Contrast Agents In Patients Research Articles

The American College of Radiology contrast-enhanced ultrasound Liver Imaging Reporting and Data System and its modified version in diagnosing hepatocellular carcinoma via Sonazoid: a meta-analysis.

The American College of Radiology (ACR) developed the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) for pure blood contrast agents, but Sonazoid was not included. Modifications to LI-RADS have been proposed for Sonazoid. The purpose of this meta-analysis was to identify and compare the diagnostic efficacy of the two LI-RADS algorithms of Sonazoid. We searched the PubMed, MEDLINE, Web of Science, Embase, and Cochrane Library databases from databases inception to August 31, 2023, to find original studies on the ACR LI-RADS and/or modified LI-RADS algorithm with Sonazoid used as the contrast agent in patients with high-risk hepatocellular carcinoma (HCC). A bivariate random-effects model was used. Data pooling, meta-regression, and sensitivity analysis were performed for meta-analysis. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess the methodological quality, and the Deeks funnel plot asymmetry test was used to evaluate the publication bias. A meta-analysis of 10 studies with 1,611 observations was conducted. The pooled data for ACR LI-RADS category 5 (LR-5) and modified LR-5 were respectively as follows: pooled sensitivity, 0.70 [95% confidence interval (CI): 0.64-0.75] and 0.81 (95% CI: 0.76-0.86) (P<0.05); pooled specificity, 0.90 (95% CI: 0.82-0.94) and 0.87 (95% CI: 0.81-0.91) (P>0.05); and pooled area under the summary receiver operating characteristic curve, 0.84 and 0.91. The diagnostic performance of LI-RADS category M (LR-M) of the two algorithms was comparable. Study heterogeneity was observed. The results indicated that modified LR-5 algorithm demonstrated improved diagnostic sensitivity compared with the ACR LR-5 algorithm of Sonazoid, with differences observed between the different versions. Further research is needed to validate and explore the optimal diagnostic criteria for HCC using Sonazoid. Before the database search was conducted, this study was registered on PROSPERO (International Prospective Register of Systematic Reviews; CRD42023455220).

Spectral computed tomography angiography using a gadolinium-based contrast agent for imaging of pathologies of the aorta

ObjectivesEspecially patients with aortic aneurysms and multiple computed tomography angiographies (CTA) might show medical conditions which oppose the use of iodine-based contrast agents. CTA using monoenergetic reconstructions from dual layer CT and gadolinium (Gd-)based contrast agents might be a feasible alternative in these patients. Therefore, the purpose of this study was to evaluate the feasibility of clinical spectral CTA with a Gd-based contrast agent in patients with aortic aneurysms.MethodsTwenty-one consecutive scans in 15 patients with and without endovascular aneurysm repair showing contraindications for iodine-based contrast agents were examined using clinical routine doses (0.2 mmol/kg) of Gd-based contrast agent with spectral CT. Monoenergetic reconstructions of the spectral data set were computed.ResultsThere was a significant increase in the intravascular attenuation of the aorta between pre- and post-contrast images for the MonoE40 images in the thoracic and the abdominal aorta (p < 0.001 for both). Additionally, the ratio between pre- and post-contrast images was significantly higher in the MonoE40 images as compared to the conventional images with a factor of 6.5 ± 4.5 vs. 2.4 ± 0.5 in the thoracic aorta (p = 0.003) and 4.1 ± 1.8 vs. 1.9 ± 0.5 in the abdominal aorta (p < 0.001).ConclusionsTo conclude, our study showed that Gd-CTA is a valid and reliable alternative for diagnostic imaging of the aorta for clinical applications. Monoenergetic reconstructions of computed tomography angiographies using gadolinium based contrast agents may be a useful alternative in patients with aortic aneurysms and contraindications for iodine based contrast agents.

Can non-contrast magnetic resonance imaging replace contrast-enhanced computerized tomography in the local staging of pediatric renal tumors?

BackgroundRenal tumors account for approximately 6–7% of the total incidence of pediatric cancers. Wilms tumor (WT) is the most common renal malignancy observed in the pediatric population under 5 years old. Computed tomography (CT) is used for staging of the renal tumors. Magnetic resonance imaging (MRI) offers enhanced soft tissue resolution and provides more comprehensive insights into tumor extension through the capsule, including tumor infiltration into the renal vein or IVC. MRI is a noninvasive imaging modality that does not involve any radiation hazards, making it safe for children. In addition, MRI can be performed without the administration of contrast agents in patients with impaired renal function. Therefore, MRI plays a vital role in screening, staging, preoperative evaluation, and follow-up. Diffusion-weighted imaging (DWI) is a functional tool that aids in locating the most receptive tumoral region to guide confirmatory biopsies. In this study, we aim to evaluate the potential value of non-contrast MRI in staging pediatric renal tumors compared to contrast-enhanced CT.ResultsThis study included 50 patients presented with renal mass, with ages ranging from 1 to 8 years and a mean age of 4.27 ± 1.27 (mean ± SD). The final diagnosis was Wilm’s tumor at 86%, clear cell sarcoma at 4%, rhabdoid tumor at 4%, rhabdomyosarcoma at 2%, and nephroblastomatosis with no malignant transformation at 4%. CT accurately diagnosed stages 4 and 5 in agreement with pathological findings while upstaging the other cases, with a CT sensitivity of 90.91%, specificity of 82.35%, PPV of 92%, and NPV of 84%. MRI is superior to CT in stages 1 and 3, accurately diagnosing stages 2, 4, and 5, with a sensitivity of 93.30%, specificity of 95.65%, PPV of 95%, and NPV of 97%.ConclusionsNon-contrast MRI could be considered the optimal radiation-free imaging modality in staging pediatric renal tumors mainly Wilm’s tumor as it offers high sensitivity and specificity of capsular and vascular infiltration, compared to contrast-enhanced CT especially in cases with impaired renal functions.

Assessing Perfusion in Steno-Occlusive Cerebrovascular Disease Using Transient Hypoxia-Induced Deoxyhemoglobin as a Dynamic Susceptibility Contrast Agent.

Resting brain tissue perfusion in cerebral steno-occlusive vascular disease can be assessed by MR imaging using gadolinium-based susceptibility contrast agents. Recently, transient hypoxia-induced deoxyhemoglobin has been investigated as a noninvasive MR imaging contrast agent. Here we present a comparison of resting perfusion metrics using transient hypoxia-induced deoxyhemoglobin and gadolinium-based contrast agents in patients with known cerebrovascular steno-occlusive disease. Twelve patients with steno-occlusive disease underwent DSC MR imaging using a standard bolus of gadolinium-based contrast agent compared with transient hypoxia-induced deoxyhemoglobin generated in the lungs using an automated gas blender. A conventional multi-slice 2D gradient echo sequence was used to acquire the perfusion data and analyzed using a standard tracer kinetic model. MTT, relative CBF, and relative CBV maps were generated and compared between contrast agents. The spatial distributions of the perfusion metrics generated with both contrast agents were consistent. Perfusion metrics in GM and WM were not statistically different except for WM MTT. Cerebral perfusion metrics generated with noninvasive transient hypoxia-induced changes in deoxyhemoglobin are very similar to those generated using a gadolinium-based contrast agent in patients with cerebrovascular steno-occlusive disease.

The use of carbon dioxide as a contrast agent in critical ischemia lower extremities

The purpose of the study was to evaluate the possibility of clinical use of medical carbon dioxide as an alternative contrast agent for visualization of the arteries of the lower extremities in patients with critical ischemia of the lower extremities. During the period from January 2018 to December 2022, 153 patients aged 37 to 75 years (mean 56.2±12.5 years) underwent 39 arteriographies using medical carbon dioxide as a contrast agent. This use of medical carbon dioxide makes it possible to get high-quality contrast of the vascular bed in the lower extremities and in some cases has advantages over the use of water-soluble or iodine containing contrast agents in patients with critically ischemia of the lower extremities.

Baseline eGFR cutoff for increased risk of post-contrast acute kidney injury in patients undergoing percutaneous coronary intervention for ST-elevation myocardial infarction in the emergency department.

Acute myocardial infarction is an acute-stage disease that requires prompt diagnosis and treatment. Primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI) is a high-risk factor for post-contrast acute kidney injury (PC-AKI). This retrospective cohort study analyzed the data of 754 patients with STEMI who underwent pPCI and were integrated into the Fast Interrogation Rule for STEMI critical pathway program between 2015 and 2019. We aimed to determine the optimal cutoff baseline eGFR for identifying a high risk of PC-AKI after multivariable adjustment with statistically significant risk factors. We also compared the incidence rates of PC-AKI between the previous and current diagnostic criteria. The probability of PC-AKI increased when the baseline estimated glomerular filtration rate (eGFR) was ≤ 79mL/min/1.73 m2. The optimal cutoff baseline eGFR for high risk of PC-AKI was found to be an eGFR of ≤ 61 mL/min/1.73 m2 after multivariable adjustment. The current diagnostic criteria more accurately identified the patient group with impaired renal function. Our results have clinically significant implications for identifying patients at a high risk of developing PC-AKI, especially before and after the use of contrast agents in patients who require PCI for STEMI in the emergency department.

Effect of Contrast Agent on Renal Functions in Patients with Renal Impairment Undergoing Percutaneous Coronary Intervention

Abstract Background Contrast induced nephropathy is one of the most important clinical complications associated with IV administration of radio-contrast media. This prospective study evaluating incidence and predictors of contrast induced nephropathy after administration of contrast agent in patients with renal impairment undergoing percutaneous coronary intervention. Objective To predict the effect of contrast agents on renal functions in patients with renal impairment undergoing percutaneous coronary intervention. Patients and Methods A prospective study that included 120 patients who underwent percutanous coronary intervention with glomerular filtration rate below 90 ml/min. All patients were subjected to full history, examination and investigation. Results were recorded using serum creatinine and glomerluar filtration rate before and 72 hours after procedure. Results CIN had occurred in 26.67% of studied group where these was high incidence of occurrence of CIN with elderly (p = 0.009), obese patients (p = 0.039), hypertensive (p = 0.004), Diabetics (p = 0.000) and amount of dye received (p = 0.000). 50% of patients who developed CIN where males and 50% where females which was non significant with p = 0.165. Conclusion CIN in patients with preexisting renal damage or risk factors for the development of kidney dysfunction is a potentially serious complication after PCI with increased short and longterm morbidity and mortality. Appropriate management of patients at risk is crucial for the prevention of CIN. Although a specific treatment for CIN is not available removal of modifiable risk factors and implementation of periprocedural measures such as CM reduction and intravenous hydration can significantly lower the risk of CIN in selected patients.

Carbon Dioxide Guided Endovascular Aortic Aneurysm Repair in Impaired Renal Function: Propensity Score Matched Study

Carbon dioxide (CO2) is the preferred contrast agent in patients with impaired renal function and or contrast allergy and, particularly, in patients who require large volumes of contrast for complex endovascular procedures. In this study, the aim was to clarify the possible protective effects of CO2 guided endovascular aneurysm repair (EVAR) for patients with impaired renal function by propensity score matching. A retrospective analysis of the database was performed for 324 patients having EVAR between January 2019 and January 2022. A total of 34 patients treated with CO2 guided EVAR were evaluated. This cohort was matched for age, sex, pre-operative serum creatinine levels and glomerular filtration rate (GFR) levels and specific comorbidities to obtain homogeneous groups that included only patients with impaired renal function (eGFR < 60 mL/min/1.73m2). The primary endpoint was to compare the decrease in eGFR from baseline and development of contrast induced nephropathy (CIN) using propensity score matching. Secondary endpoints were the need for renal replacement therapy, other peri-procedural morbidity and mortality. Thirty-one patients (9.6%) of the total population developed CIN. There was no difference in the rate of CIN development between the standard EVAR group and the CO2 guided EVAR group in the unmatched population (10% vs. 3%, p= .15). After matching, the decrease in eGFR values after the procedure was more pronounced for the standard EVAR group (from 44 to 40 mL/min/1.73m2, interaction p= .034). Meanwhile, CIN development was more frequent for the standard EVAR group (24% vs. 3%, p= .027). In matched patients, early death did not differ between the groups (5.9% vs. 0, p= .15) CONCLUSION: Patients with impaired renal function are at higher risk of CIN after an endovascular procedure. CO2 guided EVAR is a safe, effective, and feasible treatment option, especially for patients with impaired renal function. CO2 guided EVAR may be a protective measure for contrast induced nephropathy.

Microvascular Morphology MR Imaging Using Relaxation Rate Change with Gadolinium‐Based Contrast Agent in Patients with Alzheimer’s Disease

AbstractBackgroundConventional MRI techniques cannot demonstrate microvascular alterations in mild and moderate Alzheimer’s disease (AD). Thus, the diagnosis of microvascular pathology commonly relies on postmortem. The purpose of this study was to evaluate alterations of microvascular structures in patients with AD using a 3T clinical MRI system with a commercially available contrast agent.MethodEleven patients with AD and 11 non‐AD controls were included in this cross‐sectional prospective study. R2 and R2* relaxation rate changes (∆R2 and ∆R2*) before and after a Gd‐based contrast agent injection were calculated from images obtained with a multi‐echo turbo spin‐echo sequence and multi‐echo gradient‐echo sequence to obtain microvascular index maps of blood volume fraction (BVf), mean vessel diameter (mVD), vessel size index (VSI), mean vessel density (Q), and microvessel‐weighted imaging (MvWI). Two‐sample t‐test was used to compare those values between the two groups. Correlation analysis was performed to evaluate the relationship between those values and the mini‐mental state examination (MMSE) score.ResultCompared with the non‐AD group, BVf was significantly increased in the AD group at the parahippocampal gyrus (p = 0.033), gray matter area (p = 0.008), and white matter area (p = 0.010). MvWI was also significantly increased in the AD group at the hippocampus (p = 0.010), parahippocampal gyrus (p = 0.010), precuneus (p = 0.045), and globus pallidus (p = 0.008). Both mVD and VSI were only significantly decreased in the AD group at the white matter hyperintensity (WMHI) area (p = 0.045 with mVD; p = 0.033 with VSI). BVf and MvWI were significantly positively correlated with age at some areas. VSI was significantly positively correlated with MMSE at caudate (rho = 0.475/ p = 0.030) and corpus callosum (rho = 0.435/ p = 0.049).ConclusionMicrovascular index was a useful non‐invasive method to evaluate microvascular morphology alteration. The microvascular morphology of AD was manifested as vessel constriction and increasing blood volume fraction. It was associated with MMSE score.

Effect of Iodized contrast substances used in computed tomography examination on kidney apparent diffusion coefficient (ADC) value

Aim: In this prospective study, our goal is to evaluate the effect of iodine-based contrast agent on renal Apparent Diffusion Coefficient (ADC) before and after the contrast agent in patients with normal and abnormal Glomerulary Filtration Rate (GFR) values using computed tomography (CT) imaging.Methods: The patients who applied for CT examination at an age older than 40 years and met the inclusion criteria of patient and control groups were included. DWI was evaluated by two radiologist in the same session. The range of interest (ROI) was adjusted to be less than 1.5 cm².The Spearman correlation test was used for statistical analysis.Results: A total of 48 subjects (23 and 25 subjects for patient and control groups, respectively) with two DWI scans were included. ADC values were compared for both kidneys before and after the administration of the contrast agent and a significant decrease in post-ADC values was observed in the control group (right kidney pre-ADC: 2,11±0,17 x10ˉ³, post-ADC 2,07±0,15 x10ˉ³ mm²/s, p=0,016; left kidney pre-ADC: 2,11±0,17 x10ˉ³ mm²/s, post-ADC 2,04±0,14 x10ˉ³ mm²/s, p=0,011). However, there was no significant difference between the patient groups according to the administration of contrast agent (right kidney pre-ADC: 1,97±0,22 x10ˉ³ mm²/s, post-ADC: 1,97±0,24 x10ˉ³ mm²/s, p=0,95; left kidney pre-ADC: 1,96±0,23 x10ˉ³ mm²/s, post-ADC: 1,98±0,22 x10ˉ³ mm²/s, p=0,64). Moreover, pre-ADC values in the patient group were relatively low. Pre-ADC values in both groups for the right kidney were 1,97±0,22 x10ˉ³ mm²/s and 2,11±0,17 x10ˉ³ mm²/s, respectively (p=0,016). Pre ADC values in both groups for the left kidney were 1,96±0,23 x10ˉ³ mm²/s and 2,11±0,17 x10ˉ³ mm²/s, respectively (p=0,018). No significant differences in the post-ADC values were observed between the two groups.Conclusion: No decrease in ADC values was observed after the administration of iodine-based contrast agent in patients with a GFR less than 60, whereas there was a relatively high decrease in patients with normal GFR.

Microvascular morphology alteration using relaxation rate change with gadolinium-based magnetic resonance imaging contrast agent in patients with Alzheimer’s disease

Conventional magnetic resonance imaging (MRI) techniques cannot demonstrate microvascular alterations in mild Alzheimer's disease (AD). Thus, the diagnosis of microvascular pathology commonly relies on postmortem. The purpose of this study was to evaluate alterations of microvascular structures in patients with AD using a 3T clinical MRI system with a commercially available contrast agent. Eleven patients with AD and 11 cognitively normal (CN) controls were included in this cross-sectional prospective study. R2 and R2* relaxation rate changes (∆R2 and ∆R2*) before and after a Gadolinium (Gd)-based contrast agent injection were calculated from images obtained with a multi-echo turbo spin-echo sequence and multi-echo gradient-echo sequence to obtain microvascular index maps of blood volume fraction (BVf), mean vessel diameter (mVD), vessel size index (VSI), mean vessel density (Q), and microvessel-weighted imaging (MvWI). Two-sample t-test was used to compare those values between the two groups. Correlation analysis was performed to evaluate the relationship between those values and age. BVfs at the corpus callosum and at the thalamus were significantly increased in the AD group (P=0.024 and P=0.005, respectively). BVf at the gray matter (P=0.020) and white matter area (P=0.012) were also significantly increased in the AD group compared with the CN group. MvWIs at the hippocampus and parahippocampal gyrus were significantly increased in the AD group compared with the CN group (P=0.020 and P=0.006, respectively). Voxel-based analysis showed both mVD and VSI were significantly decreased at the prefrontal lobe in the AD group. Q were not significant difference between CN and AD groups. MvWI were significantly positively correlated with age. Microvascular index was a useful non-invasive method to evaluate microvascular morphology alteration. The microvascular morphology of AD was manifested as increasing BVf and microvessel-weighted.

Contrast-Enhanced Three-Dimensional Fluid-Attenuated Inversion Recovery Imaging with an Optimal Scan Interval and Angulation to Visualize Endolymphatic Hydrops

Background: There is no gold standard diagnostic test for endolymphatic hydrops (EH). Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging has been reported to depict EH with administration of gadolinium-based contrast media (GBCM). However, the optimal scan interval and angulation remain unknown in 3D-FLAIR labyrinthine imaging following double-dose injections of a gadolinium-based contrast agent in patients with vertigo and sensorineural hearing loss. Objectives: This study aimed to determine the optimal parameters of 3D-FLAIR labyrinthine imaging, including the optimal scan angulation and scan interval, for patients with sensorineural hearing loss and vertigo. Patients and Methods: In this cross-sectional clinical study, following the double-dose administration of a gadolinium contrast agent, 3D-FLAIR labyrinthine images were acquired from 22 patients with unilateral vertigo and sensorineural hearing loss at different intervals after injection. The corresponding contrast-to-noise ratios (CNRs) and signal-intensity ratios (SIRs) of these images, acquired at different intervals, were measured. Moreover, separate visualization of endolymphatic and perilymphatic spaces was scored, and angulation of the anterior skull base scan was investigated in the sagittal position. Results: The 3D-FLAIR images showed the strongest image contrast in the cochlea with a double-dose gadolinium-based contrast injection at six hours post-injection. Significantly higher SIR and CNR values were reported at six hours post-injection in both unaffected and affected ears compared to other intervals (4 h vs. 6 h in the affected side, SIR: 1.65 ± 0.24 vs. 2.09 ± 0.47, CNR: 13.88 ± 5.54 vs. 19.17 ± 6.81; in the unaffected side, SIR: 1.58 ± 0.27 vs. 1.82 ± 0.34, CNR: 12.20 ± 3.88 vs. 15.42 ± 4.58, P &lt; 0.001 for all; 6 h vs. 8 h in the affected side: SIR: 2.09 ± 0.47 vs. 1.72 ± 0.43, CNR: 19.17 ± 6.81 vs. 12.22 ± 4.96; in the unaffected side, SIR: 1.82 ± 0.34 vs. 1.57 ± 0.30, CNR: 15.42 ± 4.58 vs. 10.61 ± 3.87, P &lt; 0.001 for all). Visualization of the endo- and perilymphatic spaces for both the cochlea and vestibule was significantly better at six hours post-injection compared to four hours post-injection in both affected sides (P &lt; 0.05 for both). The optimal angulation ranged from 6.20° to 13.6° (P &lt; 0.001). Conclusion: By using an optimal scan interval, together with an optimal scan angulation, 3D-FLAIR imaging can reliably visualize the endolymphatic space and sensitively indicate cochlear blood-labyrinth barrier disruptions without requiring extra image reconstruction.

MRI findings of iatrogenic extravasation of gadolinium-based contrast agents in patients with cancer.

Magnetic resonance imaging (MRI) findings after subcutaneous extravasation of gadolinium-based contrast agent (GBCA) have not been investigated in detail. To present the MRI findings of iatrogenic extravasation and to evaluate the characteristic findings. In this retrospective study of 16,039 patients with cancer, 11 patients had significant extravasation of macrocyclic GBCA, and 7 of the 11 had MRI of the injection site. Characteristic MRI findings as well as symptoms and changes over time were evaluated. The forearms or antecubital fossa felt cold in all seven cases, and 3 (43%) patients felt pain at the injection sites. Fat-suppressed T1-weighted images showed a mosaic pattern of the extravasate with mixed high and low signal in the subcutaneous tissue in 7 (100%) cases. Contrast enhancement of the fascia toward the proximal portion was observed in 3 (43%) cases. There was no subfascial deep extension. On T2-weighted images, GBCAs were observed as low-signal fluid collection on the fascia, with linear spread to the dermis and subcutaneous tissue. Four patients underwent daily MRI scans, all of whom had their contrast disappeared within three days. Macrocyclic GBCA disappears from subcutaneous tissue quickly after extravasation and is unlikely to cause serious sequelae.

Impact of a continuous quality improvement program on contrast-induced nephropathy in outpatients with chronic kidney disease: an interrupted time-series study.

Contrast-induced nephropathy (CIN) caused by exposure to radioactive contrast media can cause acute kidney injury in patients with chronic kidney disease (CKD). We developed a multifaceted approach in a CIN-quality improvement (QI) program based on a shorter saline hydration protocol for the prevention of CIN in outpatients and assessed the effect of our CIN-QI program on decreasing both the incidence rate of CIN and overall use of contrast agents in patients undergoing contrast-enhanced computed tomography (CT). We conducted a multi-center prospective interrupted time-series study from 2006 to 2018 investigating the efficacy of a CIN-QI program in preventing CIN among outpatients with CKD. An automatic medical record system alert was implemented to instruct physicians to consult a nephrologist and administer prophylactic hydration and follow-up when ordering contrast-enhanced imaging in patients with an estimated glomerular filtration rate (eGFR) <45mL/min/1.73 m2. The primary outcomes were the rates of prophylactic hydration and follow-up kidney function assessment, and the incidence of CIN for eligible patients. The usage rate of contrast-enhanced CT was also examined. A total of 95594 patients who underwent contrast-enhanced CT were included in the study. The annual prophylactic hydration rate before the CIN-QI program ranged from 2.0% to 23.2% but increased to 59.2%-75.2% during the CIN-QI program (P<.001). The annual rate of follow-up kidney function testing also improved from 18.6%-25.8% to 34.1%-42.5% after implementation of the CIN-QI program (P<.001). The rate of CIN significantly declined in level by 10.0% at the start of the CIN-QI program (P=.002) and in trend by 2.9%/year (P<.001). The number of contrast-enhanced CT orders showed a positive level change in patients with advanced CKD, who were the CIN-QI program target group of patients with eGFR <45mL/min/1.73 m2, at the start of the implementation of the CIN-QI program. After implementing the CIN-QI program, the number of contrast-enhanced CT orders showed a negative trend change across all patients, which decreased from -1.4%/year to -10.0%/year for patients with advanced CKD. The multifaceted approach in the CIN-QI program may be associated with the decreased incidence of CIN and increased rates of prophylactic hydration and follow-up kidney function testing.

Effects of contrast medium exposure on urine albumin/creatinine ratio

Aim: Albuminuria is a direct consequence of renal glomerular injury and increases with glomerular dysfunction. Spot urine albumin/creatinine (Alb/Cr) ratio is a reasonable surrogate for 24-hour urine albumin excretion rate and certainly not without limitations. It is known that renal function can be affected following contrast agent administration. The aim of our study is to assess the changes in Alb/Cr ratio in spot urine before and after contrast agents in patients undergoing computed tomography (CT) scanning.&#x0D; Material and Method: The present study included 103 hospitalized patients aged between 18 and 75 years, who underwent contrast-enhanced CT scanning for any reason and did not develop contrast-induced nephropathy (CIN). We compared the values of Alb/Cr ratio at the 6th, 12th, 24th, 48th, and 72nd hours after the procedure (post-procedure time) with the values at pre-procedure time. &#x0D; Results: The median age of the patients were 61 years. It has been observed that there is no significant increased in microalbuminuria after the use of contrast media. When the patients were evaluated for the albuminuria level before the procedure, it has been seen that 73 patients (70.9%) had an Alb/Cr ratio of

PP146 Use Of Carbon Dioxide In Endovascular Surgery To Prevent Contrast-Induced Nephropathy

IntroductionInterventional procedures often use iodinated contrast media (ICM) to visualize the area of interest. However, the use of ICM can cause contrast-induced nephropathy (CIN), which is a frequent complication after catheterization and is associated with morbidity and mortality. CIN is also a common complication in patients with pre-existing chronic kidney disease, diabetes, and heart failure. The purpose of this analysis was to compare carbon dioxide (CO2) with conventional contrast agents.MethodsTo assess the clinical effectiveness of CO2 in preventing CIN, a systematic review of relevant literature, including international guidelines, from the Medline database was conducted. Imaging of the chest, aorta, coronary arteries, and cerebral circulation with CO2 is limited, so effectiveness was determined in the field of renal and peripheral artery angioplasty. The effect on intervention cost was the main outcome.ResultsUse of CO2 generally reduced renal toxicity and anaphylactic reaction, but the benefits remain controversial. Angiography with CO2 is reasonable when image accuracy is not crucial due to its low informative value. Strategies for preventing acute kidney injury demonstrated the effectiveness of sodium chloride administration before and after the procedure. Additionally, the absence of risk factors for kidney disease significantly reduced the risk of impaired renal function.ConclusionsAlthough CO2 is one of the alternative methods for visualization, it is not pivotal in preventing CIN, even though the manufacturers recommend CO2 as the preferred contrast agent in patients with renal insufficiency who are allergic to ICM. The economic indicators for the use of CO2 are similar to traditional visualization methods.

Study on Model Iterative Reconstruction Algorithm vs. Filter Back Projection Algorithm for Diagnosis of Acute Cerebral Infarction Using CT Images.

The aim was to explore the application value of computed tomography (CT) perfusion (CTP) imaging based on the iterative model reconstruction (IMR) in the diagnosis of acute cerebral infarction (ACI). 80 patients with ACI, admitted to hospital, were selected as the research objects and divided randomly into a routine treatment group (group A) and a low-dose group (group B) (each group with 40 patients). Patients in group A were scanned at 80 kV–150 mAs, and the traditional filtered back projection (FBP) algorithm was employed to reconstruct the images; besides, 80 kV–30 mAs was adopted to scan the patients in group B, and the images were reconstructed by IMR1, IMR2, IMR3, iDose4 (a kind of hybrid iterative reconstruction technology), and FBP, respectively. The application values of different algorithms were evaluated by CTP based on the collected CTP images of patients and detecting indicators. The results showed that the gray and white matter CT value, SD value, SNR, CNR, and subjective image scores of patients in group B were basically consistent with those of group A (p > 0.05) after the IMR1 reconstruction, and the CT and SD of gray and white matter in patients from group B reduced steeply (p < 0.05), while SNR and CNR increased dramatically after IMR2 and IMR3 reconstruction in contrast to group A (p < 0.05). Furthermore, the cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) of contrast agent, and time to peak (TTP) of contrast agent in patients from group B after iDose4 and IMR reconstruction were basically the same as those of group A (p > 0.05). Therefore, IMR combined with low-dose CTP could obtain high-quality CTP images of the brain with stable perfusion indicators and low radiation dose, which could be clinically applied in the diagnosis of ACI.

Prospective assessment of diagnostic efficacy and safety of SonazoidTM and SonoVue\xae ultrasound contrast agents in patients with focal liver lesions

ObjectivesTo assess the respective diagnostic value of Sonazoid™ and SonoVue® for characterizing FLLs as benign or malignant and the corresponding safety.MethodsThis prospective Phase 3 study was conducted at 17 centres in China and Korea (May 2014 to April 2015); 424 patients (20 to 80 years) with at least 1 untreated focal liver lesion (FLL) (< 10 cm in diameter) underwent a contrast-enhanced ultrasound (CEUS) examination (218 received Sonazoid of 0.12 μL microbubbles/kg; 206 received SonoVue of 2.4 mL). Three independent blinded readers evaluated pre- and post-contrast images characterising the FLLs as benign or malignant.ResultsSonazoid-enhanced and SonoVue-enhanced ultrasound provided a statistically significant improvement in specificity for all 3 readers comparing to unenhanced ultrasound (for Sonazoid: p = 0.0093, < 0.0001, 0.0011; for SonoVue: p = 0.002, 0.03, 0.12, respectively). Difference in accuracy improvement between the 2 groups was within the pre-specified non-inferiority margin of 20% for all 3 readers (6.1%, 95% CI: − 5.0 to 17.2; − 7.5%, 95% CI: − 18.4 to 3.5; − 0.3%, 95% CI: − 11.3 to 10.7).The diagnostic confidence level for all 3 readers increased with post-contrast images relative to pre-contrast images. Both contrast agents were well tolerated.ConclusionResults showed a similar efficacy for Sonazoid™ and SonoVue® in diagnosing FLLs as benign or malignant, and underlined the benefit of CEUS imaging over unenhanced ultrasound imaging in reaching a confident diagnosis without having to refer patients for additional imaging exams.

The Use of Contrast Agents in Interventional Pain Procedures: A Multispecialty and Multisociety Practice Advisory on Nephrogenic Systemic Fibrosis, Gadolinium Deposition in the Brain, Encephalopathy After Unintentional Intrathecal Gadolinium Injection, and Hypersensitivity Reactions.

This Practice Advisory presents a comprehensive and evidence-based set of position statements and recommendations for the use of contrast media in interventional pain procedures. The advisory was established by an international panel of experts under the auspices of 11 multinational and multispecialty organizations based on a comprehensive review of the literature up to December 31, 2019. The advisory discusses the risks of using gadolinium-based contrast agents. These include nephrogenic systemic fibrosis, gadolinium brain deposition/retention, and encephalopathy and death after an unintentional intrathecal gadolinium injection. The advisory provides recommendations on the selection of a specific gadolinium-based contrast agent in patients with renal insufficiency, those who had multiple gadolinium-enhanced magnetic resonance imaging examinations, and in cases of paraspinal injections. Additionally, recommendations are made for patients who have a history of mild, moderate, or severe hypersensitivity reactions to contrast medium.

Assessment of no-reflow phenomenon by myocardial contrast echocardiography in patients with acute myocardial infarction with ST-segment elevation

Abstract Funding Acknowledgements Type of funding sources: None. Background The noninvasive assessment of myocardial perfusion by echo contrast agents in patients with acute myocardial infarction with ST-segment elevation (STEMI) after successful revascularization is becoming a relevant clinical reality. Perfusion imaging techniques with myocardial contrast echocardiography (MCE) remains the least studied and most promising ultrasound technology for the diagnosis of no-reflow phenomenon. Purpose To study the echocardiographic and angiographic characteristics of the no-reflow phenomenon detected by MCE in patients with STEMI. Methods The study included 43 patients aged from 40 to 82 years in acute stage of myocardial infarction. Patients were divided into two groups: 32 patients characterized by sufficient myocardial reperfusion after revascularization according to MCE results and 11 patients were with the impaired perfusion. Results The patients with impaired perfusion demonstrated a greater size of the left ventricular (LV) asynergy (40.1 ± 2.2% vs 27.4 ± 8.5%, p &amp;lt; 0.001). LV dilatation (LV end-systolic volume 67.3 ± 20.3 ml vs 51.8 ± 17.2 ml, p = 0.015), impaired LV ejection fraction (39.5 ± 3.4% vs 47.2 ± 4.9%, p &amp;lt; 0.001), and significant mitral regurgitation (45.5% vs 3.1%, p = 0.011) with a decrease in DP/DT (979.9 ± 363.4 mmHg/s vs 1565.7 ± 502.8 mmHg/s, p &amp;lt; 0.001) was more often detected in this group. In more than a quarter of these patients, coronary angiography showed no perfusion disorders after revascularization. In the group with impaired perfusion by MCE, the single-vascular lesions (46.9% vs 9.1%, p = 0.033), the lesions of the anterior interventricular artery (90.9% vs 40.6%, p = 0.004), and acute occlusion (100% vs 68.8%, p = 0.043) were more often determined. Conclusion According to the results of MCE, the echo signs of LV dysfunction were more pronounced after successful revascularization in patients with STEMI and myocardial perfusion disorders. The SYNTAX score was twice higher in these patients compared to the patients with recovered perfusion. In addition, no-reflow phenomenon by MCE was observed in the most patients with anterior interventricular artery lesion.