Use of a saline chaser in abdominal computed tomography: a systematic review

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

PURPOSE

Recently, there have been a few reports regarding the usefulness of a novel saline injection technique using a spiral flow-generating tube. The purpose of this study was to evaluate whether simultaneous saline injection using a spiral flow-generating tube was able to improve hepatic contrast enhancement and lesion conspicuity of metastatic liver tumors.

METHODS

We randomized a total of 411 patients with various liver diseases including metastases by total body weight (A, n = 204) and contrast dilution protocol (B, n = 207). Group A received 400 mgI/kg of contrast medium alone without a spiral flow-generating tube; group B received contrast medium 400 mgI/kg simultaneous with injection of a 0.57-ml/kg physiologic saline solution through a spiral flow-generating tube. Abdominal aorta computed tomography (CT) number, hepatic enhancement (ΔHU), percentage of tests demonstrating an enhancement effect of the liver parenchyma exceeding Δ50 HU in 3 measured segments (S2, S6, and S8), and the contrast-to-noise ratio of the metastatic liver tumors were measured.

RESULTS

The mean aortic CT number of group B (417.0 HU ± 61.7; P < 0.01) was approximately 10% higher than that of group A (384.6 ± 79.1 HU). The average ΔHU was 59.8 ± 11.4 HU for group A and 61.7 ± 11.7 for group B. The ΔHU for group B was significantly higher than that for group A (P = 0.017). The percentage of tests demonstrating with the enhancement effect of group B was more than 80% in all subgroups; however, that of group A was less than 80% in all subgroups. The contrast-to-noise ratio of group B (7.8 ± 3.3 HU) was significantly higher compared to that of group A (6.5 ± 2.8 HU) (P < 0.05).

CONCLUSIONS

Because of the volume effect, injecting a contrast medium diluted with normal saline improved the degree of hepatic and aortic contrast enhancement and achieved better visualization of liver metastases.

CLINICAL IMPACT

The use of spiral flow-generating tube may help diagnostic of hepatic and aortic contrast enhancement and liver metastases.

IMPORTANCE

The use of a spiral flow-generating tube improved the degree of hepatic and aortic contrast enhancement and achieve better visualization of liver metastases.

POINTS

The use of low-concentration syringe formulations is limited by body weight. However, the use of spiral flow-generating tube provides low-concentration contrast medium regardless of body weight.

Contrast media shortages - medical imaging considerations: A literature review

This literature review was conducted to analyze the current and future effects of intravenous contrast media shortages and how these shortages affect patient care within the field of computed tomography (CT). Substitutions and conservation methods were examined. One of the most important results of this review was to improve current and future patient care while actively making a conscious effort to help aid others in future shortages. Limitations can be found when looking at the research field concerning the substitutions for contrast media, such as nanoparticles and saline chasers following contrast boluses. CINAHL, CINAHL Complete, MEDLINE, MEDLINE Complete, Academic Search Complete, EBSCOhost, and Google Scholar were used to compile articles, which were then eliminated until only those pertaining to this review were left. Thirty-seven articles were included; of the 37 articles, two studied contrast enhancement in animals and were determined relevant to this review. The majority of sources were published within the past 20 years; older articles were included to identify gaps for future research; and all articles selected were peer-reviewed or scholarly. This review indicates the CT field can begin preparations now to help negate future contrast shortages as well as decrease patients' health risks. Future research should revolve around furthering the field's knowledge of nanoparticles being used as ICMs in human patients. Additionally, investigating which ordering providers should have ICM ordering privileges may identify conservation strategies.

Sixty-four-slice computed tomography angiography of perigastric veins with image fusion

OBJECTIVE

The objective of this study was to assess the efficacy and clinical value of 64-slice computed tomography angiography (CTA) with image fusion for demonstrating the perigastric venous anatomy.

METHODS

Twenty-six patients with gastric cancer underwent abdominal CTA examinations. Computed tomography angiography of stomach and perigastric veins and arteries were reconstructed and fused using volume-rendering technique. The inflow and courses of perigastric veins as well as the spatial relationship among the perigastric veins, arteries, and stomach were compared with surgery.

RESULTS

Compared with surgical findings, the visualization rate of the 7 perigastric veins on CTA was 90.9% to 100%. There was a statistically significant decrease in number of short gastric veins identified on CTA compared with surgery (P = 0.004). There was no statistically significant difference between the 2 modalities in detecting other perigastric veins including the left gastric vein, right gastric vein, right gastroepiploic vein, left gastroepiploic vein, posterior gastric vein, and gastrocolic trunk (P = 0.317, P = 0.157, P = 1, P = 1, P = 0.317, P = 1, respectively).

CONCLUSIONS

Sixty-four-slice CTA with image fusion clearly depicts most of perigastric veins and their relationship with the stomach and perigastric arteries. It can facilitate gastrectomy.

The optimal contrast media policy in CT of the liver. Part I: Technical notes

Latest developments of multidetector computed tomography (MDCT), which is today considered a real volumetric technique, have revolutionized abdominal imaging. Technological improvements such as higher spatial resolution, larger volume coverage and higher temporal resolution, have reduced scan times allowing CT studies of the abdomen within a single breath-hold. Furthermore, the increased number of slices, the submillimetric collimation, and the use of multiple dynamic post-contrast phases per single examination, may all contribute to increase the radiation exposure of single patients. The aim of this review is to discuss different parameters affecting contrast media enhancement, as vascular enhancement, parenchymal enhancement and timing, in order to minimize the amount of contrast medium injected and the radiation exposure.