Radiation Dose in Prostatic Artery Embolization Using Cone-Beam CT and 3D Roadmap Software

Evaluation of Vessel Tracking Software for Prostatic Artery Embolization

PURPOSE

To evaluate Vessel Tracking software for determining the prostatic arteries feeding the prostate gland during prostatic artery embolization (PAE) using Conebeam-CT (CBCT).

MATERIALS AND METHODS

EmboGuide is a software developed to assist interventional radiologists in performing embolization of hypervascular tumors in the liver. In this study, a single-center retrospective image collection of 120 intraprocedural CBCT of 60 patients with benign prostatic hyperplasia treated using PAE between May 2017 and January 2019 was evaluated. All patients received 1 intraprocedural CBCT per side for evaluation of vessel anatomy. The "reference standard" of the vascular anatomy was defined by segmentation of the prostatic gland and marking of the prostatic artery in conjunction with pre-embolization DSA series. The datasets were then anonymized. Three interventional radiologists with experience in PAE from different centers reviewed the images and used the automatic feeder detection to determine the prostatic artery. Finally, two clinical experts compared the feeding vessels indicated in the "reference standard" and those identified by the readers. Objectives of the study were to evaluate the clinical performance of the software based on sensitivity and the agreement between interventional radiologists.

RESULTS

Sensitivity was estimated as 0.968 with a 90% confidence interval. Overall agreement was estimated as 0.801 with a 90% confidence interval. On both objectives (Sensitivity and Agreement), specifications were met.

CONCLUSIONS

The results of this study suggest that EmboGuide can be used to determine the prostate arteries in PAE. The findings could be used to expand the intended use of EmboGuide to include PAE.

Benefits and advances of Cone Beam CT use in prostatic artery embolization: review of the literature and pictorial essay

Prostatic artery embolization (PAE) has proven to be an efficacious treatment for urinary symptoms of benign prostatic hyperplasia. PAE is performed in a complex and challenging anatomical field which may pose difficulties from procedural standpoint. Cone beam computed tomography (CBCT) has been proposed as an invaluable tool during the PAE procedure. A review of different techniques and advancements, as well as demonstration of CBCT benefits via a pictorial overview of the salient examples is lacking. The techniques of CBCT are discussed herein and the virtual injection technology as an advancement in CBCT is discussed. To show the merits of CBCT in PAE, a pictorial overview of various clinical scenarios is presented where CBCT can be crucial in decision making. These scenarios are aimed at showing different benefits including identification of the origin of the prostatic artery and avoiding non-target embolization. Other benefits may include ensuring complete embolization of entire prostate gland as angiographic appearance alone can be inconclusive if it mimics a severely thickened bladder wall or ensuring adequate embolization of the median lobe to provide relief from "ball-valve" effect. Further examples include verification of embolization of the entire prostate when rare variants or multiple (> 2) arterial feeders are present.

Value of magnetic resonance angiography before prostatic artery embolization for intervention planning

Knowledge about anatomical details seems to facilitate the procedure and planning of prostatic artery embolization (PAE) in patients with symptomatic benign prostatic hyperplasia (BPS). The aim of our study was the pre-interventional visualization of the prostatic artery (PA) with MRA and the correlation of iliac elongation and bifurcation angles with technical success of PAE and technical parameters. MRA data of patients with PAE were analysed retrospectively regarding PA visibility, PA type, vessel elongation, and defined angles were correlated with intervention time, fluoroscopy time, dose area product (DAP), cumulative air kerma (CAK), contrast media (CM) dose and technical success of embolization. T-test, ANOVA, Pearson correlation, and Kruskal-Wallis test was applied for statistical analysis. Between April 2018 and March 2021, a total of 78 patients were included. MRA identified the PA origin in 126 of 147 cases (accuracy 86%). Vessel elongation affected time for catheterization of right PA (p = 0.02), fluoroscopy time (p = 0.05), and CM dose (p = 0.02) significantly. Moderate correlation was observed for iliac bifurcation angles with DAP (r = 0.30 left; r = 0.34 right; p = 0.01) and CAK (r = 0.32 left; r = 0.36 right; p = 0.01) on both sides. Comparing the first half and second half of patients, median intervention time (125 vs. 105 min.) and number of iliac CBCT could be reduced (p < 0.001). We conclude that MRA could depict exact pelvic artery configuration, identify PA origin, and might obviate iliac CBCT. Vessel elongation of pelvic arteries increased intervention time and contrast media dose while the PA origin had no significant influence on intervention time and/or technical success.

PAE planning: Radiation exposure and image quality of CT and CBCT

PURPOSE

To determine accurate organ doses, effective doses, and image quality of computed tomography (CT) compared with cone beam CT (CBCT) for correct identification of prostatic arteries.

METHOD

A dual-energy CT scanner and a flat-panel angiography system were used. Dose measurements (gallbladder (g), intestine (i), bladder (b), prostate (p), testes (t), active bone marrow of pelvis (bmp) and femura (bmf)) were performed using an anthropomorphic phantom with 65 thermoluminescent dosimeters in the pelvis and abdomen region. For the calculation of the contrast-to-noise ratio (CNR) of the pelvic arteries, a patient whose weight and height were almost identical to those of the phantom was selected for each examination type.

RESULTS

The effective dose of CT was 2.7 mSv and that of CBCT was 21.8 mSv. Phantom organ doses were lower for CT than for CBCT in all organs except the testes (g: 1.2 mGy vs. 3.3 mGy, i: 5.8 mGy vs. 23.9 mGy, b: 6.9 mGy vs. 19.4 mGy, p: 6.4 mGy vs. 13.2 mGy, t: 4.7 mGy vs. 2.4 mGy, bmp: 5.1 mGy vs. 18.2 mGy, bmf: 3.3 mGy vs. 6.6 mGy). For human pelvic arteries, the CNR of CT was better than that of CBCT, with the exception of one prostate artery that showed stenosis on CT. Evaluation by experienced radiologists also confirmed the better detectability of prostate arteries on CT examination.

CONCLUSIONS

In our study preprocedural CT had lower organ doses and better image quality comparedd with CBCT and should be considered for the correct identification of prostatic arteries.

Virtual Injection Software Reduces Radiation Exposure and Procedural Time of Prostatic Artery Embolization Performed with Cone-Beam CT

PURPOSE

To evaluate the impact of virtual injection software (VIS) use during cone-beam computed tomography (CT)-guided prostatic artery embolization (PAE) on both patient radiation exposure and procedural time.

MATERIALS AND METHODS

This institutional review board (IRB)-approved comparative retrospective study analyzed the treatment at a single institution of 131 consecutive patients from January 2020 to May 2022. Cone-beam CT was used with (Group 1, 77/131; 58.8%) or without VIS (Group 2, 54/131, 41.2%). Radiation exposure (number of digital subtraction angiography [DSA] procedures), dose area product (DAP), total air kerma (AK), peak skin dose (PSD), fluoroscopy time (FT), and procedure time (PT) were recorded. The influences of age, body mass index, radial access, and use of VIS were assessed.

RESULTS

In bivariate analysis, VIS use (Group 1) showed reduction in the number of DSA procedures (8.6 ± 3.7 vs 16.8 ± 4.3; P < .001), DAP (110.4 Gy·cm2 ± 46.8 vs 140.5 Gy·cm2 ± 61; P < .01), AK (642 mGy ± 451 vs 1,150 mGy ± 637; P = .01), PSD (358 mGy ± 251 vs 860 mGy ± 510; P = .001), FT (35.6 minutes ± 15.4 vs 46.6 minutes ± 20; P = .001), and PT (94.6 minutes ± 41.3 vs 115.2 minutes ± 39.6, P = .005) compared to those in Group 2. In multivariate analysis, AK, PSD, FT, and PT reductions were associated with VIS use (P < .001, P < .001, P = .001, and P = .006, respectively).

CONCLUSIONS

The use of VIS during PAE performed under cone-beam CT guidance led to significant reduction in patient radiation exposure and procedural time.

Benefits of Repeat Prostatic Artery Embolization on Persistent or Recurrent Lower Urinary Tract Symptoms in Patients with Benign Prostatic Hyperplasia

OBJECTIVES

To evaluate the benefits of repeat prostatic artery embolization (rePAE) for patients with persistent or recurrent symptoms after initial prostatic artery embolization (PAE).

MATERIALS AND METHODS

This is a single-center retrospective study of all patients who underwent a rePAE between December 2014 and November 2020 for persistent or recurrent lower urinary tract symptoms. Symptoms were assessed before and after PAE and rePAE, using the International Prostate Symptom Score and quality of life (QoL) questionnaires. Patient characteristics, anatomical presentations, technical success rates, and complications of both procedures were collected. Clinical failure was defined as one of the following: less than 2 points' decrease in QoL, a QoL score higher than 3, acute urinary retention, and secondary surgery.

RESULTS

A total of 21 consecutive patients (mean age: 63.8 ± 8.1; [40-75] years) who underwent rePAE were included. The median follow-up after PAE was 27.7 [18.1-36.9]) months and 8.9 [3.4-10.8] months after rePAE. rePAE was performed at a mean of 19 ± 11.1 [6.9-49.6] months following PAE, and the overall clinical success rate was 33% (7/21). In patients undergoing rePAE because of persistent symptoms, the clinical success rate (18%) was non-significantly lower than that for patients treated for recurrent symptoms (50%) [OR 4.5 (95% CI 0.63-32 P = 0.13)]. The main anatomical revascularization pattern was recanalization of the native prostatic artery (29/45, 66%).

CONCLUSION

Patients who experience recurrent symptoms after PAE may benefit more from rePAE than those with persistent symptoms after PAE. Clinical success rates seem to be relatively low in both clinical scenarios.

Radiation Exposure during Prostatic Artery Embolization: A Single Institution Review

ABSTRACT

Prostate artery embolization is a minimally invasive treatment for benign prostatic hyperplasia, and imaging is indispensable for the technical success of this procedure; however, imaging is a major source of radiation exposure for patients and healthcare providers. Radiation emission during prostate artery embolization procedures at a single institution was evaluated to determine radiation exposure with the goal to work toward minimizing exposure. All patients at a single institution that underwent outpatient unilateral/bilateral prostate artery embolization between 4 January 2019 and 16 November 2021 were retrospectively evaluated; data collected included body mass index, prostate volume, and indications for prostate artery embolization. Technical parameters recorded were air kerma, procedure time, fluoroscopy time, number of acquisitions, and intra-procedural imaging modalities. Fisher's t-test, ANOVA, and chi-square analyses were used as appropriate for statistical analysis (P < 0.05). Overall, 56 patients were included in the study. Body mass index (obesity; P = 0.0017) was a significant predictor of increased air kerma; prostate size and bilateral vs. unilateral prostate artery embolization were not significantly associated with increased air kerma despite the number of acquisitions being significantly different between bilateral and unilateral embolization (P = 0.0064). When evaluating radiation exposure during prostate artery embolization, increased body mass index significantly predicted increased air kerma. Contrary to the literature, the extent of embolization (bilateral vs. unilateral) was not associated with increased air kerma regardless of higher acquisitions and procedure time associated with bilateral prostate artery embolization. Increased radiation protection efforts should be considered for patients with higher body mass index to protect patients and practitioners.Health Phys. 124(0):000-000; 2023.

Cone Beam CT with Automatic vessel Detection Software versus Conventional 2D Fluoroscopy with Overlay for Prostate Artery Embolization: A Comparison of Prostatic Artery Catheterization Time and Radiation Exposure

Purpose To evaluate the effect of cone-beam computed tomography (CT) with automatic vessel detection software on prostate artery catheterization and fluoroscopy time in prostate artery embolization (PAE).

Methods Fifty patients undergoing PAE for BPH were enrolled in this prospective study. Twenty-five PAEs were performed using automatic vessel detection software with syngo embolization guidance (study) and were compared with 25 PAEs performed using conventional two-dimensional (2D) fluoroscopy with overlay (control). PAE was performed using 300–500 μm trisacryl gelatin spherical particles. The primary outcome parameters were prostatic artery catheterization time and fluoroscopy time.

Results Bilateral PAE was achieved in 24/25 cases in both groups. The median right and left prostatic artery catheterization times were similar between the two groups, (p = 0.473 and p = 0.659, respectively). The median fluoroscopy time (28.0 and 42.0 minutes, p = 0.046) and total procedure time (70.0 and 118.0 minutes, p < 0.001) were shorter in the study group. The median total dose area product (DAP) was not significantly different. However, the median CBCT DAP (11406 vs. 6248, p < 0.001) was higher in the study group, while median fluoroscopy DAP (7371 vs. 8426, p < .049) was higher in the control group. Median digital subtraction angiography (DSA), CBCT, and fluoroscopy DAP accounted for 27%, 45%, and 29% of the total DAP in the study group and 32%, 29%, and 39% in the control group (p < 0.001), respectively. All complications were Clavien–Dindo Grade 1.

Conclusion Although CBCT with automatic vessel detection software had no significant effect on time-to-prostatic artery catheterization and total radiation exposure, it reduced the fluoroscopy time and procedure time.

Prostatic Artery Embolization for Benign Prostatic Hyperplasia—A Primer for Interventional Radiologists

Male patients over 50 years with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) are potential candidates for prostatic artery embolization (PAE). PAE is not a perfect fit for all BPH patients. Careful pre- and postpostprocedural evaluation/consultation with correct selection of patients should be tailored on an individual basis. Evaluated parameters include the following: LUTS severity quantification with validated questionnaires as the international prostate symptom score (IPSS) and quality of life (QoL), erectile and ejaculatory evaluation with validated questionnaires, blood tests including full blood count, coagulation profile, renal function and total/free prostate-specific antigen (PSA), prostate volume measured by multiparametric magnetic resonance (mpMR) of the prostate and/or transrectal ultrasound, uroflowmetry measuring the peak urinary flowrate (Qmax), and postvoid residual urine (PVR). Correct arterial anatomy identification with either computed tomography (CT) angiography, MR angiography, or intraprocedural cone-beam CT (CBCT) are suggested for a confident procedure and avoiding potential complications. The minimally invasive nature of PAE with a faster recovery, preserving the sexual function, and comparable results to standard prostatic surgery make the procedure an attractive choice for many male patients suffering with this condition. Patients should be informed about the potential for higher retreatment rates and shorter duration of treatment effect when compared with standard prostatic surgery. In this comprehensive review, we provide an updated toolbox for all interventional radiologists interested in the PAE practice for patients with BPH. We explain how to evaluate patients during consultation before and after PAE, describe the preprocedural imaging required, explain the technique, and narrate how to optimize outcomes. Finally, we review the level of evidence of PAE for BPH.

Center experience and other determinants of patient radiation exposure during prostatic artery embolization: a retrospective study in three Scandinavian centers

OBJECTIVES

To evaluate the effects of center experience and a variety of patient- and procedure-related factors on patient radiation exposure during prostatic artery embolization (PAE) in three Scandinavian centers with different PAE protocols and levels of experience. Understanding factors that influence radiation exposure is crucial in effective patient selection and procedural planning.

METHODS

Data were collected retrospectively for 352 consecutive PAE procedures from January 2015 to June 2020 at the three centers. Dose area product (DAP (Gy·cm²)) was selected as the primary outcome measure of radiation exposure. Multiple patient- and procedure-related explanatory variables were collected and correlated with the outcome variable. A multiple linear regression model was built to determine significant predictors of increased or decreased radiation exposure as reflected by DAP.

RESULTS

There was considerable variation in DAP between the centers. Intended unilateral PAE (p = 0.03) and each 10 additional patients treated (p = 0.02) were significant predictors of decreased DAP. Conversely, increased patient body mass index (BMI, p < 0.001), fluoroscopy time (p < 0.001), and number of digital subtraction angiography (DSA) acquisitions (p < 0.001) were significant predictors of increased DAP.

CONCLUSIONS

To minimize patient radiation exposure during PAE radiologists may, in collaboration with clinicians, consider unilateral embolization, pre-interventional CTA for procedure planning, using predominantly anteroposterior (AP) projections, and limiting the use of cone-beam CT (CBCT) and fluoroscopy.

KEY POINTS

• Growing center experience and intended unilateral embolization decrease patient radiation exposure during prostatic artery embolization. • Patient BMI, fluoroscopy time, and number of DSA acquisitions are associated with increased DAP during procedures. • Large variation in radiation exposure between the centers may reflect the use of CTA before and CBCT during the procedure.

Prostatic Artery Embolization: Indications, Preparation, Techniques, Imaging Evaluation, Reporting, and Complications

Benign prostatic hyperplasia (BPH) is a noncancerous growth of the transitional zone of the prostate, which surrounds the prostatic urethra. Consequently, it can cause lower urinary tract symptoms (LUTS) and bladder outlet obstruction symptoms that may substantially reduce a patient's quality of life. Several treatments are available for BPH, including medications such as α-blockers and 5α-reductase inhibitors and surgical options including transurethral resection of the prostate and prostatectomy. Recently, prostatic artery embolization (PAE) has emerged as a minimally invasive treatment option for selected men with BPH and moderate to severe LUTS. Adequate pre- and postprocedural evaluations with clinical examinations and questionnaires, laboratory tests, and urodynamic and imaging examinations (particularly US, MRI, and CT) are of key importance to achieve successful treatment. Considering that the use of PAE has been increasing in tertiary hospital facilities, radiologists and interventional radiologists should be aware of the main technical concepts of PAE and the key features to address in imaging reports in pre- and postprocedural settings. An invited commentary by Lopera is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Advanced image guidance for prostatic artery embolization - a multicenter technical note

BACKGROUND

Prostatic artery embolization (PAE) is associated with patients' quality of life improvements and limited side effects compared to surgery. However, this procedure remains technically challenging due to complex vasculature, anatomical variations and small arteries, inducing long procedure times and high radiation exposure levels both to patients and medical staff. Moreover, the risk of non-target embolization can lead to relevant complications. In this context, advanced imaging can constitute a solid ally to address these challenges and deliver good clinical outcomes at acceptable radiation levels.

MAIN TEXT

This technical note aims to share the consolidated experience of four institutions detailing their optimized workflow using advanced image guidance, discussing variants, and sharing their best practices to reach a consensus standardized imaging workflow for PAE procedure, as well as pre and post-operative imaging.

CONCLUSIONS

This technical note puts forth a consensus optimized imaging workflow and best practices, with the hope of helping drive adoption of the procedure, deliver good clinical outcomes, and minimize radiation dose levels and contrast media injections while making PAE procedures shorter and safer.

Prostatic Artery Embolization for Benign Prostatic Hyperplasia: Anatomical Aspects and Radiation Considerations from a Case Series of 210 Patients

Context Prostatic artery embolization (PAE) has been established as a safe and effective treatment option for symptomatic benign prostatic hyperplasia (BPH). Thorough knowledge of detailed prostatic artery (PA) anatomy is essential.

Aims The aim of this study was to provide a pictorial review of PA anatomy and prevalence of related anatomical variants, in addition to other anatomical and radiation dose considerations.

Settings and Design Case series and review of literature.

Materials and Methods We performed PAE for 210 patients from November 2015 to November 2020 under local anesthesia only. Anatomy, procedure duration, fluoroscopy time, radiation dose, technical success, and complications were analyzed.

Statistical Analysis Used Descriptive statistics were analyzed using Microsoft Excel software.

Results A total of 210 patients (420 sides) were analyzed. Double arterial supply on the same side was noted in 12 patients (5.7%). In 10 patients (4.7%), only a unilateral PA was identified. In two patients (0.9%), no PA could be identified. Frequencies of PA origins were calculated. Penile, rectal, and vesical anastomoses were identified with 79 (18.8%), 54 (12.9%), and 41 (9.8%) of PAs, respectively. Median skin radiation dose, procedure time, and fluoroscopy time were 505 mGy, 73 and 38 minutes, respectively. Complications occurred in nine patients (4.3%), none of them was major.

Conclusions Knowledge of PA anatomy is essential when treating BPH by PAE for optimum results. There is no enough evidence to support routine use of preoperative computed tomography angiography and intraoperative cone-beam computed tomography as means of improving safety or efficacy.

Limiting radiation exposure during prostatic arteries embolization: influence of patient characteristics, anatomical conditions, and technical factors

OBJECTIVE

To assess the influence of patient characteristics, anatomical conditions, and technical factors on radiation exposure during prostatic arteries embolization (PAE) performed for benign prostatic hyperplasia.

MATERIALS AND METHODS

Patient characteristics (age, body mass index (BMI)), anatomical conditions (number of prostatic arteries, anastomosis), and technical factors (use of cone beam computed tomography (CBCT), large display monitor (LDM), and magnification) were recorded as well as total air kerma (AK), dose area product (DAP), fluoroscopy time (FT), and number of acquisitions (NAcq). Associations between potential dose-influencing factors and AK using univariate analysis and a multiple linear regression model were assessed.

RESULTS

Forty-one consecutive men (68 ± 8 years, min-max: 40-76) were included. LDM and CBCT decreased the use of small field of view with 13.9 and 3.8% respectively, both p < 0.001. The use of a LDM significantly reduced AK (1006.6 ± 471.7 vs. 1412 ± 754.6 mGy, p = 0.02), DAP (119.4 ± 64.4 vs. 167.9 ± 99.2, p = 0.04), FT (40.4 ± 11.5 vs. 53.6 ± 25.5 min, p = 0.01), and NAcq (16.3 ± 6.3 vs. 18.2 ± 7, p = 0.04). In multivariate analysis, AK reduction was associated with lower patient BMI (β = 0.359, p = 0.002), shorter FT (β = 0.664, p < 0.001) and CBCT use (β = - 0.223, p = 0.03), and decreased NAcq (β = 0.229, p = 0.04).

CONCLUSION

LDM and CBCT are important technical dose-related factors to help reduce radiation exposure during PAE, and should be considered in standard practice.

KEY POINTS

• The use of large display monitor (LDM) and cone beam computed tomography (CBCT) both decreased the need for magnification during prostatic arteries embolization (PAE). • The use of LDM reduces radiation exposure during PAE. • Total air kerma is associated with patient's body mass index, fluoroscopy time, CBCT, and the number of acquisitions.

Prostatic Artery Embolization: Influence of Cone-Beam Computed Tomography on Radiation Exposure, Procedure Time, and Contrast Media Use

Purpose

To evaluate the effect of cone-beam computed tomography (CBCT) on radiation exposure, procedure time, and contrast media (CM) use in prostatic artery embolization (PAE).

Materials and Methods

Seventy-eight patients were enrolled in this retrospective, single-center study. All patients received PAE without (group A; n = 39) or with (group B; n = 39) CBCT. Total dose-area product (DAP_total; Gycm²), total entrance skin dose (ESD_total; mGy), and total effective dose (ED_total; mSv) were primary outcomes. Number of digital subtraction angiography (DSA) series, CM use, fluoroscopy time, and procedure time were secondary outcomes. PAE in group A was performed by a single radiologist with 15 years experience, PAE in group B was conducted by four radiologists with 4 to 6 years experience.

Results

For groups A vs. B, respectively, median (IQR): DAP_total 236.94 (186.7) vs. 281.20 (214.47) Gycm²(p = 0.345); ED_total 25.82 (20.35) vs. 39.84 (23.75) mSv (p =  < 0.001); ESD_total 2833 (2278) vs. 2563 (3040) mGy(p = 0.818); number of DSA series 25 (15) vs. 23 (10)(p = 0.164); CM use 65 (30) vs. 114 (40) mL(p =  < 0.001); fluoroscopy time 23 (20) vs. 28 (25) min(p = 0.265), and procedure time 70 (40) vs.120 (40) min(p =  < 0.001). Bilateral PAE was achieved in 33/39 (84.6%) group A and 32/39 (82.05%) group B(p = 0.761), all other patients received unilateral PAE. There were no significant differences between clinical parameters and origins of the prostatic arteries (PA) (p = 0.206–1.00).

Conclusion

Operators with extensive expertise on PAE may not benefit from addition of CBCT to DSA runs, whereas for operators with less expertise, CBCT when used alongside with DSA runs increased the overall radiation exposure.

Motion Reduction for C-Arm Computed Tomography of the Pulmonary Arteries: Image Quality of a Motion Correction Algorithm in Patients with Chronic Thromboembolic Hypertension During Balloon Pulmonary Angioplasty

PURPOSE

 To evaluate the feasibility and image quality of a motion correction algorithm for supra-selective C-arm computed tomography (CACT) of the pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing balloon pulmonary angioplasty (BPA).

MATERIALS & METHODS

 CACT raw data acquired during 30 consecutive BPAs were used for image reconstruction using either standard (CACTorg) or a motion correction algorithm (CACTmc), using 400 iterations. Two readers independently evaluated 188 segmental and 564 sub-segmental contrast-enhanced pulmonary arteries in each reconstruction. The following categories were assessed: Sharpness of the vessel, motion artifacts, delineation of bronchial structures, vessel geometry, and visibility of treatable lesions. The mentioned criteria were rated from grade 1 to grade 3: grade 1: excellent quality; grade 2: good quality; grade 3: poor/seriously impaired quality. Inter-observer agreement was calculated using Cohen's Kappa. Due to an excellent agreement, the ratings of both readers were merged. Differences in the assessed image quality criteria were evaluated using pairwise Wilcoxon signed-rank test.

RESULTS

 Inter-observer agreement was excellent for all evaluated image quality criteria (κ > 0.81). For all assessed image quality criteria, the ratings on CACTorg were good but improved significantly for CACTmc to excellent for the whole vascular tree (p < 0.01). When considering segmental and sub-segmental levels individually, all image quality criteria improved significantly for CACTmc on both levels (p < 0.01). While ratings of CACTmc were constant for both levels (segmental and sub-segmental) for all criteria, the ratings of CACTorg were slightly impaired for the sub-segmental arteries.

CONCLUSION

 Motion correction for supra-selective contrast-enhanced CACT of the pulmonary arteries is feasible and improves the overall image quality.

KEY POINTS

  · Motion artifacts can severely impair the diagnostic accuracy of CACT.. · A motion correction algorithm can significantly improve image quality in CACT of the pulmonary arteries.. · Especially the overall image quality of sub-segmental branches is significantly improved..

CITATION FORMAT

· Maschke S, Werncke T, Becker LS et al. Motion Reduction for C-Arm Computed Tomography of the Pulmonary Arteries: Image Quality of a Motion Correction Algorithm in Patients with Chronic Thromboembolic Hypertension During Balloon Pulmonary Angioplasty. Fortschr Röntgenstr 2021; 193: 1074 - 1080.

Transjugular intrahepatic portosystemic shunt placement: portal vein puncture guided by 3D/2D image registration of contrast-enhanced multi-detector computed tomography and fluoroscopy

Background

To assess the technical feasibility, success rate, puncture complications and procedural characteristics of transjugular intrahepatic portosystemic shunt (TIPS) placement using a three-dimensional vascular map (3D-VM) overlay based on image registration of pre-procedural contrast-enhanced (CE) multi-detector computed tomography (MDCT) for portal vein puncture guidance.

Materials and methods

Overall, 27 consecutive patients (59 ± 9 years, 18male) with portal hypertension undergoing elective TIPS procedure were included. TIPS was guided by CE-MDCT overlay after image registration based on fluoroscopic images. A 3D-VM of the hepatic veins and the portal vein was created based on the pre-procedural CE-MDCT and superimposed on fluoroscopy in real-time. Procedural characteristics as well as hepatic vein catheterization time (HVCT), puncture time (PT), overall procedural time (OPT), fluoroscopy time (FT) and the dose area product (DAP) were evaluated. Thereafter, HVCT, PT, OPT and FT using 3D-VM (61 ± 9 years, 14male) were compared to a previous using classical fluoroscopic guidance (53 ± 9 years, 21male) for two interventional radiologist with less than 3 years of experience in TIPS placement.

Results

All TIPS procedure using of 3D/2D image registered 3D-VM were successful with a significant reduction of the PSG (p < 0.0001). No clinical significant complication occurred. HVCT was 14 ± 11 min, PT was 14 ± 6 min, OPT was 64 ± 29 min, FT was 21 ± 12 min and DAP was 107.48 ± 93.84 Gy cm². HVCT, OPT and FT of the interventionalist with less TIPS experience using 3D/2D image registered 3D-VM were statistically different to an interventionalist with similar experience using fluoroscopic guidance (p_HVCT = 0.0022; p_OPT = 0.0097; p_FT = 0.0009). PT between these interventionalists was not significantly different (p_PT = 0.2905).

Conclusion

TIPS placement applying registration-based CE-MDCT vessel information for puncture guidance is feasible and safe. It has the potential to improve hepatic vein catherization, portal vein puncture and radiation exposure.

Prostate artery embolization has long term efficacy for treatment of severe lower urinary tract symptoms from giant prostatic hyperplasia

Background

Patients with severe lower urinary tract symptoms (LUTS) from giant prostatic hyperplasia (GPH): prostate volume greater than 200 mL that do not respond to medical therapy may not be eligible for surgical treatments due to morbidities, technical challenges, and patient preference. This retrospective investigation examined the long-term efficacy and safety of prostatic arterial embolization (PAE) as a treatment option for severe LUTS due to GPH in a large patient cohort.

Methods

Of 529 patients who underwent PAE between January 2016 and January 2020, 72 patients had severe LUTS from GPH and were retrospectively evaluated. PAE was performed with two embolic agents in sequence: 100–250 μm particles followed by 2 mm and 3 mm coils. Clinical assessment was performed with international prostate symptoms score (IPSS), quality of life (QoL), peak flow rate (Qmax), post-void residual volume (PVR), and prostate specific antigen (PSA) measurements before and 12 months and 24 months after PAE. Prostate volume (PV) was measured by multiparametric magnetic resonance (MR) imaging before and 12 months and 24 months after PAE.

Results

Patients with severe LUTS from GPH experienced significant clinical improvements in IPSS, QoL, Qmax, PVR, PSA, and PV at 12 months and 24 months after PAE. Mean IPSS decreased from 26.5 to 18.0 (P < 0.01) to 10.5 (P < 0.01). Mean QoL decreased from 6.0 to 4.0 (P < 0.01) to 2.0 (P < 0.01). Mean Qmax increased from 8.0 to 14 mL/s (P < 0.01) to 18 mL/s (P < 0.01). Mean PVR decreased from 198.0 to 152.0 mL (P < 0.01) to 90 mL (P < 0.01). Mean PV decreased from 303.0 mL to 258.0 mL (P < 0.01) to 209.0 mL (P < 0.01). Mean PSA decreased from 11.2 ng/mL to 9.5 ng/mL (P < 0.05) to 7.9 ng/mL (P < 0.05). No major complications occurred.

Conclusions

PAE is a safe treatment with long term efficacy for severe LUTS from GPH. PAE may be a viable therapeutic option for patients with severe LUTS from GPH whom fail medical therapy and are not candidates for surgical treatments.

Influence of Interventionists' Experience on Radiation Exposure of Patients Who Underwent Prostate Artery Embolization: 4-Year Results from a Retrospective, Single-Center Study

PURPOSE

To assess radiation exposure in men undergoing prostate artery embolization (PAE) for the treatment for symptomatic, benign prostatic hyperplasia depending on growing experience of interventional radiologists over a 4-year period.

METHODS

A total of 250 consecutive patients underwent PAE at a single center. Data on radiation exposure [dose area product (DAP), effective dose (ED), entrance skin dose (ESD), and fluoroscopy time (FT)] were retrospectively evaluated. Primary outcomes of interest were patient radiation exposure in five consecutive groups of 50 patients each and Pearson correlation with the number of patients treated.

RESULTS

Median DAP, ED, and ESD during prostate artery embolization were significantly higher in the first compared to the second 50 patients (56 298 µGym² vs. 24 709 µGym², p < 0.001, 146.4 mSv vs. 64.2 mSv, p < 0.001, and 5.1 Gy vs. 2.4 Gy, p < 0.001, respectively). The following consecutive groups did not differ significantly from the respective preceding group in terms of DAP, ED, and ESD. Number of digital subtraction angiography series, FT, and procedure time decreased with increasing operator experience (Pearson's r = - 0.240, p < 0.001, r = - 0.269, p < 0.001, and r = - 0.504, p < 0.001, respectively). Bilateral prostate artery embolization was associated with less ESD and shorter FT than unilateral embolization (median 2.5 vs. 3.5 Gy, p = 0.02, and 26 min vs. 42 min, p < 0.001, respectively).

CONCLUSION

Exposure to radiation in men who underwent PAE decreased with growing operator experience and decreasing complexity of procedures.

Prostatic Artery Embolization-Anatomic Predictors of Technical Outcomes

PURPOSE

To determine if cone-beam CT and digital subtraction angiography analysis of pelvic arterial anatomy has predictive value for radiation exposure and technical success of prostatic artery embolization (PAE).

MATERIALS AND METHODS

This prospective, nonrandomized, single-center study included 104 consecutive patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia. Cone-beam CT was performed in 160/208 (76.9%) hemipelves to determine prostatic artery (PA) origin. Classification of pelvic arterial tortuosity was possible in 73/104 (70.2%) patients. Learning curves of 2 interventionalists who performed 86.5% of PAEs were analyzed.

RESULTS

Tortuosity of pelvic arteries was classified as mild in 25 (34.2%) patients median age 64 years, moderate in 40 (54.8%) patients median age 69 years, and severe in 8 (11.0%) patients median age 70 years (mild vs moderate, P = .002; mild vs severe, P = .019); median fluoroscopy times were 24, 36, and 46 minutes (P = .008, P = .023); median contrast volumes were 105, 122.5, and 142 mL (P = .029, P = .064); and bilateral PAE rates were 84.0%, 77.5%, and 62.5% (P = .437), respectively. PA origin from superior vesical artery was most frequent (27.5%) and showed higher dose area product (median 402.4 vs 218 Gy ∙ cm², P = .033) and fluoroscopy time (median 42.5 vs 27 min, P = .01) compared with PA origin from obturator artery, which was least frequent. Interventionalist experience revealed significant impact on procedure times (median 159 vs 130 min, P = .006).

CONCLUSIONS

Tortuosity of pelvic arteries was more frequent in older patients and predicted worse technical outcomes of PAE. PA origin from obturator artery was associated with lower dose area product and fluoroscopy time, especially compared with PA origin from superior vesical artery. Interventionalist experience showed significant influence on technical outcome.