Two-dimensional Perfusion Angiography Research Articles

Two-dimensional perfusion angiography permits direct visualization of redistribution of flow in hepatocellular carcinoma during b-TACE.

To demonstrate in vivo redistribution of the blood flow towards HCC's lesions by utilizing two-dimensional perfusion angiography in b-TACE procedures. In total, 30 patients with 35 HCC nodules treated in the period between January 2019 and November 2021. For each patient, a post-processing software leading to a two-dimensional perfusion angiography was applied on each angiography performed via balloon microcatheter, before and after inflation. On the colour map obtained, reflecting the evolution of contrast intensity change over time, five regions of interests (ROIs) were assessed: one on the tumour (ROI-t), two in the immediate peritumoural healthy liver parenchyma (ROI-ihl) and two in the peripheral healthy liver parenchyma (ROI-phl). The results have been interpreted with a novel in silico model that simulates the hemodynamics of the hepatic arterial system. Among the ROIs drawn inside the same segment of target lesion, the time-to-peak of the ROI-t and of the ROI-ihl have a significantly higher mean value when the balloon was inflated compared with the ROIs obtained with deflated balloon (10.33 ± 3.66s vs 8.87 ± 2.60s (p = 0.015) for ROI-t; 10.50 ± 3.65s vs 9.23 ± 2.70s (p = 0.047) for ROI-ihl). The in silico model prediction time-to-peak delays when balloon was inflated, match with those observed in vivo. The numerical flow analysis shows how time-to-peak delays are caused by the obstruction of the balloon-occluded artery and the opening of intra-hepatic collateral. The measurements identify predictively the flow redistribution in the hepatic arteries during b-TACE, supporting a proper positioning of the balloon microcatheter.

Clinical Applications of Quantitative Perfusion Imaging with a C-Arm Flat-Panel Detector-A Systematic Review.

C-arm systems with digital flat-panel detectors are used in interventional radiology and hybrid operating rooms for visualizing and performing interventions on three-dimensional structures. Advances in C-arm technology have enabled intraoperative quantitative perfusion imaging with these scanners. This systematic review provides an overview of flat-panel detector C-arm techniques for quantifying perfusion, their clinical applications, and their validation. A systematic search was performed for articles published between January 2000 and October 2022 in which a flat-panel detector C-arm technique for quantifying perfusion was compared with a reference technique. Nine articles were retrieved describing two techniques: two-dimensional perfusion angiography (n = 5) and dual-phase cone beam computed tomography perfusion (n = 4). A quality assessment revealed no concerns about the applicability of the studies. The risk of bias was relatively high for the index and reference tests. Both techniques demonstrated potential for clinical application; however, weak-to-moderate correlations were reported between them and the reference techniques. In conclusion, both techniques could add new possibilities to treatment planning and follow-up; however, the available literature is relatively scarce and heterogeneous. Larger-scale randomized prospective studies focusing on clinical outcomes and standardization are required for the full understanding and clinical implementation of these techniques.

Abstract No. 476 Two-dimensional perfusion angiography of hepatic tumors at the time of Yttrium-90 transarterial radio-embolization mapping

Abstract No. 476 Two-dimensional perfusion angiography of hepatic tumors at the time of Yttrium-90 transarterial radio-embolization mapping

Abstract No. 416 Two-dimensional perfusion angiography and its suitability in diagnosing and documenting early treatment response in patients with non-occlusive mesenteric ischemia: a retrospective analysis

Evaluation of the feasibility of 2D-perfusion angiography (2D-PA) in assessing the intraprocedural treatment response of the splanchnic vessel territory after vasodilatory therapies in patients suffering from non-occlusive mesenteric ischemia (NOMI). 19 procedures in 17 NOMI patients (mean age, 60.9 ± 11 years) were included in this retrospective study. We performed postprocessing of the acquired digital subtraction angiography (DSA) series to evaluate flow and perfusion changes after vasodilatory prostaglandin therapy. We placed target regions of interest (ROIs) in the portal vein, the aorta, and a reference ROI in the superior mesenteric artery (SMA). The peak density (PD), time to peak (TTP) and area under the curve (AUC) were then assessed and the following ratios ‘target ROI (TTP, AUC)/ reference ROI’ computed. Furthermore, the simplified NOMI score was assessed pre- and post-NOMI therapy. Significant changes could be recorded in the individual categories as well as in the overall simplified NOMI score following interventional NOMI therapy (4 to 1, P <0.0001). Both PD and AUC values in the aorta decreased significantly pre- to postinterventionally (PD: P = 0.04; AUC: P = 0.03), while the AUC in the portal vein (PV) was significantly increased (P = 0.04) after prostaglandin application. Though without statistical significance, TTP measured in the PV demonstrated an increase after vasodilator therapy as well (P = 0.13). Our findings are in concordance with the simplified NOMI score. 2D-PA is a suitable method for the analysis of immediate perfusion changes following vasodilatory therapies of NOMI patients and may be a valuable addition to previously published angiographic scoring systems, such as the subjective simplified NOMI score.

Below-the-Ankle Arrival Time as a Novel Limb Tissue Perfusion Index: Two-dimensional Perfusion Angiography Evaluation

Purpose: To identify lower limb 2-dimensional (2D) perfusion angiographic parameters that are related to skin perfusion pressure (SPP), a predictor of wound healing in patients with chronic limb-threatening ischemia (CLTI) undergoing below-the-knee (BTK) endovascular treatment (EVT). Materials and Methods: Thirty-three consecutive patients (mean age 74.5 years; 18 men) with 47 isolated BTK lesions in 33 limbs (Rutherford category 3–5) underwent EVT. Dorsal and plantar SPPs were measured before EVT and the day after. The indexed blood flow below the ankle was measured using 2D perfusion angiography before and after EVT to determine changes in perfusion parameters [arrival time (AT), time to peak, wash-in rate, mean transit time, and width and area under the time-density curve] at rest vs during hyperemia induced with a 20-mg intra-arterial papaverine infusion. Correlations between the 2D perfusion parameters and SPPs were assessed using the Pearson coefficient. The cutoff points to predict mean SPPs >40 mm Hg were analyzed using a receiver operating characteristic curve; outcomes are reported as the area under the curve (AUC) with 95% confidence interval (CI). Results: After EVT at rest and during hyperemia, only AT was significantly changed, although hyperemia produced significant changes in all the pre-/post-EVT 2D perfusion parameters except the wash-in rate. Dorsal and plantar SPPs after EVT were significantly increased and correlated with hyperemic AT and the AT ratio (hyperemia/at rest values) below the ankle. Hyperemic ATs <6.3 seconds and AT ratios <0.78 were predictive factors for a mean SPP >40 mm Hg, with AUCs of 0.83 (95% CI 0.67 to 0.99) and 0.78 (95% CI 0.61 to 0.95), respectively. Conclusion: Hyperemic ATs <6.3 seconds or AT ratios <0.78 below the ankle may be essential to obtain sufficient SPPs for limb salvage in BTK lesions. Thus, the use of 2D perfusion angiography enabled the monitoring of lower limb tissue perfusion throughout EVT and may thereby optimize treatment of CLTI.

2D perfusion-angiography during endovascular intervention for critical limb threatening ischemia - A feasibility study.

PurposeTwo-dimensional perfusion angiography is a new method to quantify and evaluate tissue perfusion during endovascular intervention. The aim was to evaluate time-patterns and dynamics of contrast arrival and distribution before and after endovascular intervention in patients with critical limb threatening ischemia.MethodsData were collected from 37 patients with critical limb threatening ischemia due to infra-inguinal occlusive disease having a successful endovascular procedure. two-dimensional perfusion angiography was used as a post-processing software with analysis of numeric parameters related to arrival and distribution patterns of contrast.ResultsThirty-three patients were successfully analysed whereas four patients were excluded due to motion artefacts. All patients were successfully treated with recanalization of the superficial femoral, popliteal, below the knee-vessels or a combination. Short-term improvement at 30-day follow-up was noted both clinically and by ankle-brachial index and toe pressure measurements. A significant reduction in contrast arrival time between pre-and post-angioplasty runs was noted as measured by arrival time median 3.2 and interquartile range (2.5–4.2) vs. 2.6 (1.6–3.4) and time-to-peak 4.1 (3.6–5.0) vs. 3.1 (2.3–3.9) p = 0.009. An increased wash-in rate was also observed 18.3 (12.6–21) vs. 30.1 (22–30.5) p = 0.001 between pre-and post-angioplasty runs.ConclusionsThe use of perfusion angiography for evaluation of foot-circulation during endovascular interventions provides new information regarding quantitative assessment of contrast inflow before and after endovascular intervention without the need for extra contrast or runs. No selective catheterisation is necessary. The technique is easily adopted in a clinical setting. Further studies are necessary to create robust clinical endpoints.

To evaluate the role of two-dimensional perfusion angiography as a predictor in wound healing outcomes in patients of critical limb ischemia

Aim: The study was aimed to evaluate the role of two-dimensional (2D) perfusion angiography (PA) as a predictor in wound healing outcomes in patients of critical limb ischemia. Subject and Methods: It was a pilot study conducted over a period of 16 months after taking informed consent and institutional ethical clearance. The study included 40 patients of which 8 were lost to follow-up, hence the prospective data of 32 patients was collected and analyzed. Patients were subjected to endovascular intervention and 2D perfusion software was applied to the digital subtraction angiography images and its parameters were assessed. Transcutaneous oxygen tension (TcPO2) was measured pre- and postintervention and patients were closely followed up for the time taken for wound healing. Results: The median age was 62 years ranging from 30 to 85 years. Most common comorbidity was diabetes (21/32 patients). The mean Ankle–Brachial Index in the study was 0.55 and mean TcPO2 at admission was 26.5 mm of Hg. Most common involved angiosome was percutaneous transluminal angioplasty angiosome. Fifteen patients underwent direct, 9 indirect, and remaining 8 patients underwent revascularization in both territories. The mean percent improvement in TcPO2 was higher in indirect when compared to direct revascularization but it was not statistically significant. The time taken in wound healing was significantly higher in diabetics when compared to nondiabetics with P = 0.03. Most reliable parameter in 2D PA was area under the curve (AUC) which correlated with increase in volume of tissue perfusion. Patients with >100% improvement in AUC showed significantly better wound healing rates when compared to patients with <100% improvement (P = 0.04). Conclusion: This proved 2D PA as a reliable method for immediate assessment of improvement in microcirculation and as a predictor for wound healing. It can also be used as a real-time tool in optimizing the need and determining the end point for revascularization.

Change in Perfusion Angiography During Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma Predicts Short-Term Outcomes.

OBJECTIVE. The purpose of this study is to quantitatively assess perfusion reductions occurring in hepatocellular carcinoma (HCC) during transcatheter arterial chemoembolization (TACE) using 2D perfusion angiography and to evaluate the relationships between various 2D perfusion angiography parameter changes and short-term tumor response. SUBJECTS AND METHODS. This prospective study included 172 patients (144 men and 28 women; mean [± SD] age, 65.4 ± 10.2 years) who underwent TACE for HCC between November 2015 and November 2017. Two-dimensional perfusion angiography was performed before and after TACE. Pre- and postprocedural CT images were also reviewed. Index lesions were defined as all discrete lesions 1.5 cm or larger. The tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors. Periprocedural 2D perfusion angiography parameters, including the arrival time, time to peak, wash-in rate, width, AUC, and mean transit time, were compared using the Wilcoxon signed rank test. Correlations between 2D perfusion angiography parameter changes and objective tumor response were evaluated using multivariate logistic regression analysis. RESULTS. A total of 187 lesions meeting the inclusion criteria were identified in 172 patients. All analyzed 2D perfusion angiography parameters were significantly different after versus before TACE (p < 0.001). A significant relationship between periprocedural change in AUC and short-term tumor response was found (odds ratio, 1.535; 95% CI, 1.314-1.793; p < 0.001). CONCLUSION. Two-dimensional perfusion angiography could objectively quantify perfusion reductions and predict short-term tumor response to TACE in patients with HCC.

Efficacy of Two-Dimensional Perfusion Angiography for Evaluations after Infrapopliteal Bypass Surgery for Critical Limb Ischemia.

Two-dimensional perfusion angiography (2DPA) is utilized in hybrid operating rooms. 2DPA produces color map images and functional parameters to provide more robust visual and quantitative evaluations than conventional angiography. Its efficacy was suggested in five patients following bypass surgery; unexpected results were obtained in one patient, leading to a decision to perform surgical re-anastomosis. Furthermore, we found that the general anesthesia eliminates body movements that tend to disrupt 2DPA results. 2DPA was more useful during surgical revascularization than conventional angiography and provided more detailed information.

3:18 PM Abstract No. 53 Changes in two-dimensional perfusion angiography before and after inferior vena cava filter retrieval

To investigate differences in hemodynamic flow parameters acquired in two-dimension (2D) perfusion angiography before and after inferior vena cava (IVC) filter retrieval. IVC filter retrievals at a single institution were retrospectively reviewed. Standardized breath-hold, digital subtraction angiography was performed at 2-3 frames per second before and after removal, and 2D-perfusion images were reconstructed on a dedicated workstation (Philips Allura Xper FD20, Philips Medical Systems, Best, Netherlands). Changes in the density per pixel per second within a region of interest (ROI) were used to calculate contrast arrival time, time-to-peak (TTP), wash-in-rate (WIR), area under the curve (AUC), and mean transit time (MTT). Measurements were obtained inferior, superior, and at the level of the filter. Differences in the hemodynamic parameters before and after filter removal were assessed with Mann-Whitney U analysis. A p-value of <0.05 was considered statistically significant. At the level of the filter, the TTP was significantly longer before filter removal when compared to after, with mean times of 1.28 and 0.78 seconds, respectively (p = 0.042). The MTT inferior to the filter was longer before filter removal when compared to after, with mean times of 0.8 and 0.5 seconds, respectively. The WIR inferior to the filter was longer before filter removal when compared to after, with mean of 435 and 250 HU/second, respectively. Preliminary data evaluating differences in flow parameters acquired in 2D-perfusion angiography before and after IVC filter retrieval demonstrate a significantly longer TTP when filters are in place, suggesting a functional hemodynamic delay secondary to filter presence.

Two-Dimensional Perfusion Angiography of the Foot

Purpose: To report the feasibility, technical considerations, and initial results of 2-dimensional (2D) perfusion angiography of the foot before and after endovascular interventions. Methods: A retrospective single-center study involved 21 patients (mean age 73.4±10.5 years; 14 men) with severe peripheral vascular disease [Fontaine stage III (n=10) or IV (n=14)] who underwent lower limb digital subtraction angiography (DSA) prior to and following endovascular treatment of above- and/or below-knee lesions. A standardized contrast administration protocol (15 mL iodixanol 320 mg I/mL at 3 mL/s via a 5/6-F antegrade sheath) was applied during DSA using a 2D perfusion–enabled image intensifier. Representative hindfoot and forefoot regions of interest were analyzed, and representative numeric density values [time to peak (TTP), peak density value (PDV), and area under the (time-density) curve (AUC)] were calculated using 2D perfusion–enabled angiographic software to assess foot perfusion. Values were compared before and after angioplasty and by level of treatment (above or below knee). The parameters were correlated with disease severity (stenosis vs occlusion) and symptom level (Fontaine stage). Results: A clinically significant improvement (29.4%) in the AUC was noted following angioplasty, reaching statistical significance within the hindfoot (p=0.03). No significant change in TTP or PDV was detected following angioplasty. Foot movement remained problematic when measuring time-density values. No statistical difference in perfusion values was appreciable between above- and below-knee angioplasty. Conclusion: Two-dimensional perfusion angiography of the foot allows quantitative evaluation using various density values with potential benefit for treatment planning and technical outcome analysis. Methodical restrictions currently remain, mainly regarding patient movement.