Portugal and we propose preliminary national estimates for the six more common body FGIP. The results of this study will be presented and discussed with all Portuguese IR departments, to promote procedures optimisation.

Comparison of clinical outcomes between transthoracic echocardiography- and X-ray-guided left bundle branch pacing for bradycardia: A randomized controlled trial.

INTRODUCTION: Left bundle branch pacing (LBBP) is a physiological pacing modality. However, the long procedure and fluoroscopy time of LBBP is still a problem. This study aims to compare the clinical outcomes between transthoracic echocardiography (TTE)- and X-ray-guided LBBP. METHODS: This is a single-center, prospective, randomized controlled study. Consecutive patients who underwent LBBP in our team from June 2022 to November 2022 were enrolled. Procedure and fluoroscopy time, pacing parameters, electrophysiological and echocardiographic characteristics, as well as complications were recorded at implantation and during follow-up. RESULTS: In this study, 60 patients were enrolled and divided into two groups: 30 patients were allocated to the X-ray group and the remaining 30 to the TTE group. There was no significant difference in the success rate between the two groups (86.7% vs. 76.7%, p = .317). The procedure time of TTE group was comparable to that of the X-ray group (9.0 vs. 12.0 min, p = .063). However, the fluoroscopy time in the TTE group was significantly lower than that of the X-ray group (2.5 vs. 5.0 min, p = .002). There were no statistically significant differences in pacing parameters, electrophysiological and echocardiographic characteristics, or complications between the two groups at implantation and during follow-up. CONCLUSION: TTE-guided LBBP is a feasible and safe method. Compared with X-ray, TTE showed a comparable success rate and procedure time, but it could significantly reduce the fluoroscopy time of LBBP.

X-ray Doses in Relation to Body Mass, Indication, and Substrate During Pediatric Electrophysiological Procedures on the Heart.

The main goal of this study is to determine typical values of dose area product (DAP) and difference in the effective dose (ED) for pediatric electrophysiological procedures on the heart in relation to patient body mass. This paper also shows DAP and ED in relation to the indication, the arrhythmia substrate determined during the procedure, and in relation to the reason for using radiation. Organ doses are described as well. The subjects were children who have had an electrophysiological study done with a 3D mapping system and X-rays in two healthcare institutions. Children with congenital heart defects were excluded. There were 347 children included. Significant difference was noted between mass groups, while heavier children had higher values of DAP and ED. Median DAP in different mass groups was between 4.00 (IQR 1.00-14.00) to 26.33 (IQR 8.77-140.84) cGycm2. ED median was between 23.18 (IQR 5.21-67.70) to 60.96 (IQR 20.64-394.04) µSv. The highest DAP and ED in relation to indication were noted for premature ventricular contractions and ventricular tachycardia-27.65 (IQR 12.91-75.0) cGycm2 and 100.73 (IQR 53.31-258.10) µSv, respectively. In arrhythmia substrate groups, results were similar, and the highest doses were in ventricular substrates with DAP 29.62 (IQR 13.81-76.0) cGycm2 and ED 103.15 (IQR 60.78-266.99) µSv. Pediatric electrophysiology can be done with very low doses of X-rays when using 3D mapping systems compared to X-rays-based electrophysiology, or when compared to pediatric interventional cardiology or adult electrophysiology.

True Costs of Uterine Artery Embolization: Time-Driven Activity-Based Costing in Interventional Radiology Over a 3-Year Period.

PURPOSE: The aim of this study is to uncover potential areas for cost savings in uterine artery embolization (UAE) using time-driven activity-based costing, the most accurate costing methodology for direct health care system costs. METHODS: One hundred twenty-three patients who underwent outpatient UAE for fibroids or adenomyosis between January 2020 and December 2022 were retrospectively reviewed. Utilization times were captured from electronic health record time stamps and staff interviews using validated techniques. Capacity cost rates were estimated using institutional data and manufacturer proxy prices. Costs were calculated using time-driven activity-based costing for personnel, equipment, and consumables. Differences in time utilization and costs between procedures by an interventional radiology attending physician only versus an interventional radiology attending physician and trainee were additionally performed. RESULTS: The mean total cost of UAE was $4,267 ± $1,770, the greatest contributor being consumables (51%; $2,162 ± $811), followed by personnel (33%; $1,388 ± $340) and equipment (7%; $309 ± $96). Embolic agents accounted for the greatest proportion of consumable costs, accounting for 51% ($1,273 ± $789), followed by vascular devices (15%; $630 ± $143). The cost of embolic agents was highly variable, driven mainly by the number of vials (range 1-19) of tris-acryl gelatin particles used. Interventional radiology attending physician only cases had significantly lower personnel costs ($1,091 versus $1,425, P = .007) and equipment costs ($268 versus $317, P = .007) compared with interventional radiology attending physician and trainee cases, although there was no significant difference in mean overall costs ($3,640 versus $4,386; P = .061). CONCLUSIONS: Consumables accounted for the majority of total cost of UAE, driven by the cost of embolic agents and vascular devices.

Safety and Effectiveness of Fibrin Sheath Stripping of Pediatric Chest Ports.

PURPOSE: To report the safety and effectiveness of fibrin sheath stripping of pediatric chest ports. MATERIALS AND METHODS: Fibrin sheath stripping procedures for pediatric chest ports between 2018 and 2023 were retrospectively reviewed. The treatment indication was the inability to aspirate blood from the port. The technical success, adverse events, days of primary and secondary service intervals, fluoroscopy time, and fluoroscopy dose were recorded. RESULTS: Fibrin sheath stripping procedures were performed in 15 patients for a total of 18 procedures. All patients treated with fibrin sheath stripping had failed fibrinolytic treatment and a preprocedural fluoroscopy examination suggestive of fibrin sheath before attempting stripping. All fibrin sheath stripping procedures were technically successful. The median and mean total days of primary service interval from the date of port placement to the date of suspected fibrin sheath were 666 and 617 days, respectively. The median and mean total number of days of secondary service interval were 385 and 561 days, respectively. The mean fluoroscopy time was 16.9 minutes. The mean fluoroscopy air kerma was 29.8 mGy. No adverse events were observed. CONCLUSIONS: Fibrin sheath stripping is a safe and effective minimally invasive option to maintain the function of pediatric chest ports.

Factors affecting the success of CT-guided core biopsy of musculoskeletal lesions with a 13-G needle.

OBJECTIVE: To determine the value of CT-guided bone core biopsy and investigate factors that affect diagnostic yield and biopsy outcome. MATERIALS AND METHODS: The single-centre retrospective analysis included 447 patients who had CT-guided core biopsy with a 13-G needle (Bonopty®) from January 2016 to December 2021. Histological results or ≥ 6 months of clinical and radiological follow-up served as outcome references. A successful biopsy was classified as "diagnostic" when a definitive diagnosis was made and "adequate" when only the malignant or benign nature of the tumour could be determined. Biopsies were "nondiagnostic" when the nature of the lesion could not be determined. The occult lesions were defined as not seen on CT but visible on other modalities. RESULTS: In 275 (62%) females and 172 (38%) males, the overall success rate was 85% (383 biopsies), with 314 (70%) diagnostic biopsies and 69 (15%) adequate biopsies. There was no relationship between biopsy success and the localisation of the lesion, length of biopsy material, or number of biopsy attempts. The lesions' nature had a statistically significant effect on biopsy success with lytic and mixed lesions having the highest success rate. Occult lesions had the lowest success rate. CONCLUSION: CT-guided bone core biopsy is an effective method in the workup of musculoskeletal diseases with the highest success rate in lytic and mixed lesions. No apparent relationship was found between biopsy success and biopsy length, number of attempts, or localisation of the lesion.

Development and Validation of an Electronic Adverse Event Model for Patient Safety Surveillance in Interventional Radiology.

BACKGROUND: Comprehensive adverse event (AE) surveillance programs in interventional radiology (IR) are rare. Our aim was to develop and validate a retrospective electronic surveillance model to identify outpatient IR procedures that are likely to have an AE, to support patient safety and quality improvement. METHODS: We identified outpatient IR procedures performed in the period from October 2017 to September 2019 from the Veterans Health Administration (n = 135,283) and applied electronic triggers based on posyprocedure care to flag cases with a potential AE. From the trigger-flagged cases, we randomly sampled n = 1,500 for chart review to identify AEs. We also randomly sampled n = 600 from the unflagged cases. Chart-reviewed cases were merged with patient, procedure, and facility factors to estimate a mixed-effects logistic regression model designed to predict whether an AE occurred. Using model fit and criterion validity, we determined the best predicted probability threshold to identify cases with a likely AE. We reviewed a random sample of 200 cases above the threshold and 100 cases from below the threshold from October 2019 to March 2020 (n = 20,849) for model validation. RESULTS: In our development sample of mostly trigger-flagged cases, 444 of 2,096 cases (21.8%) had an AE. The optimal predicted probability threshold for a likely AE from our surveillance model was >50%, with positive predictive value of 68.9%, sensitivity of 38.3%, and specificity of 95.3%. In validation, chart-reviewed cases with AE probability >50% had a positive predictive value of 63% (n = 203). For the period from October 2017 to March 2020, the model identified approximately 70 IR cases per month that were likely to have an AE. CONCLUSIONS: This electronic trigger-based approach to AE surveillance could be used for patient-safety reporting and quality review.

Image Fusion Technology in Interventional Radiology.

Image fusion technology aims to improve patient outcomes for image-guided interventions by leveraging the strengths of multimodality imaging datasets. This most commonly involves the overlay or co-display of advanced cross-sectional imaging permitting freedom of device placement via conventional image guidance such as ultrasound, fluoroscopy, and computed tomography. This can allow the interventionalist to target and treat lesions that would otherwise be difficult or impossible to visualize and access using conventional imaging guidance. Furthermore, the use of image fusion can allow for procedures traditionally performed with cross-sectional imaging to be performed under ultrasound or fluoroscopy, by importing the data from preacquired cross-sectional imaging into the interventional procedure. This manuscript provides an overview of image fusion technologies used for interventional radiology (IR) guidance, with an emphasis on technical considerations.

Intraoperative cone-beam computed tomography-guided curettage for osteoid osteoma.

Recently, cone-beam computed tomography (CBCT)-guided surgeries have been developed for bone and soft tissue tumors. The present study aimed to evaluate the efficacy of CBCT-guided curettage for osteoid osteoma. Our study population included 13 patients who underwent primary curettage for osteoid osteoma using intraoperative CBCT in a hybrid operating room between April 2019 and November 2022. We collected the following data: sex, age, follow-up period, symptom onset to time of surgery, tumor size and location, length of skin incision, operating time, radiation dose, recurrence, postoperative complications, and visual analog scale for pain during the last follow-up. There were 10 male and 3 female patients, and the mean age was 25.0 years (range, 9-49 years). The mean follow-up period was 10.6 months (range, 0.4-24.0 months). The locations of the tumors were the proximal femur in 6 patients, the acetabular region in 2 patients, and the ilium, tibial shaft, calcaneus, cuboid, and talus in 1 patient each. The mean time of symptoms onset to surgery was 18.7 months (range, 2.3-69.9 months). The mean maximum diameter of the tumor was 5.9 mm (range, 3.5-10.0 mm). The mean length of the skin incision was 2.2 cm (range, 1.5-3.5 cm). The mean operating time was 96.9 minutes (range, 64-157 minutes). The mean dose of radiation was 193.2 mGy (range, 16.3-484.0 mGy). No recurrences, postoperative complications, and reoperation were observed in this study. All the patients reported 0 mm on the visual analogue scale for pain on the last follow-up. CBCT-guided curettage for osteoid osteoma was minimally invasive and reliable. This procedure can be effective for the treatment of lesions found in deep locations such as the pelvic bone and proximal femur or an invisible lesion that cannot be detected by regular fluoroscopy.

Efficacy and User Experience of a Novel X-Ray Shield on Operator Radiation Exposure During Cardiac Catheterization: A Randomized Controlled Trial.

BACKGROUND: Radiation shielding is mandatory during cardiac catheterization, but there is a need to improve efficacy and ease of use. METHODS: The aim of the study was to assess the shielding effect and user feedback for a novel flexible multiconfiguration x-ray shield (FMX). The 0.5-mm Pb equivalent FMX can be selectively configured to accommodate for variations in patient morphology, access site, and type of procedure with maintained visualization, vascular access, and shielding. To evaluate efficacy, relative operator dose (operator dose indexed for given dose) was measured during 103 consecutive procedures randomized in a 1:1 proportion to the current routine setup or FMX+routine. User feedback was collected on function, relevance, and likelihood of adoption into clinical practice. RESULTS: Median relative operator dose was 3.63 µSv/µGy·m2×10-3 (IQR, 2.62-6.37) with routine setup and 0.57 µSv/µGy·m2×10-3 (IQR, 0.27-1.06) with FMX+routine, which amounts to an 84.4% reduction (P<0.001). For 500 procedures/year, this corresponds to an estimated yearly dose reduction from 3.6 to 0.7 mSv. User feedback regarding size, functionality, ease of use, likely to use, critical issues, shielding, draping, procedure time, vascular access, patient discomfort, and risk was 99% positive. No critical issues were identified. There was no significant difference in patient radiation exposure. CONCLUSIONS: The FMX reduces radiation exposure considerably. The FMX represents an effective and attractive solution for radiation protection that can easily be implemented in existing workflow. FMX has potential for general use with maintained visualization, vascular access, and shielding in routine cardiac catheterization.