Confirmed and presumed canine insulinomas and their presumed metastases are most conspicuous in the late arterial phase in a triple arterial phase CT protocol.

Arterial enhancement is the commonly described characteristic of canine insulinomas in contrast-enhanced computed tomography (CECT). However, this finding is also reported as inconsistent. The main aim of this single-center retrospective observational study was to describe the contrast enhancement (CE) pattern of canine presumed and confirmed insulinomas and presumed metastases in three consecutive (early, mid, and late) arterial phases. Included dogs had a medical-record-based clinical or cytological/histopathological diagnosis of insulinoma and quadruple-phase CECT. The arterial phases were identified according to published literature. The arterial enhancement of confirmed and presumed lesions was assessed using a visual grading score. Twelve dogs with a total of 17 pancreatic nodules were analyzed. Three dogs had multiple pancreatic nodules and nine had solitary findings. Four insulinomas were histopathologically confirmed. Late arterial phase (LAP) images demonstrated the largest number of pancreatic nodules reaching the highest enhancement scores (n = 13, 76%). All analyzed dogs had CT evidence of arterially enhancing nodules in the liver (n = 12), seven in the hepatic, splenic, or colic lymph nodes, and three in the spleen. Three out of five sampled livers and three lymph nodes were metastatic. All sampled spleens were benign. Avid arterial enhancement was the most dominant feature of canine presumed and confirmed insulinomas and presumed metastases in quadruple-phase CECT. The highest enhancement scores were observed primarily in LAP, followed by MAP. Authors, therefore, recommend including LAP in the standard CT protocol for dogs with suspected pancreatic insulinomas.

Effect of Gadoxetic Acid Injection Duration on Tumor Enhancement in Arterial Phase Liver MRI.

RATIONALE AND OBJECTIVES: Rapid injection of gadoxetic acid has been shown not to increase tumor enhancement in arterial phase liver MRI for unknown reasons. This study aimed to investigate the effect of injection durations on peak contrast concentration in tumors and to correlate it with signal enhancement in gadoxetic acid-enhanced arterial phase MRI. MATERIALS AND METHODS: Gadoxetic acid-enhanced arterial phase MRI was obtained using a bolus-tracking technique with injection durations of 1, 3, and 6s in six rabbits with VX2 liver tumors. The peak concentration of gadoxetic acid in the aorta and tumor was estimated by iopromide-enhanced time-resolved CT using the same injection volume and durations with those for MRI. Signal enhancement on MRI and peak enhancement on CT were compared and correlated. RESULTS: There was no significant difference in MR signal enhancement of tumors among the 3 injection durations (p = 0.87). In CT, shorter injection durations significantly increased peak contrast concentration in the aorta (p < 0.01) but produced equivalent peak contrast concentration in tumors (p = 0.24). The longer injections resulted in the stronger correlation between peak contrast concentration in CT and MR signal enhancement in tumors (r = 0.31, 0.43, and 0.86 with 1s-, 3s-, and 6s-injection, respectively) with a statistical significance only found with 6s-injection (p = 0.03). CONCLUSION: Estimation of contrast concentration by CT demonstrated that shorter injections did not increase peak contrast concentration in tumors despite increased peak concentration in the aorta. Furthermore, tumor signal enhancement in gadoxetic acid-enhanced arterial phase MRI was less correlated with the peak contrast concentration with shorter injections.

Hold the device against the skin: the impact of injection duration on user's force for handheld autoinjectors.

Background: The recent development of high-volume subcutaneous drug delivery using handheld autoinjectors has resulted in longer injection durations. However, the usability of long injections has been neglected. This study aimed to investigate the effects of injection duration on users' ability to apply injections while holding the device against the skin at the injection site.Methods: Thirty-two participants among patients, caregivers, and health-care professionals simulated three injections with different injection durations to evaluate usability and user's force. Linear and quantile regression were then applied to determine the impact of the injection duration on response variables related to user's force.Results: A significant negative effect of injection time was found on both the minimum and mean user's force applied. Initial empirical evidence was also determined on the negative association being more pronounced for users exerting lower force to hold the device against the skin.Conclusions: The results that are subject to future clinical validation suggest the feasibility of injections lasting up to approximately 30 s using handheld autoinjectors. The participants of the simulated use study successfully applied long-duration injections regardless of disease states, age, or visual and dexterity impairments.

Effect of catheter size and injection rate of contrast agent on enhancement and image quality for triple-phase helical computed tomography of the liver in small dogs.

Rapid contrast injection is recommended for triple-phase helical computed tomography (CT) of the liver. However, a large-gauge catheter is needed for faster contrast injection and this is not practical for small breed dogs or cats. The purpose of this crossover group study was to evaluate applicability of a lower injection rate with a small-gauge (G) catheter for triple-phase hepatic CT in small dogs. Triple-phase CT images were acquired for six beagle dogs using three protocols: an injection rate of 1.5 ml/s with a 24 G catheter, 3.0 ml/s with a 22 G catheter, and 4.5 ml/s with a 20 G catheter. Enhancement of the aorta, portal vein, and hepatic parenchyma was measured in each phase (arterial, portal, and delayed) and image quality was scored subjectively by two observers. Injection duration, time to scan delay, and time to peak enhancement were also recorded. Contrast injection duration decreased with a higher injection rate (n = 6, P ≤ 0.01), but time to peak enhancement and time to scan delay were not significantly affected by injection rates and catheter sizes. Contrast injection rate did not significantly affect aortic, portal, and hepatic enhancement. In addition, separation between each phase and quality of images was subjectively scored as good regardless of injection rate. Findings from the current study supported using an injection rate of 1.5 ml/s with a catheter size of 24 G for triple-phase hepatic CT in small dogs (weight < 12 kg).

Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs.

This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration.

Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs

This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration.

Effect of injection duration and local pressing duration on subcutaneous hemorrhage after the subcutaneous injection of low molecular weight heparin / 中国实用护理杂志

Objective To investigate the effect of two different injection durations and four local pressing durations on the incidence of subcutaneous hemorrhage after low molecular weight heparin, and find a optimum injection duration and pressing time to reduce the incidence of subcutaneous hemorrhage associated with subcutaneous low molecular weight heparin. Methods 80 patients, who were deep venous thrombosis (DVT), pulmonary embolism (PE), and undergone inferior vena cava filter (IVCF) after the operation and received low molecular weight heparin (LWMH) for eight times were selected. The injection time and pressing duration after the injection were randomized into 30 s and 2 min, 30 s and 6 min, 30 s and 10 min, 30s and 14 min, 10s and 2 min, 10s and 6 min, 10 s and 10 min, 10 s and 14 min respectively. The incidence of subcutaneous hemorrhage were measured after 12 h. Single and multiple factor logistic regression analysis were used to analyze the data. Results The injection time and pressing duration after the injection were randomized into 30 s and 2 min, 30 s and 6 min, 30 s and 10 min, 30 s and 14 min, 10 s and 2 min, 10 s and 6 min, 10 s and 10 min, 10 s and 14 min respectively. The results of the incidence rate of subcutaneous hemorrhage were 46.25% (37/80), 22.50% (18/80), 23.75% (19/80), 25.00% (20/80), 71.25% (57/80), 43.75% (35/80), 50.00% (40/80), 50.00% (40/80) respectively. By the single factor test, the results showed that pressing duration and injection duration are associated with the incidence of subcutaneous hemorrhage after low molecular weight heparin. With regard to the incidence of subcutaneous hemorrhage, there was significantly difference between 2 min group and the other 3 groups (P0.05). By multiple factors logistic regression analysis, it was revealed that pressing duration and injection duration were significant factors (P|b'(pres ing duration)|=|-1.0729|). Compared with inject 10 s, there was a significantly lower incidence of bruising in inject 30 s. There was a significantly lower incidence of bruising in the longer pressing duration (b|b'(pres ing duration)|). Compared with inject 10 s, there was a significantly lower incidence of bruising in inject 30 s (b<0). there was significantly difference between 2min group and the other 3 groups (P<0.01), while other adjacent groups had no significant differences. Compared with others, there was a significantly high incidence of bruising in pressing 2min and the pressing duration for at least 6 min. Conclusions It is suggested that inject 30 s with pressing for 6 min can effectively reduce the incidence of subcutaneous hemorrhage resulted from subcutaneous injection of LMWH.

EFFECTS OF TWO CONTRAST INJECTION PROTOCOLS ON FELINE AORTIC AND HEPATIC ENHANCEMENT USING DYNAMIC COMPUTED TOMOGRAPHY.

This prospective study compared aortic and hepatic enhancement achieved using a contrast injection protocol with a fixed rate of 5 ml/s vs. that achieved using a protocol with fixed injection duration of 20 s in eight cats. Cats were assigned into two groups (Group 1, rate 5 ml/s; Group 2, duration 20 s). The dose of contrast was the same in both groups (740 mgI/kg). Regions of interest (ROI) were drawn in the aorta and liver for transverse scans acquired at the hepatic hilus. Time to peak aortic enhancement occurred significantly earlier in Group 1 (M = 11s, SD = 1.63) than in Group 2 (M = 25.5 s, SD = 2.51). Peak aortic enhancement was significantly higher in Group 1 (M = 1906.51 HU, SD = 368.64) than in Group 2 (M = 745.08 HU, SD = 201.84). Duration of aortic enhancement equal to or above 300 HU was statistically longer in Group 2 (M = 24.5 s, SD = 8.39) than in Group 1 (M = 10 s, SD = 1.63). There were no significant differences in time to peak liver enhancement, peak liver enhancement, or duration of hepatic arterial phase between groups. Findings supported the hypothesis that longer injection duration results in a broader bolus geometry with a longer time to peak and a lower peak aortic enhancement in cat. This strong influence of injection duration on timing of aortic enhancement may help future users optimize protocols for CT angiography of the aorta and multiphasic evaluation of the liver, pancreas, and small intestine.

Whole-body CT screening: scan delay and contrast injection duration for optimal enhancement of abdominal organs and deep vessels.

PURPOSE: To assess the optimal scan delays and contrast injection durations for contrast-enhanced whole-body computed tomography (CT). MATERIALS AND METHODS: One hundred forty-two patients were randomized into three groups: protocol A-scan delay of 65 s after starting contrast injection over 30 s; protocol B-105 and 70 s; and protocol C-145 and 110 s, respectively. Contrast enhancement and diagnostic acceptability were assessed. RESULTS: Qualitative assessment was subtle among the three protocols. Homogenous enhancement of deep veins was more assuredly achieved with protocol C. CONCLUSION: With protocol C, qualitatively acceptable enhancement can be obtained in whole-body CT.

Effects of subcutaneous injection duration of heparin on side effects: A Meta-analysis / 中国实用护理杂志

Objective To evaluate the effect of injection duration on bruising and pain after the subcutaneous injection of heparin.Methods The relevant randomized controlled trials,quasi-randomized controlled trials about subcutaneous heparin injection duration of ≥30 s and ≤ 10 s were searched in the databases of CNKI,CBM,VIP Database for Chinese Technical Periodicals,PubMed,Highwire,ScienceDirect,Chinese Cochrane Library,Wanfang database and Google.The quality of RCTs was assessed and Metaanalysis was conducted by RevMan 5.0 Software.Results Twelve RCTs involving 1 986 injections were included.The results of Meta-analysis showed that:There was significant difference between the two groups in the occurrence of bruising.The injection duration of 30 s was much better to prevent bruising.Statistical differences existed in pain intensity between the two groups.Conclusions Prolonging the injection duration to 30 s may reduce the occurrence of subcutaneous bruising.There is no enough evidence to draw a conclusion on pain intensity.Adequately,the current study is limited to a small sample,powered and high quality randomized controlled trials are still needed to be conducted.

The effect of injection duration and injection site on pain and bruising of subcutaneous injection of heparin.

AIMS AND OBJECTIVES: To determine and compare the effects of four methods of subcutaneous heparin injection on pain and bruising in abdomen and thighs. BACKGROUND: Subcutaneous heparin injection is a common nursing clinical intervention. Nurses frequently inject heparin subcutaneously and this action often results in some complications such as bruising, haematoma, pain and induration in the injection site. There are also some other factors inducing complications associated with heparin injection, including the injection site and the injection duration. DESIGN: A quasi-experimental within-subject design. METHODS: This study was conducted on 90 patients with COPD hospitalised in two ICU wards at two teaching hospitals in urban areas of Iran. They were administered heparin subcutaneously, 4000 units every 12 hours. Each patient received four injections in their abdomen and thighs, using four different methods. The number and size of bruising at the injection site were measured through a flexible millimetre ruler, 48 hours after each injection. The severity of pain was measured through pain visual analogue scale immediately after each injection. Collected data were analysed by descriptive and analytical statistics using spss 11.5 software. RESULTS: In the method 15 seconds injection duration and waiting for 5 seconds before withdrawing the needle, the number of bruising was significantly lower and size of bruising was significantly smaller, but no significant difference was found in the severity of pain. However, in other methods, the severity of pain in thighs was significantly higher than in abdomen, but no statistically significant difference was reported between the size and number of bruising in abdomen and thighs. CONCLUSIONS: The method 15 seconds injection duration and waiting for 5 seconds before withdrawing the needle is recommended to be used for subcutaneous heparin injection by clinical nurses. As to the results, the severity of pain in abdomen was lower than in thighs. RELEVANCE TO CLINICAL PRACTICE: This study proposed a suitable method for subcutaneous heparin injection in order to reduce pain and bruising.