Contrast Injection Research Articles

Establishment of a selective puncture method of the temporomandibular joint targeting the superior and inferior joint spaces using a human cadaver under the guidance of an ultrasound device

To investigate an ultrasound-guided selective puncture method for the temporomandibular joint (TMJ), targeting superior (SJS) and inferior joint spaces (IJS), using a human cadaver. The study utilized five cadavers donated by members of our university. The cadaver's left side was aimed at the SJS, while the right side was at the IJS. Nonionic contrast was injected into each joint using a crossing technique, with the linear ultrasound probe placed parallel to the long axis of the mandibular branch and punctured perpendicularly into the joint cavity. Cone-beam computed tomography scans assessed both the TMJs examining discs and other components for damage using a gross anatomical technique. Computed tomography images confirmed successful contrast agent injection into all joint spaces without damaging the articular discs or cartilage of the mandibular head. Our findings suggest that the ultrasound device can selectively puncture the TMJ in the SJS and IJS. In the future, the success rate is expected to improve with additional cadaver punctures. We aim to establish this technique as a viable treatment method that can be performed by oral surgeons with limited clinical experience in cadaver surgery training and a surgical technique training program using human cadavers.

Impact of arthroscopy on post-procedure intra-articular elbow injections: A cadaveric study.

To determine the influence of arthroscopy and injection volume on post-procedure intra-articular (IA) injection extravasation. Ex vivo prospective study. A total of 40 paired canine cadaver forelimbs. After radiographs and computed tomography (CT) scans with three-dimensional (3D) digital bone model reconstructions, elbows were randomly assigned to the arthroscopy or control group and randomly assigned to receive an IA injection of 2 or 4 mL of contrast. Elbow arthroscopy was performed on assigned specimens, followed by IA injections of contrast in all elbows, and imaging was repeated. 3D digital model volumes were compared. Images were interpreted and scored for extravasation by a radiologist unaware of treatment and volume assignments. Based on CT images and regardless of treatment group, IA injections of 4 mL resulted in a mean extravasation score of 2.25 (SD 0.97) versus 1.55 (SD 1.05) (p = .02) for 2 mL IA injections. The change in 3D model volumes after IA injections was a mean of 13.2 cm3 (SD 5.85) after 4 mL injections, compared to 6.97 cm3 (SD 6.28) (p = .003) after 2 mL injections. On radiographic evaluation, but not CT, the mean extravasation scores were 2.45 (SD 1.15) for the arthroscopy group and 1.25 (SD 0.79) for the control group (p < .001). A larger volume of IA injection resulted in higher CT extravasation scores and larger 3D volumes regardless of arthroscopic treatment. IA injections performed immediately after arthroscopy resulted in 50% or less extravasation, especially with a smaller IA injection volume.

Comparison of Safety and Diagnostic Efficacy of Iohexol 240 mgI/mL, Iopamidol 250 mgI/mL, and Iodixanol 270 mgI/mL in Cerebral Angiography: A Prospective, Multicenter Study.

This multicenter prospective study aimed to evaluate the quality and diagnostic effectiveness of cerebral angiography images obtained using low-concentration iodinated contrast agents (iohexol 240 mgI/mL, iopamidol 250 mgI/mL, and iodixanol 270 mgI/mL) and to assess the safety thereof. The study addresses the need for safer contrast agent alternatives without compromising the diagnostic quality of identifying cerebrovascular disease. Conducted in 5 medical centers in South Korea, we enrolled patients aged 19 years or older who were referred for diagnostic cerebral angiography under non-emergency conditions, excluding those with specific health conditions and sensitivities. The study design included a prospective, observational approach with a 1-way analysis of variance (ANOVA) for sample size calculation, aiming for a total sample of 231 participants for adequate power. Image quality was evaluated using a 4-level scale by 2 independent, blinded radiologists, and adverse reactions were monitored both immediately and up to 7 days post-procedure. Statistical analysis involved 1-way ANOVA and Kruskal-Wallis tests to assess the image quality and safety profiles of the contrast agents. Among 266 patients screened, 243 were included in the final analysis. The evaluation revealed no statistically significant differences in image quality among the 3 types of low-concentration contrast agents. Adverse events were observed in 28.8% of patients, with 27.2% experiencing acute reactions, primarily mild reactions, and 3.3% experiencing delayed reactions. The overall safety profile showed no significant changes in vital signs or electrocardiogram readings before and after contrast agent injection. Using low-concentration iodinated contrast agents for cerebral angiography provides image quality comparable to that of conventional high-concentration agents, with no significant increase in adverse events, suggesting a safer alternative for patients.

Low-iodine-dose computed tomography coupled with an artificial intelligence-based contrast-boosting technique in children: a retrospective study on comparison with conventional-iodine-dose computed tomography

BackgroundLow-iodine-dose computed tomography (CT) protocols have emerged to mitigate the risks associated with contrast injection, often resulting in decreased image quality.ObjectiveTo evaluate the image quality of low-iodine-dose CT combined with an artificial intelligence (AI)-based contrast-boosting technique in abdominal CT, compared to a standard-iodine-dose protocol in children.Materials and methodsThis single-center retrospective study included 35 pediatric patients (mean age 9.2 years, range 1–17 years) who underwent sequential abdominal CT scans—one with a standard-iodine-dose protocol (standard-dose group, Iobitridol 350 mgI/mL) and another with a low-iodine-dose protocol (low-dose group, Iohexol 240 mgI/mL)—within a 4-month interval from January 2022 to July 2022. The low-iodine CT protocol was reconstructed using an AI-based contrast-boosting technique (contrast-boosted group). Quantitative and qualitative parameters were measured in the three groups. For qualitative parameters, interobserver agreement was assessed using the intraclass correlation coefficient, and mean values were employed for subsequent analyses. For quantitative analysis of the three groups, repeated measures one-way analysis of variance with post hoc pairwise analysis was used. For qualitative analysis, the Friedman test followed by post hoc pairwise analysis was used. Paired t-tests were employed to compare radiation dose and iodine uptake between the standard- and low-dose groups.ResultsThe standard-dose group exhibited higher attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of organs and vessels compared to the low-dose group (all P-values < 0.05 except for liver SNR, P = 0.12). However, noise levels did not differ between the standard- and low-dose groups (P = 0.86). The contrast-boosted group had increased attenuation, CNR, and SNR of organs and vessels, and reduced noise compared with the low-dose group (all P < 0.05). The contrast-boosted group showed no differences in attenuation, CNR, and SNR of organs and vessels (all P > 0.05), and lower noise (P = 0.002), than the standard-dose group. In qualitative analysis, the contrast-boosted group did not differ regarding vessel enhancement and lesion conspicuity (P > 0.05) but had lower noise (P < 0.05) and higher organ enhancement and artifacts (all P < 0.05) than the standard-dose group. While iodine uptake was significantly reduced in low-iodine-dose CT (P < 0.001), there was no difference in radiation dose between standard- and low-iodine-dose CT (all P > 0.05).ConclusionLow-iodine-dose abdominal CT, combined with an AI-based contrast-boosting technique exhibited comparable organ and vessel enhancement, as well as lesion conspicuity compared to standard-iodine-dose CT in children. Moreover, image noise decreased in the contrast-boosted group, albeit with an increase in artifacts.Graphical

Pathomorphological features of confirmed bronchogenic cyst with atypical localization

Among all formations of the mediastinum in the adult population, cysts make up about 20 %, of which more than 60 % are bronchogenic cysts, where up to 50% have an asymptomatic course, and therefore in most cases are detected accidentally. Regardless of the course and origin, cysts are subject to complete surgical removal. In connection with the clinical and radiological polymorphism of bronchogenic cysts, histological confirmation of the origin of the cysts does not lose its relevance. The purpose of the work is to study and highlight the pathomorphological characteristics of a cyst localized in the pericardium. Using video-assisted thoracic surgery (VATS) and thoracotomy approaches, 16 people aged 28 to 62 with cystic lesions of the mediastinum were operated on. The patients underwent radiographic examination, computed tomography with intravenous contrast injection and, in 2 cases, magnetic resonance imaging. Ultrasound examination was performed on 6 patients in whom cystic lesions were a diagnostic finding. The location of the cyst, maximum diameter, density, and calcification were evaluated. Clinically and radiologically, asymptomatic pericardial (coelomic) cysts were detected in 2 persons in the prevascular department. In the visceral part of the mediastinum, 3 patients had a pericardial cyst, 10 patients were diagnosed with 10 bronchial cysts with parenchymal and perihilar localization, among which one patient was diagnosed with an asymptomatic bronchial cyst with an atypical localization in the pericardium. In the paravertebral part of the mediastinum, 1 paraesophageal cyst was established, which was intimately connected with the lower third of the thoracic part of the esophagus. All types of cysts were histologically confirmed. Statistical processing of the obtained results was carried out using the Excel program. After a clinical examination of a patient with a pericardial cyst of the visceral mediastinum, right VATS surgery and removal of the cyst was performed. Histological examination of fragments of the cyst wall showed the presence of multi-rowed ciliated cylindrical epithelium, pronounced infiltration by lymphoid elements with hemorrhages and foci of fibrotization in separate areas. The histological structure of the removed pericardial cyst confirmed its bronchogenic origin. So, we discovered a rare form of abnormality of embryonic growth of the ventral part of the foregut with localization of a bronchogenic cyst in the anterior-inferior mediastinum on the right, which significantly expanded the understanding of the disease.

Effect of patient characteristics on aortic attenuation in iodinated contrast-enhanced Abdominopelvic CT: A retrospective study

IntroductionContrast Enhanced Computed Tomography (CECT) abdomen and pelvis is a common imaging procedure. Hospitals typically follow fixed protocols of contrast volume administration for triple-phase CECT abdomen and pelvis scans and have found that patients are either underdosed or overdosed with respect to their body habitus. The aim of the study was to correlate different patient characteristics such as Total body weight (TBW), Lean Body Mass (LBM), Body Mass Index (BMI), Body Surface Area (BSA) and Blood Volume (BV) with aortic enhancement in the arterial and portal venous phases for CECT Abdomen and pelvis. MethodsA total of 106 patients who underwent triple-phase CECT abdomen & pelvis were retrospectively studied. A circular region-of-interest (ROI) of 100 mm2 was positioned on descending aorta for unenhanced, arterial, and portal venous phases to measure the aortic enhancement in Hounsfield's units. Measure of contrast attenuation (ΔH) was calculated from the difference of CT values on unenhanced images and contrast images. Correlation analysis was performed to evaluate the relation of patient body characteristics with aortic enhancement. ResultsCorrelation analysis revealed that BMI exhibited the least correlation when compared to the other characteristics in both arterial (r = −0.3; p = 0.002) and portovenous phases (r = −0.35; p < 0.001) whereas TBW, LBW, BSA and BV reported moderate inverse correlations. BV was found to be the strongest of all characteristics under linear regression. ConclusionThe study supports the use of protocols that adjust contrast volume to either TBW, LBW, BSA, or BV for CT abdomen and pelvis scan. Implication of practiceThe right body parameter ensures optimal contrast enhancement, improving the visualization of anatomical structures and helps in adapting tailored contrast injection protocols.

Clinical audit of the image quality and customised contrast volume using P3T contrast injection software versus standard injection protocol in CT coronary angiography

IntroductionThe implications of shorter scan time and lower tube voltage in the dual-source CT coronary angiography (CTCA) scan protocol necessitate the adaptation of contrast media (CM) injection parameters. This audit evaluates the coronary arteries' vascular attenuation and image quality by comparing the personalised patient protocol technology (P3T) contrast injection software with standard injection protocol. The secondary aim is to determine the relationship between CM volume and the patient's weight. MethodologyA Siemens Somatom Definition Force CT Unit was used to scan 30 sets of patients between August 2020 and October 2020. Patients were selected retrospectively and separated into Standard Injection and P3T injection protocols. An experienced radiologist blinded to the groups reviewed the coronary vessels' contrast enhancement and image quality. ResultsOverall, the mean HU of all the main coronary artery vessels obtained from P3T injection software reached above 350 HU and was diagnostically sufficient. The mean attenuation at the proximal region of RCA in the 80–99 kg weight category was significantly higher in the P3T injection software than the standard injection protocol (p < 0.001). The CM volume proposed by P3T injection software for 40–59 kg was approximately 57 ± 5 mls, while 75 ml was used for the standard injection protocol. ConclusionP3T injection software in CTCA resulted in an adequate diagnostic attenuation of coronary arteries (>350HU) in all weight groups, most effectively in the higher weight group, while maintaining diagnostic image quality. Further, the P3T software reduces CM volumes in lower-weight patients. ImplicationsP3T software enables reducing CM volume in lower-weight patients while improving vascular enhancement in CTCA scans in higher-weight patients.

Meningeal contrast enhancement in multiple sclerosis: Assessment of field strength, acquisition delay, and clinical relevance.

Leptomeningeal enhancement (LME) on post-contrast FLAIR is described as a potential biomarker of meningeal inflammation in multiple sclerosis (MS). Here we report an assessment of the impact of MRI field strength and acquisition timing on meningeal contrast enhancement (MCE). This was a cross-sectional, observational study of 95 participants with MS and 17 healthy controls (HC) subjects. Each participant underwent an MRI of the brain on both a 7 Tesla (7T) and 3 Tesla (3T) MRI scanner. 7T protocols included a FLAIR image before, soon after (Gd+ Early 7T FLAIR), and 23 minutes after gadolinium (Gd+ Delayed 7T FLAIR). 3T protocol included FLAIR before and 21 minutes after gadolinium (Gd+ Delayed 3T FLAIR). LME was seen in 23.3% of participants with MS on Gd+ Delayed 3T FLAIR, 47.4% on Gd+ Early 7T FLAIR (p = 0.002) and 57.9% on Gd+ Delayed 7T FLAIR (p < 0.001 and p = 0.008, respectively). The count and volume of LME, leptomeningeal and paravascular enhancement (LMPE), and paravascular and dural enhancement (PDE) were all highest for Gd+ Delayed 7T FLAIR and lowest for Gd+ Delayed 3T FLAIR. Non-significant trends were seen for higher proportion, counts, and volumes for LME and PDE in MS compared to HCs. The rate of LMPE was different between MS and HCs on Gd+ Delayed 7T FLAIR (98.9% vs 82.4%, p = 0.003). MS participants with LME on Gd+ Delayed 7T FLAIR were older (47.6 (10.6) years) than those without (42.0 (9.7), p = 0.008). 7T MRI and a delay after contrast injection increased sensitivity for all forms of MCE. However, the lack of difference between groups for LME and its association with age calls into question its relevance as a biomarker of meningeal inflammation in MS.

Simultaneous Injection of Contrast and Saline Using Spiral Flow-Generating Tube for Hepatic Dynamic Computed Tomography: Effect on Enhancement of Liver Parenchyma and Metastases to the Liver.

Recently, there have been a few reports regarding the usefulness of a novel saline injection technique using a spiral flow-generating tube. The purpose of this study was to evaluate whether simultaneous saline injection using a spiral flow-generating tube was able to improve hepatic contrast enhancement and lesion conspicuity of metastatic liver tumors. We randomized a total of 411 patients with various liver diseases including metastases by total body weight (A, n = 204) and contrast dilution protocol (B, n = 207). Group A received 400 mgI/kg of contrast medium alone without a spiral flow-generating tube; group B received contrast medium 400 mgI/kg simultaneous with injection of a 0.57-ml/kg physiologic saline solution through a spiral flow-generating tube. Abdominal aorta computed tomography (CT) number, hepatic enhancement (ΔHU), percentage of tests demonstrating an enhancement effect of the liver parenchyma exceeding Δ50 HU in 3 measured segments (S2, S6, and S8), and the contrast-to-noise ratio of the metastatic liver tumors were measured. The mean aortic CT number of group B (417.0 HU ± 61.7; P < 0.01) was approximately 10% higher than that of group A (384.6 ± 79.1 HU). The average ΔHU was 59.8 ± 11.4 HU for group A and 61.7 ± 11.7 for group B. The ΔHU for group B was significantly higher than that for group A (P = 0.017). The percentage of tests demonstrating with the enhancement effect of group B was more than 80% in all subgroups; however, that of group A was less than 80% in all subgroups. The contrast-to-noise ratio of group B (7.8 ± 3.3 HU) was significantly higher compared to that of group A (6.5 ± 2.8 HU) (P < 0.05). Because of the volume effect, injecting a contrast medium diluted with normal saline improved the degree of hepatic and aortic contrast enhancement and achieved better visualization of liver metastases. The use of spiral flow-generating tube may help diagnostic of hepatic and aortic contrast enhancement and liver metastases. The use of a spiral flow-generating tube improved the degree of hepatic and aortic contrast enhancement and achieve better visualization of liver metastases. The use of low-concentration syringe formulations is limited by body weight. However, the use of spiral flow-generating tube provides low-concentration contrast medium regardless of body weight.

Extracellular volume measured by whole body CT scans predicts chronic cardiotoxicity in breast cancer patients treated with neoadjuvant therapies based on anthracyclines: A retrospective study

IntroductionNeoadjuvant chemotherapies for breast cancer (BC) are effective but potentially cardiotoxic, and expose long survivors at risk of chemotherapy-related cardiac dysfunction (CTRCD). Unfortunately, early screening for CTRCD has actual diagnostic limits. Myocardial extracellular volume (mECV) is a radiological marker used in cardiac CT scans and cardiac magnetic resonance for diagnosis and follow-up of CTRCD. It can be measured in whole-body CT (WB-CT) scan, routinely performed in patients at high risk of relapse, to evaluate CTRCD occurrence during oncological follow-up. Methods82 WB-CT scans were examined at baseline (T0) and during oncological follow-up at first year (T1) and fifth year (T5) after the end of neoadjuvant treatment. mECV was measured at 1 min (PP) and 5 min (DP) after contrast injection. 31 echocardiograms were retrieved in T1 to perform a linear correlation between mECV and left ventricular ejection fraction (LVEF). ResultsmECV values in T0 were similar between the two groups both in PP and in DP. Significant results were found for PP values in T1 (37.0 % vs 32 %, p = 0.0005) and in T5 (27.2 % vs 31.2 %, p = 0.025). A cut-off value of 35 % in PP proved significant in T1 (OR = 12.4, p = 0.004), while mECV was inversely correlated with LVEF both in PP (adj-S = −3.54, adj-p = 0.002) and in DP (adj-S = −2.51, adj-p = 0.0002), suggesting a synergistic action with the age at diagnosis (p < 0.0001, respectively). ConclusionsWB-CT scans performed during oncological reassessment in patients at high-risk of recurrence could be used for CTRCD screening in cardiovascular low-risk patients, especially in aging patients with mECV values above 35 %.

Grading of skull base meningiomas by combined perfusion: arterial spin labeling and T2* dynamic susceptibility perfusion

BackgroundConventional MRI has no distinction between high- and low-grade meningiomas, which has a crucial for choice of therapeutic plan, especially skull base meningiomas which need more meticulous endoscopy-approached surgery. The aim of our study was to evaluate role of perfusion by arterial spin labeling and dynamic susceptibility perfusion in grading of skull base meningiomas.ResultsThe relative arterial spin labeling (ASL), tumor blood flow (TBF), and tumor blood volume (TBV) ratios showed significant differences between low- and high-grade meningiomas.ConclusionsMRI perfusion is a useful in differentiation between low- and high-grade meningiomas. There is significant correlation between ASL and DSC perfusion supporting possibility of using ASL in clinical practice as an alternative technique to DSC perfusion, particularly for patients with renal impairment where no contrast injection needed.

Fully automatic quantification for hand synovitis in rheumatoid arthritis using pixel-classification-based segmentation network in DCE-MRI.

A classification-based segmentation method is proposed to quantify synovium in rheumatoid arthritis (RA) patients using a deep learning (DL) method based on time-intensity curve (TIC) analysis in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). This retrospective study analyzed a hand MR dataset of 28 RA patients (six males, mean age 53.7years). A researcher, under expert guidance, used in-house software to delineate regions of interest (ROIs) for hand muscles, bones, and synovitis, generating a dataset with 27,255 pixels with corresponding TICs (muscle: 11,413, bone: 8502, synovitis: 7340). One experienced musculoskeletal radiologist performed ground truth segmentation of enhanced pannus in the joint bounding box on the 10th DCE phase, or around 5min after contrast injection. Data preprocessing included median filtering for noise reduction, phase-only correlation algorithm for motion correction, and contrast-limited adaptive histogram equalization for improved image contrast and noise suppression. TIC intensity values were normalized using zero-mean normalization. A DL model with dilated causal convolution and SELU activation function was developed for enhanced pannus segmentation, tested using leave-one-out cross-validation. 407 joint bounding boxes were manually segmented, with 129 synovitis masks. On the pixel-based level, the DL model achieved sensitivity of 85%, specificity of 98%, accuracy of 99% and precision of 84% for enhanced pannus segmentation, with a mean Dice score of 0.73. The false-positive rate for predicting cases without synovitis was 0.8%. DL-measured enhanced pannus volume strongly correlated with ground truth at both pixel-based (r = 0.87, p < 0.001) and patient-based levels (r = 0.84, p < 0.001). Bland-Altman analysis showed the mean difference for hand joints at the pixel-based and patient-based levels were -9.46 mm3 and -50.87 mm3, respectively. Our DL-based DCE-MRI TIC shape analysis has the potential for automatic segmentation and quantification of enhanced synovium in the hands of RA patients.

Impact of ACIST CVi contrast delivery system on iodinated contrast media administration and waste.

The COVID-19 pandemic led to disruptions in iodinated contrast media (ICM) production and produced a global product shortage in the spring of 2022. The ACIST CVi system is an automated contrast injector system approved by the FDA for multi-patient dosing of ICM from a single container. A transition from the traditional manifold system for contrast injection to the ACIST CVi automated injector system in our cardiac angiographic labs during the COVID-19 pandemic led to reductions in contrast waste and cost while limiting patient exposure to ICM.

Single-shot simplified cardioneuroablation

Abstract Introduction Cardioneuroablation (CNA) is a promising therapy of a spectrum of arrhythmias dependent on increased activity of parasympathetic tone. The right anterior ganglionated plexus (RAGP), localized paraseptally between right atrium and right superior pulmonary vein, is frequently a primary target for CNA. Methods are sought to determine exact locations of RAGP to minimize ablation lesion set during CNA. Immediate and accurate intraprocedural visualization of RAGP area in patients undergoing CNA is desirable. Methods Consecutive patients who underwent right-atrial CNA for reflex syncope, symptomatic bradycardia or vagal atrial fibrillation were included into the study. After venous contrast injection a 3-dimensional rotational atrial scan (3DRAS) was used to obtain digital images. Next, manual segmentation (MS) of hypodense areas between the right atrium (RA) and the right superior pulmonary vein (RSPV) was performed to reconstruct RAGP. Using 3-dimensional mapping system such created 3D RAGP area visualisation was automatically synchronized with fluoroscopy and these sites were targeted for CNA. Heart rate (HR) acceleration ≥30% and ultra-short-term deceleration capacity (UST-DC) were used for determination of acute CNA outcomes. Results Five patients (3 males, age 37±17) underwent 3DRAS and MS of RAGP area during CNA. A single radiofrequency lesion was delivered in each patient (mean RF time - 33±15s, power - 25W). The mean procedure time was 40±13 minutes. Targeted HR acceleration was achieved in all patients (baseline HR vs post-CNA HR, 57±8bpm vs 93±11bpm; p=0.0007; mean HR acceleration 65±15%). UST-DC significantly decreased after CNA (pre-CNA UST-DC vs post-CNA UST-DC, 13.6ms vs 3.2ms, p=0.00096). There were no complications. Conclusions Single-shot simplified CNA is feasible. Visualization of RAGP area using 3DRAS and MS is safe, effective and can very rapidly delineate CNA target.Figure

Atrial fibrillation cryoablation guided by pressure waveform: a prospective multicentre registry

Abstract Background Cryoballoon ablation (CA) procedures require optimal occlusion of the pulmonary veins (PV), which is conventionally evaluated by iodine contrast injection through the catheter tip. This technique has some weaknesses such as risk of allergic reactions, nephrotoxicity, requirement of fluoroscopy (sometimes at high doses), requirement of a second operator, among others. PV pressure waveform assessment is an alternative method for confirming occlusion, however, multicentre assessment of periprocedural efficacy and safety is lacking. Purpose To describe the intra-procedural performance and safety of routine pressure-based CA. Methods In this independent prospective multicentre observational study, baseline and procedure data from consecutive pressure-guided CB ablations were collected. Operators were not required to have experience in pressure-guided CA for participating in the registry. They were asked to classify the pressure waveform curves into type 1 (presence of "a-wave" and/or symmetric "v-wave", meaning incomplete PV occlusion) and type 2 (absence of "a-wave" and asymmetric "v-wave", meaning complete PV occlusion), Figure 1. The primary endpoint was PV isolation in all veins without use of contrast. Procedure performance and adverse events were also analyzed. Results A total of 150 patients (mean age: 61 ± 10 y.) with paroxysmal (62%) or persistent AF (38%) were included and underwent pressure-guided CA in 9 centres from Spain. Complete PV isolation was achieved in 148 patients (98%). The operators switched to contrast use in 14 cases (9%), mainly to double check the occlusion. Total procedure and fluoroscopy time were 97 ± 39 and 19 ± 10 min respectively. There were 7 (4.7%) procedure related adverse events: 4 phrenic nerve palsy (3 of them were transient), 1 transient coronary ST elevation (before ablation), 1 gastroparesis and 1 femoral pseudoaneurysm. Most relevant results are summarized in Figure 2. Conclusion In this multicentre and multi-brand assessment, CA guided by pressure waveforms provided outstanding procedural outcomes, which were equivalent to those reported with the conventional approach. All operators could easily obtain and identify the waveform without a specific learning curve, avoiding the use of iodine contrast in most cases. The long-term efficacy of this approach will be presented in future analyses.Pressure waveforms types in cryoablationProcedural data

Investigation in image quality and immediate patient safety using pre-dual-flow injection for low-contrast dose spectral pulmonary artery CT angiography

PurposeThe patient safety of iodine contrast-enhanced pulmonary artery CT angiography (CTPA) is widely concerned. This study aimed to investigate the image quality and immediate patient safety of spectral CTPA using a lower-contrast dose pre-dual-flow injection method. MethodsThis retrospective study included 120 patients with suspected pulmonary embolisms who received spectral CTPA between February and December 2022. Patients were divided into normal contrast injection (Group A, n=60) and pre-dual-flow group (Group B, n=60). CT values of pulmonary arteries (PAs) at different levels, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), arteriovenous separation performance, and beam hardening artifact (BHA) index of two sets of images were measured or calculated. The subjective image quality and immediate patient safety were also scored using the three-point method. ResultsGroup B had a contrast dose reduction by 42.5 % (60 vs. 34.5 mL). Radiation exposure dose was not statistically different between the two groups (P>0.05). CT values of different-level PAs on group B images were higher than those on group A images (P<0.05). Group B images had higher SNR and CNR, better arteriovenous separation between PA trunk and pulmonary vein, and lower BHA index on soft tissue and PA (all P<0.05). For subjective evaluation of image quality, group B had a better score in beam hardening artifact (P<0.05). For immediate patient safety, the score in comfortability was statistically higher in group B, with P<0.05. ConclusionsComparing with the normal injection method, pre-dual-flow spectral CTPA with a lower contrast dose injected results in better image quality and shows potential in patient-safety promotion.

Time conditioning for arbitrary contrast phase generation in interventional computed tomography

Minimally invasive ablation techniques for renal cancer are becoming more popular due to their low complication rate and rapid recovery period. Despite excellent visualisation, one drawback of the use of computed tomography (CT) in these procedures is the requirement for iodine-based contrast agents, which are associated with adverse reactions and require a higher x-ray dose. The purpose of this work is to examine the use of time information to generate synthetic contrast enhanced images at arbitrary points after contrast agent injection from non-contrast CT images acquired during renal cryoablation cases. To achieve this, we propose a new method of conditioning generative adversarial networks with normalised time stamps and demonstrate that the use of a HyperNetwork is feasible for this task, generating images of competitive quality compared to standard generative modelling techniques. We also show that reducing the receptive field can help tackle challenges in interventional CT data, offering significantly better image quality as well as better performance when generating images for a downstream segmentation task. Lastly, we show that all proposed models are robust enough to perform inference on unseen intra-procedural data, while also improving needle artefacts and generalising contrast enhancement to other clinically relevant regions and features.

The effect of time-delayed contrast-enhanced scanning in determining the gross tumor target volume of large-volume brain metastases

Background and PurposeTo assess the variation of large-volume brain metastases (BMs) boundaries and shapes using enhanced magnetic resonance (MR) scanning with different delay times and to provide a basis for determining the gross tumor target volume (GTV) for radiotherapy of BMs. Materials and MethodsWe prospectively enrolled 155 patients initially diagnosed with BMs (561 lesions > 1 cm). Contrast-enhanced (CE) T1-weighted imaging scans were performed 1, 3, 5, 10, 18, and 20 min after gadolinium-based contrast agent injection and GTVs were determined as GTV-1min, GTV-3min, GTV-5min, GTV-10min, GTV-18min, and GTV-20min, respectively, which were subsequently fused in different phases. Fusion of the six GTVs was defined as GTV-total, which was set as the reference GTV. The volume, shape, and signal intensity of the GTVs and brain white matter (BWM) were compared at different delay times. ResultsGTV-3min, GTV-5min, GTV-10min, GTV-18min, and GTV-20min volumes increased by 2.2 %, 3.8 %, 6.5 %, 9.5 %, and 10.6 %, respectively (P < 0.05) compared with GTV-1min. Compared with GTV-total, GTV-1min, GTV-3min, GTV-5min, GTV-10min, GTV-18min, and GTV-20min volumes reduced by 25.4 %, 22.1 %, 18.7 %, 15.0 %, 11.2 %, and 10.3 %, respectively (P < 0.05). Compared with GTV-total, 29 (51.8 %) fused GTVs had a volume reduction rate < 5 %, 45 (80.4 %) had a Dice similarity coefficient > 0.95, and all contained GTV-10min, GTV-18min or GTV-20min. The signal intensity ratio between the GTV and BWM peaked at 5 min (0.351 ± 0.24). ConclusionEnhanced MR scans with different delay times show significant differences in the boundaries and shapes of large-volume BMs, and time-delayed multi-phase CE scanning should be used in GTV determination, with time phases ≥ 10 min being mandatory.

Conventional versus Hepatic Arteriography and C-Arm CT-Guided Ablation of Liver Tumors (HepACAGA): A Comparative Analysis.

Hepatic Arteriography and C-Arm CT-Guided Ablation of liver tumors (HepACAGA) is a novel technique, combining hepatic-arterial contrast injection with C-arm CT-guided navigation. This study compared the outcomes of the HepACAGA technique with patients treated with conventional ultrasound (US) and/or CT-guided ablation. In this retrospective cohort study, all consecutive patients with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) treated with conventional US-/CT-guided ablation between 1 January 2015, and 31 December 2020, and patients treated with HepACAGA between 1 January 2021, and 31 October 2023, were included. The primary outcome was local tumor recurrence-free survival (LTRFS). Secondary outcomes included the local tumor recurrence (LTR) rate and complication rate. 68 patients (120 tumors) were included in the HepACAGA cohort and 53 patients (78 tumors) were included in the conventional cohort. In both cohorts, HCC was the predominant tumor type (63% and 73%, respectively). In the HepACAGA cohort, all patients received microwave ablation. Radiofrequency ablation was the main ablation technique in the conventional group (78%). LTRFS was significantly longer for patients treated with the HepACAGA technique (p = 0.015). Both LTR and the complication rate were significantly lower in the HepACAGA cohort compared to the conventional cohort (LTR 5% vs. 26%, respectively; p < 0.001) (complication rate 4% vs. 15%, respectively; p = 0.041). In this study, the HepACAGA technique was safer and more effective than conventional ablation for HCC and CRLM, resulting in lower rates of local tumor recurrence, longer local tumor recurrence-free survival and fewer procedure-related complications.

THROW YOUR LEAD OVER THE OBSTACLE: A CHALLENGING CRT UPGRADING

Abstract High percentage of right ventricular pacing could lead to pacing induced cardiomyopathy in a non–negligible proportion of patients. Cardiac resynchronization therapy upgrading could represent an option to improve ventricular function, reducing heart failure hospitalizations. A 82 yo male was admitted to hospital with symptomatic heart failure. He had history of complete AV block treated with dual chamber pacemaker implantation five years earlier following coronary artery bypass graft surgery, bioprosthetic aortic valve replacement and septal myectomy. He had also history of cardiac arrest occurred in the context of acute coronary syndrome treated with PCI so that ICD implant was not considered at that time, and two more HF hospitalizations in previous years. Progressive LVEF decline was documented since PM impantation until last echo showed severe left ventricular dysfunction (EF 20% from baseline EF 60%). The ECG showed sinus rhythm and wide paced QRS (206 ms) with 100% pacing percentage. A CRT device upgrading was planned. Baseline venography initially showed pervious axillary–subclavian left axis, but unfortunately the guidewire encountered a complete occlusion before entering the superior vena cava. Nevertheless, dye contrast injection documented the presence of a proximal collateral branch (fig A) having a vertical course in the thorax and reaching the lateral wall of the left ventricle with an extrapericardic course then entering the right heart through inferior vena cava. Using a IM 5Fr sheath (usually used by interventional cardiologists to cannulate internal mammary artery) we could reach this branch, inserting a guidewire and finally advancing a quadripolar lead (Fig B–C) which reached the lateral left ventricular wall. LV capture was confirmed when pacing from the three proximal poles, while the distal one caused phrenic nerve capture. The quadripolar lead was connected to the LV port of a three chamber PM along with previous implanted leads thus obtaining biventricular pacing. QRS paced was 50 ms shorter than baseline. No peri–procedural complications occurred. Lead–related venous occlusion might represent an obstacle to CRT upgrade requiring high technical expertise. The presence of a complete venous occlusion might cause procedural failure, particularly in hospitals without surgical facility. In this case, the presence of a collateral branch reaching the lateral wall of the left ventricle allowed to successfully complete the CRT upgrade.