Comparing multi-use syringeless and conventional single-use dual-syringe injectors in contrast-enhanced CT: efficiency, cost, and technologist satisfaction.

Comparison of Dual-Syringe and Syringeless Power Injectors in Outpatient MDCT Practice: Impact on the Operator's Performance, CT Workflow, and Operation Cost

Background The development of an accurate, practical, noninvasive, and widely available diagnostic approach to characterize lipid-poor adrenal lesions (greater than 10 HU at unenhanced CT) remains an ongoing demand. Purpose To investigate whether combined assessment of unenhanced and portal venous phase CT allows for the differentiation of lipid-poor adrenal adenomas from nonadenomas. Materials and Methods Patients with lipid-poor adrenal lesions who underwent unenhanced and portal venous phase CT with a single-energy scanner between January 2016 and March 2020 were identified retrospectively. For each lesion, the unenhanced and contrast-enhanced attenuation were measured; the absolute enhancement (contrast-enhanced minus unenhanced attenuation [HU]) and relative enhancement ratio ([absolute enhancement divided by unenhanced attenuation] × 100%) were calculated. The sensitivity achieved at 95% specificity to distinguish adenomas from nonadenomas was determined with receiver operating characteristic curve analysis and compared among parameters with use of the McNemar test. Results A total of 220 patients (mean age ± standard deviation, 66 years ± 12; 134 men) with 131 lipid-poor adenomas and 89 nonadenomas were analyzed. The sensitivity (achieved at 95% specificity) of the relative enhancement ratio (86% [113 of 131 adenomas; 95% CI: 79, 92] at a threshold of >210%) was higher than that of unenhanced attenuation (50% [66 of 131 adenomas; 95% CI: 42, 59] at a threshold of ≤21 HU), contrast-enhanced attenuation (3% [four of 131 adenomas; 95% CI: 1, 8] at a threshold of >120 HU), and absolute enhancement (24% [32 of 131 adenomas; 95% CI: 17, 33] at a threshold of >74 HU; all P < .001). The sensitivities of the relative enhancement ratio were 100% (58 of 58 adenomas; 95% CI: 94, 100), 83% (52 of 63 adenomas; 95% CI: 71, 91), and 30% (three of 10 adenomas; 95% CI: 7, 65) for adenomas measuring unenhanced attenuation of more than 10 HU up to 20 HU, 21-30 HU, and more than 30 HU, respectively. Conclusion A relative enhancement ratio threshold of greater than 210%, measured at unenhanced and portal venous phase CT, accurately differentiated lipid-poor adenomas from nonadenomas, particularly for lesions with unenhanced attenuation of 10-30 HU. © RSNA, 2021 Online supplemental material is available for this article.

ObjectiveThe utilization of diagnostic imaging has substantially increased over the past decade in Europe and North America and continues to grow worldwide. The purpose of this study was to develop an economic evaluation of a syringeless power injector (PI) versus a dual-syringe PI for contrast enhanced computed tomography (CECT) in a hospital setting.Materials and methodsPatients (n=2379) were enrolled at the Legnano Hospital between November 2012 and January 2013. They had been referred to the hospital for a CECT analysis and were randomized into two groups. The first group was examined with a 256-MDCT (MultiDetector Computed Tomography) scanner using a syringeless power injector, while the other group was examined with a 64-MDCT scanner using a dual-syringe. Data on the operators’ time required in the patient analysis steps as well as on the quantity of consumable materials used were collected. The radiologic technologists’ satisfaction with the use of the PIs was rated on a 10-point scale. A budget impact analysis and sensitivity analysis were performed under the base-case scenario.ResultsA total of 1,040 patients were examined using the syringeless system, and 1,339 with the dual-syringe system; the CECT examination quality was comparable for both PI systems. Equipment preparation time and releasing time per examination for syringeless PIs versus dual-syringe PIs were 100±30 versus 180±30 seconds and 90±30 and 140±20 seconds, respectively. On average, 10±3 mL of contrast media (CM) wastage per examination was observed with the dual-syringe PI and 0±1 mL with the syringeless PI. Technologists had higher satisfaction with the syringeless PI than with the dual-syringe system (8.8 versus 8.0). The syringeless PI allows a saving of about €6.18 per patient, both due to the lower cost of the devices and to the better performance of the syringeless system. The univariate sensitivity analysis carried out on the base-case results within the standard deviation range confirmed the saving generated by using the syringeless device, with saving values between €5.40 and €6.20 per patient.ConclusionThe syringeless PI was found to be more user-friendly and efficient, minimizing contrast wastage and providing similar contrast enhancement quality compared to the dual-syringe injector, with comparable CECT examination quality.

Background Contrast medium (CM) administration during computed tomography (CT) enhances the accuracy in the detection and interpretation of abnormalities. Evidence from literature also validate the essence of CM in imaging studies. CT, by virtue of its ubiquity, ease of use, speed, and lower financial footprint, is usually the first investigation in cases of headache. Through a multicenter retrospective analysis, we compared findings of contrast-enhanced CT (CECT) to noncontrast-enhanced CT (NCECT) head examinations among patients presenting with headache. Methods A multicenter retrospective analysis of four years' CT head examination data at two radiology centers located in Central and Western Regions of Ghana were reviewed. Records of patients who presented with headache as principal complaint between January 2017 and December 2020 were reviewed. A total of 477 records of patients with headache were identified, retrieved and evaluated. A Chi-square test and Fisher exact test were used to compare the CECT and NCECT groups. Binary logistic regression analysis was computed to assess association between CECT and each CT findings. Statistical significance was considered at p < 0.05 with a 95% confidence interval. Results A significant proportion of the patients was females (51.8% in CECT and 60% in NCECT). The NCECT group (40.06 ± 14.76 years) was relatively older than the CECT group (38.43 ± 17.64 years). There was a significant difference between the CECT and NCECT in terms of age (p=0.002) and facility CT was performed (p < 0.0001). The rate of abnormalities was higher in CECT (43.5%, 166/382) compared NCECT (37.9%, 36/95). There was no significant association between CT head findings and contrast enhancement. Conclusion CECT examination accounted for 5.6% increase in the detection of head abnormalities. Efforts required to establish local standard operation procedures (SOPs) for contrast medium use especially in CT head examinations. Further studies to improve the knowledge of agents, mechanism of action, and safety of contrast media used among practitioners in Ghana is recommended.

Traditional knowledge is nowadays one of the most important intellectual property issues. While its significance for the development of intellectual products is undoubtedly recognized, there has been no international accord on intellectual property that deals with the extent to which the knowledge should be protected. Hence, it is for individual nations to decide how the knowledge should be protected. The article analyses the stance of the current Indonesian intellectual property law on the issue and then proposes some recommendations.\nThe article demonstrates that the current Indonesian intellectual property legislation has not adequately dealt with the issue of traditional knowledge. Only Indonesian Copyright Act of 2002, which touches on the protection of folklores and works of popular culture, is relevant. It is therefore recommended that Indonesian intellectual property law he amended. However, the amendment of the law is not sufficient without any support by an international agreement on the issue since there is possibility that a traditional knowledge in Indonesia can be stolen by a nation that does not recognize and protect foreign traditional knowledge. Therefore, Indonesia together with other developing countries should be active in proposing the amendment of the Agreement on Trade-Related Aspects of Intellectual Property Rights to protect traditional knowledge.\n\nKara kunci : pengetahuan traditional, perlindungan, amandemen

The aim of contrast enhancement is to increase the difference in attenuation coefficients between pathological lesions and the surrounding normal tissues. Unlike cranial CT, in body CT the contrast-enhanced scans should be taken when the blood and normal tissue levels of contrast enhancement are at their maximum possible levels. This has not been feasible in most currently available scanners, and most reports in the literature on contrast enhancement in CT have used suboptimal enhancement. In most cases, maximal enhancement will occur immediately at the end of a rapid intravenous injection using a high dose of contrast media. Repeat scans of certain slice levels at fixed time intervals may further improve diagnostic accuracy. Computers are only beginning to be used to analyze the reconstructed CT image, and recent increases in scanning rapidity make optimum contrast enhancement much more feasible. Renal toxicity from high doses of contrast media places a rather indefinite upper limit to contrast enhancement, which can be partially overcome with intra-arterial contrast media injection at CT. Nonenhanced scans should always precede contrast enhancement in body CT. In this article the experimental and theoretical background to CT contrast enhancement is reviewed and suggestions for optimum application are made in the light of present limitations of the technique. Improvement in both detection and differentiation of pathological lesions should result from minimizing the overlap of CT attenuation measurements of normal and pathological tissue by increasing the difference between their means and decreasing the range of variability of individual attenuation measurements.

Specificity of stroke imaging: disregarded and neglected.

AimsTo characterise keratomas using contrast enhanced computed tomography (CECT) to facilitate complete surgical excision and provide information regarding post operative morbidity.MethodsRecords of horses with histologically confirmed keratomas who underwent CECT were reviewed. Historical and clinical details, CECT characteristics, surgical approach and outcome were reviewed.ResultsTen horses, mean age 9.3 years, exhibiting recurrent or chronic grade 3 to 5/5 lameness for 5 weeks to 2 years, had histologically confirmed keratomas characterised and removed following CECT. Radiographs failed to reveal evidence of keratomas in 5/10 cases. Eleven keratoma lesions affecting the dorsal midline (n = 5), lateral hoof wall (n = 2), medial hoof wall (n = 3) and solar surface of the third phalanx (P3) (n = 1) were identified. Keratomas had a broad (n = 6) or narrow (n = 4) based attachment to the laminar surface, were classified as columnar (n = 5) or spherical (n = 5), measured 3–15 mm wide and 5–52 mm in length. Contrast material delineated keratoma margins by contrast enhancement within the lesion (n = 4) or attenuation of contrast material by the lesion (n = 6) suggesting surrounding hypervascularity or compression of surrounding vasculature, respectively. Defects in the distal phalanx (n = 5), abnormal vascularity (n = 10) and abscessation (n = 6) around the lesion were also identified. Proximal to distal and medial to lateral limits of the keratoma were marked on the hoof wall allowing complete excision via a partial hoof wall (PHWR [n = 7]) or complete hoof wall resection (CHWR [n = 3]). Soundness (mean 7 weeks) and no recurrence was achieved in all cases. Hoof wall defect healing was protracted in cases in which CECT attenuation of vascularity was evident around the defect.ConclusionsContrast enhanced computed tomography allows comprehensive characterisation of keratomas, determining location, vascularity and extent of laminar and P3 involvement. Accurate surgical landmarks are obtained so complete surgical excision is facilitated, the degree of hoof wall resection is minimised and recurrence is prevented. Those lesions with attenuation of vascularity around them on CECT are more likely to have protracted healing of the hoof wall defect.Ethical animal researchNot required by this Congress: retrospective clinical study. Sources of funding: None. Competing interests: None.

Computed tomographic imaging of hepatocellular carcinoma

To evaluate the image quality of ultralow-dose computed tomography (ULDCT) reconstructed with knowledge-based iterative model reconstruction (IMR) in patients with pulmonary tuberculosis (TB). This IRB-approved prospective study enrolled 59 consecutive patients (mean age, 43.9 ± 16.6years; F:M 18:41) with known or suspected pulmonary TB. Patients underwent a low-dose CT (LDCT) using automatic tube current modulation followed by an ULDCT using fixed tube current. Raw image data were reconstructed with filtered-back projection (FBP), hybrid iterative reconstruction (iDose), and IMR. Objective measurements including CT attenuation, image noise, and contrast-to-noise ratio (CNR) were assessed and compared using repeated-measures analysis of variance. Overall image quality and visualization of normal and pathological findings were subjectively scored on a five-point scale. Radiation output and subjective scores were compared by the paired Student t test and Wilcoxon signed-rank test, respectively. Compared with FBP and iDose, IMR yielded significantly lower noise and higher CNR values at both dose levels (p < 0.01). Subjective ratings for pathological findings including centrilobular nodules, consolidation, tree-in-bud, and cavity were significantly better with ULDCT IMR images than those with LDCT iDose images (p < 0.01), but blurred edges were observed. With IMR implementation, a 59% reduction of the mean effective dose was achieved with ULDCT (0.28 ± 0.02mSv) compared with LDCT (0.69 ± 0.15mSv) without impairing image quality (p < 0.001). IMR offers considerable noise reduction and improvement in image quality for patients with pulmonary TB undergoing chest ULDCT at an effective dose of 0.28mSv. • Radiation dose is a major concern for tuberculosis patients requiring repeated follow-up CT. • IMR allows substantial radiation dose reduction in chest CT without compromising image quality. • ULDCT reconstructed with IMR allows accurate depiction of CT features of pulmonary tuberculosis.

Few studies have investigated the adequate contrast enhancement (CE) evaluation depending on concentration, volume, and rate of administration of contrast media (CM) and the scan parameters in equine contrast enhanced computed tomography (CECT). To investigate CE of the deep digital flexor tendon (DDFT) and veins depending on the computed tomography (CT) voltage and concentration, volume, and rate of CM administration during intra-arterial CECT of equine distal forelimbs. In vivo experiments. Six horses underwent 54 CT scans. First, the CE of DDFT and veins was evaluated depending on the voltage (80 kV and 250 mA or 120 kV and 150 mA) and CM concentration (150, 120, or 90 mg I/mL in 50 mL of CM). Second, CE of DDFT and veins was evaluated depending on the CM volume (50, 100, or 150 mL) and administration rate (2, 4, or 6 mL/s) with a fixed iodine delivery rate (IDR; 300 or 180 mg I/s). Contrast enhancement of DDFT was significantly higher at 80 kV of voltage and 150 mg I/mL of CM concentration (Median: 29.65; IQR: 1.74; p < 0.05). CE of the DDFT positively correlated with CM concentration (p < 0.001; r = 0.75). At 180 mg I/s IDR, contrast attenuation in the medial and lateral palmar veins significantly decreased at a CM of 30 mg I/mL, rate of 6 mL/s, and volume of 150 mL (median and IQR: 985.93 and 71.8 Hounsfield units [HU] and 988.73 and 41.16 HU, respectively); the CE was sufficient to distinguish between the vessels and the adjacent structures. The number of animals was small. Our results suggest that a low CM concentration could yield sufficient CE of the DDFT and arteries with adjusted CT scanning parameters or volume and injection rate of CM.

Power Injection of Contrast Media via Peripherally Inserted Central Catheters for CT

Because CT protocols for staging lung cancer vary and little information exists regarding the diagnostic importance of using i.v. contrast material, our intent was to evaluate intra- and interobserver agreement in the detection of enlarged mediastinal lymph nodes, comparing i.v. contrast-enhanced and unenhanced CT. Fifty patients with known or suspected bronchogenic carcinoma underwent unenhanced thoracic CT followed by contrast-enhanced CT. Three observers noted enlarged lymph nodes (> 10 mm in the short axis) and assigned the enlarged nodes to American Thoracic Society nodal station designations. Enlarged lymph nodes were grouped two ways: by assigning the exact number of enlarged lymph nodes found (zero, one, two, three, four or more), and by assigning whether at least one, or no, enlarged mediastinal lymph nodes were found at a station ("one or none"). Agreement levels were determined for inter- and intraobserver interpretations using weighted kappa statistics and the McNemar test. The number of enlarged lymph nodes with enhanced CT was 11% higher than on unenhanced studies (418 versus 377; p = .044). Numbers of enlarged lymph nodes were different for five stations; however, the numbers were small except for the right upper paratracheal station (2R) (contrast-enhanced, 68 enlarged lymph nodes; unenhanced, 44 enlarged lymph nodes; p = .014). With regard to all stations together, intraobserver agreement between contrast-enhanced and unenhanced studies was almost perfect (kappa range, .85-.94), and no difference was found for any observer in the proportion of patients with at least one enlarged lymph node. Interobserver agreement was substantial or almost perfect for the total number of enlarged lymph nodes. For specific stations, the lowest kappa value was .48 at 2R. One observer reported more patients with at least one enlarged lymph node with contrast enhancement at station 2R (p = .031). Greater agreement existed between two observers at station 2R with contrast enhancement versus no enhancement (kappa = .85 versus .48; p = .02). Conclusions matched, and calculations of estimated kappa values gave similar results for determination of the specific number of enlarged lymph nodes at a station and the "one or none" category. We found high agreement for intra- and interobserver interpretations for contrast-enhanced and unenhanced CT, although contrast-enhanced CT revealed more enlarged lymph nodes, especially at station 2R.

PNS39 Wastage and Costs of Contrast MEDIA in Computed Tomography in the UK: Comparison of MULTI-Dose Versus Single-Dose Bottles

Contrast‐enhanced computed tomography (CECT) is increasingly used to screen for abdominal pathology in dogs, and the contrast dose used is commonly calculated as a linear function of total body weight (TBW). Body fat is not metabolically active and contributes little to dispersing or diluting contrast medium (CM) in the blood. This prospective, analytic, cross‐section design pilot study aimed to establish the feasibility of intravenous CM dosed according to lean body weight (LBW) for abdominal CECT in dogs compared to TBW. We hypothesized that when dosing intravenous CM according to LBW, studies will remain at diagnostic quality, there will be a reduced interindividual contrast enhancement (CE) variability, and there will be less change to heart rate and blood pressure in dogs compared to when administering CM calculated on TBW. Twelve dogs had two CECT studies with contrast doses according to TBW and LBW at least 8 weeks apart. Interindividual organ and vessel CE variability, diagnostic quality of the studies, and changes in physiological status were compared between protocols. The LBW‐based protocol provided less variability in the CE of most organs and vessels (except the aorta). When dosed according to LBW, liver enhancement was positively associated with grams of iodine per kg TBW during the portal venous phase (P = 0.046). There was no significant difference in physiological parameters after CM administration between dosing protocols. Our conclusion is that a CM dose based on LBW for abdominal CECT lowers interindividual CE variability and is effective at maintaining studies of diagnostic quality.