mL Of Contrast Research Articles

A Comprehensive and Repeatable Contrast-Enhanced Ultrasound Quantification Approach for Clinical Evaluations of Tumor Blood Flow.

The aim of this study is to define a comprehensive and repeatable contrast-enhanced ultrasound (CEUS) imaging protocol and analysis method to quantitatively assess lesional blood flow. Easily repeatable CEUS evaluations are essential for longitudinal treatment monitoring. The quantification method described here aims to provide a structure for future clinical studies. This retrospective analysis study included liver CEUS studies in 80 patients, 40 of which contained lesions (primarily hepatocellular carcinoma, n = 28). Each patient was given at least 2 injections of a microbubble contrast agent, and 60-second continuous loops were acquired for each injection to enable evaluation of repeatability. For each bolus injection, 1.2 mL of contrast was delivered, whereas continuous, stationary scanning was performed. Automated respiratory gating and motion compensation algorithms dealt with breathing motion. Similar in size regions of interest were drawn around the lesion and liver parenchyma, and time-intensity curves (TICs) with linearized image data were generated. Four bolus transit parameters, rise time (RT), mean transit time (MTT), peak intensity (PI), and area under the curve (AUC), were extracted either directly from the actual TIC data or from a lognormal distribution curve fitted to the TIC. Interinjection repeatability for each parameter was evaluated with coefficient of variation. A 95% confidence interval was calculated for all fitted lognormal distribution curve coefficient of determination (R2) values, which serves as a data quality metric. One-sample t tests were performed between values obtained from injection pairs and between the fitted lognormal distribution curve and direct extraction from the TIC calculation methods to establish there were no significant differences between injections and measurement precision, respectively. Average interinjection coefficient of variation with both the fitted curve and direct calculation of RT and MTT was less than 21%, whereas PI and AUC were less than 40% for lesion and parenchyma regions of interest. The 95% confidence interval for the R2 value of all fitted lognormal curves was [0.95, 0.96]. The 1-sample t test for interinjection value difference showed no significant differences, indicating there was no relationship between the order of the repeated bolus injections and the resulting parameters. The 1-sample t test between the values from the fitted lognormal distribution curve and the direct extraction from the TIC calculation found no statistically significant differences (α = 0.05) for all perfusion-related parameters except lesion and parenchyma PI and lesion MTT. The scanning protocol and analysis method outlined and validated in this study provide easily repeatable quantitative evaluations of lesional blood flow with bolus transit parameters in CEUS data that were not available before. With vital features such as probe stabilization ideally performed with an articulated arm and an automated respiratory gating algorithm, we were able to achieve interinjection repeatability of blood flow parameters that are comparable or surpass levels currently established for clinical 2D CEUS scans. Similar values and interinjection repeatability were achieved between calculations from a fitted curve or directly from the data. This demonstrated not only the strength of the protocol to generate TICs with minimal noise, but also suggests that curve fitting might be avoided for a more standardized approach. Utilizing the imaging protocol and analysis method defined in this study, we aim for this methodology to potentially assist clinicians to assess true perfusion changes for treatment monitoring with CEUS in longitudinal studies.

Outcomes of ultra-low contrast percutaneous coronary intervention in patients with advanced chronic kidney disease.

Coronary angiography and percutaneous coronary intervention (PCI) in patients with chronic kidney disease (CKD) is associated with increased risk of contrast induced nephropathy (CIN) and requirement for renal replacement therapy (RRT). We aimed to evaluate our single center experience of ultra-low contrast PCI in patients with CKD and to characterize 1 year outcomes. We performed a retrospective analysis of ultra-low contrast PCI at our institution between 2016 and 2022. Patients with CKD3b-5 (eGFR <45 mL/min/1.73m2), not on RRT who underwent ultra-low contrast PCI ( < 30 mL of contrast during PCI) were included. Primary outcomes included change in eGFR post-procedurally, and death, RRT requirement, and major adverse cardiac events (MACE) at 1 year follow-up. One hundred patients were included in the study. The median age was 67 years old and 28% were female. The median baseline eGFR was 21.5 mL/min/1.73m2 (IQR 14.08-32.0 mL/min/1.73m2). A median of 8.0 mL (IQR 0-15 mL) of contrast was used during PCI. Median contrast use to eGFR ratio was 0.37 (IQR 0-0.59). There was no significant difference between pre-and postprocedure eGFR (p = 0.84). At 1 year, 8% of patients died, 11% required RRT and 33% experienced MACE. The average time of RRT initiation was 7 months post-PCI. Forty-four patients were undergoing renal transplant evaluation, of which 17 (39%) received a transplant. In patients with advanced CKD, ultra-low contrast PCI is feasible and safe with minimal need for peri-procedural RRT. Moreover, ultra-low contrast PCI may allow for preservation of renal function in anticipation of renal transplantation.

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.

SuperDyna: Unlocking the Potential of Post-Treatment Device Evaluation

BackgroundCurrent imaging algorithms for post-device evaluation are limited by either poor representation of the device or poor delineation of the treated vessel. Combining the high-resolution images from a traditional three-dimensional...

Pharmacoeconomic analysis of costs for radiopaque agents and a method to minimize them

The aim of the work is to minimize the costs of a multidisciplinary hospital in the city of Volgograd for radiopaque substances.&#x0D; Materials and research methods: In the first part, the costs of the hospital for the purchase of x-ray contrast medications were studied and the average cost of direct costs for radiopaque agents for one coronary angiography procedure was determined. In the second part, a comparative analysis of the cost of radiopaque agents presented on the Russian market was carried out on the basis of the State Register of Selling Prices.&#x0D; Results of the study and their discussion: A retrospective analysis of 147 case histories of patients undergoing percutaneous coronary intervention showed that the average volume of radiopaque drug during coronary angiography was (126.19 36.35) ml. In 66 (44.9 %) patients, more than 100 ml was used per procedure. For one coronary angiography procedure, on average (126 ml of contrast), 1927.8 rubles were spent for a radiopaque preparation. Among the radiopaque drugs recommended for coronary angiography, according to the state register of maximum ex-works prices, Iohexol preparations 350 mg/ml of Russian production had the lowest cost.&#x0D; Conclusions: Procurement of domestic preparations Iohexol 350 mg/ml, 100 ml bottles will reduce the cost of percutaneous coronary intervention.

Bacteriological assessment of pipe-borne, borehole, and well water sources available to students in Nasarawa State University Keffi, Nasarawa State, Nigeria

The provision of clean water, microorganisms-free water is crucial in preventing the transmission of waterborne diseases. This study was conducted with the objective of evaluating the bacteriological quality of water sources accessible to students within Nasarawa State University Keffi. Sixteen samples, comprising ten from piped source, three from boreholes, and three from wells, were subjected to bacteriological quality assessment. The total bacterial count was analyzed using the pour plate technique, while the total coliform count and bacteriological index were assessed through the most probable number technique. Among the various water sources examine, pipe-borne water exhibited the lower bacterial contamination with a mean of 0.6×106 CFU/100 mL in contrast to borehole and well water sources, which recorded mean of 1.6×106 and 3.2×106 CFU/100 mL, respectively. Additionally, pipe-borne water demonstrated the lowest mean total coliform count, registering 22 MPN/100 mL. Notably, Notably, the water samples were found to harbor bacteria such as Escherichia coli, Klebsiella pneumonia, Enterobacter aerogens, and Citrobacter sp. Alarming findings from this study highlight the unsuitability of most water samples for human consumption, as they fail to meet the quality standards established by the World Health Organization. Consequently, it is necessary to implement measures aimed at safeguarding water sources from contamination and curbing the proliferation of diseases. Furthermore, it is pertinent to prioritize adequate treatment of domestic water sources prior to consumption to ensure public health and well-being.

Angiographic challenges of spinal dural and epidural arteriovenous fistulas: report on 45 cases.

The localization of the fistula level in spinal dural arteriovenous fistulas (dAVFs) and epidural arteriovenous fistulas (edAVFs) remains a diagnostic challenge. Consecutive patients with spinal dAVFs and edAVFs in the thoracic, lumbar, and sacral regions were included. The primary endpoint was to describe the characteristics of patients who required angiography with multiple catheterizations of segmental arteries (10 or more). Forty-five patients (median age 69years; male 89%; dAVFs, n = 31; edAVFs, n = 14) were included. Spinal dAVFs commonly developed in the thoracic region and edAVFs in the lumbosacral region. Fistulas were predicted at the correct level or plus/minus 2 level in less invasive examinations using multi-detector CT angiography (n = 28/36, 78%) and/or contrast-enhanced MR angiography (n = 9/14, 64%). We encountered diagnostic challenges in the localization of fistulas in 6 patients. They underwent angiography a median of 2 times. In each patient, spinal levels were examined at a median of 25 levels with a median radiation exposure of 3971mGy and 257ml of contrast. Fistulas were finally localized at the high thoracic region (T4-6) in 3 patients, the sacral region (S1-2) in 2, and the lumbar region (L3) in 1. Four patients were diagnosed with edAVFs and 2 with dAVFs. The correlation coefficient between the fistula level and the rostral end of the intramedullary T2 high-signal intensity on MRI was interpreted as none. In patients in whom less invasive examinations failed for fistula localization, high thoracic or sacral AVFs need to be considered.

Acute Kidney Injury Risk and Contrast Volume in Intact Versus Ruptured Endovascular Aneurysm Repair in the Vascular Quality Initiative.

Renal impairment after repair of ruptured abdominal aortic aneurysm has been associated with post-operative mortality. Acute kidney injury (AKI) risk specifically related to contrast administration in endovascular aneurysm repair (EVAR) for intact vs ruptured aneurysms has not been previously described. It was our objective to evaluate the risk of AKI and the association with contrast administration in EVAR for ruptured (rEVAR) and intact (iEVAR) aneurysm repair in the Vascular Quality Initiative (VQI). Adult patients less than 90 years old undergoing EVAR in the VQI without prior abdominal aortic surgery or who were not actively on dialysis preoperatively were included. Patients immediately converted to an open repair were excluded. Patients were grouped by repair urgency, and patient and operative characteristics and outcomes compared. Univariable and multivariable analyses were performed to identify factors associated with the primary outcome of AKI. Survival was evaluated by Kaplan-Meier analysis. Of 38,775 EVAR patients identified, 86.5% underwent elective surgery for an intact aneurysm, 8.4% had urgent surgery for a symptomatic, intact aneurysm, and 5.1% had emergent repair for a ruptured aneurysm. Significant risk factors for AKI included contrast volume, a preoperative eGFR <30mL/min, procedure urgency, COPD, congestive heart failure (CHF), and total procedure time. The factor most associated with AKI was aneurysm rupture prior to repair (OR 8.6, CI 7.2-10.3, P <.01). The association of contrast volume with the outcome was the least strong with a 4% increase in risk per 25mL of contrast (OR 1.04, 95% CI 1.01-1.07). With the development of AKI, postoperative survival was reduced regardless of indication. Of all factors assessed, aneurysm rupture was the most and contrast volume the least associated with AKI after EVAR. Further studies should evaluate methods of preventing post-EVAR AKI.

Ultrasound-guided retrobulbar nerve block in donkey cadavers

ObjectiveTo develop and describe an acoustic window to access and inject the retrobulbar region in donkey cadavers. Study designProspective cadaveric experimental study. AnimalsA total of 14 donkey cadaver heads. MethodsUltrasound landmarks for retrobulbar injection were identified by dissection of two cadavers. Ultrasound-guided retrobulbar injection of 3, 6 and 9 mL of contrast–lidocaine mixture (1:1) were evaluated using computed tomography (CT) in 12 cadavers for needle position and spread of injectate into the extraocular muscle cone. ResultsReal-time visualization of needle, extraocular muscle cone and optic nerve enabled successful intraconal instillation of injectate, as documented on CT images. Conclusions and clinical relevanceUltrasound-guided retrobulbar injections in cadaver donkeys provided adequate infiltration of the intraconal space.

Contrast-induced nephropathy after staged balloon pulmonary angioplasty: lower risk compared with left-sided cardiac procedures

Abstract Introduction The risk of contrast-induced nephropathy (CIN) after left-sided cardiac procedures is reported as 10–15%. When the ratio of total contrast volume in ml to glomerular filtration rate (GFR) in mL/min (ratio V/GFR) exceeds 3.7, the risk increases significantly. However, there are few reports regarding the risk of CIN in patients (pts) with right-sided cardiac interventions such as balloon pulmonary angioplasty (BPA) and ratio V/GFR is not validated for use in this procedures. Purpose To assess the prevalence of CIN in pts with chronic thromboembolic pulmonary disease with or without hypertension (CTEPH/CTED) undergoing BPA. Methods Prospective single-centre study that included all BPA sessions performed from 2017 to 2020. Serum creatinine concentration (SC) was measured and the GFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) before and 48 hours after each BPA procedure and 6 months after BPA treatment completion. CIN was defined as an increase of ≥25% and/or ≥0.5 mg/dL in SC from the baseline value within 48h of contrast administration. Results 76 consecutive BPA sessions were performed in 15 CTEPH/CTED pts: mean age 63.2±14.0 years, 60% female, 86.7% CTEPH, mean of 5.3±1.9 sessions per patient with 4.3±1.9 vessels dilated per session. Mean value of GFR before BPA program was 73.5±26.3 mL/min. All the procedures were performed using low-osmolality contrast agent with a 1:1 dilution ratio with normal saline solution. Pts received 273.0±73.0 mL of contrast per session with a ratio V/GFR 3.7±1.7 mL. SC and GFR did not change significantly within 48h after BPA (+3.1%, p=0.07 and −3.0%, p=0.13, respectively). Ratio V/GFR &amp;gt;3.7 occurred in 44.3% of cases (n=31), but CIN occurred in only 5.3% (n=4) with an increase in SC &amp;lt;0.5 mg/dL but ≥25% in 3 cases (+33% in mean) and ≥0.5 mg/dL in 1 case. None of the pts required renal replacement therapy. Higher SC and lower GFR 48h after BPA were significantly correlated with greater rato V/GFR during procedure (r=0.75, p&amp;lt;0.01 and r=−0.74, p&amp;lt;0.01, respectively) – see figure. But neither higher values of ratio V/GFR (OR 1.43; CI95% 0.84–2.41; p=0.19) nor V/GFR &amp;gt;3.7 (OR 1.28; CI95% 0.17–9.6; p=0.81) were predictors of CIN. GFR before procedure did not influence the contrast volume administered (p=0.901), number of vessels (p=0.63) and segments treated by session (p=0.45). At 6 months follow-up, there was a trend for SC (1.3±0.2 mg/dL vs 1.1±0.2 mg/dL, −15%, p=0.43) and GFR (44.5±8.3 mg/dL vs 53.0±12.6 mg/dL, +16%, p=0.34) improvement in pts with impaired renal function at baseline (GFR&amp;lt;60 mL/min). Conclusions These findings suggested that the occurrence of CIN after BPA was low, raising the hypothesis that the influence of contrast agent on renal function could differ in right-sided cardiac interventions. Although the ratio V/GFR may be correlated with the risk of nephropathy, it is necessary to find a new cut-off to predict CIN in BPA pts. Funding Acknowledgement Type of funding sources: None.

English

BACKGROUND Cardiac syndrome X (CSX) is not benign, and it needs long-term follow up and risk factor modification. In this study, we wanted to calculate microcirculatory transit time on coronary angiography in patients with cardiac syndrome X (CSX), compare microcirculatory transit time in patients with and without CSX and to see whether microcirculatory transit time can be proposed as a risk stratification method in CSX. METHODS Cross sectional study of 52 patients. The angiogram was taken at 15 frames per second. The left coronary artery was injected with 7 ml of contrast approximately. Microcirculatory transit time (MCTT) was obtained offline. The microcirculatory transit time in seconds is calculated as last frame count minus first frame count/15. Microcirculatory transit time was compared and analysed in both groups. RESULTS A total of 52 subjects were analysed. There were 26 cases in the angina group with a mean age of 49.96 years and 26 cases in the control group with a mean age of 50.32 years. Dyslipidemia, smoking and statin use were more common in the angina group, which was statistically significant (P &lt; 0.05). The mean MCTT of the group with angina and positive treadmill test (TMT) was 6.76 seconds, whereas the negative TMT group was 6.39 seconds. The mean frame count was 58.1, and the mean MCTT was 3.8 seconds in the control group, whereas the mean frame count and mean MCTT were 98.1 and 6.5 seconds in the angina group, which was statistically significant (P &lt; 0.001). CONCLUSIONS CSX patients had longer MCTT than patients without chest pain and normal coronary arteries. MCTT can be used to assess the risks of CSX. Long-term followup studies with a large sample size should be conducted. KEYWORDS Cardiac Syndrome X, Angina, Coronary Artery Disease, Microcirculation

The Influence of Ultrasound-Guided Technique Using a Catheter-Over-Needle on the Incidence of Accidental Intravascular Injection during Caudal Block-A Retrospective Case Series Study.

Background and Objectives: This study was conducted to investigate the influence of an ultrasound-guided technique using a catheter-over-needle when an intravascular injection occurs in patients undergoing a caudal block. Material and Methods: We retrospectively investigated 41 cases of an ultrasound-guided technique using an angiocatheter for caudal block. These had been performed between November 2019 through August 2020 to manage pain of lumbosacral origin. Under ultrasound guidance, after advancing the introducer needle through the sacrococcygeal ligament and then slowly withdrawing it, the outer catheter was continuously advanced into the sacral hiatus. We confirmed proper needle placement under fluoroscopic imaging, using 5 mL of contrast media. We assessed the contrast spread pattern with fluoroscopic imaging and checked it for the presence of intravascular injection. Results: In all recruited cases, the catheter-over-needle was guided successfully to the sacral hiatus and into the caudal epidural space. There was 100% accuracy under ultrasound guidance, without intravascular uptake, as confirmed by contrast media fluoroscopy. The incidence of ventral spread was 84.2% above the S1 with 5 mL of contrast. Conclusions: The technique of using a catheter-over-needle under ultrasound induced successful block without intravascular injection. Thus, this technique is a reliable option for conventional caudal block.

A New Technique for Computed-Tomography Urethrography in Males: The Clamp Method

The aim of the present study is to describe and evaluate a new technique for performing Computed-Tomography Retrograde Urethrography (CT-RUG). Males with urethral anomalies detected by retrograde urethrography (RUG) and/or retrograde sonourethrography (RSUG) underwent CT-RUG using the clamp method and three radiologists evaluated the anomalies in each technique separately and blindly. CT-RUG was done successfully in all the cases (n = 22), with means of 6 min duration and 95 mL of contrast; no pain was reported by 81% of the patients (VAS: 0) and very mild pain by the rest (VAS: 0.5–1.2). CT-RUG showed better diagnostic efficacy in cases of periurethral fistula (n = 8), urethral stent (n = 3), previous urethroplasty and urethral lithiasis (n = 2), a similar accuracy to RSUG for measuring the length of anterior urethral strictures (n = 9) and greater accuracy than RUG (p = 0.008). Six cases received 2 CT sweeps, with an effective dose of 4.96 mSv, and the remaining 16 had 1 sweep and received 3.456 mSv. To the best of our knowledge, this is the first study to describe the clamp method for CT-RUG, a method that is effective and comfortable for both the patient and the operator (retrograde infusion of contrast).

Evaluation of Contrast Flow Patterns with Cervical Interlaminar Epidural Injection: Comparison of Midline and Paramedian Approaches.

Background and objectives: The purpose of this study was to compare and to analyze contrast spread patterns between the paramedian and midline approaches to cervical interlaminar epidural injection (CIEI). Materials and Methods: We retrospectively enrolled 84 CIEI cases that had been performed for unilateral cervical spinal pain from April 2019 to April 2020. After 3 mL of contrast had been injected into the epidural space, fluoroscopic images were obtained. The CIEI was divided into a midline (Group M, n = 42) and a paramedian (Group P, n = 42) approach by anteroposterior imaging. The P Group was classified into a more medial (Group Pm, n = 26) and a more lateral (Group Pl, n = 16) group. Using ImageJ on an anteroposterior image, we assessed the grayscale brightness ratio of the ipsilateral or contralateral side of the vertebral body as well as the intervertebral disc space one level just above the needle location. We identified the dispersion of contrast into the ventral epidural space. Results: The grayscale brightness ratio was significantly higher in Group P than in Group M (p < 0.001). The incidence of ventral epidural spread in Group M was 57.1% versus 88.1% in Group P, which was significantly different (p = 0.001). Conclusions: The fluoroscopic CIEI finding in the paramedian approach predominantly showed an excellent delivery of the injectate to the ipsilateral side in comparison to the contralateral side. This showed a greater advantage in delivery toward ventral epidural space as compared to the midline approach.

Efficacy of radiofrequency RDN may be significantly improved if the procedure is guided by impedance drop during the treatment

Abstract Background Experimental studies of radiofrequency renal denervation (RDN) have shown a strong relation of the depth of structural lesions and completeness of renal nerve injury to the relative drop in impedance during the treatment caused by the increased permeability of the cell membranes. Thus, the otherwise successful treatments but with low impedance drop may be, in fact, totally ineffective. Objective We assessed the relation between impedance drop during single radiofrequency treatments and local structural changes of vascular wall at the electrode positions using optical coherence tomography. Methods Optical coherence tomography of the treated segments was performed during radiofrequency RDN in 14 patients with resistant hypertension. The parameters of contrast injection depended on the position of the guiding catheter: for selective branch imaging 15 ml volume was injected at 8 ml/sec speed; otherwise 30 ml of contrast was injected at the speed 15 ml/sec to flush the whole renal artery. Automatic pullback of the sensor was done with the standard speed 20 mm/sec. In total, 423 mm of treated segments in 22 renal vessels (mostly distal branches) had sufficient quality of imaging and were studied for structural changes. Results There was almost no local structural changes of the arterial wall after the treatments with low impedance drop &amp;lt;10% reflecting a rather weak heating of even superficial tissue layers. No effect on the deeper tissue layers is expected in this case because these layers are heated almost exclusively by the heat transfer from superficial layer. In contrast, the treatments with the impedance drop 10% or greater were able to significantly affect the arterial structure causing local edema, small dissections, and local thrombi formation as a result of significant resistive heating of the superficial tissue, and, therefore, high potential for heating of the deep layers containing the renal nerves. Only approximately 40% of the point treatments had the impedance drop 10% or greater suggesting adequate lesion depth and sufficient completeness of renal nerve injury. This may indicate a rather low procedural efficacy of the current mode of radiofrequency RDN due to a large proportion of small-depth treatments marked by only a few percent decrease in impedance yet considered fully “successful”. Also, it means a potential for significant increase in the efficacy of radiofrequency RDN through controlling/guiding the treatment by the impedance drop. Conclusion Our study shows that variable efficacy of radiofrequency RDN may be explained by a significant proportion of the small-depth point treatments ineffective in terms of renal nerve injury, and, thereby, may be significantly improved if the procedure is guided by the impedance drop during the treatment. Funding Acknowledgement Type of funding source: None

Abstract No. 672 A quantitative venography technique using time-modulated contrast injections

The intraprocedural evaluation of venous intervention is difficult due to limited number of techniques for measuring venous blood flow. Quantitative angiography methods have been described for quantifying blood flow in arteries using transient contrast boluses developed by cardiac pulsatility. The objective of this study was to determine the feasibility of performing quantitative venography by generating a pulsatile signal via modulated contrast injection. Preliminary in vivo evaluation of the quantitative venography techniques were performed in 2 50 kg female domestic swine. In animal 1, a flush catheter was positioned in the main portal vein. A 2D-DSA sequence was acquired during which contrast was manually injected (40 mL of contrast delivered in 10 pulses for 20 seconds). In animal 2, a flush catheter was positioned in the infra-renal inferior vena cava (IVC), and 2D-DSA sequences were acquired during which a modulated contrast injection (5-9 mL/s contrast pulses at 0.67Hz interleaved with 0-6 mL/s saline pulses at 0.67 Hz, for 10 seconds total) was performed using a custom-built power-injector. Blood velocity measurements were concurrently made in the IVC using an indwelling Doppler flow wire. A post-hoc analysis of all DSA sequences was performed using a shifted-least squares method for quantifying blood velocity. Triplicate calculations in the target regions were made on each DSA sequence. Calculated blood velocities using 2D-DSA (mean ± STD) in the IVC and portal vein were 12.4 ± 0.7 and 14.0 ± 2.0 cm/s respectively. Measured blood velocity in the IVC using the Doppler flow wire was 17.3 ± 6.5 cm/s. Hepatopetal blood velocity in the porcine portal vein has been previously reported to be 15.6 ± 9.0 cm/s. In the inferior vena cava, the calculated blood velocities were similar to measurements made using a Doppler flow wire. In the portal vein, calculated blood velocities were similar to values reported previously in porcine models. These results indicate the feasibility of quantitative venography, a novel method for intraprocedural characterization of changes in venous blood flow in response to venous intervention.

Pulmonary embolism: Low dose contrast MSCT pulmonary angiography with modified test bolus technique

PurposeThis study aims to prove that the test bolus technique provides a better selective imaging study of the pulmonary arterial system in comparison to the automatic bolus-tracking technique. MethodA prospective study included 600 patients, classified into 2 groups where each group consisted of 300 patients. In group A, we used the bolus tracking technique with 80−100 ml of contrast while in group B test bolus technique was used with 50 mL of contrast. ResultsIt was clear that the Main PA average density was 260.5 HU in group A and increased to 320 HU in group B with P value < 0.002. The Ascending aorta average density decreased from 250 HU in group A to 130 HU in group B with P value <.001. The average score was increased by 35 % (from 1.75 in group A to 2.8 in group B with P value < .001). The Volume of IV contrast needed decreased by 40 % in group B compared to group A. ConclusionMSCTPA using test bolus method reduces the amount of the contrast used with better opacification of the pulmonary artery and its sub segmental branches in addition to reduced artifact.

P1909Cryobaloon pulmonary vein isolation without pulmonary venography

Abstract Introduction Cryoballoon pulmonary vein isolation (PVI) has been shown to be non-inferior to radiofrequency PVI and have several advantages including shorter procedure times. Cryoballoon PVI traditionally requires the use of occlusive pulmonary venography to assess for balloon position and contact however, some patients have contraindications to the use of iodinated radiocontrast. Purpose We assessed the feasibility of performing cryoballoon PVI without pulmonary venography. Methods Thirty-five initial consecutive patients with paroxysmal or persistent atrial fibrillation underwent cryoballoon PVI as a primary procedure under conscious sedation by a single operator. None had a contraindication to radiocontrast administration. Left atrial CT was obtained the day prior in all patients to assess pulmonary vein anatomy. Transeptal puncture was performed using 1–5 ml of contrast given the non-routine availability of intracardiac echocardiography. CT images obviated the requirement for pre-balloon deployment venography and pulmonary vein balloon occlusion was assessed by tactile feedback as well as the fluoroscopic appearance of balloon deformation (Fig 1.). If adequate temperature was not obtained with initial cooling during ablation, application was discontinued and the balloon repositioned. If repeated ablation did not result in sufficient cooling and vein isolation, pulmonary venography was utilised to assess adequacy of vein occlusion and sites of leak. Results The median age was 57 yrs with 69% male and 63% having paroxysmal AF. 137/138 pulmonary veins were successfully isolated with mean 1.77 ablations per vein. Median nadir ablation temperature was −45°C (range −62 to −30°C) with a median time to isolation of 36.5 seconds. 120/138 (87%) of veins were isolated without the use of contrast, however 18/138 required venography. Overall, 63% of patients had successful PVI without requiring any pulmonary venography. Average procedure time was 104 minutes. One patient sustained a mediastinal hematoma that resolved with conservative management. Median follow up was 3.6 months, with 74% of patients being free from atrial fibrillation at last follow up. Conclusion This study demonstrates that it is feasible to perform cryoballoon PVI without pulmonary venography in 87% of targeted veins. In this series, 63% of patients had successful 4 vein isolation without pulmonary vein contrast administration. This technique combined with imaging guided transeptal puncture can allow for truly contrast-less PVI in patients with severe contrast allergy or severe renal dysfunction.

Ultrasonography of the Adult Male Urinary Tract for Urinary Functional Testing.

The incidence of clinical benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) is increasing due to the aging population, resulting in a significant economic and quality of life burden. Transgenic and other mouse models have been developed to recreate various aspects of this multifactorial disease; however, methods to accurately quantitate urinary dysfunction and the effectiveness of new therapeutic options are lacking. Here, we describe a method that can be used to measure bladder volume and detrusor wall thickness, urinary velocity, void volume and void duration, and urethral diameter. This would allow for the evaluation of disease progression and treatment efficacy over time. Mice were anesthetized with isoflurane, and the bladder was visualized by ultrasound. For non-contrast imaging, a 3D image was taken of the bladder to calculate volume and evaluate shape; the bladder wall thickness was measured from this image. For contrast-enhanced imaging, a catheter was placed through the dome of the bladder using a 27-gauge needle connected to a syringe by PE50 tubing. A bolus of 0.5 mL of contrast was infused into the bladder until a urination event occurred. Urethral diameter was determined at the point of the Doppler velocity sample window during the first voiding event. Velocity was measured for each subsequent event yielding a flow rate. In conclusion, high frequency ultrasound proved to be an effective method for assessing bladder and urethral measurements during urinary function in mice. This technique may be useful in the assessment of novel therapies for BPH/LUTS in an experimental setting.

Frequency Domain-optical Coherence Tomography of Coronary Arteries Using a Diluted Iodinated Contrast-saline Mix with 5-Fr Guide Catheters.

BackgroundOptical coherence tomography (OCT) is currently mostly performed using 6-Fr coronary guide catheters via femoral access. Catheters with such large internal diameters are necessary to deliver viscous contrast media and achieve sufficient red blood cell washout. Currently, undiluted iodinated contrast media (15 mL/injection) is used to clear the coronary arteries of red blood cells (RBCs). This leads to an increase in the total amount of contrast used and often the need for femoral artery access. Our objective is to assess the feasibility of performance of OCT using a 5-Fr guide catheter via radial access using diluted iodinated contrast.MethodsWe present a case series of 11 patients where second-generation frequency domain (FD)-OCT was used to assess the coronary arteries using a novel 70:30 dilution mixture of iodinated contrast medium with heparinized normal saline. All procedures were performed with a 5-Fr coronary guide catheter via the radial artery approach.ResultsAll procedures were successfully performed vial radial access with good quality imaging obtained. The target vessel was the left anterior descending artery in eight patients, the right coronary artery in two patients, and the left main coronary artery in one patient. OCT resulted in a change in management in 7/11 (64%) patients; no complications were reported with OCT. On average, 10 mL of contrast was used per injection.ConclusionsThe current study demonstrates the feasibility of FD-OCT using 5-Fr guide catheters and diluted iodinated contrast media. This approach lowers contrast exposure and potentially decreases vascular complications without sacrificing image quality.