Peripheral intravenous power injection of iodinated contrast media through 22G and 20G cannulas: can high flow rates be achieved safely? A clinical feasibility study

Intravenous contrast medium extravasation: systematic review and updated ESUR Contrast Media Safety Committee Guidelines

NEED FOR A REVIEW

Guidelines for management and prevention of contrast media extravasation have not been updated recently. In view of emerging research and changing working practices, this review aims to inform update on the current guidelines.

AREAS COVERED

In this paper, we review the literature pertaining to the pathophysiology, diagnosis, risk factors and treatments of contrast media extravasation. A suggested protocol and guidelines are recommended based upon the available literature.

KEY POINTS

• Risk of extravasation is dependent on scanning technique and patient risk factors. • Diagnosis is mostly clinical, and outcomes are mostly favourable. • Referral to surgery should be based on clinical severity rather than extravasated volume.

An audit of the adequacy of contrast enhancement in CT pulmonary angiograms in a South African tertiary academic hospital setting

Background

Undiagnosed pulmonary embolism carries high mortality and morbidity. Computed tomography pulmonary angiogram (CTPA) is the diagnostic method of choice for accurate diagnosis. Inadequate contrast opacification is the second most common cause of indeterminate CTPAs.

Objectives

Audit the adequacy of CTPA contrast enhancement and determine whether inadequate enhancement is affected by the size and site of the intravenous cannula, flow rate, contrast volume, contrast leakage and day shift versus after hours services.

Method

Retrospective and prospective audits of the adequacy of contrast enhancement of CTPAs at the Charlotte Maxeke Johannesburg Academic Hospital were conducted using the Royal College of Radiologists guidelines (≤ 11% of studies with < 210 HU). Protocol variables were collected prospectively from questionnaires completed by radiographers performing the CTPAs. Adequate versus inadequate groups were analysed.

Results

A total of 63 (retrospective) and 130 (prospective) patients were included with inadequate contrast enhancement rates of 19% (12/63) and 20.8% (27/130), respectively. The majority of CTPAs were performed during the day 56.2% (73/130) with a 20G cannula 66.2% (86/130) in the forearm 33.8% (44/130) injecting 100 mL – 120 mL contrast 43.1% (56/130) at 3 mL/s 63.1% (82/130). The median flow rate (3 mL/s) and contrast volume (80 mL) were identical in both adequate and inadequate groups, while the remaining variables showed no statistical difference.

Conclusion

The rate of inadequately enhanced CTPAs in this study was high. The protocol variables did not have a significant influence on the rate of inadequate enhancement. Further research, particularly using flow rates > 4 mL/s, is required for protocol optimisation.

Closed versus conventional IV catheter in performing coronary CT Angiography

Background

The purpose of this study was to compare the performance of a closed IV catheter system (CICS) with conventional IV catheters for IV contrast infusion in terms of contrast enhancement and associated complications during coronary CT angiography.

It is a retrospective study of 54 patients for whom a follow-up CCTA was requested were included for this study. Those patients had previous experience with the insertion of a 18 g conventional IV catheter which allows a flow rate of ≥ 6 ml/s and the complications during injection were registered. Patients were informed that a new IV catheter (The BD Nexiva™ Diffusics™ Closed IV Catheter System 22 g while still meeting a high flow rate > 6 m/s) will be used for their examination. We analyzed mean vascular attenuations in the ascending aorta, left main coronary artery, left ventricular (LV) cavity, and descending aorta (DA). Their feedback was collected regarding pain and the number of trials for catheter insertion. In addition, the access site was evaluated for any complication e.g. perforation, contrast extravasation or contamination.

Result

All patients were very satisfied with the new cannula. The catheter was inserted from the first trials. No one has perforation or extravasation. Mean vascular attenuations of the left main coronary artery, LV cavity, and DA were significantly higher during the use 0f the BD Nexiva™ Diffusics™ Closed IV Catheter System (all P ≤ 0.001).

Conclusion

Although the CICS has a small lumen, it allows a high flow rate; therefore, IV access required for CCTA can be secured with higher vascular attenuation and fewer complications. It is encouraged to use the CIVC system for CT angiographic studies, in particular CCTA.

More holes, more contrast? Comparing an 18-gauge non-fenestrated catheter with a 22-gauge fenestrated catheter for cardiac CT

Objective

To compare the performance of an 18-gauge nonfenestrated catheter (18-NFC) with a 22-gauge fenestrated catheter (22-FC) for cardiac CT angiography (CCTA) in patients with suspected coronary heart disease.

Subjects and methods

74 consecutive patients imaged on a 2^nd generation dual-source CT with arterial phase CCTA were included in this retrospective investigation to either an 18-NFC or 22-FC. In comparison to the 18-NFC, the 22-FC has three additional perforations for contrast agent dispersal proximal to the tip. We examined the two groups for differences in their average attenuation in the right and left ventricles (RV, LV) and in the atrium (RA, LA) as well as in the proximal right coronary artery (RCA) and the left main coronary artery (LM). The averages were calculated for both the 18-NFC and 22-FC.

Results

Catheters were successfully placed on the first attempt 97% (36/37) for 18-NFC and 95% (35/37) for the 22-FC. The following enhancement levels were measured: 22-FC (in Hounsfield-Units (HU)): RV = 203±29, LV = 523±36, RA = 198±29, LA = 519±38, RCA = 547±26, LM = 562±25; 18-NFC: RV = 146±26, LV = 464±32, RA = 141±24, LA = 438±35, RCA = 501±23, LM = 523±23; RV (p = 0,03), LV (p = 0.12), RA (p = 0.02), LA (p = 0.04), RCA (p = 0.3), LM (p = 0.33).

Conclusion

No significant differences in attenuation levels as well as in image quality of the coronary arteries were found between NFC and FC. Nevertheless, the 22-gauge FC examinations showed significantly higher attenuation in the left and right atrium as well as the right ventricle. Patients with poor venous access may benefit from a smaller gauge catheter that can deliver sufficiently high flow rates for CCTA.

Prospective safety evaluation of automated iomeprol 400 injections for CT through peripheral venous cannulas

AIM

To evaluate prospectively the safety of contrast medium injection through standard peripheral intravenous cannulas at standard injection sites during clinical routine using iomeprol 400, a contrast agent with high viscosity.

MATERIALS AND METHODS

Three thousand, five hundred and fourteen clinical CT examinations undertaken at Saarland University Medical Center were included in this prospective observational trial. The size and site of the cannula as well as the contrast medium injection rate and volume were assessed for each patient. In addition, the ability to aspirate blood though the cannula and the occurrence of complications, such as extravasation or abortion of injection by the automated injector, were recorded.

RESULTS

The overall complication rate was 30/3,514 (0.85%). With 22 G cannulas, the complication rate was 8/541 (1.48%) applying flow rates of 1-3.5 ml/s (mean 2.1 ml/s). With 20 G cannulas, complications occurred in 21/2,601 cases (0.81%) with flow rates of 1.5-5 ml/s (mean 3 ml/s). The complication rate using 18 G cannulas was 1/377 (0.26%) for flow rates of 2-6 ml/s (mean 3.5 ml/s). No relationship between the site and size of the cannula to the occurrence of complications was found. The inability to aspirate blood correlated with the development of extravasation.

CONCLUSIONS

The injection of contrast agent using standard peripheral venous cannulas is a safe and reliable procedure yielding diagnostic image contrast, even when using highly viscous contrast agents such as iomeprol 400; an aspiration test should be performed before each injection.

The Usefulness of Fenestrated Intravenous Catheters Compared With Nonfenestrated Catheter for Cardiac Multidetector Computed Tomography

PURPOSE

To compare the fenestrated intravenous (IV) catheter and nonfenestrated conventional IV catheter in terms of contrast enhancement and injection pressure for coronary computed tomography angiography.

METHODS

Three hundred patients were prospectively and consecutively enrolled to either the 20-gauge nonfenestrated conventional (group 1) IV catheter group or the 20-gauge fenestrated (group 2) or 22-gauge fenestrated (group 3) IV catheter groups. We analyzed mean vascular attenuations in the ascending aorta, left main coronary artery, left ventricular (LV) cavity, and descending aorta. Injection pressure using pound-force per square inch (PSI) and extravasation of contrast media were recorded.

RESULTS

Mean attenuations of the left main coronary artery, LV cavity, and descending aorta were significantly higher in group 2 than in group 1 (P ≤ 0.001, P ≤ 0.001, P ≤ 0.001, respectively). Moreover, injection pressure was significantly lower in group 2 than in group 1 (208.3 vs 216.9 PSI, P = 0.006). Mean vascular attenuations of the left main coronary artery, LV cavity, and descending aorta were significantly higher in group 3 than in group 1 (P = 0.016, P = 0.029, P = 0.001, respectively). However, injection pressure was not statistically significant between group 3 and group 1 (213.6 vs 216.9 PSI, P = 0.355). No extravasation occurred in any patient groups during the study.

CONCLUSIONS

We suggest that fenestrated IV catheter is useful in terms of higher vascular attenuation and lower injection pressure for coronary computed tomography angiography. It has a potential merit in patients with fragile and small veins.

Standard Short Peripheral Catheters (SPCs) Versus Power Injectable SPCs During Contrast Computed Tomography and Magnetic Resonance Imaging Angiography: A Quality Improvement Study

To perform high-resolution computed tomography and magnetic resonance imaging angiographies, contrast typically is rapidly injected through a 20-gauge or larger short peripheral catheter (SPC). Intravenous access in infants and children can be challenging, and the use of large-gauge catheters is not always feasible. An institutional review board-approved quality improvement study was undertaken at a 250-bed pediatric hospital on Florida's Gulf Coast that compared the use and outcomes of standard SPCs (nonfenestrated) versus a power injectable SPC (fenestrated with 3 side holes distal to the catheter tip).

Contrast media extravasations in patients undergoing computerized tomography scanning: a systematic review and meta-analysis of risk factors and interventions

OBJECTIVE

To identify risk factors and interventions preventing or reducing contrast medium extravasation.

INTRODUCTION

Computed tomography (CT) is a radiological examination essential for the diagnosis and monitoring of many diseases. It is often performed with the intravenous (IV) injection of contrast agents. Use of these products can result in a significant complication, extravasation, which is the accidental leakage of IV material into the surrounding tissue. Patients may feel a sharp pain and skin ulceration or necrosis may develop.

INCLUSION CRITERIA

This review considered studies that included patients (adults and children) undergoing a CT with IV administration of contrast media. The risk factors considered were patient demographics, comorbidities and medication history. This review also investigated any strategies related to: contrast agent, injection per se, material used for injection, apparatus used, healthcare professionals involved, and patient risk assessment performed by the radiology personnel. The comparators were other interventions or usual care. This review investigated randomized controlled trials and non-randomized controlled trials. When neither of these were available, other study designs, such as prospective and retrospective cohort studies, case-control studies and case series, were considered for inclusion. Primary outcomes considered were: extravasation frequency, volume, severity and complications.

METHODS

The databases PubMed, CINAHL, Embase, the Cochrane Register of Controlled Trials, Web of Science PsycINFO, ProQuest Dissertations and Theses A&I, TRIP Database and ClinicalTrials.gov were searched to find both published and unpublished studies from 1980 to September 2016. Papers were assessed by two independent reviewers for methodological validity using the Joanna Briggs Institute System for the Unified Management, Assessment and Review of Information (JBI SUMARI). Data were extracted using the standardized data extraction tool from JBI SUMARI. In one case, quantitative data from two cohort studies were pooled in a statistical meta-analysis. However, generally, statistical pooling was not possible due to heterogeneity of the interventions, populations of interest or outcomes. Accordingly, the findings have been presented in narrative form.

RESULTS

Fifteen articles were selected from a total of 2151 unique studies identified. Two were randomized controlled trials and 13 were quasi-experimental and observational studies. The quality of these studies was judged to be low to moderate. Some patient characteristics, such as female sex and inpatient status, appeared to be risk factors for extravasation. Additionally, injection rate, venous access site and catheter dwelling time could affect the volume extravasated. Preliminary studies seemed to indicate the potential of extravasation detection accessories to identify extravasation and reduce the volume extravasated. The other interventions either did not result in significant reduction in the frequency/volume of extravasation, or the results were mixed across the studies.

CONCLUSIONS

The majority of the studies included in this review evaluated the outcomes of extravasation frequency and volume. Given the quality of the primary studies, this systematic review identified only potential risk factors and interventions. It further highlighted the research gap in this area and the importance of conducting trials with solid methodological designs.

Computed Tomography Angiography With High Flow Rates: An In Vitro and In Vivo Feasibility Study

OBJECTIVE

The aims of this study were to test high-flow application of contrast media (CM) using novel high-flow needles and to assess injection- and flow-related parameters in a circulation phantom and in an in vivo population.

MATERIALS AND METHODS

A circulation phantom simulating physiological parameters was used. Preheated CM (300 mg/mL) was injected at flow rates varying between 5 and 15 mL/s through a novel 18-gauge high-flow intravenous injection needle. In addition, feasibility of these high-flow needles was tested with administration of flow rates of 9 mL/s in 20 patients referred for pre-transcatheter aortic valve implantation assessment. Injection parameters (eg, peak pressures, peak flow rates) in both phantom and in vivo setup were continuously monitored by a data acquisition program. Attenuation at predefined levels of the aorta (eg, aortic root to common femoral arteries) was measured in all patients to determine clinical applicability.

RESULTS

In the phantom setup, injection rates up to 15 mL/s were feasible. An enhancement plateau was reached at 11 mL/s (464 [20] HU). In patients, no pressure- or flow-related complications (eg, extravasation) were recorded (mean [SD] peak pressure, 154 [8] psi; mean [SD] peak flow rate, 9.2 [0.1 mL/s; range, 9.1-9.6]). Diagnostic attenuation values were reached at all predefined levels of the aorta (330.8 [113.1] HU to 622.9 [81.5] HU).

CONCLUSIONS

These results indicate that injections with 9 mL/s using high-flow injection needles are safe. The pressure limit of 325 psi was not reached, and the injections resulted in diagnostic attenuation values. Using this dedicated needle, high flow rates should not be considered a drawback for CM application in routine CT angiography examinations.

Influence of contrast media viscosity and temperature on injection pressure in computed tomographic angiography: a phantom study

PURPOSE

Iodinated contrast media (CM) in computed tomographic angiography is characterized by its concentration and, consecutively, by its viscosity. Viscosity itself is directly influenced by temperature, which will furthermore affect injection pressure. Therefore, the purposes of this study were to systematically evaluate the viscosity of different CM at different temperatures and to assess their impact on injection pressure in a circulation phantom.

MATERIALS AND METHODS

Initially, viscosity of different contrast media concentrations (240, 300, 370, and 400 mgI/mL) was measured at different temperatures (20°C-40°C) with a commercially available viscosimeter. In the next step, a circulation phantom with physical conditions was used. Contrast media were prepared at different temperatures (20°C, 30°C, 37°C) and injected through a standard 18-gauge needle. All other relevant parameters were kept constant (iodine delivery rate, 1.9 g I/s; total amount of iodine, 15 g I). Peak flow rate (in milliliter per second) and injection pressure (psi) were monitored. Differences in significance were tested using the Kruskal-Wallis test (Statistical Package for the Social Sciences).

RESULTS

Viscosities for iodinated CM of 240, 300, 370, and 400 mg I/mL at 20°C were 5.1, 9.1, 21.2, and 28.8 mPa.s, respectively, whereas, at 40°C, these were substantially lower (2.8, 4.4, 8.7, and 11.2 mPa.s). In the circulation phantom, mean (SD) peak pressures for CM of 240 mg I/mL at 20°C, 30°C, and 37°C were 107 (1.5), 95 (0.6), and 92 (2.1) psi; for CM of 300 mg I/mL, 119 (1.5), 104 (0.6), and 100 (3.6) psi; for CM of 370 mg I/mL, 150 (0.6), 133 (4.4), and 120 (3.5) psi; and for CM of 400 mg I/mL, 169 (1.0), 140 (2.1), and 135 (2.9) psi, respectively, with all P values less than 0.05.

CONCLUSIONS

Low concentration, low viscosity, and high temperatures of CM are beneficial in terms of injection pressure. This should also be considered for individually tailored contrast protocols in daily routine scanning.

I.v. contrast administration with dual source 128-MDCT: a randomized controlled study comparing 18-gauge nonfenestrated and 20-gauge fenestrated catheters for catheter placement success, infusion rate, image quality, and complications

OBJECTIVE

The purpose of this study was to compare the performance of a 20-gauge fenestrated catheter with an 18-gauge nonfenestrated catheter for i.v. contrast infusion during MDCT.

SUBJECTS AND METHODS

Two hundred five adult outpatients imaged on a dual-source 128-MDCT scanner with arterial phase body CT (flow rates, 5.0-7.5 mL/s) were randomized to either an 18-gauge nonfenestrated or 20-gauge fenestrated catheter. After randomization, any 18-gauge nonfenestrated subjects whose veins were deemed insufficient for that catheter gauge were assigned to a third cohort for placement of a 20-gauge fenestrated catheter. Catheter placement success, infusion rate, contrast volume, maximum pressure, complications, and aortic enhancement levels were recorded.

RESULTS

Catheters were placed on the first attempt in 97% (100/103) for 18-gauge nonfenestrated and 94% (96/102) for 20-gauge fenestrated placements and in two or fewer attempts in 99% of both groups. Mean infusion rates (5.74 mL/s for 18-gauge nonfenestrated and 5.58 mL/s for 20-gauge fenestrated placements) and aortic enhancement levels were not significantly different. Maximum pressure was higher with 20-gauge fenestrated catheters (mean ± SD, 230.5 ± 27.6 pounds per square inch [psi]) than 18-gauge nonfenestrated catheters (mean ± SD 215.6 ± 32.8 psi) (p = 0.002). One subject with an 18-gauge nonfenestrated catheter had a high-pressure alarm. In the third cohort, a 20-gauge fenestrated catheter was successfully placed in two or fewer attempts in 85% (28/33), with one minor extravasation attributed to vein insufficiency.

CONCLUSION

A 20-gauge fenestrated catheter performs similarly to an 18-gauge nonfenestrated catheter with respect to i.v. contrast infusion rates and aortic enhancement levels and can be placed in most subjects whose veins are deemed insufficient for an 18-gauge catheter.

Catheter insertion for intravenous (IV) contrast infusion in multidetector-row computed tomography (MDCT): defining how catheter caliber selection affects procedure of catheter insertion, IV contrast infusion rate, complication rate, and MDCT image quality

PURPOSE

This study evaluated the effect of intravenous (IV) catheter gauge size on catheter placement, contrast infusion, and image quality for patients undergoing IV contrast-enhanced multidetector computed tomography (MDCT).

MATERIALS AND METHODS

One thousand consecutive adult outpatients undergoing IV contrast-enhanced MDCT and 10 IV insertion CT nurses were observed from IV catheter selection through IV removal. Patients' demographics, number of sticks required, catheter gauge during each attempt, time for catheter placement, IV nurses' assessment of vein quality and contrast infusion parameters were recorded. Scan quality was assessed subjectively.

RESULTS

Subjects included 547 men and 453 women, with a mean age 59.2 years (range, 19-92 years). Median number of catheter attempts was 1 per patient (range, 1-9). Catheters were successfully placed in 98%. First and final catheters were most commonly 20 gauge (59% and 56%, respectively), followed by 22 gauge (34% for both), 18 gauge (6% for both), and 24 gauge (2% and 3%, respectively). Mean infusion rate correlated with catheter gauge: 5.3 mL/s for 18 gauge; 3.5 mL/s for 20 gauge; 2.3 mL/s for 22 gauge; and 1.7 mL/s for 24 gauge (P < 0.0001). Target infusion rate of ≥ 3 mL/s was related to catheter gauge (100% of 18 gauge, 71% of 20 gauge, 11% of 22 gauge, and 0% of 24 gauge; P < 0.0001). Nine hundred sixty-eight subjects underwent imaging. Most of the CT examinations (935/968 [97%]) were of acceptable quality.

CONCLUSION

Experienced IV starters usually achieve IV access in one attempt by tailoring IV catheter gauge to vein quality; however, target infusion rates are not likely to be achieved with 22- and 24-gauge catheters, used in nearly 1/3 of the patients in this study.

Lessons learned from 118,970 multidetector computed tomographic intravenous contrast material administrations: impact of catheter dwell time and gauge, catheter location, rate of contrast material administration, and patient age and sex on volume of extravasate

OBJECTIVES

The aim of this study was to determine the impact of catheter dwell time and gauge, catheter location, rate of contrast material administration, and patient age and sex on volume of extravasate at intravenous contrast-enhanced multidetector computed tomography.

METHODS

Incident reports were reviewed for all extravasation events that occurred in adult patients between March 2006 and December 2009 at 2 institutions. Patient age and sex; catheter dwell time, gauge, and location; rate of contrast material administration; and estimated volume of extravasated contrast material were recorded.

RESULTS

Three hundred thirty extravasation events were recorded for the 118,970 contrast material administrations (0.3%). Mean volume of extravasated contrast material was statistically significantly less for catheters newly placed in the radiology department, for higher flow rates, for smaller gauge catheters, and for catheters placed in the hand. Mean volume of extravasated contrast material did not vary significantly based on patient age or sex.

CONCLUSIONS

The volume of extravasate was likely to be smaller for smaller-gauge catheters in the hand with higher flow rates and for catheters newly placed in the radiology department.

Feasibility of power contrast injections and bolus triggering during CT scans in oncologic patients with totally implantable venous access ports of the forearm

BACKGROUND

Conventional totally implantable venous access ports (TIVAPs) are not approved for power contrast injections but often remain the only venous access site in oncologic patients. Therefore, these devices can play an important role if patients with a TIVAP are scheduled for a contrast-enhanced computed tomography (ceCT) as vascular access may become more difficult during the course of chemotherapy.

PURPOSE

To evaluate the feasibility and safety of power injections in conventional TIVAPs in the forearm and to analyze the feasibility of bolus triggering during CT scans.

MATERIAL AND METHODS

In this retrospective study we analyzed 177 power injections in 141 patients with TIVAPs in the forearm. Between October 2008 and March 2010 all patients underwent power injections (1.5 mL/s, 150 psi) via the TIVAP for ceCT because conventional vascular access via a peripheral vein had failed. Adequate functioning and catheter's tip location after injection were evaluated. Peak injection pressure and attenuation levels of aorta, liver and spleen were analyzed and compared with results of 50 patients who were injected via classical peripheral cannulas (3 mL/s, 300 psi). Feasibility of automatic scan initiation was evaluated. In vitro the port was stressed with 5 mL/s (300 psi).

RESULTS

One TIVAP showed tip dislocation with catheter rupture. Three (2.1%) devices were explanted owing to assumed infection within 4 weeks after the injection. Mean injection pressure was 121.9 +/-24.1 psi. Triggering with automatic scan initiation succeeded in 13/44 (29.6%) scans. Injection via classical cannulas resulted in significantly higher enhancement (p < 0.05). In vitro the port system tolerated flow rates of up to 5 mL/s, injection pressures of up to 338 psi.

CONCLUSION

Power injection is a safe alternative for patients with TIVAPs in the forearm if classic vascular access ultimately fails. Triggering was successful in one-third of the attempts. Image quality in the arterial phase scan may be hampered. In vitro results suggest that the device tolerates even higher flow rates.

Multidetector CT in children: current concepts and dose reduction strategies

The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks ("as low as reasonably achievable" principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols.

Peripheral intravenous power injection of iodinated contrast media: the impact of temperature on maximum injection pressures at different cannula sizes

RATIONALE AND OBJECTIVES

Modern computed tomographic scanners and examination protocols often require high injection rates of iodinated contrast media (CM). The purpose of this study was to investigate the maximum injection pressures (MIPs) with different CM at different temperatures in the most common intravenous cannula (IVC) sizes.

MATERIALS AND METHODS

Three IVC sizes, 22, 20, and 18 gauge, were evaluated. All examinations were performed with a pressure-limited (300 psi) power injector. The MIPs of three different CM (Solutrast 300, Imeron 350, and Imeron 400) were measured at room temperature (20 degrees C) and at 37 degrees C using increasing flow rates (1-9 mL/s). The intactness of the IVCs was checked after injection.

RESULTS

Heating the CM led to reductions in injection pressures (P < .001). Using constant flow rates, the difference in MIP between 20-gauge and 22-gauge IVCs was higher than that between 20-gauge and 18-gauge IVCs. By heating the CM, the manufacturer's suggested operating pressure limit was exceeded at higher flow rates, such as with an 18-gauge cannula at 8 mL/s instead of 6 mL/s using warmed iomeprol 400. Even with pressures of up to 159.7 psi, none of the IVCs ruptured.

CONCLUSIONS

Heating of CM effectively reduces MIPs using power injection in common IVCs. Although the manufacturer's suggested MIP was exceeded at higher flow rates, safe CM injection seems to be possible even in small cannulas using power injection. The compilation of the obtained data is meant to serve as guidance for future decisions on parameters of the power injection of iodinated CM.