Patient Radiation Dose Reduction during Transarterial Chemoembolization Using a Novel X-Ray Imaging Platform

Arms Down Cone Beam CT Hepatic Angiography Performance Assessment: Vascular Imaging Quality and Imaging Artifacts

INTRODUCTION

The practice of positioning patients' arms above the head during catheter-injected hepatic arterial phase cone beam CT (A-CBCT) imaging has been inherited from standard CT imaging due to image quality concerns, but interrupts workflow and extends procedure time. We sought to assess A-CBCT image quality and artifacts with arms extended above the head versus down by the side.

METHODS

We performed an IRB approved retrospective evaluation of reformatted and 3D-volume rendered images from 91 consecutive A-CBCTs (43 arms up, 48 arms down) acquired during hepatic tumor arterial embolization procedures. Two interventional radiologists reviewed all A-CBCT imaging and assigned vessel visualization scores (VVS) from 1 to 5, ranging from non-diagnostic to optimal visualization. Streak artifacts across axial images were rated from 1 to 3 based on resulting image quality (none to significant). Presence of respiratory or cardiac motion during acquisition, body mass index and radiation dose area product (DAP) were also recorded and analyzed. Univariate and multivariate analyses were used to assess the impact of arm position on VVS and imaging artifacts.

RESULTS

VVS were not significantly associated with arm position during A-CBCT imaging. One reader reported more streak artifacts across axial images in the arms down group (p = 0.005). DAP was not statistically different between the groups (23.9 Gy cm² [6.1-73.4] arms up, 26.1 Gy cm² [4.2-102.6] arms down, p = 0.54).

CONCLUSION

A-CBCT angiography performed with the arms above the head is not superior for clinically relevant hepatic vascular visualization compared to imaging performed with the arms by the patient's side.

Characteristics of a New X-Ray Imaging System for Interventional Procedures: Improved Image Quality and Reduced Radiation Dose

Purpose

To compare image quality and radiation exposure between a new angiographic imaging system and the preceding generation system during uterine artery embolization (UAE).

Materials and Methods

In this retrospective, IRB-approved two-arm study, 54 patients with symptomatic uterine fibroids were treated with UAE on two different angiographic imaging systems. The new system includes optimized acquisition parameters and real-time image processing algorithms. Air kerma (AK), dose area product (DAP) and acquisition time for digital fluoroscopy (DF) and digital subtraction angiography (DSA) were recorded. Body mass index was noted as well. DF image quality was assessed objectively by image noise measurements. DSA image quality was rated by two blinded, independent readers on a four-rank scale. Statistical differences were assessed with unpaired t tests and Wilcoxon rank-sum tests.

Results

There was no significant difference between the patients treated on the new (n = 36) and the old system (n = 18) regarding age (p = 0.10), BMI (p = 0.18), DF time (p = 0.35) and DSA time (p = 0.17). The new system significantly reduced the cumulative AK and DAP by 64 and 72%, respectively (median 0.58 Gy and 145.9 Gy*cm² vs. 1.62 Gy and 526.8 Gy*cm², p < 0.01 for both). Specifically, DAP for DF and DSA decreased by 59% (75.3 vs. 181.9 Gy*cm², p < 0.01) and 78% (67.6 vs. 312.2 Gy*cm², p < 0.01), respectively. The new system achieved a significant decrease in DF image noise (p < 0.01) and a significantly better DSA image quality (p < 0.01).

Conclusions

The new angiographic imaging system significantly improved image quality and reduced radiation exposure during UAE procedures.

Electronic supplementary material

The online version of this article (doi:10.1007/s00270-017-1821-z) contains supplementary material, which is available to authorized users.

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.