The addition of a leaded arm sleeve to leaded aprons further decreases operator upper outer quadrant chest wall radiation dose during fluoroscopically guided interventions

OBJECTIVE

Breast cancer most commonly occurs in the upper outer quadrant (UOQ) chest wall (CW). The effectiveness of routine leaded aprons to protect this region of the body in interventionalists during fluoroscopically guided interventions (FGIs) is unknown. Given the high lifetime attributable risks of prolonged occupational exposure to ionizing radiation and the increasing number of practicing female vascular surgeons and interventionalists, we sought to determine if the use of a leaded arm shield would offer additional protection to the lateral CW and axilla in operators compared with routine leaded aprons.

METHODS

Effectiveness of leaded sleeves in attenuating radiation dose to the axilla and UOQ was evaluated in clinical practice and simulated scenarios. In the clinical setting, optically stimulated luminescence nanoDot detectors were placed at the UOQ lateral CW position, both over and under a standard leaded apron vest with and without the addition of an antimony/bismuth Enviro-Lite sleeve on two vascular surgeons performing FGIs. In the simulation, nanoDots were similarly placed on an anthropomorphic phantom positioned to represent a primary operator performing right femoral access. Fluorography was performed on 12-inch-thick acrylic scatter phantom at 80 kVp for an exposure of 3 Gy reference air kerma. Experiments were done with and without the sleeve. Paired Wilcoxon and χ2 tests were performed to identify the statistical significance of radiation attenuation.

RESULTS

Operator UOQ CW dose was measured during 61 FGIs: 33 cases (54%) with and 28 cases (46%) without the sleeve. Median procedure reference air kerma and fluoroscopy time was 180 mGy (interquartile range [IQR], 85-447 mGy) and 21 minutes (IQR, 11-39 minutes) when the sleeve was worn vs 100 mGy (IQR, 67-270 mGy) and 11 minutes (IQR, 6.3-25 minutes) without the sleeve. Radiation dose to the operator's UOQ was reduced by 96% (IQR, 85%-96%) when the sleeve was present and by 62% (IQR, 44%-82%; P < .001) without the sleeve. In the simulated setting, the sleeve reduced the radiation dose to the UOQ compared with the apron alone (96% vs 67%; P < .001).

CONCLUSIONS

Routine leaded aprons do attenuate the majority of UOQ chest wall radiation dose; however, the addition of a lead-equivalent sleeve further significantly reduces this dose. Because this area of the body has a high incidence of cancer formation, additional protection, especially to female interventionalists, seems prudent. Vascular surgeons should consider using a protective sleeve with their personal protective equipment when performing complex fluoroscopically guided procedures.

Fusion Imaging Guidance Does Not Affect Radiation Exposure During Endovascular Procedures for Lower Extremity Arterial Disease: A Randomized Controlled Trial

PURPOSE

Radiation exposure for vascular interventionalists is still a concern. The aim of this study was to assess the value of advanced imaging guidance on radiation exposure and iodinated contrast volume during endovascular treatment of lower extremity arterial disease (LEAD).

MATERIALS AND METHODS

It was a prospective, randomized, monocentric, pilot, single-operator study, conducted from June 2018 to October 2019. Consecutive patients requiring a preoperative computed tomography angiography (CTA) for a symptomatic LEAD and scheduled for an iliac and/or femoropopliteal endovascular repair in a hybrid room were included. Patients were randomly assigned to the use of fusion imaging guidance (Vessel Navigator®, Philips) or not. The primary endpoint was the dose area product (DAP, Gy.cm²). Secondary endpoints were DAP for fluoroscopy, DAP for fluorography, Air Kerma, fluoroscopy time, volume of contrast, and number of digital subtraction angiography (DSA). Data were expressed in median [Q1-Q3].

RESULTS

In all, 64 of the 77 patients enrolled (34 in fusion group, 30 in control group, 82% men, 65.8 years [61-71]) were included. Groups were similar in terms of comorbidities, BMI (26 kg/cm2 [24-28]), but lesion location were not equally distributed (p=0.004). There was no significant difference between the groups regarding DAP (31.6 Gy.cm2 [23.4; 46.9] for fusion group vs 25.6[16.9; 34.0] Gy.cm2; p=0.07), Air Kerma (160 mGy [96;3365] vs 115 mGy [76;201]; p=0.12, fluoroscopy time (560 seconds [326;960] vs 454 seconds [228;1022]; p=0.44), contrast volume (60 ml [42;80] vs 50 ml [40;66]; p=0.10), or operative time (68 minutes [55;90] vs 46 minutes [30;80]; p=0.06). The median number of DSA was 14 [10-18] in the fusion group versus 11 [6-18]; p=0.049.

CONCLUSION

Fusion imaging guidance does not affect radiation exposure and contrast volume during endovascular revascularisation of iliac and femoropopliteal occlusive disease in a hybrid room environment.

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.

Computed Tomography-Guided Microcoil Localization of Pulmonary Nodules: Effects of Multiple Punctures

BACKGROUND

The aim of the study is to analyze the effect of multiple punctures in computed tomography (CT)-guided microcoil localization of pulmonary nodules with other risk factors for common complications.

METHODS

Consecutive patients who underwent CT-guided microcoil localization and subsequent video-assisted thoracoscopic surgery (VATS) between January 2020 and February 2021 were enrolled. Nodules successfully located after only one puncture were defined as the single puncture group, and nodules requiring two or more punctures were defined as the multiple puncture group. Binary logistic regression analysis was performed to assess the relationship between the number of punctures and pneumothorax and intrapulmonary hemorrhage.

RESULTS

A total of 121 patients were included. There were 98 (68.1%) pulmonary nodules in the single puncture group compared with 46 (31.9%) nodules in the multiple puncture group. The frequencies of pneumothorax and intrapulmonary hemorrhage were higher in the multiple puncture group than in the single puncture group (p = 0.019 and <0.001, respectively). Binary logistic regression demonstrated that independent risk factors for developing pneumothorax included lateral positioning of the patient (p < .001) and prone positioning (p = 0.014), as well as multiple punctures (p = 0.013). Independent risk factors for intrapulmonary hemorrhage included the distance between the distal end of the coil and the surface of the pleura (p = 0.033), multiple punctures (p = 0.003), and passage through the pulmonary vasculature (p < 0.001).

CONCLUSION

Multiple punctures resulted in an increased incidence of pneumothorax and intrapulmonary hemorrhage compared with single puncture during CT-guided microcoil localization of pulmonary nodules and were independently associated with both pneumothorax and intrapulmonary hemorrhage.

Risk factors for air embolism following computed tomography-guided percutaneous transthoracic needle biopsy: a systematic review and meta-analysis

To quantitatively analyze the risk factors for air embolism following computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) and qualitatively review their characteristics. The databases of PubMed, Embase, Web of Science, Wanfang Data, VIP information, and China National Knowledge Infrastructure were searched on January 4, 2021, for studies reporting the occurrence of air embolisms following CT-guided PTNB. After study selection, data extraction, and quality assessment, the characteristics of the included cases were qualitatively and quantitatively analyzed. A total of 154 cases of air embolism following CT-guided PTNB were reported. The reported incidence was 0.06% to 4.80%, and 35 (22.73%) patients were asymptomatic. An unconscious or unresponsive state was the most common symptom (29.87%). Air was most commonly found in the left ventricle (44.81%), and 104 (67.53%) patients recovered without sequelae. Air location (P < 0.001), emphysema (P = 0.061), and cough (P = 0.076) were associated with clinical symptoms. Air location (P = 0.015) and symptoms (P < 0.001) were significantly associated with prognosis. Lesion location [odds ratio (OR): 1.85, P = 0.017], lesion subtype (OR: 3.78, P = 0.01), pneumothorax (OR: 2.16, P = 0.003), hemorrhage (OR: 3.20, P < 0.001), and lesions located above the left atrium (OR: 4.35, P = 0.042) were significant risk factors for air embolism. Based on the current evidence, a subsolid lesion, being located in the lower lobe, the presence of pneumothorax or hemorrhage, and lesions located above the left atrium were significant risk factors for air embolism.

Patient Radiation Doses in IR Procedures: The American College of Radiology Dose Index Registry-Fluoroscopy Pilot

PURPOSE

To update normative data on fluoroscopy dose indices in the United States for the first time since the Radiation Doses in Interventional Radiology study in the late 1990s.

MATERIALS AND METHODS

The Dose Index Registry-Fluoroscopy pilot study collected data from March 2018 through December 2019, with 50 fluoroscopes from 10 sites submitting data. Primary radiation dose indices including fluoroscopy time (FT), cumulative air kerma (Ka,r), and kerma area product (PKA) were collected for interventional radiology fluoroscopically guided interventional (FGI) procedures. Clinical facility procedure names were mapped to the American College of Radiology (ACR) common procedure lexicon. Distribution parameters including the 10th, 25th, 50th, 75th, 95th, and 99th percentiles were computed.

RESULTS

Dose indices were collected for 70,377 FGI procedures, with 50,501 ultimately eligible for analysis. Distribution parameters are reported for 100 ACR Common IDs. FT in minutes, Ka,r in mGy, and PKA in Gy-cm2 are reported in this study as (n; median) for select ACR Common IDs: inferior vena cava filter insertion (1,726; FT: 2.9; Ka,r: 55.8; PKA: 14.19); inferior vena cava filter removal (464; FT: 5.7; Ka,r: 178.6; PKA: 34.73); nephrostomy placement (2,037; FT: 4.1; Ka,r: 39.2; PKA: 6.61); percutaneous biliary drainage (952; FT: 12.4; Ka,r: 160.5; PKA: 21.32); gastrostomy placement (1,643; FT: 3.2; Ka,r: 29.1; PKA: 7.29); and transjugular intrahepatic portosystemic shunt placement (327; FT: 34.8; Ka,r: 813.0; PKA: 181.47).

CONCLUSIONS

The ACR DIR-Fluoro pilot has provided state-of-the-practice statistics for radiation dose indices from IR FGI procedures. These data can be used to prioritize procedures for radiation optimization, as demonstrated in this work.

Interventional cardiology and X-ray exposure of the head: overview of clinical evidence and practical implications

Interventional cardiologists are significantly exposed to X- rays and no dose of radiation may be considered well tolerated or harmless. Leaded aprons protect the trunk and the thyroid gland, leaded glasses protect the eyes. The operator's legs, arms, neck and head are, instead, not fully protected. In fact, the operator's brain remains the closest part to the primary X-ray beam and scatter in most interventional procedures and specifically the physician's front head is the most exposed region during device implantation performed at the patient's side. After the initial description of cases of brain and neck tumours, additional reports on head and neck malignancies have been published. Although a direct link between operator radiation exposure and brain cancer has not been established, these reports have heightened awareness of a potential association. The use of lead-based cranial dedicated shields may help reduce operator exposure but upward scattered radiation, weight and poor tolerability have raised concerns and hindered widespread acceptance. The purpose of this review is to describe current knowledge on occupational X-ray exposure of interventional cardiologists, with a special focus on the potential risks for the head and neck and efficacy of available protection devices.

Radiation Exposure in Pediatric Interventional Procedures

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. The expanding applications of interventional procedures coupled with the potential harmful effects of ionizing radiation highlight the need to assess the delivered radiation dose and establish an effective radiation protection program, particularly in the radiosensitive pediatric population. Given the complexity and heterogeneity of interventional procedures as well as the unique characteristics of children, the management of radiation dose is proving to be quite challenging. The aim of the current article is to provide an overview of the radiation exposure in pediatric patients during interventional procedures focusing on the importance of radiation protection in the pediatric population, the reported radiation doses and the techniques of minimizing radiation dose.

Ovarian Vein Embolization: How and When Should It Be Done?

Pelvic Venous Disease (PeVD) is characterized by pelvic varicosities and chronic pelvic pain, defined as noncyclic pelvic pain that persists for more than 6 months. Pain and discomfort related to PeVD typically worsen with upright positioning and occur more frequently in multiparous and premenopausal women. The most common cause of PeVD is pelvic venous insufficiency (PVI) due to incompetent valves. Noninvasive imaging modalities such as ultrasound, computed tomography, or magnetic resonance imaging, and invasive catheter-based venography can help characterize varicosities and venous insufficiency, supporting the diagnosis of PeVD. In patients with PeVD, ovarian and/or internal iliac vein embolization demonstrate excellent technical and clinical success rates with relatively low complication rates and should be considered as standard management, in conjunction with medical therapy. Appropriate diagnostic work-up and patient selection are important prior to any intervention for achieving therapeutic success, as multiparous women have a higher success rate compared to patients with dyspareunia after embolization therapy. Post-procedure follow-up is critical for assessing symptom improvement and need for repeat intervention. However, further research is needed to identify additional predictors of successful outcomes after embolization therapy. This article aims to provide an overview of patient selection, interventional technique, challenges, and outcomes of ovarian vein embolization.

Interventional Radiologist's Approach to Fallopian Tube Recanalization

Fallopian tube obstruction (FTO) is a common cause of female infertility. In the setting of proximal FTO, fallopian tube recanalization (FTR) is a minimally invasive, ambulatory procedure with a technical success rate of up to 100%, with minimal postprocedural adverse events. One-year pregnancy rate following FTR is approximately 41%, with successful delivery of full-term infants in 84% of pregnancies. This minimally invasive, outpatient, image-guided procedure is an alternative to vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) and should be top-of-mind in the setting of infertility due to proximal FTO.

Uterine Artery Embolization for Secondary Postpartum Hemorrhage

Postpartum hemorrhage (PPH) affects approximately 14 million women yearly, accounts for 25% of delivery-related deaths in the world and is the main cause of emergency peripartum hysterectomy. Traditionally, PPH is defined as at least 500 mL of blood loss after vaginal delivery or 1000 mL of blood loss after cesarean-section. However, several authors have suggested a simpler definition to include women who experience hemodynamic instability after birth regardless of amount of blood loss. Secondary PPH is defined as bleeding that occurs after 24 hours to 12 weeks from delivery, and can fail medical management. It is imperative that the clinical team recognize the signs and symptoms of secondary PPH and, if necessary, consult the interventional radiology service for a minimally invasive option of uterine artery embolization, which has shown up to 95% success rate.

Percutaneous Image-Guided Core Needle Biopsy of Neuroendocrine Tumors: How Common Is Intraprocedural Carcinoid Crisis?

PURPOSE

To retrospectively evaluate the incidence of carcinoid crisis, other complications, and physiologic disturbances during percutaneous image-guided core needle biopsy of neuroendocrine tumors (NETs) in the lung and the liver.

MATERIALS AND METHODS

Between January 2010 and January 2020, 106 computed tomography (CT) or ultrasound (US)-guided core needle biopsies of lung and liver NETs were performed in 95 consecutive adult patients. The mean age was 64 ± 13 years, and 48% were female. The small bowel was the most common primary site (33%, 31/95), and 32 (34%) patients had pre-existing symptoms of carcinoid syndrome. The mean tumor size was 3.2 ± 2.6 cm, and mean number of passes was 3.4 ± 1.6. A 17/18-gauge needle was used in 91% (96/106) of the biopsies. Thirteen (12%) patients received either outpatient or prophylactic octreotide.

RESULTS

No patients experienced carcinoid crisis or needed octreotide, inotropes, vasopressors, or resuscitation. A single biopsy procedure (0.9%, 1/106) was complicated by bleeding that required angiographic hepatic artery embolization. Changes in pre-biopsy- versus post-biopsy systolic blood pressure and heart rate were -1.6 mm Hg (P = .390) and 0.6 beat/min (P = .431), respectively. Tumor functional status, overall tumor burden, and the elevation of neuroendocrine markers were not associated with intraprocedural physiologic disturbances. There were 4 minor complications (0.4%, 4/106) associated with the biopsy procedure that were not attributed to hormone excretion from tumor manipulation.

CONCLUSIONS

Percutaneous image-guided core biopsy of NETs is safe, with low complication rate and no definite carcinoid crisis in the current cohort.

Improving IR Ergonomics Using a Flexible C-Arm System

PURPOSE

To evaluate the impact of a versatile flexible ceiling-mounted C-arm on active table and gantry repositioning during interventions and its effect on operator discomfort, system usability, and patient safety compared with a traditional ceiling-mounted system.

MATERIALS AND METHODS

There were 100 IR procedures studied: 50 in a traditional IR system (standard group) and 50 with a novel multiaxis ceiling-mounted system (test group). FlexArm was capable of multiple gantry rotation points allowing increased access to the patient in addition to 236 cm of lateral x-ray detector travel. For each procedure, both the table and the gantry repositioning were measured. Patient safety, patient/equipment repositioning effort, and physical discomfort were evaluated through an operator survey.

RESULTS

Table repositioning was reduced from 42 to 16 instances per procedure (P < .001) in the test group compared with the standard group. The operators perceived less table and gantry repositioning effort (P < .0001) and decreased risks of equipment collisions, displacement of vascular access, and dislodgment of tubes/lines with the test group (P < .0001). Operator discomfort was reduced for all body areas in the test group over the standard group (P < .0001).

CONCLUSIONS

The FlexArm system geometry enhances operator ergonomics, as there was a decrease need to move the table, leading to a perceived decrease in patient risk and decrease operator physical discomfort when compared to a traditional imaging system.

CT Fluoroscopy for Image-Guided Procedures: Physician Radiation Dose During Full-Rotation and Partial-Angle CT Scanning

PURPOSE

To determine physician radiation exposure when using partial-angle computed tomography (CT) fluoroscopy (PACT) vs conventional full-rotation CT and whether there is an optimal tube/detector position at which physician dose is minimized.

MATERIALS AND METHODS

Physician radiation dose (entrance air kerma) was measured for full-rotation CT (360°) and PACT (240°) at all tube/detector positions using a human-mimicking phantom placed in a 64-channel multidetector CT. Parameters included 120 kV, 20- and 40-mm collimation, and 100 mA. The mean, standard deviation, and increase/decrease in physician dose compared with a full-rotation scan were reported.

RESULTS

Physician radiation exposure during CT fluoroscopy with PACT was highly dependent on the position of the tube/detector during scanning. The lowest PACT physician dose was when the physician was on the detector side (center view angle 116°; -35% decreased dose vs full-angle CT). The highest PACT physician dose was with the physician on the tube side (center view angle 298°; +34% increased dose vs full-angle CT), all doses P <.05 vs full-rotation CT.

CONCLUSIONS

Partial-angle CT has the potential to both significantly increase or decrease physician radiation dose during CT fluoroscopy-guided procedures. The detector/tube position has a profound effect on physician dose. The lowest dose during PACT was achieved when the physician was located on the detector side (ie, distant from the tube). This data could be used to optimize CT fluoroscopy parameters to reduce physician radiation exposure for PACT-capable scanners.

Helping to know if you are properly protected while working in interventional cardiology

Occupational protection is still a challenge for interventional cardiology. One of the main problems is the occasional improper use of the ceiling suspended screen. We present a methodology to audit the correct use of the shielding using active electronic dosimeters. To improve the protection, we suggest the use of an alert based on the ratio between the occupational dose per procedure, measured by a personal electronic dosimeter over the lead apron, and the dose measured by an unshielded dosimeter, located at the C-arm. The new electronic dosimeters and the automatic dose management systems allow processing the dosimetric data for individual procedures and for the radiation events, sending the values (wireless) to a central database. We selected six interventional cardiologists and analysed 385 interventional procedures involving about 30 000 radiation events. Our results suggest that for individual procedures, standard values of the ratio between operator dose and the C-arm reference dose, should be between 1%-2% for a proper use of the shielding. Percentage values ≥5%-10% for individual procedures, require an analysis of the different radiation events to identify the lack of occupational protection and suggest corrective actions. In our sample, half of the operators should improve the use of the shielding in around 20% of the procedures. Using this ratio as an alert to operators allows optimising occupational radiation protection and discriminating between high occupational doses derived from complex procedures and high doses due to the improper use of the protective screen.

Interventional Cryoneurolysis: An Illustrative Approach

The application of advanced imaging guidance and the interventional radiology skill set has expanded the breadth of nerve and nerve plexus targets in the body for potential cryoneurolysis. Advancement of the basic science supporting cryoneurolysis has further solidified proceduralists' confidence and ability to select and manage patients clinically. As these procedures continue to evolve, a structured approach to the wide variety of indications is necessary.

Prostatic Artery Embolization in Refractory Hematuria of Prostatic Origin

Hematuria of prostatic origin has multiple etiologies including benign prostatic hyperplasia (BPH), iatrogenic urological trauma, prostate cancer, and radiation therapy. Hematuria secondary to benign prostatic hyperplasia can occur because of the increased vascularity of the primary gland, itself, or because of the vascular re-growth following a transurethral resection of the prostate. Prostatic hematuria usually resolves with conservative measures; however, refractory hematuria of prostatic origin may require hospitalization with treatment with blood transfusions, repeated indwelling urinary catheterization, and continuous bladder irrigation. Prostate artery embolization is an emerging minimally invasive procedural therapy for men with BPH that was originally utilized for the treatment of refractory hematuria of prostatic origin . This article aims to summarize the currently available evidence around prostate artery embolization for the treatment of refractory hematuria of prostatic origin.

Cooled Radiofrequency Genicular Neurotomy

Knee osteoarthritis, a chronic degenerative condition, can be a debilitating and limiting process with affected patients presenting with symptoms such as pain, restrictive range of motion, and swelling. This condition commonly afflicts millions of people with a higher incidence among the elderly that results from chronic mechanical repetitive loading. The treatment of pain generating conditions such as arthritis in large joints is complex requiring interventions of varying focuses such as weight loss, anti-inflammatory medications, corticosteroid, hyaluronic and viscosupplementation injections, and prescription opioids. A gap in the treatment options of this ailment currently exists between short term pain solutions and surgical approaches such as total knee arthroplasty that may offer longer pain relief. Cooled radiofrequency ablation is an emerging technique that offers a minimally invasive alternative for treating knee pain with a clinical relevance in patients who are not surgical candidates due to coexistent medical comorbidities or those who are undesiring of surgery. This procedure uses radiofrequency ablation that blocks genicular nerves from transmitting knee pain signals to the brain. Further research will allow the application of this technique to treat other sensory nerves in large joints such as the hip and shoulder.

Intra-procedural three-dimensional rotational angiography in cryoballoon ablation for atrial fibrillation

Cryoballoon (CB) is an established technology for atrial fibrillation (AF) ablation and is usually performed using solely fluoroscopy. We aimed to study the feasibility of three-dimensional rotational angiography (3DRA) as intra-procedural imaging in CB ablation. Analyzed data were retrospectively collected from patients that underwent second generation CB ablation from February 2015 to August 2017. We studied 68 consecutive patients that received 3DRA (3DRA group). Sixty-six patients who received conventional X-ray imaging served as a control group. 3DRA was performed via an introducer placed in the left atrium. Angiographic images were segmented and fused with live fluoroscopy to guide the ablation. We have analyzed 134 CB patients (73.8% male, 56.9 ± 11.4 years). Paroxysmal AF was present in 77.6% of patients. 3DRA was successfully performed in all 3DRA group patients. The mean procedure time was significantly shorter in the control group (82.4 ± 26.3 min) than in the 3DRA group (121.1 ± 21.4 min) (p < 0.0001). Total radiation dose (419.3 ± 317.9 vs 998.3 ± 673 mGy, p < 0.0001) and contrast administration (83.2 ± 22.3 mL vs 191.6 ± 33.4 mL, p < 0.0001) were significantly lower in control group. There was no significant difference in 2-year success rate, 35.2% of patients had AF recurrence in the 3DRA group and 30.3% in the control group (p = 0.584). Major complications occurred in 2.9% and 1.5% of patients in 3DRA group and control group, respectively (p = 1.000). 3DRA is a feasible method of intra-procedural imaging to guide CB ablation. However, it prolongs procedure time, increases radiation dose and contrast administration with no significant effect on procedure outcomes and complication rates.

Fusion Imaging with a Mobile C-Arm for Peripheral Arterial Disease

BACKGROUND

Fusion imaging makes it possible to improve endovascular procedures and is mainly used in hybrid rooms for aortic procedures. The objective of this study was to evaluate the feasibility of fusion imaging for femoropopliteal endovascular procedures with a mobile flat plane sensor and dedicated software to assist endovascular navigation.

MATERIALS AND METHODS

Between May and December 2017, 41 patients requiring femoropopliteal endovascular revascularization were included. Interventions were carried out in a conventional surgical room equipped with a mobile plane sensor (Cios Alpha, Siemens). The numerical video stream was transmitted to an angionavigation station (EndoNaut (EN), Therenva). The software created an osseous and arterial panorama of the treated limb from the angiographies carried out at the beginning of procedure. After each displacement of the table, the software relocated the current image on the osseous panorama, with 2D-2D resetting, and amalgamated the mask of the arterial panorama. The success rates of creation of osseous and arterial panorama and the success of relocation were evaluated. The data concerning irradiation, the volume of contrast (VC) injected, and operative times were recorded.

RESULTS

Osseous panoramas could be automatically generated for the 41 procedures, without manual adjustment in 33 cases (80.5%). About 35 relocations based on a 2D-2D resetting could be obtained in the 41 procedures, with a success rate of 85%. The causes of failure were a change in table height or arch angulation. The average duration of intervention was 74.5 min. The irradiation parameters were duration of fluoroscopy 17.8 ± 13.1 min, air kerma 80.5 ± 68.4 mGy, and dose area product 2140 ± 1599 μGy m². The average VC was 24.5 ± 14 mL.

CONCLUSIONS

This preliminary study showed that fusion imaging is possible in a nonhybrid room for peripheral procedures. Imagery of mobile C-arms can be improved for femoropopliteal endovascular procedures without heavy equipment. These imagery tools bring an operative comfort and could probably reduce irradiation and the injected VC. The clinical benefit must be evaluated in more patients in a randomized comparative study with a rigorous methodology.

Assessment of Eye Lens Dose Reduction When Using Lateral Lead Shields on the Patient's Head during Neurointerventional Fluoroscopic Procedures and Cone-beam Computed Tomography (CBCT) Scans

The purpose of this study was to evaluate the effect of placing small lead shields on the temple region of the skull to reduce radiation dose to the lens of the eye during interventional fluoroscopically-guided procedures and cone-beam computed tomography (CBCT) scans of the head. EGSnrc Monte-Carlo code was used to determine the eye lens dose reduction when using lateral lead shields for single x-ray projections, CBCT scans with different protocols, and interventional neuroradiology procedures with the Zubal computational head phantom. A clinical C-Arm system was used to take radiographic projections and CBCT scans of anthropomorphic head phantoms without and with lead patches, and the images were compared to assess the effect of the shields. For single lateral projections, a 0.1 (0.3)-mm-thick lead patch reduced the dose to the left-eye lens by 40% to 60% (55% to 80%) from 45° to 90° RAO and to the right-eye lens by around 30% (55%) from 70° to 90° RAO. For different CBCT protocols, the reduction of lens dose with a 0.3-mm-thick lead patch ranged from 20% to 53% at 110 kVp. For CBCT scans of the anthropomorphic phantom, the lead patch introduced streak artifacts that were mainly in the orbital regions but were insignificant in the brain region where most neurointerventional activity occurs. The dose to the patient's eye lens can be reduced considerably by placing small lead shields over the temple region of the head without substantially compromising image quality in neuro-imaging procedures.

Pneumothorax after CT-guided transthoracic lung biopsy: A comparison between immediate and delayed occurrence

Background

In CT-guided transthoracic lung biopsy (CTLB), pneumothorax can occur as a late complication (delayed pneumothorax). The incidence, risk factors, and clinical significance of delayed pneumothorax are not well known.

Objectives

To compare the risk factors for immediate and delayed pneumothorax after CTLB and to know their clinical significance.

Methods

Images and medical records of 536 consecutive patients who underwent CTLB were reviewed. All biopsies were performed as inpatient procedures. Follow-up chest radiographs were obtained at least twice at 4 h after procedure and before discharge. Risk factors for immediate and delayed pneumothorax were assessed based on patient-, lesion-, and procedure-related variables. Rates of chest tube insertion were also compared.

Results

Pneumothorax developed in 161 patients (30.0%) including 135 (25.2%) immediate and 26 (4.9%) delayed cases. Lesion size was an independent risk factor for both immediate and delayed pneumothorax (OR = 0.813; CI = 0.717–0.922 and OR = 0.610; CI = 0.441–0.844, respectively). While emphysema, lower lobe location, and long intrapulmonary biopsy track were risk factors (OR = 1.981; CI = 1.172–3.344, OR = 3.505; CI = 2.718–5.650, and OR = 1.330; CI = 1.132–1.563, respectively) for immediate pneumothorax, upper lobe location and increased number of pleural punctures were independent risk factors (OR = 5.756; CI = 1.634–20.274 and OR = 3.738; CI = 1.860–7.511, respectively) for delayed pneumothorax. The rate of chest tube insertion was significantly (p < 0.001) higher in delayed pneumothorax.

Conclusion

Pneumothorax tends to occur immediately after CTLB in patients with emphysema, lower lobe lesion, and long intrapulmonary biopsy track. Further attention and warnings are needed for those with multiple punctures of small lesions involving upper lobes due to the possibility of delayed development of pneumothorax and higher requirement for chest tube drainage.

Usefulness of an additional lead shielding device in reducing occupational radiation exposure during interventional endoscopic procedures: An observational study

Adoption of interventional endoscopic procedures is increasing with increasing prevalence of diseases. However, medical radiation exposure is concerning; therefore, radiation protection for medical staff is important. However, there is limited information on the usefulness of an additional lead shielding device during interventional endoscopic procedures. Therefore, we aimed to determine whether an additional lead shielding device protects medical staff from radiation.An X-ray unit (CUREVISTA; Hitachi Medical Systems, Tokyo, Japan) with an over-couch X-ray system was used. Fluoroscopy-associated scattered radiation was measured using a water phantom placed at the locations of the endoscopist, assistant, nurse, and clinical engineer. For each location, measurements were performed at the gonad and thyroid gland/eye levels. Comparisons were performed between with and without the additional lead shielding device and with and without a gap in the shielding device. Additionally, a clinical study was performed with 27 endoscopic retrograde cholangiopancreatography procedures.The scattered radiation dose was lower with than without additional lead shielding at all medical staff locations and decreased by 84.7%, 82.8%, 78.2%, and 83.7%, respectively, at the gonad level and by 89.2%, 86.4%, 91.2%, and 87.0%, respectively, at the thyroid gland/eye level. Additionally, the scattered radiation dose was lower without than with a gap in the shielding device at all locations.An additional lead shielding device could protect medical staff from radiation during interventional endoscopic procedures. However, gaps in protective equipment reduce effectiveness and should be eliminated.

Evaluation of protective equipment for the reduction of radiation exposure to physicians performing fluoroscopically guided lumbar transforaminal epidural steroid injections: A randomized controlled trial

BACKGROUND

Spine interventionists frequently employ fluoroscopy to guide injection procedures. The increase in fluoroscopically guided procedures in recent years has led to a growing concern about radiation exposure. A new method of covering the C-arm tube with a lead apron has been suggested to reduce radiation exposure. This study aimed to compare the radiation exposure when performing lumbar transforaminal epidural steroid injections (TFESIs) using this new method to a control group.

METHODS

A total of 200 patients who underwent lumbar TFESIs by a single physician were recruited. Patients were divided into 2 groups, the new method group (group A) and the control group (group C), and the amount of radiation exposure was compared. The dosimetry badge locations were marked as outside of apron, inside of apron, outside of thyroid collar, inside of thyroid collar, ring, and glasses.

RESULTS

The cumulative dose equivalents of all the measurement sites were reduced in group A compared with group C, and the most reduced site was inside the thyroid collar.

CONCLUSIONS

Covering the C-arm tube with a lead apron can be effective in reducing the cumulative radiation exposure when performing fluoroscopically guided TFESIs.

Liver Tumor Ablation Procedure Duration and Estimated Patient Radiation Dose: Comparing Positron Emission Tomography/CT and CT Guidance

PURPOSE

To compare procedure duration and patient radiation dose in positron emission tomography/computed tomography (PET/CT) and CT-guided liver tumor ablation procedures.

MATERIALS AND METHODS

In this retrospective, case-control study, 275 patients underwent 368 image-guided ablation procedures to treat 537 tumors. Radiologists used PET/CT guidance for 117 procedures and CT guidance for 251 procedures. PET/CT-guided procedures were performed by one radiologist (C: P.B.S.). All 3 radiologists (A: J.G.S., B: a radiologist who is not an author on this article, and C: P.B.S.) performed CT-guided procedures. Potential confounders included patient demographics, clinical and tumor characteristics, and procedural variables.

RESULTS

The mean duration and estimated patient radiation dose of PET/CT-guided procedures performed by radiologist C were 21.5 ± 4.9 minutes longer and 0.7 ± 2.8 mSv higher than CT-guided procedures performed by all radiologists in an unadjusted comparison. Adjusting for confounding, mean duration and estimated dose of PET/CT-guided procedures performed by radiologist C were 28.3 ± 3.8 minutes longer (P < .0001) and 6.2 ± 2.9 mSv higher (P = .03) than CT-guided procedures performed by the same radiologist. Comparing CT-guided procedures performed by all 3 radiologists, adjusted mean durations and estimated patient doses of procedures by the least experienced radiologist, radiologist A, and the second most experienced radiologist, radiologist B, were 24.2 ± 5.1 (P < .0001) and 18.1 ± 8.9 (P = .04) minutes longer and 13.1 ± 3.7 (P < .001) and 14.5 ± 6.4 (P = .02) mSv higher, respectively, than procedures performed by the most experienced radiologist, radiologist C.

CONCLUSIONS

PET/CT-guided liver ablations had a slightly longer duration with slightly higher estimated patient radiation dose than similar CT-guided liver ablations. Procedure duration and patient dose do not appear to be major impediments to the emerging field of PET/CT-guided tumor ablation.

Machine Learning Offers Exciting Potential for Predicting Postprocedural Outcomes: A Framework for Developing Random Forest Models in IR

PURPOSE

To demonstrate that random forest models trained on a large national sample can accurately predict relevant outcomes and may ultimately contribute to future clinical decision support tools in IR.

MATERIALS AND METHODS

Patient data from years 2012-2014 of the National Inpatient Sample were used to develop random forest machine learning models to predict iatrogenic pneumothorax after computed tomography-guided transthoracic biopsy (TTB), in-hospital mortality after transjugular intrahepatic portosystemic shunt (TIPS), and length of stay > 3 days after uterine artery embolization (UAE). Model performance was evaluated with area under the receiver operating characteristic curve (AUROC) and maximum F1 score. The threshold for AUROC significance was set at 0.75.

RESULTS

AUROC was 0.913 for the TTB model, 0.788 for the TIPS model, and 0.879 for the UAE model. Maximum F1 score was 0.532 for the TTB model, 0.357 for the TIPS model, and 0.700 for the UAE model. The TTB model had the highest AUROC, while the UAE model had the highest F1 score. All models met the criteria for AUROC significance.

CONCLUSIONS

This study demonstrates that machine learning models may suitably predict a variety of different clinically relevant outcomes, including procedure-specific complications, mortality, and length of stay. Performance of these models will improve as more high-quality IR data become available.

Novel modification to leaded eyewear results in significant operator eye radiation dose reduction

OBJECTIVE

Ocular radiation exposure from fluoroscopically guided interventions (FGIs) can cause cataracts. Standard lead eyewear may not significantly reduce eye radiation dose as the majority of scattered radiation penetrates the operator's eye obliquely. Our aim was to evaluate the efficacy of standard leaded eyewear and a customized eyewear design in lowering eye radiation dose to vascular surgeons.

METHODS

The attenuating efficacy of three forms of leaded eyewear (standard eyewear, eyewear with built-in leaded side shields, and our modified eyewear) was tested in both a simulated setting and clinical practice. The modified design consisted of safety eyewear with 0.75 mm of added lead shielding attached to the lateral and inferior borders of the eyewear frame to attenuate oblique radiation. We performed simulated experiments using an anthropomorphic head phantom (ATOM model 701; CIRS, Norfolk, Va) positioned to represent a primary operator performing right femoral access. Optically stimulated, luminescent nanoDot detectors (Landauer, Glenwood, Ill) were placed inside the phantom's ocular spaces and at the surface of the left eye within and outside the leaded glasses to measure the eye radiation dose reduction provided by each eyewear type. All three eyewear types were also tested during clinical FGIs by placing nanoDots below the operator's left eye, inside and outside of the eyewear coverage. Means and standard errors were calculated using a pooled linear mixed model with repeated measurements.

RESULTS

This prospective, single-center study included 60 FGIs, 30 with traditional eyewear and 30 with our modified design. There was no significant eye radiation dose reduction (P > .05) with the standard eyewear or leaded side shield eyewear in both the simulated and clinical settings. In the simulated environment, our modified design resulted in an 86% radiation dose reduction to the surface of the left eye and an 80% reduction in left lens radiation dose (P < .0001). In the clinical FGIs, the modified eyewear led to a 62% left ocular radiation dose reduction (P < .0001).

CONCLUSIONS

Standard lead-equivalent glasses are ineffective at reducing ocular radiation dose during FGIs. Eyewear modification with lateral and inferior lead shielding molded to the operator's face significantly decreases radiation exposure to the eye closest to the X-ray source.

CT-Guided Percutaneous Drainage Catheter Placement in the Abdomen and Pelvis: Predictors of Outcome and Protocol for Follow-up

PURPOSE

To determine predictors of outcomes for patients who undergo computed tomography (CT)-guided percutaneous abdominal or pelvic drainage catheter placement and to identify which patients benefit from fluoroscopic drainage catheter interrogation (abscessogram).

MATERIALS AND METHODS

A retrospective review of 383 patients (mean, 52 years old; range 8-89 years old; 158 males: 225 females) who underwent 442 CT-guided procedures and 489 catheter placements for fluid collections in the abdomen or pelvis from January 1, 2015, to December 31, 2016 was performed. Variables including underlying disease, fluid location, number of collections drained, number of catheter exchanges and follow-up abscessograms performed, catheter size, and fistula detection were analyzed to determine factors associated with fistula formation and increased catheter dwell time.

RESULTS

A single abscessogram followed by catheter removal was performed for 217 catheters (44%). An increased number of abscessograms was significantly associated with drainage catheter size (P < .001) and presence of a fistula (P < .001). Fistulae were detected in 95 cases (19%) and were significantly associated with an increased number of drain exchanges (P < .001) and an underlying diagnosis of Crohn's disease (P = .02). Based on these data, a clinical algorithm for drain management is presented.

CONCLUSIONS

Abscessograms performed after CT-guided percutaneous drainage catheter placement are useful to detect catheter malposition, occluded catheters, and fistulae but are not necessary for all patients. If performed selectively, particularly in patients with an underlying diagnosis of Crohn's disease or those at high risk for developing fistulae, unnecessary examinations can be avoided, reducing cost, extra hospital visits, and radiation dose.

REDUCTION OF STAFF RADIATION DOSE IN PROSTATIC ARTERY EMBOLISATION

Prostatic artery embolisation (PAE) is used to treat patients with benign prostatic hyperplasia and with lower urinary obstructive tract symptoms. It is an interventional procedure which uses fluoroscopy equipment and can result in exposure to high doses of radiation in patients and staff. We aimed to demonstrate the reduction of radiation doses received by staff during PAE by implementing an optimised protocol called Radiation Exposure Curtailment for Embolisation (RECiFE). This protocol was implemented in cooperation with the medical team and technical team using Siemens Combined Applications to Reduce Exposure (CARE) protocol. The results showed approximately 83% reduction in the radiation doses received by the main physician during PAE. Thus, by adjusting the acquisition parameters of the angiographic equipment and implementing the RECiFE protocol, it is possible to optimise the PAE procedure and reduce the staff radiation dose.

IMPACT OF PELVIC AND RAD-BOARD LEAD SHIELDS ON OPERATOR AND PATIENT RADIATION DOSE IN TRANS-RADIAL CORONARY PROCEDURES

BACKGROUND

Trans-radial approach for cardiac catheterisation procedures has long been associated with high operator and patient radiation dose. The aim of the present study was to determine the effect of pelvic and radial shields on decreasing coronary procedure radiation doses.

METHODS

A total of 418 patients randomly underwent diagnostic and therapeutic cardiac procedures with and without the pelvic and rad-board lead shields during the procedures. The operator and patient doses were then determined by means of a personal dosimeter and dose area product (DAP), respectively.

RESULTS

The shields decreased the operator radiation dose by 40% in coronary angiography (CA) and by 45% during angioplasty (PCI). These results were achieved at the cost of increased patient radiation dose.

CONCLUSION

Pelvic lead shields combined with rad-board shields are highly effective in reducing operator radiation dose in trans-radial approach, but it is only achieved at the cost of increased patient DAP.

Multicenter experience in translumbar type II endoleak treatment in the hybrid room with needle trajectory planning and fusion guidance

OBJECTIVE

The objective of this study was to evaluate the efficacy of treating type II endoleaks (T2Ls) after aortic endovascular repair with image guidance translumbar puncture using intraoperative cone beam computed tomography with preprocedure computed tomography angiography fusion in hybrid operating rooms.

METHODS

Twenty-six consecutive T2L patients in three different institutions were treated between March 2015 and September 2017 by direct translumbar puncture of the abdominal aortic aneurysm (AAA) sac after previous endovascular aortic repair. All patients were treated at a single setting in a cardiovascular hybrid operating room with a workstation featuring needle trajectory planning and guidance software. Aneurysm sac size change from the index treatment, freedom from recurrent endoleak after treatment, demographics, risk factors, and procedure factors were analyzed with univariate analysis.

RESULTS

All patients (N = 26; 19 male, 7 female; age range, 59-95 years; mean body mass index, 27.44 ± 3.06 kg/m²) underwent treatment for AAA sac expansion or symptoms. Four patients had failed to respond to previous catheter-directed T2L treatment. The most common risk factors included hypertension, hypercholesterolemia, coronary artery disease, tobacco use, and diabetes. Time to initial endoleak diagnosis ranged from 2 to 1914 days (average, 404 days). Aneurysm size after initial repair was 60.3 ± 7.5 mm; sac size had increased 10.1 ± 6.5 mm at the time of treatment. Onyx (Medtronic, Irvine, Calif) or glue (n-butyl cyanoacrylate) and coil embolization was used in 20 cases, and 6 patients were treated with coiling alone. There was no difference between the patients treated with coils alone and those treated with coils or glue (P > .05) in terms of freedom from failure. Total procedure time was 75.9 ± 40.7 minutes; contrast material volume, 19.9 ± 29 mL; fluoroscopy time, 13.74 ± 12.2 minutes; and radiation dose, 121.16 ± 167.7 mGy. After embolization, the mean sac diameter decreased by 2.2 mm to 67.5 ± 9.8 mm. Average follow-up period was 214 days. In 19 patients, the sac reduced in size between 0.2 and 19.1 mm per 100 days; in 2 patients, there was continued AAA expansion (3.4-4.3 mm per 100 days); there was no change in the sac size in 5 patients after the procedure. There were no AAA ruptures during the study period. Once T2L was treated, the recurrence rate was low at 11.5%.

CONCLUSIONS

This initial multicenter evaluation of the effectiveness of fusion image-guided translumbar obliteration of T2L demonstrated that the technique was effective at all three study centers and showed excellent efficacy to reduce AAA sac size. This may become a more effective and efficient method of treating T2L compared with transarterial or transcaval embolization because of its high success rate and technical ease.

X-ray fused with MRI guidance of pre-selected transcatheter congenital heart disease interventions

OBJECTIVES

To determine whether X-ray fused with MRI (XFM) is beneficial for select transcatheter congenital heart disease interventions.

BACKGROUND

Complex transcatheter interventions often require three-dimensional (3D) soft tissue imaging guidance. Fusion imaging with live X-ray fluoroscopy can potentially improve and simplify procedures.

METHODS

Patients referred for select congenital heart disease interventions were prospectively enrolled. Cardiac MRI data was overlaid on live fluoroscopy for procedural guidance. Likert scale operator assessments of value were recorded. Fluoroscopy time, radiation exposure, contrast dose, and procedure time were compared to matched cases from our institutional experience.

RESULTS

Forty-six patients were enrolled. Pre-catheterization, same day cardiac MRI findings indicated intervention should be deferred in nine patients. XFM-guided cardiac catheterization was performed in 37 (median age 8.7 years [0.5-63 years]; median weight 28 kg [5.6-110 kg]) with the following prespecified indications: pulmonary artery (PA) stenosis (n = 13), aortic coarctation (n = 12), conduit stenosis/insufficiency (n = 9), and ventricular septal defect (n = 3). Diagnostic catheterization showed intervention was not indicated in 12 additional cases. XFM-guided intervention was performed in the remaining 25. Fluoroscopy time was shorter for XFM-guided intervention cases compared to matched controls. There was no significant difference in radiation dose area product, contrast volume, or procedure time. Operator Likert scores indicated XFM provided useful soft tissue guidance in all cases and was never misleading.

CONCLUSIONS

XFM provides operators with meaningful three-dimensional soft tissue data and reduces fluoroscopy time in select congenital heart disease interventions.

Cone-Beam CT-Guided Chemoembolization in Patients with Complete Response after Previous Chemoembolization but Subsequent Elevated α-Fetoprotein without Overt Hepatocellular Carcinoma

PURPOSE

To evaluate the performance of C-arm computed tomography (CT)-guided chemoembolization in patients with hepatocellular carcinoma (HCC) with serum α-fetoprotein (AFP) level > 20 ng/mL but with no overt tumor on CT and/or magnetic resonance imaging.

MATERIALS AND METHODS

From May 2010 to May 2017, 34 patients with HCC (25 men and 9 women; mean age, 59.7 y) who had elevated serum AFP levels (> 20 ng/mL) but no overt tumor on 6-mo imaging studies and had shown complete response (CR) after previous chemoembolization underwent C-arm CT-guided conventional chemoembolization. Three radiologists retrospectively reviewed the imaging studies (preprocedural images, C-arm CT scans, and follow-up images) in consensus, and clinical data including AFP levels were retrospectively obtained. Tumor detection by C-arm CT and treatment response after chemoembolization were assessed.

RESULTS

HCC was imaged at the time of chemoembolization in 24 of 34 patients (70.6%). C-arm CT detected tumors in 25 patients (73.5%); 23 detections were true positives, 2 were false positives, and 1 was a false negative (diaphragm metastasis). Among the 23 patients with true-positive results, the first follow-up enhanced imaging studies showed CR (n = 17), partial response (n = 1), progressive disease (n = 4), and indeterminate status (n = 1; treated by percutaneous ethanol injection).

CONCLUSIONS

C-arm CT-guided chemoembolization may help to detect and treat recurrent tumors in patients who have shown CR after previous chemoembolization but subsequently, during follow-up surveillance, had serum AFP levels > 20 ng/mL without an overt tumor evident on imaging studies.

Cerebral arterial air embolism after computed tomography-guided hook-wire localization of a pulmonary nodule: A case report

RATIONALE

Cranial arterial air embolism is a rare but potentially fatal complication after computed tomography (CT)-guided pulmonary interventions.

PATIENT CONCERNS

A 64-year-old man was diagnosed with a pulmonary nodule (diameter: approximately 1 cm) in the right lower lobe. The patient developed convulsions after CT-guided hook-wire localization.

DIAGNOSIS

Cranial CT revealed arborizing/linearly distributed gas in the territory of the right middle cerebral artery.

INTERVENTIONS

The patient was administered hyperbaric oxygen, antiplatelet aggregation therapy, and dehydration treatment.

OUTCOMES

Clinical death occurred 55 hours after air embolism.

LESSONS

Systemic air embolism is a serious complication of lung puncture. Clinicians should improve their understanding of this complication and remain vigilant against air embolism.

Complications of CT-guided lung biopsy with a non-coaxial semi-automated 18 gauge biopsy system: Frequency, severity and risk factors

Objectives

To evaluate frequency and severity of complications after CT-guided lung biopsy using the Society of Interventional Radiology (SIR) classification, and to assess risk factors for overall and major complications.

Materials and methods

311 consecutive biopsies with a non-coaxial semi-automated 18 gauge biopsy system were retrospectively evaluated. Complications after biopsy were classified into minor SIR1-2 and major SIR3-6. Studied risk factors for complications were patient-related (age, sex and underlying emphysema), lesion-related (size, location, morphologic characteristic, depth from the pleura and histopathology), and technique-related (patient position during procedure, thoracic wall thickness at needle path, procedure time length and number of procedural CT images, number of pleural passes, fissure penetration and needle-to-blood vessel angle). Data were analyzed using logistic and ordinal regression.

Results

Complications were pneumothorax and pulmonary hemorrhage. The complications were minor SIR1-2 in 142 patients (45.6%), and major SIR3-4 in 25 patients (8%). SIR5-6 complications were not present. Emphysema, smaller deeply located lesion, increased puncture time length and number of procedural CT images, multiple pleural passes and fissure puncture were significant risk factors for complication severity in univariate analysis. Emphysema (OR = 8.8, p<0.001), lesion depth from the pleura (OR = 1.9 per cm, p<0.001), and fissure puncture (OR = 9.4, p = 0.01) were the independent factors for major complications in a multiple logistic regression model. No statistical difference of complication rates between the radiologists performing biopsies was observed.

Conclusions

Knowledge about risk factors influencing complication severity is important for planning and performing CT-guided lung biopsies.

Hybrid Therapy Consisting of Bowel Resection and Fluoroscopic-Assisted Balloon Thrombectomy for Small Bowel Infarction Caused by Acute Mesenteric Venous Thrombosis

BACKGROUND

To investigate the effect of bowel resection combined with fluoroscopic-assisted balloon thrombectomy for small bowel infarction caused by acute mesenteric venous thrombosis (AMVT).

METHODS

Between June 2016 and August 2017, nine patients (seven males and two females; range, 40-73 years; mean, 55.11 ± 10.08 years) with small bowel infarction caused by AMVT underwent bowel resection combined with fluoroscopic-assisted balloon thrombectomy. The demographics, risk factors, therapeutic effect, complications, mortality, and follow-up of the study population were assessed.

RESULTS

The effective rate was 100% with substantial clinical improvement in symptoms. All patients underwent small bowel resection with primary anastomosis. The length of bowel resection ranged from 60 to 170 cm (108.67 ± 35.05). In none of the cases there was surgery with second look. The patients were discharged 13-42 days (20.11 ± 8.75) after admission without perioperative complication or death. The follow-up period was 8-21 months (12.89 ± 4.65), and the follow-up rate was 100%. All patients returned to normal activities, regained lost body weight, and remained asymptomatic during the follow-up period.

CONCLUSIONS

The combination therapy of bowel resection and fluoroscopic-assisted balloon thrombectomy is technically feasible and may be beneficial for small bowel infarction caused by AMVT in removing a thrombus efficiently, relieving symptoms rapidly, averting second-look surgery, lowering extensive surgical resections, and improving the prognosis.

Radiation Risk Categories in Cardiac Catheterization for Congenital Heart Disease: A Tool to Aid in the Evaluation of Radiation Outcomes

To stratify diverse procedure types into categories with similar radiation exposure in cardiac catheterization for congenital heart disease. Radiation exposures for a comprehensive list of specific procedure types and stratification of outcomes based on radiation risk are not currently available. Data between January 2014 and December 2015 were collected on all cases performed at sites participating in C3PO-QI (Congenital Cardiac Catheterization Outcomes Project-Quality Improvement Initiative) and 9 centers were included. Using expert consensus, 40 unique procedure types were defined by diagnostic characteristics or the intervention(s) performed, and dose area product (DAP) per kilogram of body weight (µGy × m²/kg) was summarized. Using empiric and consensus methods, three radiation risk categories were created. A total of 11,735 cases were included for analysis. Thirteen (n = 7918) procedure types with median DAP/kg < 100 were categorized in the low radiation exposure category (median DAP/kg 39). The medium exposure category (n = 1807) consisted of 16 procedure types with median DAP/kg values ranging 100 to < 200 (overall median DAP/kg 131). Finally, the high radiation exposure category (n = 1073) consisted of 11 procedure types with median DAP/kg ≥ 200 (overall median DAP/kg of 231). The radiation exposure risk categories created in this multi-center dataset are a critical step towards the development of a robust risk adjustment methodology for radiation exposure in catheterization for congenital heart disease.

Eye lens dose levels in interventional rooms using simple phantom simulation, dose management software and Monte Carlo method of uncertainty assessment

This paper presents a fast method to estimate the annual eye lens dose levels for interventional practitioners applying the Monte Carlo method of uncertainty assessment. The estimation was performed by placing an anthropomorphic phantom in the typical working position, and applying the habitually employed protocol. No radiation protection devices were considered in the simulation. The results were compatible with the measurements performed during interventions by placing dosimeters in the vicinity of the eyes of two paediatric interventional cardiologists working with a fluoroscopic biplane system.

Ionizing Radiation Dose Exposure to the Ocular Region of Pain Physicians During C-arm Guided Pain Interventions

BACKGROUND

The growth of interventional pain medicine in recent years has resulted in more procedures being carried out under fluoroscopic guidance. The proximity of the pain physician (PP) to ionization radiation (IR) potentially increases the risk of radiation exposure to the ocular region. A European directive has reduced the limits of occupational ocular dose 7.5-fold.

OBJECTIVES

The objectives of this study are to quantify the typical IR exposure in the ocular region of PP and to compare it to recommended international guidelines.

STUDY DESIGN

Three consultants involved in the pain unit service were enrolled in the study to reflect the dose implications involved with different caseloads, training obligations, and procedure types. All 3 consultants were experienced primary operators.

SETTING

The study was undertaken at the pain management suite in the South Infirmary Victoria University Hospital (SIVUH). Annually, this unit performs 2,800 fluoroscopic guide pain procedures.

METHODS

Thermoluminescent dosimeters (TLDs) calibrated to measure eye lens doses [Hp (0.07)] and whole-body doses (WBDs) were fitted to 3 pain consultants while they undertook imaging-guided pain procedures using mobile C-arm fluoroscopy over a 3-month period. The duration of radiation exposure, screening time (seconds), and procedure type were recorded. Radiation dose was calculated to estimate the effective radiation dose to the ocular region using (i) dose-area product (DAP) in milliGray per centimeter squared (mGycm2) and (ii) Air Kerma (AK) values in mGy.

RESULTS

IR doses were effectively recorded in 682 cases over 3 months and the data extrapolated. The estimated annual lens dose experienced by pain physicians performing fluoroscopy-guided procedures is less than the recommended international guidelines. A significant linear relationship between screening time and IR exposure was estimated (rs = 0.93, P < 0.01).

LIMITATIONS

In many centers, including our own, fluoroscopy procedures are undertaken by nonconsultant staff. Therefore, a small single-center cohort recruiting experienced consultant staff and not including pain fellows or registrars/residents with varying levels of experience is a limitation.

CONCLUSION

While IR to the ocular region was significantly less than the recommended European safety guidelines, the annual dose needs to be confirmed in pain physicians with a lesser degree of clinical experience.

KEY WORDS

Ionizing radiation, ocular, radiation protection, pain medicine, interventional.

Comparison of the efficacy and characteristics of metallic foreign body extraction by incision surgery and x-ray guided forceps after body-surface projection positioning: A STROBE-compliant article

A foreign body retained in soft tissue may give rise to infection and dysfunction, which may pose a potential threat to patient health. Our study is to compare the efficacy and characteristics of metallic foreign body (MFB) extraction from soft tissue by incision surgery and x-ray-guided forceps after body surface projection positioning.This study enrolled 775 patients who underwent percutaneous MFB extraction between January 2011 and December 2016. A total of 257 cases underwent extraction by incision surgery and 518 cases underwent x-ray-guided forceps extraction after body surface projection positioning.All patients were diagnosed by x-ray and the diagnostic accuracy rate was 100%. In the incision surgery group, MFB extraction was successful in 193 of 257 cases. All cases in the forceps extraction group were successful, and the success rate was significantly higher than that of the incision surgery group (100% vs.75.1%, P < .01). Sixty-four patients in the incision surgery group who failed treatment were subsequently treated with x-ray-guided forceps extraction and all MFBs were extracted. The symptoms in all patients were relieved, wound healing was good, and there were no major bleeding, incision infection, or other complications.Compared with incision surgery, x-ray-guided foreign body forceps extraction after body surface projection positioning is a less invasive, safer, and more effective treatment for MFB extraction.

Contemporary Arterial Access in the Cardiac Catheterization Laboratory

Obtaining femoral and radial arterial access in the cardiac catheterization laboratory using state-of-the-art techniques is essential to optimize outcomes, patient satisfaction, and procedural efficiency. Although transradial access is increasingly used for coronary angiography and percutaneous coronary intervention, femoral access remains necessary for numerous procedures, many requiring large-bore access, including complex high-risk coronary interventions, structural procedures, and procedures involving mechanical circulatory support. For femoral access, contemporary access techniques should combine the use of fluoroscopy, ultrasound, micropuncture needle, femoral angiography, and vascular closure devices, when feasible. For radial access, ultrasound may reveal important anatomic features and expedite access. Despite randomized controlled trials supporting use of routine ultrasound guidance for femoral and/or radial arterial access, ultrasound remains underused in cardiac catheterization laboratories. This article reviews contemporary techniques to achieve optimal arterial access in the cardiac catheterization laboratory.

Radiation Protection for Interventional Fluoroscopy: Results of a Survey Among Dutch Hospitals

A survey was conducted among 20 Dutch hospitals about radiation protection for interventional fluoroscopy. This was a follow-up of a previous study in 2007 that led to several recommendations for radiation protection for interventional fluoroscopy. The results indicate that most recommendations have been followed. However, radiation-induced complications from interventional procedures are still often not recorded in the appropriate register. Furthermore, even though professionals with appropriate training in radiation protection are usually involved in interventional procedures, this often is not the case when these procedures are carried out outside the radiology department. Although this involvement is not required by Dutch law, it is recommended to have radiation protection professionals present more often at interventional procedures. Further improvements in radiation protection for interventional fluoroscopy may come from a comparison of dose-reducing practices among hospitals, the introduction of diagnostic reference levels for interventional procedures, and a more thorough form of screening and follow-up of patients.

Increased Radiation but No Benefits in Pedicle Screw Accuracy With Navigation versus a Freehand Technique in Scoliosis Surgery

BACKGROUND

The clinical value of pedicle screws in spinal deformity surgery is well known; however, screw insertion is demanding and sometimes associated with complications. Navigation systems based on intraoperatively obtained three-dimensional (3-D) images were developed to minimize pedicle screw misplacements. However, there is a lack of data confirming superiority of navigation above other techniques. There are also concerns regarding increased radiation used during the procedure.

QUESTIONS/PURPOSES

The purposes of this study were (1) to compare accuracy of the two methods of pedicle screws placement: intraoperative 3-D image navigation versus a freehand technique in patients with idiopathic scoliosis; and (2) to assess the radiation dose received by patients with both methods.

METHODS

Between 2014 and 2016, 49 patients underwent posterior spinal fusion with all pedicle screw constructs for idiopathic scoliosis performed by two surgeons. The study design involved alternating the use of the freehand technique and navigation to position pedicle screws in consecutive patients, forming groups of 27 patients with 451 navigated screws and 22 patients with 384 screws positioned freehand. The two groups did not differ in age, sex, or magnitude of deformity. Two observers not involved in the treatment evaluated the position of the screws. The pedicle breach was assessed on intraoperatively obtained 3-D O-arm® scans according to a grading system: Grade 0 = no pedicle wall violation; Grade 1 = perforation ≤ 2 mm; Grade 2 = 2 to 4 mm; and Grade 3 = perforation > 4 mm. Grades 0 and 1 were considered properly positioned and Grades 2 and 3 represented malposition.

RESULTS

In terms of accuracy, we found no differences, with the numbers available, between the freehand and navigated groups in terms of the proportion of screws that were properly positioned (96% freehand and 96% in the navigation group, respectively; p = 0.518). Grade 3 pedicle screws were observed only in the freehand group and were all located in the upper thoracic spine. Patients undergoing navigated pedicle screw placement received a greater mean radiation dose than those whose screws were placed freehand (1071 ± 447 mGy-cm versus 391 ± 53 mGy-cm; mean difference, 680 mGy-cm; 95% confidence interval, 217-2053 mGy-cm; p < 0.001).

CONCLUSIONS

In patients with moderate idiopathic scoliosis undergoing primary surgery, we did not observe benefits of pedicle screw placement with CT-based navigation, but the patients experienced greater exposure to radiation.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Staff radiation dose during percutaneous coronary procedures: Role of adjunctive protective drapes

BACKGROUND

The use of adjunctive protective drapes placed on the patient protects the operating physician from scatter radiation during percutaneous coronary procedures (PCP). No data are available on the effect of these drapes for staff members' radio-protection.

PURPOSE

To evaluate staff radiation exposure during PCP and the effect of adjunctive protective drapes on dose reduction.

METHODS

The RADIANT study (NCT01974453) is a prospective, observational study evaluating operator radiation exposure during PCP using electronic dosimeter. In a sub-group of procedures all the staff members (II operator, nurse circulator and technologist) were also equipped with a dedicated electronic dosimeter.

RESULTS

From a total of 2028 procedures included in the RADIANT study, staff members' doses were available for 122 procedures (67 coronarography and 55 percutaneous coronary interventions). Median fluoroscopy time was 306 s (Interquartile range 155-526 s) and the dose area product (DAP) was 18.0 Gy*cm² (10-35.5 Gy*cm²). The radiation exposure was highest for the operating physician (6.7 μSv) and progressively lower for the nurse circulator (1.8 μSv), the II operator (1 μSv) and the technologist (0.7 μSv, p < 0.001). Protective pelvic drapes were used in 43 procedures and associated with a lower radiation exposure for all staff members (14 μSv vs 2.2 μSv for operating physician, p < 0.001, 1.7 μSv vs 0.49 μSv for II operator, p < 0.001, 2.16 μSv vs 0.93 μSv for nurse circulator, p = 0.02 and 0.85 μSv vs 0.39 μSv for technologist, p = 0.01).

CONCLUSIONS

The use of adjunctive protective drapes is effective in reducing radiation protection for all staff members during PCP.

Radiation Reduction in the Pediatric Catheterization Laboratory Using a Novel Imaging System

OBJECTIVES

Radiation dose was compared between two modern imaging systems with different x-ray tube technology (Megalix vs Gigalix) and detector type (amorphous vs crystalline silicon) at the same institution.

BACKGROUND

Further reduction in radiation dose than currently reported may be achievable with advances in x-ray tube and detector technology.

METHODS

Radiation dose (air kerma, dose-area product [DAP]) was retrospectively compared for post-transplant pediatric patients undergoing right heart catheterization/biopsy (fluoroscopy only) or "annual" catheterization with coronary angiography in one of two imaging systems between January 2014 and December 2016. Comparisons were also made with published radiation doses.

RESULTS

A total of 122 right heart catheterizations with biopsy were performed in the Megalix/amorphous silicon (Si) lab and 168 in the Gigalix/crystalline Si lab. Age and weight were not statistically different for the two groups. There was a 50% decrease in median air kerma (2.2 mGy vs 1.1 mGy; P<.001) and 66% decrease in median DAP (52.2 μGy•m² vs 18.0 μGy•m²; P<.001) for the Gigalix/crystalline Si lab. A total of 24 "annual" catheterizations were performed in the Megalix/amorphous Si lab and 22 were performed in the Gigalix/crystalline Si lab. There was a 57% reduction in median air kerma (458.6 mGy vs 198.6 mGy; P<.001) and a 46% reduction in median DAP (2548.0 μGy•m² vs 1367.1 μGy•m²; P<.01) for the Gigalix/crystalline Si lab. Similar reductions were found on comparison with published doses.

CONCLUSION

The Gigalix tube and crystalline Si detector decrease radiation dose by 50%-60% for fluoroscopy and cine acquisition in pediatric patients.

Radiation Safety in Children With Congenital and Acquired Heart Disease: A Scientific Position Statement on Multimodality Dose Optimization From the Image Gently Alliance

There is a need for consensus recommendations for ionizing radiation dose optimization during multimodality medical imaging in children with congenital and acquired heart disease (CAHD). These children often have complex diseases and may be exposed to a relatively high cumulative burden of ionizing radiation from medical imaging procedures, including cardiac computed tomography, nuclear cardiology studies, and fluoroscopically guided diagnostic and interventional catheterization and electrophysiology procedures. Although these imaging procedures are all essential to the care of children with CAHD and have contributed to meaningfully improved outcomes in these patients, exposure to ionizing radiation is associated with potential risks, including an increased lifetime attributable risk of cancer. The goal of these recommendations is to encourage informed imaging to achieve appropriate study quality at the lowest achievable dose. Other strategies to improve care include a patient-centered approach to imaging, emphasizing education and informed decision making and programmatic approaches to ensure appropriate dose monitoring. Looking ahead, there is a need for standardization of dose metrics across imaging modalities, so as to encourage comparative effectiveness studies across the spectrum of CAHD in children.

Radiation Exposure of Patients and Interventional Radiologists during Prostatic Artery Embolization: A Prospective Single-Operator Study

PURPOSE

To prospectively analyze the radiation exposure of patients and interventional radiologists during prostatic artery embolization (PAE).

MATERIALS AND METHODS

Twenty-five consecutive PAE procedures performed with an Artis zee system in a single center by an interventional radiologist were prospectively monitored. The mean age, weight, and prostate volume of the patients were 65.7 year (range, 43-85 y), 71.4 kg (range, 54-88 kg), and 79 cm³ (range, 36-157 cm³), respectively. In addition to Digital Imaging and Communications in Medicine radiation data, direct measures were also obtained. Radiochromic film was used to evaluate peak skin dose (PSD). The radiologist wore a protective apron and a thyroid collar, and a ceiling-suspended screen and a table curtain were used. To estimate the absorbed doses, nine pairs of dosimeters were attached to the operator's body.

RESULTS

The average fluoroscopy time was 30.9 minutes (range, 15.5-48.3 min). The mean total dose-area product (DAP) was 450.7 Gy·cm² (range, 248.3-791.73 Gy·cm²) per procedure. Digital subtraction angiography was responsible for 71.5% of the total DAP, followed by fluoroscopy and cone-beam computed tomography. The mean PSD was 2,420.3 mGy (range, 1,390-3,616 mGy). The average effective dose for the interventional radiologist was 17 μSv (range, 4-47 μSv); values for the eyes, hands, and feet were obtained, and were all greater on the left side.

CONCLUSIONS

PAE may lead to high x-ray exposures to patients and interventional radiologists.