Evaluation of a Noise Reduction Imaging Technology in Iliac Digital Subtraction Angiography: Noninferior Clinical Image Quality with Lower Patient and Scatter Dose

Radiation dose reduction during adrenal vein sampling using a new angiographic imaging technology

To compare the patient radiation doses during angiographic selective adrenal vein sampling (AVS) before and after an imaging technology upgrade. In this retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), fluoroscopy time and contrast agent dosage were recorded from 70 patients during AVS. 35 procedures were performed before and 35 after an imaging processing technology upgrade. Mean values were calculated and compared using an unpaired student’s t-test. DSA image quality was assessed independently by two blinded readers using a four-point Likert scale (1 = poor; 4 = excellent) and compared using Wilcoxon signed-rank test. After the technology upgrade we observed a significant reduction of 35% in AK (1.7 ± 0.7 vs. 1.1 ± 0.7 Gy, p = 0.01) and a significant reduction of 28% in DAP (235.1 ± 113 vs. 170.1 ± 94 Gy*cm², p = 0.01) in comparison to procedures before the upgrade. There were no significant differences between the number of exposure frames (143 ± 86 vs. 132 ± 61 frames, p = 0.53), fluoroscopy time (42 ± 23 vs. 36 ± 18 min, p = 0.22), or the amount of contrast medium used (179.5 ± 84 vs. 198.1 ± 109 ml, p = 0.41). There was also no significant difference regarding image quality (3 (2–4) vs. 3 (2–4), p = 0.67). The angiographic imaging technology upgrade significantly decreases the radiation dose during adrenal vein sampling without increasing time of fluoroscopy or contrast volume and without compromising image quality.

New imaging technology system reduces patient radiation dose during peripheral arterial endovascular interventions

BACKGROUND

Radiation exposure and imaging quality are among the main concerns in endovascular procedures. The Clear VD11 PURE platform technology system (Siemens Healthineers, Erlangen, Germany) has been reported to lower the radiation dose and improve image quality. In the present study, we evaluated whether the radiation dose during peripheral arterial endovascular procedures had decreased after implementation of this new imaging system.

METHODS

The patient characteristics (age, gender, body mass index [BMI]), procedure type (diagnostic, balloon angioplasty, atherectomy, stenting), body location (aortoiliac, superficial femoral artery, tibial artery), reference air kerma (RAK), kerma area product (KAP), and fluoroscopy time (FT) were recorded during peripheral artery interventions performed 1 year before (group A) and 1 year after (group B) the CLEAR system upgrade. The procedures were performed in an Artis zeego hybrid room (Siemens Healthineers) with the same providers. A general linear model was used to estimate the average difference between groups adjusted by procedure type and patient age, gender, and BMI. Additionally, to control for variations in case complexity, groups A and B were matched by age, gender, BMI, lesion location, and intervention type. Propensity score matching and a paired t test were used to compare the KAP, RAK, and FT stratified by single intervention procedures.

RESULTS

A total of 487 endovascular procedures were performed: 209 in group A and 278 in group B. A total of 111 single intervention procedures from each group were matched (1:1), with a mean age of 61 ± 8 years and a BMI of 26.5 ± 4 kg/m². The median KAP, RAK, and FT for group A were 28.8 Gy · cm² (interquartile range [IQR], 24-34 Gy · cm²), 146 mGy (IQR, 123-173 mGy), and 12 minutes (IQR, 10-14 minutes), respectively. The median KAP, RAK, and FT for group B were 18.3 Gy · cm² (IQR, 16-22 Gy · cm²), 71.2 mGy (IQR, 60-85 mGy), and 10.4 minutes (IQR, 9-12 minutes), respectively. The KAP, RAK, and FT were significantly decreased in group B by 24% (P = .005), 41% (P < .001), and 22% (P = .002), respectively, compared with the values for group A. Stratified by single intervention procedures, the KAP and RAK had decreased significantly in group B (36% [P = .002] and 51% [P < .001], respectively) compared with group A. The FT decrease of 13% in group B was not statistically significant (P = .20).

CONCLUSIONS

Use of the Clear VD11 PURE platform system (Siemens Healthineers) reduced the patient radiation dose by 51% during endovascular peripheral interventions. The similar FTs for the matched single intervention procedures before and after the upgrade indicated consistent case complexity and surgeon practice. This platform appears to be an effective system for lowering the radiation dose.

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

This study sought to achieve radiation dose reductions for patients receiving uterine artery embolisation (UAE) by evaluating radiation dose measurements for the preceding generation (Allura) and upgraded (Azurion) angiography system. Previous UAE regression models in the literature could not be applied to this centre's practice due to being based on different angiography systems and radiation dose predictor variables. The aims of this study were to establish whether radiation dose is reduced with the upgraded angiography system and to develop a regression model to determine predictors of radiation dose specific to the upgraded angiography system. A comparison between Group I (Allura,n= 95) and Group II (Azurion,n= 95) demonstrated a significant reduction in kerma-area product (KAP) and Ka, r (reference air kerma) by 63% (143.2 Gy cm²vs 52.9 Gy cm²;P< 0.001,d= 0.8) and 67% (0.6 Gy vs 0.2 Gy;P< 0.001,d= 0.8), respectively. The multivariable linear regression (MLR) model identified the UAE radiation dose predictors for KAP on the upgraded angiography system as total fluoroscopy dose, Ka, r, and total uterus volume. The predictive accuracy of the MLR model was assessed using a Bland-Altman plot. The mean difference was 0.39 Gy cm²and the limits of agreement were +28.49 and -27.71 Gy cm², and thus illustrated no proportional bias. The resultant MLR model was considered system-dependent and validated the upgraded angiography system and its advance capabilities to significantly reduce radiation dose. Interventional radiologist and interventional radiographer familiarisation of the system's features and the implementation of the newly established MLR model would further facilitate dose optimisation for all centres performing UAE procedures using the upgraded angiography system.

Digital Variance Angiography in Selective Lower Limb Interventions

PURPOSE

To evaluate the potential benefits of digital variance angiography (DVA) in selective lower limb angiography and to compare the performance of 2 DVA algorithms (conventional DVA1 and the recently developed DVA2) to that of digital subtraction angiography (DSA).

MATERIALS AND METHODS

From November 2019 to May 2020, 112 iodinated contrast media (ICM) and 40 carbon dioxide (CO₂) angiograms were collected from 15 and 13 peripheral artery disease patients, respectively. The DVA files were retrospectively generated from the same unsubtracted source file as DSA. The objectively calculated contrast-to-noise ratio (CNR) and the subjective visual image quality of DSA, DVA1, and DVA2 images were statistically compared using the Wilcoxon signed-rank test. The images were evaluated by 6 radiologists (R.P.T., S.V., A.M.K., S.S.A., O.E., and J.S.) from 2 centers using a 5-grade Likert scale.

RESULTS

Both DVA algorithms produced similar increase (at least 2-fold) in CNR values (P < .001) and significantly higher image quality scores than DSA, independent of the contrast agent used. The overall scores with ICM were 3.61 ± 0.05 for DSA, 4.30 ± 0.04 for DVA1, and 4.33 ± 0.04 for DVA2 (each P < .001 vs DSA). The scores for CO₂ were 3.10 ± 0.14 for DSA, 3.63 ± 0.13 for DVA1 (P < .001 vs DSA), and 3.38 ± 0.13 for DVA2 (P < .05 vs DSA).

CONCLUSIONS

DVA provides higher CNR and significantly better image quality in selective lower limb interventions irrespective of the contrast agent used. Between DVA algorithms, DVA1 is preferred because of its identical or better image quality than DVA2. DVA can potentially help the interventional decision process and its quality reserve might allow dose management (radiation/ICM reduction) in the future.

Radiation dose reduction during intra-arterial chemotherapy for retinoblastoma: a retrospective analysis of 96 consecutive pediatric interventions using five distinct protocols

BACKGROUND

Intra-arterial chemotherapy (IAC) represents a mainstay of retinoblastoma treatment in children. Patients with retinoblastoma are uniquely at risk for secondary malignancies and are sensitive to the ionizing effects of radiation.

OBJECTIVE

To retrospectively review a single institution's experience with IAC for retinoblastoma and the effect of variable intra-procedural imaging techniques on radiation exposure.

MATERIALS AND METHODS

Twenty-four consecutive patients, with a mean age of 30.8±16.3 months (range: 3.2-83.4 months), undergoing IAC for retinoblastoma between May 2014 and May 2020 (72 months) were included. No patients were excluded. The primary outcome was radiation exposure and secondary outcomes included technical success and procedural adverse events. Technical success was defined as catheterization of the ophthalmic or meningolacrimal artery and complete delivery of chemotherapy. Each procedure was retrospectively reviewed and categorized as one of five imaging protocol types. Protocol types were characterized by uniplanar versus multiplanar imaging and digital subtraction angiographic versus roadmap angiographic techniques. Radiation exposure, protocol utilization, the association of protocol and radiation exposure were assessed.

RESULTS

During 96 consecutive interventions, 109 ocular treatments were performed. Thirteen of the 96 (15.5%) treatments were bilateral. Ocular technical success was 106 of 109 (97.2%). All three treatment failures were successfully repeated within a week. Mean fluoroscopy time was 6.4±6.2 min (range: 0.7-31.1 min). Mean air kerma was 36.2±52.2 mGy (range: 1.4-215.0 mGy). There were two major (1.8%) complications and four (3.7%) minor complications. Of the 96 procedures, 10 (10.4%), 9 (9.4%), 13 (13.5%), 28 (29.2%) and 36 (37.5%) were performed using protocol types A, B, C, D and E, respectively. For protocol type A, mean fluoroscopy time was 10.3±6.8 min (range: 3.0-25.4 min) and mean air kerma was 118.2±61.2 mGy (range: 24.5-167.3 mGy). For protocol type E, mean fluoroscopy time was 3.1±3.2 min (range: 0.7-15.1 min) and mean air kerma was 5.4±4.2 mGy (range: 1.4-19.5 mGy). Fluoroscopy time and air kerma decreased over time, corresponding to the reduced use of multiplanar imaging and digital subtraction angiography. In the first quartile (procedures 1-24), 8 (33.3%), 7 (29.2%), 2 (8.3%), 6 (25.0%) and 1 (4.2%) were performed using protocol types A, B, C, D and E, respectively. Mean fluoroscopy time was 10.5±8.2 min (range: 2.4-28.1 min) and mean air kerma was 84.2±71.6 mGy (range: 12.8-215.0 mGy). In the final quartile (procedures 73-96), 24 (100%) procedures were performed using protocol type E. Mean fluoroscopy time was 3.5±4.0 min (range: 0.7-15.1 min) and mean air kerma was 5.0±4.3 mGy (range: 1.4-18.0 mGy), representing 66.7% and 94.1% reductions from the first quartile, respectively. Technical success in the second half of the experience was 100%.

CONCLUSION

Sequence elimination, consolidation from biplane imaging to lateral-only imaging, and replacing digital subtraction with roadmap angiography dramatically reduced radiation exposure during IAC for retinoblastoma without adversely affecting technical success or safety.

A new imaging technology to reduce the radiation dose during uterine fibroid embolization

BACKGROUND

Uterine fibroid embolization (UFE) is a minimally invasive imaging-guided treatment using radiation exposure.

PURPOSE

To compare the patients' radiation exposure during UFE before and after introduction of a new X-ray imaging platform.

MATERIAL AND METHODS

Forty-one patients were enrolled in a prospective, comparative two-arm project before and after introduction of a new X-ray imaging platform with reduced dose settings, i.e. novel real-time image processing techniques (AlluraClarity). Demographic, pre-interventional imaging, and procedural data, including dose area product (DAP) and estimated organ dose on the ovaries and uterus, were recorded and angiographic quality of overall procedure was assessed.

RESULTS

There were no significant differences in demographic characteristics and preoperative fibroid and uterine volumes in the two groups. The new imaging platform led to a significant reduction in mean total DAP (102 vs. 438 Gy.cm²; P < 0.001), mean fluoroscopy DAP (32 vs. 138 Gy.cm²; P < 0.001), mean acquisition DAP (70 vs. 300 Gy.cm²; P < 0.001), and acquisition DAP estimated organ dose in ovaries (42 vs. 118 mGy; P < 0.001) and uterus (40 vs. 118 mGy, P < 0.001), without impairment of the procedure and angiographic image quality.

CONCLUSION

A substantial 77% reduction of DAP values and 64% and 66% reduction in organ dose on ovaries and uterus, respectively, was demonstrated with the new imaging platform, while maintaining optimal imaging quality and efficacy.

Evaluation of patient and staff exposure with state of the art X-ray technology in cardiac catheterization: A randomized controlled trial

INTRODUCTION

Cardiac catheterization procedures result in high patient radiation exposure and corresponding staff doses are reported to be among the highest for medical staff. The purpose of current randomized controlled study was to quantify the potential radiation dose reduction for both patient and staff, enabled by recent X-ray technology. This technology is equipped with advanced image processing algorithms, real-time dose monitoring, and an acquisition chain optimized for cardiac catheterization applications.

METHODS

A total of 122 adult patients were randomly assigned to one of two cath labs, either the reference X-ray modality (Allura Xper FD10, Philips Healthcare, the Netherlands) or the new X-ray system (AlluraClarity FD20/10 Philips Healthcare, the Netherlands). Exposure parameters and staff dosimeter readings were recorded for each exposure. Technical measurements were performed to define the radiation scatter behavior.

RESULTS

With the newer equipment, patient radiation dose is reduced (as total dose-area product) by 67% based on geometric means with 95%CI of 53%, 77% for diagnostic and interventional procedures. The C-arm and leg dosimeter readings were both reduced with 65% (P < 0.001), while for the collar and chest dosimeter readings no statistically significant reduction was noticed.

CONCLUSION

The new x-ray and image processing technology, significantly reduces patient dose in coronary angiographies, and PCIs by 67%. In general, scatter dose was also reduced, yet for some dosimeters the reduction was limited and not statistically significant. This study clearly indicates that the scatter behavior is highly dependent on C-arm rotation, operator movement and height, dosimeter position, beam filtration, clinical procedure type and system geometry.

Noise reduction angiographic imaging technology reduces radiation dose during bronchial artery embolization

PURPOSE

Comparison of radiation doses in patients undergoing angiographic bronchial artery embolization (BAE) before and after a noise reduction imaging technology upgrade.

METHODS

We performed a retrospective study of 70 patients undergoing BAE. Procedures were performed before (n=32) and after (n=38) the technology upgrade containing additional filters and improved image-processing. Cumulative air kerma (AK), cumulative dose area product (DAP), number of exposure frames, total fluoroscopy time and amount of contrast agent were recorded. Mean values were calculated and compared using two-tailed t-tests. DSA image quality was assessed independently by two blinded readers and compared using the Wilcoxon signed-rank test.

RESULTS

Using the new technology resulted in a significant reduction of 59% in DAP (149.2 (103.1-279.1) vs. 54.8 (38.2-100.7) Gy*cm², p<0.001) and a significant reduction of 60% for AK (1.3 (0.6-1.9) vs. 0.5 (0.3-0.9) Gy, p<0.001) in comparison to procedures before the upgrade. There was no significant difference between the number of exposure frames in both groups (251±181 vs. 254±133 frames, p=0.07), time of fluoroscopy (28.8 (18.5-50.4) vs. 28.1 (23.3-38.7) min, p=0.73), or the amount of contrast agent used (139.5±70.8 vs. 163.1±63.1ml, p=0.11). No significant difference regarding image quality could be detected (3 (2,3) vs. 3 (2-4), p=0.64).

CONCLUSIONS

The new angiographic noise reduction technology significantly decreases the radiation dose during bronchial artery embolization without compromising image quality or increasing time of fluoroscopy or contrast volume.

Modern Fixed Imaging Systems Reduce Radiation Exposure to Patients and Providers

High-definition fluoroscopic imaging is required to perform endovascular procedures safely and precisely, especially in complex cases, resulting in longer procedures and increased radiation exposure. This is of importance for training institutions as trainees, even with sound instruction in as low as reasonably achievable (ALARA) principles, tend to have high radiation exposures. Recently, there was an upgrade in the imaging system allowing for comparison of radiation exposure to patients and providers. We performed an analysis of consecutive endovascular aneurysm repair (EVAR) and superficial femoral artery (SFA) interventions in the years 2013 to 2014. We recorded body mass index (BMI) and fluoroscopy time (FT) and subsequently matched 1:1 based on BMI, FT, or both. We determined radiation dose using air kerma (AK) and also recorded individual surgeons’ badge readings. Allura Xper FD20 was upgraded to AlluraClarity with ClarityIQ. We identified a total of 77 EVARs (52 pre and 25 post) and 134 SFA interventions (99 pre and 35 post). Unmatched results for EVAR were BMI pre 26.2 versus post 25.8 (kg/m2, P = .325), FT 28.1 versus 21.2 (minutes, P = .051), and AK 1178.5 versus 581 (mGy, P < .001), respectively. After matching, there was a 53.2% reduction in AK (846.1 vs 395.9 mGy; P = .004) for EVAR. Unmatched results for SFA interventions were BMI pre 28.1 versus post 26.6 ( P = .327), FT 18.7 versus 16.2 ( P = .282), and AK 285.6 versus 106.0 ( P < .001), respectively. After matching, there was a 57.0% reduction in AK (305.0 vs 131.3, P < .001). The total deep dose equivalent from surgeons’ badge readings decreased from 39.5 to 17 mrem ( P = .029). Aortic and peripheral endovascular interventions can be performed with reduced radiation exposure to patients and providers, employing modern fixed imaging systems with advanced dose reduction technology. This is of particular importance in the light of the increasing volume and complexity of endovascular and hybrid procedures as well as the prospect of decades of radiation exposure during training and practice.

Reducing Radiation Exposure in an Electrophysiology Lab with Introduction of Newer Fluoroscopic Technology

The use of fluoroscopic devices exposes patients and operators to harmful effects of ionizing radiation in an electrophysiology (EP) lab. We sought to know if the newer fluoroscopic technology (Allura Clarity) installed in a hybrid EP helps to reduce prescribed radiation dose. We performed radiation dose analysis of 90 patients who underwent various procedures in the EP lab at a community teaching hospital after the introduction of newer fluoroscopic technology in June of 2016. Watchman device insertion, radiofrequency ablation procedures, permanent pacemaker (PPM)/implantable cardioverter defibrillator (ICD) placement and battery changes were included in the study to compare radiation exposure during different procedures performed commonly in an EP lab. In all cases of watchman device placement, radiofrequency ablation procedures, PPM/ICD placement and battery changes, there was a statistically significant difference (<0.05) in radiation dose exposure. Significant reduction in radiation exposure during various procedures performed in an EP lab was achieved with aid of newer fluoroscopic technology and better image detection technology.

Radiation Dose Reduction during Uterine Fibroid Embolization Using an Optimized Imaging Platform

PURPOSE

To assess radiation dose reduction during uterine fibroid embolization (UFE) using an optimized angiographic processing and acquisition platform.

MATERIALS AND METHODS

Radiation dose data for 70 women (mean age, 46 y; range, 34-67 y) who underwent UFE were retrospectively analyzed. Twenty-one patients underwent UFE using the baseline fluoroscopic and angiographic image acquisition platform, and 49 underwent UFE after implementing an optimized imaging platform in otherwise identical angiography suites. Cumulative kerma-area product (CKAP), cumulative air kerma (CAK), total fluoroscopy time, and image exposure number were collected for each procedure. Image quality was assessed by 3 interventional radiologists blinded to the platform used for image acquisition and processing.

RESULTS

Patients undergoing UFE using the new x-ray fluoroscopy platform had significantly lower CKAP and CAK indicators than patients for whom baseline settings were used. Mean CKAP decreased by 60% from 438.5 Gy · cm² (range, 180.3-1,081.1 Gy · cm²) to 175.2 Gy · cm² (range, 47.1-757.0 Gy · cm²; P < .0001). Mean CAK decreased by 45% from 2,034.2 mGy (range, 699.3-5,056.0 mGy) to 1,109.8 mGy (range, 256.6-4,513.6 mGy; P = .001). No degradation of image quality was identified through qualitative evaluation.

CONCLUSIONS

Significant reduction in patient radiation dose indicators can be achieved with use of an optimized image acquisition and processing platform.

The Effect of a New Angiographic Imaging Technology on Radiation Dose in Visceral Embolization Procedures

PURPOSE

To evaluate the impact of a new angiographic imaging technology on radiation dose during visceral embolization procedures involving both fluoroscopy and digital subtraction angiography.

MATERIAL AND METHODS

A retrospective analysis from a single-center consecutive series of patients was performed comparing 2 angiographic imaging systems. The AlluraClarity (CIQ; Philips Healthcare, Best, the Netherlands) was used in 100 patients (n = 59 male, mean age: 70.6 years) from July 2013 to April 2014 and compared to the former AlluraXper (AX) technology used in 139 patients (n = 71 male, mean age: 70.1 years) from May 2011 to June 2013. Patients were categorized according to body mass index (BMI [kg/m²])-group 1: BMI <25, group 2: BMI ≥25 and <30, and group 3: BMI ≥30. Fluoroscopy time, the total dose of iodinated contrast administered, and procedural AirKerma (Ka, r [mGy]) were obtained.

RESULTS

Mean BMI was 26.4 ± 5.0 kg/m² in the CIQ and 26.4 ± 7.1 kg/m² in the AX group ( P = .93). Fluoroscopy time and the amount of contrast media were equally distributed. Ka, r was 1342.9 mGy versus 2214.8 mGy ( P < .001, t test) when comparing CIQ to AX. Comparing CIQ to AX, BMI subgroup analysis revealed a mean Ka, r of 970.1 to 1586.1 mGy ( P = .003, t test), 1484.7 to 2170.1 mGy ( P = .02, t test), and 1848.8 to 3348.9 mGy ( P = .001, t test) in BMI groups 1, 2, and 3, respectively.

CONCLUSION

The CIQ technology significantly reduced mean radiation dose by 39.4% for visceral embolization procedures when compared to fluoroscopy time and contrast media dose. This dose relationship was consistent across all BMI groups.

Radiation Awareness for Endovascular Abdominal Aortic Aneurysm Repair in the Hybrid Operating Room. An Instant Patient Risk Chart for Daily Practice

Purpose: To determine which patient and C-arm characteristics are the strongest predictors of intraoperative patient radiation dose rates (DRs) during endovascular aneurysm repair (EVAR) procedures and create a patient risk chart. Methods: A retrospective analysis was performed of 74 EVAR procedures, including 16,889 X-ray runs using fixed C-arm imaging equipment. Four multivariate log-linear mixed models (with patient as a random effect) were constructed. Mean air kerma DR (DR_AK, mGy/s) and the mean dose area product DR (DR_DAP, mGycm²/s) were the outcome variables utilized for fluoroscopy as differentiated from digital subtraction angiography (DSA). These models were used to predict the maximum radiation duration allowed before a 2-Gy skin threshold (for DR_AK) or a 500-Gycm² threshold (for DR_DAP) was reached. Results: The strongest predictor of DR_AK and DR_DAP for fluoroscopy imaging was the radiation protocol, with an increase of 200% when changing from “low” to “medium” and 410% from “low” to “normal.” The strongest predictors of DR_AK and DR_DAP for DSA were C-arm angulation, with an increase of 47% per 30° of angulation, and body mass index (BMI), with an increase of 58% for every 5-point increase in BMI. Based on these models, a patient with a BMI of 30 kg/m², combined with 45° of rotation and a field size of 800 cm² in the medium fluoroscopy protocol has a predicted DR_AK of 0.39 mGy/s (or 85.5 minutes until the 2-Gy skin threshold is reached). While using comparable settings but switching the acquisition to a DSA with a “2 frames per second” protocol, the predicted DR_AK will be 6.6 mGy/s (or 5.0 minutes until the 2-Gy threshold is reached). Conclusion: X-ray radiation DRs are constantly fluctuating during and between patients based on BMI, the protocols, C-arm position, and the image acquisitions that are used. An instant patient risk chart visualizes these radiation dose fluctuations and provides an overview of the expected duration of X-ray radiation, which can be used to predict when follow-up dose thresholds are reached during abdominal endovascular procedures.

Reduced Patient Radiation Exposure during Neurodiagnostic and Interventional X-Ray Angiography with a New Imaging Platform

BACKGROUND AND PURPOSE

Advancements in medical device and imaging technology as well as accruing clinical evidence have accelerated the growth of the endovascular treatment of cerebrovascular diseases. However, the augmented role of these procedures raises concerns about the radiation dose to patients and operators. We evaluated patient doses from an x-ray imaging platform with radiation dose-reduction technology, which combined image noise reduction, motion correction, and contrast-dependent temporal averaging with optimized x-ray exposure settings.

MATERIALS AND METHODS

In this single-center, retrospective study, cumulative dose-area product inclusive of fluoroscopy, angiography, and 3D acquisitions for all neurovascular procedures performed during a 2-year period on the dose-reduction platform were compared with a reference platform. Key study features were the following: The neurointerventional radiologist could select the targeted dose reduction for each patient with the dose-reduction platform, and the statistical analyses included patient characteristics and the neurointerventional radiologist as covariates. The analyzed outcome measures were cumulative dose (kerma)-area product, fluoroscopy duration, and administered contrast volume.

RESULTS

A total of 1238 neurointerventional cases were included, of which 914 and 324 were performed on the reference and dose-reduction platforms, respectively. Over all diagnostic and neurointerventional procedures, the cumulative dose-area product was significantly reduced by 53.2% (mean reduction, 160.3 Gy × cm²; P < .0001), fluoroscopy duration was marginally significantly increased (mean increase, 5.2 minutes; P = .0491), and contrast volume was nonsignificantly increased (mean increase, 15.3 mL; P = .1616) with the dose-reduction platform.

CONCLUSIONS

A significant reduction in patient radiation dose is achievable during neurovascular procedures by using dose-reduction technology with a minimal impact on workflow.

A Multicenter Survey of Endovascular Theatre Equipment and Radiation Exposure in France during Iliac Procedures

BACKGROUND

The aim of this study is to evaluate radiation exposure, endovascular theatre equipment, and practices in France during iliac angioplasty.

METHODS

A prospective observational study was performed among vascular surgeons who attended a half day of radiation safety training in 2012 and 2015 and had to collect data on 3 patients undergoing iliac procedure. In 2012, 330 surgeons performed 899 procedures, compared with 114 surgeons and 338 procedures in 2015. Due to exclusions, 653 and 306 procedures were analyzed in 2012 and 2015, respectively. Endovascular environment, practices, anatomical characteristics, and radiation parameters were collected, analyzed, and compared generally and between the 2 groups.

RESULTS

Endovascular theatre equipment significantly improved over the 3 years: mobile flat-panel detector (1.1% vs. 5.9%), hybrid rooms (1.5% vs. 14.7%), and dedicated radiology tables (37.2% vs. 51.2%). Lesion's classification (Trans-Atlantic Society Consensus) was similar between groups but procedure complexity increased overtime: more than one stent implanted (32.3% vs. 41%, P < 0.01), cross over (11.5% vs. 16%, P < 0.05), and kissing procedures (19.3% vs. 24.2%, P = 0.05). The mean dose area product (DAP) was 14.2 ± 18.9 Gy cm² in 2012 and 21.5 ± 37.6 Gy cm² in 2015 (P < 0.01), and the mean fluoroscopy time was 4.8 ± 5.5 min and 5.2 ± 5.9 min, respectively (nonsignificant). Overall, hybrid rooms, body mass index over 25 kg/m², more than one stent implanted, and crossover technique were associated with a significantly higher DAP.

CONCLUSIONS

Over 3 years, a large population of vascular surgeons improved radiation safety knowledge, operative environment, and technical complexity. However, these changes have led to an increased DAP in 2015, which underline the outmost importance of low dose settings and application of ALARA (as low as reasonably achievable) principles in every day practice.

Impact of new X-ray technology on patient dose in pacemaker and implantable cardioverter defibrillator (ICD) implantations

PURPOSE

New X-ray technology providing new image processing techniques may reduce radiation exposure. The aim of this study was to quantify this radiation exposure reduction for patients during pacemaker and implantable cardioverter defibrillator (ICD) implantation.

METHODS

In this retrospective study, 1185 consecutive patients who had undergone de novo pacemaker or ICD implantation during a 2-year period were included. All implantations in the first year were performed using the reference technology (Allura Xper), whereas in the second year, the new X-ray technology (AlluraClarity) was used. Radiation exposure, expressed as the dose area product (DAP), was compared between the two time periods to determine the radiation exposure reduction for pacemaker and ICD implantations without cardiac resynchronization therapy (CRT) and with CRT. Procedure duration and contrast volume were used as measures to compare complexity and image quality.

RESULTS

The study population consisted of 591 patients who had undergone an implantation using the reference technology, and 594 patients with the new X-ray technology. The two groups did not differ in age, gender, or body mass index. The DAP decreased with 69 % from 16.4 ± 18.5 to 5.2 ± 6.6 Gy cm2 for the non-CRT implantations (p < 0.001). The DAP decreased with 75 % from 72.1 ± 60.0 to 17.8 ± 17.4 Gy cm2 for the CRT implantations (p < 0.001). Nevertheless, procedure duration and contrast volume did not differ when using the new technology (p = 0.09 and p = 0.20, respectively).

CONCLUSIONS

Introduction of new X-ray technology resulted in a radiation exposure reduction of more than 69 % for patients during pacemaker and ICD implantation while image quality was unaffected.

Radiation dose reduction during transjugular intrahepatic portosystemic shunt implantation using a new imaging technology

OBJECTIVE

To compare patient radiation dose in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) implantation before and after an imaging-processing technology upgrade.

METHODS

In our retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), total fluoroscopy time and contrast agent were collected from an age- and BMI-matched collective of 108 patients undergoing TIPS implantation. 54 procedures were performed before and 54 after the technology upgrade. Mean values were calculated and compared using two-tailed t-tests. Two blinded, independent readers assessed DSA image quality using a four-rank likert scale and the Wilcoxcon test.

RESULTS

The new technology demonstrated a significant reduction of 57% of mean DAP (402.8 vs. 173.3Gycm², p<0.001) and a significant reduction of 58% of mean AK (1.7 vs. 0.7Gy, p<0.001) compared to the precursor technology. Time of fluoroscopy (26.4 vs. 27.8min, p=0.45) and amount of contrast agent (109.4 vs. 114.9ml, p=0.62) did not differ significantly between the two groups. The DSA image quality of the new technology was not inferior (2.66 vs. 2.77, p=0.56).

CONCLUSIONS

In our study the new imaging technology halved radiation dose in patients undergoing TIPS maintaining sufficient image quality without a significant increase in radiation time or contrast consumption.

Flow cytometry what you see matters: Enhanced clinical detection using image-based flow cytometry

Image-based flow cytometry combines the throughput of traditional flow cytometry with the ability to visually confirm findings and collect novel data that would not be possible otherwise. Since image-based flow cytometry borrows measurement parameters and analysis techniques from microscopy, it is possible to collect unique measures (i.e. nuclear translocation, co-localization, cellular synapse, cellular endocytosis, etc.) that would not be possible with traditional flow cytometry. The ability to collect unique outcomes has led many researchers to develop novel assays for the monitoring and detection of a variety of clinical conditions and diseases. In many cases, investigators have innovated and expanded classical assays to provide new insight regarding clinical conditions and chronic disease. Beyond human clinical applications, image-based flow cytometry has been used to monitor marine biology changes, nano-particles for solar cell production, and particle quality in pharmaceuticals. This review article summarizes work from the major scientists working in the field of image-based flow cytometry.

Reducing Patient Radiation Dose With Image Noise Reduction Technology in Transcatheter Aortic Valve Procedures

X-ray radiation exposure is of great concern for patients undergoing structural heart interventions. In addition, a larger group of medical staff is required and exposed to radiation compared with percutaneous coronary interventions. This study aimed at quantifying radiation dose reduction with implementation of specific image noise reduction technology (NRT) in transcatheter aortic valve implantation (TAVI) procedures. We retrospectively analyzed 104 consecutive patients with TAVI procedures, 52 patients before and 52 after optimization of x-ray radiation chain, and implementation of NRT. Patients with 1-step TAVI and complex coronary intervention, or complex TAVI procedures, were excluded. Before the procedure, all patients received a multislice computed tomography scan, which was used to size aortic annulus, select the optimal implantation plane, valve type and size, and guide valve implantation using a software tool. Air kerma and kerma-area product were compared in both groups to determine patient radiation dose reduction. Baseline parameters, co-morbidity, or procedural data were comparable between groups. Mean kerma-area product was significantly lower (p <0.001) in the NRT group compared with the standard group (60 ± 39 vs 203 ± 106 Gy × cm(2), p <0.001), which corresponds to a reduction of 70%. Mean air kerma was reduced by 64% (494 ± 360 vs 1,355 ± 657 mGy, p <0.001). In conclusion, using optimized x-ray chain combined with specific image noise reduction technology has the potential to significantly reduce by 2/3 radiation dose in standard TAVI procedures without worsening image quality or prolonging procedure time.

AlluraClarity Radiation Dose–Reduction Technology in the Hybrid Operating Room During Endovascular Aneurysm Repair

Purpose: To evaluate the effect of radiation dose reduction with the Allura ClarityIQ image processing technology for fixed C-arms in comparison with a mobile C-arm and an Allura fixed C-arm without ClarityIQ technology during endovascular aneurysm repair (EVAR) procedures. Methods: Radiation dose data from 85 patients (mean age 74.2±7.8 years; 68 men) undergoing EVAR with mobile and fixed C-arm fluoroscopy were retrospectively analyzed. The radiation dose parameters included the kerma area product (KAP), fluoroscopic time (FT), and number of digital subtraction angiography (DSA) frames (FrDSA). KAPtotal consisted of KAPfluoro (KAP for fluoroscopic imaging) and KAPDSA (KAP for DSA and single shots). Linear regression analysis was used to explore differences in the association of KAP with the FT, FrDSA, and body mass index (BMI) among the 3 C-arms. Results: The mean KAPtotal values for mobile, Allura C-arm, and AlluraClarity C-arm for noncomplex EVARs were 56±39, 245±142, and 157±120 Gy·cm2 (p<0.001); for complex EVARs, the values were 110±43, 874±653, and 598±319 Gy·cm2 (p<0.001), respectively. On average, KAPfluoro tripled when the mobile C-arm was replaced by the fixed C-arm. There were no significant differences in the KAPfluoro adjusted for the FT between Allura and AlluraClarity (p=0.69). However, there was a major 61% reduction in KAPDSA from 1.36 Gy·cm2 per DSA frame for Allura to 0.54 Gy·cm2 per DSA frame with AlluraClarity (p=0.03). For the mobile C-arm, BMI was not associated with KAP (p=0.13). The associations of BMI with KAPfluoro and KAPDSA were significant for both fixed C-arms but were more robust for Allura compared to AlluraClarity (p=0.02 for KAPfluoro and p<0.001 for KAPDSA). Conclusion: Changing a mobile C-arm for a fixed C-arm in a hybrid operating suite increased the average intraoperative dose during EVAR. Upgrading the Allura fixed C-arm with ClarityIQ technology resulted in a 61% reduction in the radiation per DSA frame.