Total Amount Of Contrast Medium Research Articles

Factors Associated with the Onset of Acute Kidney Injury Following Subarachnoid Hemorrhage

BackgroundAcute kidney injury (AKI) is a complication often observed in critically ill patients, indicating a worsening prognosis. However, factors predicting AKI in subarachnoid hemorrhage (SAH) patients are unclear. This study aims to elucidate the predictors of AKI occurrence. MethodsAll patients with SAH admitted to the intensive care unit between 2013 and 2019 were included. Patients with very severe SAH who are unsuitable to receive aggressive treatment, those who previously received a contrast medium at another medical institution within 24 hours before admission, and those on maintenance dialysis were excluded. We retrospectively examined blood tests conducted upon admission, oral medications administered, and the total amount of contrast medium used after initiating treatment to investigate their association with AKI occurrence. ResultsOf the 254 SAH patients treated during the relevant period, 195 (median age 64 years, 72 males) met the inclusion/exclusion criteria and 32 patients (16.3%) developed AKI. When multivariate analysis was performed using sex, uric acid level, and hemoglobin, which obtained p < 0.01 in the univariate analysis, as variables, only uric acid level was found as an independent predictor of AKI [odds ratio, 1.501; 95% confidence interval, 1.109–2.033, p-value of 0.009]. There was no difference in the occurrence of AKI between survivors and nonsurvivors (12/163 vs. 2/32, P = 0.824). ConclusionsAKI occurred in 16.3% of the patients with SAH. Patients who developed AKI had significantly higher uric acid levels. SAH with high uric acid levels warrants attention for AKI.

Abstract 11731: Efficacy of a New Generation Fast-Pullback, High-Frequency Intracoronary Optical Coherence Tomography Imaging on the Reduction of Contrast Medium in Clinical Practice

Introduction: Intracoronary optical coherence tomography (OCT) is an imaging modality that uses near-infrared light to generate high-resolution images, and now plays an important role in research and clinical practice as it provides insights into vascular biology and diagnostic guidance for percutaneous intervention (PCI). An existing concern is that OCT imaging could increase the total amount of contrast media administered during the procedure, resulting in adverse outcomes such as impairment of renal function or worsening of heart failure in some patients. Aims: We sought to investigate whether a novel, fast-pullback, high-frequency OCT (HF-OCT) enables acquisitions with a reduced amount of contrast agents while retaining the same qualitative and quantitative lesion assessment to conventional OCT. Methods: This study is a single-center, prospective, observational study including 10 patients with stable coronary artery disease. A total of 28 individual coronary arteries were assessed by both fast-pullback HF-OCT and by conventional OCT. The fast-pullback, HF-OCT system consists of a 1.8-Fr Vis-Rx® Micro-Imaging Catheter and an HF-OCT Imaging console (Gentuity LLC, Sudbury, MA). Results: The contrast volume used in each OCT run for the HF-OCT system was significantly lower than for the conventional OCT system (5.0±0.0 vs. 7.8±0.7ml, P&lt;0.001). No significant difference was found in the median value of the clear image length between the 2 OCT systems (74 mm [IQR; 63, 81], 74 mm [IQR; 71, 75], P=0.89). Fast-pullback HF-OCT showed comparable measurements to conventional OCT, including minimum lumen area (3.27±1.53 vs. 3.21±1.53 mm2, P=0.27), proximal reference area (7.03±2.28 vs. 7.03±2.34 mm2, P=0.96), and distal reference area (5.93±1.96 vs. 6.03±2.02 mm2, P=0.23). Qualitative OCT findings were comparable between the fast-pullback HF-OCT runs and conventional OCT with respect to identifying lipid-rich plaques, calcifications, layered plaques, macrophages, and cholesterol crystals. Conclusions: With the fast pullback function of a novel HF-OCT imaging system, we acquired OCT images using a significantly lower amount of contrast volume while retaining a comparable qualitative and quantitative lesion assessment to conventional OCT.

Reduced Radiation Exposure Protocol during Computer Tomography of the Left Atrium Prior to Catheter Ablation in Patients with Atrial Fibrillation.

(1) Background: Computer tomography (CT) is an imaging modality used in the pre-planning of radiofrequency catheter ablation (RFA) procedure in patients with cardiac arrhythmias. However, it is associated with a considerable ionizing radiation dose for patients. This study aims to develop and validate low-dose CT scanning protocols of the left atrium (LA) for RFA guidance. (2) Methods: 68 patients scheduled for RFA of atrial fibrillation were sequentially assigned to four groups of ECG-gated scanning protocols, based on the set tube current (TC): Group A (n = 20, TC = 33 mAs), Group B (n = 18, TC = 67 mAs), Group C (n = 10, TC = 135 mAs), and control Group D (n = 20, TC = 600 mAs). We used a 256-row multidetector CT with body weight-dependent tube voltage of 80 kVp (<70 kg), 100 kVp (70–90 kg), and 120 kVp (>90 kg). We evaluated scanning parameters including radiation dose, total scanning procedure time and signal-to-noise ratio (SNR). (3) Results: The average effective radiation dose (ED) was lower in Group A in comparison to Group B, C and D (0.83 (0.76–1.10), 1.55 (1.36–1.67), 2.91 (2.32–2.96) and 9.35 (8.00–10.04) mSv, p < 0.05). The total amount of contrast media was not significantly different between groups. The mean SNR was 6.5 (5.8–7.3), 7.1 (5.7–8.2), 10.8 (10.1–11.3), and 12.2 (9.9–15.7) for Group A, B, C and D, respectively. The comparisons of SNR in group A vs. B and C vs. D were without significant differences. (4) Conclusions: Optimized pre-ablation CT scanning protocols of the LA can reduce an average ED by 88.7%. Three dimensional (3D) models created with the lowest radiation protocol are useful for the integration of electro-anatomic-guided RFA procedures.

Quantitative assessment of renal obstruction in multi-phase CTU using automatic 3D segmentation of the renal parenchyma and renal pelvis: A proof of concept

PurposeQuantitative evaluation of renal obstruction is crucial for preventing renal atrophy. This study presents a novel method for diagnosing renal obstruction by automatically extracting objective indicators from routine multi-phase CT Urography (CTU). Material and methodsThe study included multi-phase CTU examinations of 6 hydronephrotic kidneys and 24 non-hydronephrotic kidneys (23,164 slices). The developed algorithm segmented the renal parenchyma and the renal pelvis of each kidney in each CTU slice. Following a 3D reconstruction of the parenchyma and renal pelvis, the algorithm evaluated the amount of the contrast media in both components in each phase. Finally, the algorithm evaluated two indicators for assessing renal obstruction: the change in the total amount of contrast media in both components during the CTU phases, and the drainage time, "T1/2", from the renal parenchyma. ResultsThe algorithm segmented the parenchyma and renal pelvis with an average dice coefficient of 0.97 and 0.92 respectively. In all the hydronephrotic kidneys the total amount of contrast media did not decrease during the CTU examination and the T1/2 value was longer than 20 min. Both indicators yielded a statistically significant difference (p < 0.001) between hydronephrotic and normal kidneys, and combining both indicators yielded 100% accuracy. ConclusionsThe novel algorithm enables accurate 3D segmentation of the renal parenchyma and pelvis and estimates the amount of contrast media in multi-phase CTU examinations. This serves as a proof-of-concept for the ability to extract from routine CTU indicators that alert to the presence of renal obstruction and estimate its severity.

546 Antegrade in-stent CTO recanalization

Abstract Methods and results A 64-year-old man with prior PCI and stent of proximal LAD due to an anterior ST-elevation myocardial infarction (STEMI) presented with exertional angina (CCS III), despite optimal medical therapy (OMT). The echocardiogram showed a dilatated left ventricle with anterior and apical akinesia and a severely reduced left ventricle ejection fraction. Coronarography was performed and a chronic total occlusion was found at the proximal edge of the stent previously implanted in the proximal LAD, with a thin tapered entry (J-CTO score 1). Moderate angiographic disease was present in the circumflex (LCX) and in the right coronary artery (RCA). Interventional collaterals were absent. Dobutamine stress echocardiogram was performed to unmask myocardial viability. Indeed, during intravenous Dobutamine administration, we registered an increase in the left ventricle function, whereas only apex remained still akinetic. Accordingly, the patient underwent LAD CTO PCI using a 7 Fr EBU 4.0 guiding catheter, via right femoral artery access. The RCA ostium was engaged with a 6 Fr Judkins right 4.0 guiding catheter, via right radial artery access. Antegrade wire escalation technique was attempted. Due to scarce support, a 7 Fr Guidion guiding catheter extension and a Corsair microcatheter were placed in the proximal LAD. Antegrade crossing was very difficult due to intrastent high plaque burden. The occlusion was crossed with an Asahi Conquest Pro 9 guidewire. Subsequently, an Asahi Gaia third guidewire was advanced through the intrastent segment and then in the distal part of LAD. The advance of microcatheter was challenging but successfully achieved taking advantage of the low profile, high torqueability and trackability of the Asahi Corsair Pro microcatheter. Microcatheter tip injection confirmed the correct position in the vessel’s true lumen. An Asahi Grand Slam guidewire was placed in the distal LAD to provide extra support for delivery of interventional devices. The lesion was pre-dilated with progressively larger balloon, starting from a 1.1 mm diameter semi-compliant over-the-wire balloon (OTW). Two stents were implanted with a minimal overlap at the distal edge of the proximal stent (Resolute Onyx 3.0 × 38 mm and 2.5 × 24 mm). The result was improved with stents high-pressure post-dilatation and with selective intracoronary adenosine and nitroglycerin administration with final Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow. The total amount of contrast media used was 210 ml. The total procedure time was with 125 min with 45 min of fluoroscopy. No complications occurred. Conclusions CTO PCI still represents one of the most challenging subsets of coronary interventions despite the improvement in technology and techniques. Although data regarding percutaneous PCI CTO are still inconsistent, successful CTO recanalization has been associated with relief of angina and ischemia-related dyspnoea (Werner at al., 2018). In stable patients CTO PCI has been associated with a lower risk of death, stroke, and coronary artery bypass grafting and less recurrent angina pectoris in some registry studies (Christakopoulos et al., 2015). Additionally, CTO PCI increased left ventricle function in a subgroup of patients with LAD CTO (Henriques et al., 2016). Conversely, randomized multicentre failed to demonstrate a superiority of CTO PCI medical to OMT in terms of major adverse cardiac events (MACE) and all-cause mortality.

Real-time venography-guided extrathoracic puncture technique for cardiovascular implantable electronic device implantation.

Central venous access is an essential technique for cardiovascular implantable electronic device (CIED) implantation, and the use of axillary vein approach has recently been increasing. This study sought to examine whether real-time venography-guided extrathoracic puncture facilitates the procedure. We retrospectively analyzed 179 consecutive patients who underwent CIED implantation using the axillary vein puncture method. Patients were divided into two groups: the conventional method group (CG, n = 107) and the real-time venography-guided group (RG, n = 82). The application of real-time venography was at the discretion of individual operators. Operators with experience of less than 50 CIED implantations were defined as inexperienced operators in this study. Puncture duration and number of attempts were significantly less in the RG group than in the CG group (283 ± 198 vs. 421 ± 361s, p < 0.01, and 3.19 ± 2.00 vs. 4.18 ± 2.85, p < 0.01). These benefits of real-time venography were observed in inexperienced operators, but not in experienced operators. In addition, the success rate without extra attempts at puncture was higher in the RG group (54% vs. 32%, p < 0.01). Although the total amount of contrast medium was higher in the RG group (16.3 ± 4.1mL vs. 11.9 ± 6.6mL, p < 0.01), serum levels of creatinine pre- and post-operation were not different in the two groups (p = NS). We concluded that real-time venography is a safe and effective method for axillary vein puncture, especially in inexperienced operators.

Clinical outcomes of patients undergoing percutaneous left atrial appendage occlusion in general anaesthesia or conscious sedation: data from the prospective global Amplatzer Amulet Occluder Observational Study

ObjectiveTo evaluate the safety and efficacy of percutaneous left atrial appendage occlusion (LAAO) using conscious sedation (CS).BackgroundSeveral percutaneous structural heart disease interventions are safely and efficiently performed using CS instead...

Safety of Percutaneous Coronary Intervention for Chronic Total Occlusion in Patients With Multi-Vessel Disease: Sub-Analysis of the Japanese Retrograde Summit Registry

BackgroundThe success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has gradually increased thanks to the continuous development of devices and techniques. However, the impact of multi-vessel disease (MVD) on its success rate and safety is not well known. MethodsThe clinical records of 5009 patients enrolled in the Japanese Retrograde Summit Registry and who had undergone PCI for CTO at 65 centers between 2012 and 2015 were reviewed. We compared the outcome for patients with and without MVD. ResultsTwo thousand nine hundred and seventy-eight patients (59%) had MVD. Although there was no significant difference in the J-CTO score between the two groups [MVD group 1.51 ± 1.07 vs. SVD group 1.48 ± 1.07, p = 0.48], the procedural success rate of CTO-PCI in the MVD group was significantly lower than that in the SVD group (87.2% vs. 90.2%, p = 0.001). However, occurrence of procedure-related adverse events (4% vs. 5%, p = 0.11), total fluoroscopy (70 ± 45 min vs. 69 ± 50 min, p = 0.75) and procedural time (154 ± 86 min vs. 151 ± 89 min, p = 0.36), and total amount of contrast media (219 ± 102 mL vs. 222 ± 105 mL, p = 0.33) did not differ between the two groups. ConclusionsAlthough MVD had an impact on the success rate of CTO-PCI, it did not affect procedure-related adverse events.

Combined Coronary CT-Angiography and TAVI-Planning: A Contrast-Neutral Routine Approach for Ruling-out Significant Coronary Artery Disease.

Background: Significant coronary artery disease (CAD) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI). Assessment of CAD prior to TAVI is recommended by current guidelines and is mainly performed via invasive coronary angiography (ICA). In this study we analyzed the ability of coronary CT-angiography (cCTA) to rule out significant CAD (stenosis ≥ 50%) during routine pre-TAVI evaluation in patients with high pre-test probability for CAD. Methods: In total, 460 consecutive patients undergoing pre-TAVI CT (mean age 79.6 ± 7.4 years) were included. All patients were examined with a retrospectively ECG-gated CT-scan of the heart, followed by a high-pitch-scan of the vascular access route utilizing a single intravenous bolus of 70 mL iodinated contrast medium. Images were evaluated for image quality, calcifications, and significant CAD; CT-examinations in which CAD could not be ruled out were defined as positive (CAD+). Routinely, patients received ICA (388/460; 84.3%; Group A), which was omitted if renal function was impaired and CAD was ruled out on cCTA (Group B). Following TAVI, clinical events were documented during the hospital stay. Results: cCTA was negative for CAD in 40.2% (188/460). Sensitivity, specificity, PPV, and NPV in Group A were 97.8%, 45.2%, 49.6%, and 97.4%, respectively. Median coronary artery calcium score (CAC) was higher in CAD+-patients but did not have predictive value for correct classification of patients with cCTA. There were no significant differences in clinical events between Group A and B. Conclusion: cCTA can be incorporated into pre-TAVI CT-evaluation with no need for additional contrast medium. cCTA may exclude significant CAD in a relatively high percentage of these high-risk patients. Thereby, cCTA may have the potential to reduce the need for ICA and total amount of contrast medium applied, possibly making pre-procedural evaluation for TAVI safer and faster.

Successful contemporary reverse controlled antegrade and retrograde subintimal tracking without contrast medium: a case report

BackgroundContrast-induced acute kidney injury is one of the common adverse events related to percutaneous coronary intervention and a predictor for worse outcome. In the setting of percutaneous coronary intervention for chronic total occlusion, large amounts of contrast medium, more than 200–400 mL, are generally injected. A higher dose of contrast medium causes contrast-induced acute kidney injury more frequently. Therefore, patients who undergo chronic total occlusion-percutaneous coronary intervention are at risk for contrast-induced acute kidney injury.Case presentationWe present the case of a 77-year-old Japanese man with post-acute myocardial infarction angina pectoris, heart failure, and chronic kidney disease who underwent percutaneous coronary intervention for chronic total occlusion in his right coronary artery. In the procedure, the retrograde wire was a visible penetration mark that made contrast medium unnecessary. Contemporary reverse controlled antegrade and retrograde subintimal tracking was successfully achieved and stents were implanted without contrast medium. Contrast medium was injected two times after stent implantation to confirm coronary flow and no perforation. The total amount of contrast medium was only 8 mL for chronic total occlusion-percutaneous coronary intervention.ConclusionChronic total occlusion-percutaneous coronary intervention with contemporary reverse controlled antegrade and retrograde subintimal tracking without contrast medium may be safe and feasible in selected patients.

Comparison of the Effect of Dual-Axis Rotational Coronary Angiography Versus Conventional Coronary Angiography on Frequency of Acute Kidney Injury, X-Ray Exposure Time, and Quantity of Contrast Medium Injected

Dual-axis rotational coronary angiography (DARCA) has already been shown to reduce both the amount of contrast medium and radiation exposure compared with conventional coronary angiography (CCA). However, a clinical benefit of such imaging modality has never been demonstrated. The aim of this study was to evaluate the efficacy of DARCA to prevent acute kidney injury (AKI) compared with CCA. Consecutive patients who underwent coronary angiography were enrolled to DARCA (n = 80) or CCA (n = 80). Patients presenting with ST-segment elevation myocardial infarction or previously underwent coronary artery bypass graft were excluded. The 2 groups were homogeneous in terms of both clinical and procedural characteristics. Total x-ray time and total amount of contrast medium were significantly lower in the DARCA group compared with the CCA group (x-ray time 3.2 minutes [1.8 to 7.0] vs 5.1 minutes [2.6 to 9.9], p = 0.002; contrast medium amount 40 ml [31 to 116] vs 80 ml [50 to 150], p <0.001). AKI more often occurred in the CCA group compared with the DARCA group (16 [20%] vs 4 [5%], p = 0.007). Moreover, in patients presenting with acute coronary syndrome (ACS) or who underwent percutaneous coronary intervention (PCI), AKI more often occurred in the CCA group compared with the DARCA group (ACS patients, 6 [29%] vs 2 [6%], p = 0.04, and PCI patients, 11 [33%] vs 0 [0%], p <0.001). In addition, in patients with high pretest probability of coronary artery disease, AKI more often occurred in the CCA group compared with the DARCA group (11 [55%] vs 2 [6%], p <0.001). In conclusion, DARCA significantly reduces both x-ray exposure and amount of contrast medium usage, thereby reducing the occurrence of AKI compared with CCA.

Patient Discomfort during Carotid Artery Stenting: A Comparison Study between Iodixanol versus Iopamidol

The aim of this study was to compare the adverse effects of iodixanol and iopamidol in terms of patient's discomfort in subjects undergoing carotid artery stenting (CAS). We retrospectively analyzed data of all successful CAS procedures performed in our department during a 15-year period study. All patients judged to be collaborative were included. From December 2000 to December 2005, we adopted iopamidol as contrast media (CM), thereafter iodixanol. Any transient unpleasant sensation of bitter taste or warmth perceived by the patient after intra-arterial injection of CM was recorded. Injection-associated discomfort was assessed by visual analog scale (VAS) score. Comparison between the 2 CMs with regard to the overall discomfort was carried out by using the Mann-Whitney test. Spearman correlation was performed to assess the correlation among discomfort, age, and CM used. A univariate analysis was performed for slightly bitter taste and warmth sensation to compare these clinical outcomes and CM used; subsequently, a logistic multivariate analysis regression was performed with the "backward elimination." Data from 1,633 patients were evaluated. A total of 608 patients underwent CAS procedure using iopamidol, and 1,025 using iodixanol. The total amount of CM used during a single procedure was 85±17mL/patient (range 60-135). The median VAS value was statistically significantly lower in the iodixanol group than in the iopamidol group (P<0.001). A significant Spearman correlation coefficient was found between age and discomfort for both CMs used (Spearman rho 0.18 for iodixanol, 0.17 for iopamidol). The univariate analysis showed that patients undergoing CAS with iopamidol had an odds ratio (OR) of 8.48 (P<0.001) to perceive warmth sensation. When adjusted for age and gender, the multivariate analysis still showed an OR of 8.03. For slightly bitter taste sensation, the crude analysis showed an OR of 1.31 (P=0.018); adjusting for age and gender, OR became 1.15 and the difference was not statistically significant (P=0.257). During CAS, less overall discomfort was reported in patients receiving iodixanol than iopamidol; in terms of warmth sensation, patients undergoing procedure using iopamidol as CM have a higher risk to perceive this clinical symptom than iodixanol. Slightly bitter taste seems to have a statistically significant relation with age and gender, and not with CM used.

Applied research of CT angiography of lower extremities by using 100 kVp and iodixanol(270 mg I/ml) combined with iDose(4) iterative reconstruction technique

To evaluate the feasibility of CT angiography of lower extremities by using 100 kVp as tube voltage and Iodixanol(270 mg I/ml) as contrast medium combined with iDose(4) iterative reconstruction technique. A total of 52 continuous patients with clinically suspected lesions of lower extremity arteries underwent CT angiography of lower extremities, divided into 2 groups, and different scan protocols were adopted. "double low" group included 26 patients using 100 kVp, Iodixanol (270 mg I/ml) and iDose(4) -4 iterative reconstruction algorithm; routine group included 26 patients using 120 kVp, Iopromide(370 mg I/ml) and filtered back projection reconstruction algorithm. The total amount of contrast medium in both groups was 95 ml. Artery CT value and background noise at the level of L4 vertebral, hip, knee and ankle were measured, signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated, and the quality of images was evaluated subjectively. Scan length (L), volume CT dose index (CTDI(VOL)) and dose length product(DLP) were recorded, and the effective dose (ED) was calculated. The measurement results and subjective evaluation were analyzed statistically. CTA results were analyzed with the digital subtraction angiography (DSA) as the "gold standard". (1) No significant difference was existed in gender, age, height, weight and body mass index (BMI) of these two groups (P > 0.05). (2) No significant difference was existed in artery CT value, SNR and CNR at the level of L4 vertebral, hip, knee and ankle of the two groups (P > 0.05). Compared with routine group, background noise of "double low" group at the level of hip and knee increased by 16.6% and 13.8%, respectively (P < 0.05). (3) The image quality of the two groups met the requirement of diagnosis, no significant statistical difference was existed in subjective evaluation (P > 0.05). (4) The CTDI(VOL), DLP, ED of "double low" group were lower than that of routine group, with significant statistical difference (P < 0.05). The total amount of iodine in "double group" was lower than that of routine group (25.6 g vs 35.2 g). (5) A total of 7 cases from "double low" group underwent DSA examination, and 18 pathological changes (stenosis and occlusion) were found totally, in which 16 matched CTA; 6 cases from routine group underwent DSA examination, and 15 pathological changes (stenosis and occlusion) were found totally, in which 13 matched. CTA. No significant statistical difference was existed between the two groups in diagnostic efficacy (P = 0.626). Using 100 kVp and Iodixanol (270 mg I/ml) combined with iDose(4) -4 iterative reconstruction technique for CT angiography of lower extremities, the image quality could meet the requirement for clinical diagnosis, the radiation dose and the volume of contrast medium could be lowered.

Possible Contrast Media Reduction with Low keV Monoenergetic Images in the Detection of Focal Liver Lesions: A Dual-Energy CT Animal Study.

ObjectiveTo investigate the feasibility of dual-energy CT for contrast media (CM) reduction in the diagnosis of hypervascular and hypovascular focal liver lesions (FLL).Subjects and MethodsThe Institutional Animal Care and Use Committee approved this study. VX2 tumors were implanted in two different segments of the liver in 13 rabbits. After 2 weeks, two phase contrast enhanced CT scans including the arterial phase (AP) and portal-venous phase (PVP) were performed three times with 24-hour intervals with three different concentrations of iodine, 300 (I300), 150 (I150) and 75 mg I/mL (I75). The mean HU and standard deviation (SD) were measured in the liver, the hypervascular portion of the VX2 tumor which represented hypervascular tumors, and the central necrotic area of the VX2 tumor which represented hypovascular tumors in 140kVp images with I300 as a reference standard and in monoenergetic images (between 40keV and 140keV) with I150 and I75. The contrast-to-noise ratio (CNR) for FLLs and the ratio of the CNRs (CNRratio) between monoenergetic image sets with I150 and I75, and the reference standard were calculated.ResultsFor hypervascular lesions, the CNRratio was not statistically different from 1.0 between 40keV and 70keV images with I150, whereas the CNRratio was significantly lower than 1.0 in all keV images with I75. For hypovascular lesions, the CNRratio was similar to or higher than 1.0 between 40keV and 80keV with I150 and between 40keV and 70keV with I75.ConclusionsWith dual-energy CT, the total amount of CM might be halved in the diagnosis of hypervascular FLLs and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving CNRs.

Risk Factors of Ischemic Lesions Related to Cerebral Angiography and Neuro-interventional Procedures

Embolic stroke is not a rare complication of cerebral angiography. The risk factors for incidental embolism after cerebral angiography were retrospectively examined using diffusion-weighted magnetic resonance imaging (DWI) in 180 patients who underwent 247 angiography procedures, consisting of 174 diagnostic angiography and 73 interventional procedures, and magnetic resonance imaging including DWI within 72 hours after angiography. The two neuroradiologists in our hospital detected embolism after cerebral angiography as high-intensity lesions (HIL) on DWI. The relationships between HIL on DWI and procedural factors were evaluated. DWI after cerebral angiography revealed HIL related to the procedure in 72 of 247 angiographies. In all procedures, age (p < 0.01), past history of cerebral infarction (p < 0.05), anti-platelet therapy (p < 0.05), neuro-intervention (p < 0.01), and total amount of contrast medium (odds ratio [OR] 2.125, 95% confidence interval [CI] 1.045-4.321) were significantly correlated with HIL. In diagnostic angiography, the performance of the procedure by a resident operator (OR 2.526, 95% CI 1.214-5.254) was significantly correlated with HIL. Age, past history of cerebral infarction, and previous anti-platelet therapy determined the risk of atherosclerotic changes in patients. The neuro-intervention and total amount of contrast medium used could predict the risk of time limitations for angiography. Resident operator is also a risk factor. This study demonstrates the importance of improving the risk of time limitations for angiography and the risk due to operator inexperience. Further training of residents may be needed to reduce the occurrence of embolic complications.

Comparison of Contrast Media and Low-Molecular-Weight Dextran for Frequency-Domain Optical Coherence Tomography

Although an intracoronary frequency-domain optical coherence tomography (FD-OCT) system overcomes several limitations of the time-domain OCT (TD-OCT) system, the former requires injection of contrast media for image acquisition. The increased total amount of contrast media for FD-OCT image acquisition may lead to the impairment of renal function. The safety and usefulness of the non-occlusion method with low-molecular-weight dextran L (LMD-L) via a guiding catheter for TD-OCT image acquisition have been reported previously. The aim of the present study was to compare the image quality and quantitative measurements between contrast media and LMD-L for FD-OCT image acquisition in coronary stented lesions. Twenty-two patients with 25 coronary stented lesions were enrolled in this study. FD-OCT was performed with the continuous-flushing method via a guiding catheter. Both contrast media and LMD-L were infused at a rate of 4 ml/s by an autoinjector. With regard to image quality, the prevalence of clear image segments was comparable between contrast media and LMD-L (97.9% vs. 96.5%, P=0.90). Furthermore, excellent correlations were observed between both flushing solutions in terms of minimum lumen area, mean lumen area, and mean stent area. The total volumes of contrast media and of LMD-L needed for OCT image acquisition were similar. FD-OCT image acquisition with LMD-L has the potential to reduce the total amount of contrast media without loss of image quality.

Study on effect and influence factors of the coronary artery imaging by 64-slice spiral CT

Objective To study the various factors that influence image quality of 64-slice spiral CT coronary artery imaging, their impact extent and the assessment effect of coronary artery stonnsis. Methods Through examination of 838 clinical coronary heart disease suspect patients, by 64-slice spiral CT coronary artery imaging, in which, 218 patients were also examined by conventional coronary angiagraphy in a week, we took the conventional coronary angiography as the standard, analyzed the 64-slice spiral CT coronary artery imaging in the assessment of coronary artery stenosis by sensitivity, accuracy, positive predictive value and negative predictive value. Results The factors which affect the image quality of 64-slice spiral CT coronary artery imaging include heart rate, heart rate change range, delay time setting, β-blocker, respiratory rate, breath-holding or not, total amount of contrast medium and the speed of injection, image reconstruction phase, coronary artery calcification, the scan parameters, age and sex of patients, machine hardware and software performance and so on. The accuracy of the 64-slice spiral CT coronary artery imaging assessment of coronary artery stenasis was 95.9 % while the predictive values were 92.3%, 90.0% for positive and negative, respectively. Conclusion The influential factors are introduced as well as the methods that wig reduce or eliminate these factors. In the application of assessing coronary artery stonnsis, 64-slice spiral CT coronary artery imaging can basically meet the clinical requirements. Key words: 64 slice spiral CT ; Coronary artery imaging ; Quality control ; Coronary angiography ; Coronary artery stenosis ;

Migration of left ventricular thrombus causing abdominal aortic embolism during cardiac surgery in a child with severe left ventricular dysfunction

A 1-year-old girl with severe left ventricular dysfunction presented with large floating thrombi in the left ventricle. Surgical thrombectomy was urgently required. During cannulation, transesophageal echocardiogram detected that the thrombus had vanished from the left ventricle. Whole body angiogram under very low-flow cardiopulmonary bypass successfully obtained the exact site of embolization with reducing total amount of contrast media in the operating room. Consequently, under deep hypothermic circulatory arrest, the obstructive thrombi at the abdominal aorta were successfully removed using Fogarty catheters from ascending aortotomy. Although delayed sternal closure was postoperatively required, no complication including thromboembolic events were observed for a 1.5-year follow-up period.

Gadolinium:Nonionic Contrast Media (1:1) Coronary Angiography in Patients With Impaired Renal Function

This study was to test safety and efficacy of 1:1 mixture of gadolinium:nonionic contrast media in avoiding contrast nephropathy during coronary angiography in patients with renal dysfunction. Although "off label" for x-ray angiography, gadolinium has drawn attention for its potential to avoid contrast nephropathy during coronary angiography. Initial data seem promising. Patients with a baseline creatinine of 1.5 mg/dl or more were included. In order to minimize contrast nephropathy risk, all patients were thoroughly hydrated and treated by N-acetylcysteine. After coronary angiography and/or percutaneous coronary intervention, renal function tests were remeasured on days 1, 2, and 3. A rise of 0.5 mg/dl or more in creatinine value in the following 3 days or the need for dialysis were considered as a contrast nephropathy event. Twenty-six patients were enrolled in this study. Ten were women and 16 were men. The mean age was 65.7 +/- 11. Baseline creatinine value was 2.47 +/- 0.74 mg/dl. The total amount of contrast medium used on 1:1 fashion was 57.1 +/- 27.2 ml. No procedure-related cardiac complication or contrast nephropathy event occurred in this study. Although there was a slight loss in image quality, we felt that the results were adequate for interpretation. Although "off label," using gadolinium contrast media in a 1:1 mixture with standard nonionic low osmolar contrast media seems to be a viable option in decreasing the likelihood of contrast nephropathy. Further evaluation appears to be warranted.

The ACIST power injection system reduces the amount of contrast media delivered to the patient, as well as fluoroscopy time, during diagnostic and interventional cardiac procedures

The ACIST injection system is an automatic power injection device that allows for online control of injection rate and volume of contrast. Limited data is available whether this technology allows reducing use of contrast and fluoroscopy time. Accordingly, we compared the use of this system to manual injection among 450 consecutive patients who underwent diagnostic coronary angiography and/or angioplasty who were randomly assigned to either manual contrast injection (control; n=198) or to the ACIST system (study group; n=252). The amount of contrast, fluoroscopy and total procedural times were recorded for each patient. In the diagnostic group, the mean total amount of contrast (including wasted) was reduced by 63% when the ACIST was used compared to control (100+/-42 ml versus 163+/-56 ml; P<0.001, respectively). When only the net amount of contrast delivered to the patient was considered, the differences were smaller (20%, P=0.004). During angioplasty, the amount of contrast was also lower in the ACIST group (206+/-65 versus 230+/-69, P=0.008), whereas no difference were noted in net amount of contrast. Fluoroscopy time was significantly shorter in the ACIST group compared to control both during diagnostic catheterization (4.7+/-3.5 min versus 6.3+/-5.5 min, respectively; P=0.014), and angioplasty (16.7+/-9.1 min versus 19.6+/-12.4 min, respectively; P=0.05). Routine utilization of the ACIST system during diagnostic and interventional procedure significantly reduced the total amount of contrast media used and fluoroscopy time.