Organic Nanoplatforms for Iodinated Contrast Media in CT Imaging.

X-ray computed tomography (CT) imaging can produce three-dimensional and high-resolution anatomical images without invasion, which is extremely useful for disease diagnosis in the clinic. However, its applications are still severely limited by the intrinsic drawbacks of contrast media (mainly iodinated water-soluble molecules), such as rapid clearance, serious toxicity, inefficient targetability and poor sensitivity. Due to their high biocompatibility, flexibility in preparation and modification and simplicity for drug loading, organic nanoparticles (NPs), including liposomes, nanoemulsions, micelles, polymersomes, dendrimers, polymer conjugates and polymeric particles, have demonstrated tremendous potential for use in the efficient delivery of iodinated contrast media (ICMs). Herein, we comprehensively summarized the strategies and applications of organic NPs, especially polymer-based NPs, for the delivery of ICMs in CT imaging. We mainly focused on the use of polymeric nanoplatforms to prolong circulation time, reduce toxicity and enhance the targetability of ICMs. The emergence of some new technologies, such as theragnostic NPs and multimodal imaging and their clinical translations, are also discussed.

A quadruple blinded placebo controlled randomised trial to evaluate the effectiveness of an Iodine complex for patients with mild to moderate COVID-19 in Pakistan (I-COVID-PK): A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: The objective of the study is to measure the efficacy of ionic-iodine polymer complex [1] for clinical and radiological improvement in coronavirus disease 2019 (COVID-19) patients. TRIAL DESIGN: The trial will be closed label, randomized and placebo-controlled with a 1:1:1:1 allocation ratio and superiority framework. PARTICIPANTS: All PCR confirmed COVID-19 adult patients including non-pregnant females, with mild to moderate disease, will be enrolled from Shaikh Zayed Post-Graduate Medical Complex, Ali Clinic and Doctors Lounge in Lahore (Pakistan). Patients with any pre-existing chronic illness will be excluded from the study. INTERVENTION AND COMPARATOR: In this multi-armed study ionic-iodine polymer complex with 200 mg of elemental iodine will be given using three formulations to evaluate efficacy. Patients will be receiving either encapsulated iodine complex of 200 mg (arm A), iodine complex syrup form 40 ml (arm B), iodine complex throat spray of 2 puffs (arm C) or empty capsule (arm D) as placebo; all three times a day. All the 4 arms will be receiving standard care as per version 3.0 of the clinical management guidelines for COVID-19 established by the Ministry of National Health Services of Pakistan. MAIN OUTCOMES: Primary outcomes will be viral clearance with radiological and clinical improvement. SARS-CoV-2 RT-PCR and HRCT chest scans will be done on the admission day and then after every fourth day for 12 days or till the symptoms are resolved. RT-PCR will only be shown as positive or negative while HRCT chest scoring will be done depending on the area and severity of lung involvement [2]. Time taken for the alleviation of symptoms will be calculated by the number of days the patient remained symptomatic. 30-day mortality will be considered as a secondary outcome. RANDOMISATION: Stratification for initial COVID-19 status (or days from initial symptoms as a proxy), age groups, gender, baseline severity of symptoms and co-morbidities will be used to ensure that the study arms remain balanced in size for the 1:1:1:1 allocation ratio. Randomization will be done using the lottery method. As patients are being admitted at different times, they will be recruited after obtaining their voluntary written informed consent following all standard protocols of the infection, control and disinfection. BLINDING (MASKING): This is a quadruple (participants, care providers, investigators and outcomes assessors) blinded study where only the study's Primary Investigator will have information about the arms and their interventions. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): 200 patients will be randomized into four groups with three experimental and one placebo arm. TRIAL STATUS: Protocol Version Number is 2.3 and it is approved from IRB Shaikh Zayed Hospital with ID SZMC/IRB/Internal0056/2020 on July 14th, 2020. The recruitment is in progress. It was started on July 30, 2020, and the estimated end date for the trial is August 15, 2021. TRIAL REGISTRATION: Clinical Trial has been retrospectively registered on www.clinicaltrials.gov with registration ID NCT04473261 dated July 16, 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). With the intention of expediting dissemination of this trial, the conventional formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines.

Virtual monoenergetic images preserve diagnostic assessability in contrast media reduced abdominal spectral detector CT.

OBJECTIVES: To investigate if low-keV virtual monoenergetic images (VMI40keV) from abdominal spectral detector CT (SDCT) with reduced intravenous contrast media application (RCM) provide abdominal assessment similar to conventional images with standard contrast media (SCM) dose. METHODS: 78 patients with abdominal SDCT were retrospectively included: 41 patients at risk for adverse reactions who received 44 RCM examinations with 50 ml and 37 patients who underwent 44 SCM examinations with 100 ml of contrast media (CM) and who were matched for effective body diameters. RCM, SCM images and RCM-VMI40keV were reconstructed. Attenuation and signal-to-noise ratio (SNR) of liver, pancreas, kidneys, lymph nodes, psoas muscle, aorta and portal vein were assessed ROIs-based. Contrast-to-noise ratios (CNR) of lymph nodes vs aorta/portal vein were calculated. Two readers evaluated organ/vessel contrast, lymph node delineation, image noise and overall assessability using 4-point Likert scales. RESULTS: RCM were inferior to SCM images in all quantitative/qualitative criteria. RCM-VMI40keV and SCM images showed similar lymph node and muscle attenuation (p = 0.83,0.17), while for all other ROIs, RCM-VMI40keV showed higher attenuation (p ≤ 0.05). SNR was comparable between RCM-VMI40keV and SCM images (p range: 0.23-0.99). CNR of lymph nodes was highest in RCM-VMI40keV (p ≤ 0.05). RCM-VMI40keV received equivalent or higher scores than SCM in all criteria except for organ contrast, overall assessability and image noise, where SCM were superior (p ≤ 0.05). However, RCM-VMI40keV received proper or excellent scores in 88.6/94.2/95.4% of the referring cases. CONCLUSIONS: VMI40keV counteract contrast deterioration in CM reduced abdominal SDCT, facilitating diagnostic assessment. ADVANCES IN KNOWLEDGE: SDCT-derived VMI40keV provide adequate depiction of vessels, organs and lymph nodes even at notable CM reduction.

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation.

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m2 who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m2 at the discretion of the ordering clinician. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.

Intravascular Iodinated Contrast Is an Independent Cause of Acute Kidney Injury Following Coronary Angiography.

OBJECTIVES: Recent studies have questioned whether intravascular iodinated contrast remains an independent cause of acute kidney injury (AKI). We sought to assess whether iodinated contrast administered during coronary angiography is an independent cause of AKI. METHODS: We identified all of the patients who underwent coronary angiography between July 1, 2015 and June 30, 2017 with a discharge diagnosis of AKI that developed within 7 days following angiography. Using chart review, we categorized patients as having multifactorial AKI if ≥1 insults other than intravascular contrast potentially contributed to kidney injury or contrast-induced AKI (CI-AKI) if the only insult was contrast administration. We compared the severity of AKI and renal function upon discharge between patients with CI-AKI and multifactorial AKI. RESULTS: We identified 78 patients who experienced AKI within 7 days following angiography, 10 (13%) of whom had CI-AKI and 68 of whom (87%) experienced multifactorial AKI. Nine (90%) patients with CI-AKI manifested stage 1 disease, 1 (10%) had stage 2 disease, and 9 (90%) experienced full recovery of kidney function. More patients with multifactorial AKI developed stage 2 or 3 disease (42% vs 10%, χ2 = 3.73, P = 0.05) and experienced either partial recovery of kidney function or persistent kidney impairment compared with patients with CI-AKI (25% vs 10%, χ2 = 1.9, P = 0.17), although the latter comparison was not statistically significant. CONCLUSIONS: The intravascular administration of iodinated contrast remains an independent cause of AKI. Compared with those with multifactorial AKI, patients with CI-AKI appear to be more likely to experience mild decrements in kidney function that recover completely.

Relationship between Lower Dose and Injection Speed of Iodinated Contrast Material for CT and Acute Hypersensitivity Reactions: An Observational Study.

BackgroundThere are few data on the relationship between acute hypersensitivity reactions and the dose and injection rate of iodinated contrast material for CT.PurposeTo determine the relationship between lower dose and injection speed of iodinated contrast material for CT and the rate of acute hypersensitivity reactions.Materials and MethodsThis retrospective study included adults (age ≥18 years) undergoing nonionic iodinated contrast material-enhanced abdominal CT between August 2016 and January 2017 (control period) and between August 2017 and January 2018 (intervention period); all examinations were conducted in an outpatient setting. Compared with CT during the control period, CT during the intervention period involved a reduced dose of contrast material achieved by lowering the CT tube voltage. CT examinations in the control period were performed with 120 kVp, a contrast material dose of 2 mL/kg (maximum, 150 mL), and an injection speed of 3 or 4 mL/sec. CT examinations in the intervention period were performed with 100 kVp, a contrast material dose of 1.5 mL/kg (maximum, 130 mL), and an injection speed of 2.5 or 3 mL/sec. Per-examination rates of acute hypersensitivity reactions to iodinated contrast material were compared between the control and intervention periods with use of a multivariable Poisson regression model, the parameters of which were estimated by using generalized estimating equations with an independence correlation structure.ResultsA total of 21947 adults (mean age ± standard deviation, 59 years ± 12; 8797 women [40%]) underwent 25119 CT examinations during the control period; 23019 adults (mean age, 59 years ± 12; 9538 women [41%]) underwent 26491 CT examinations during the intervention period. The rate of acute hypersensitivity reactions was 1.42% (376 of 26491 examinations; 95% confidence interval [CI]: 1.28%, 1.57%) in the intervention period and 1.86% (468 of 25119 examinations; 95% CI: 1.70%, 2.04%) in the control period, with a multivariable-adjusted relative risk of 0.85 (95% CI: 0.74, 0.99; P = .03).ConclusionReduction in the dose and injection speed of iodinated contrast material for CT was associated with a lower rate of acute hypersensitivity reactions to iodinated contrast material.© RSNA, 2019Online supplemental material is available for this article.

In vitro qualitative and quantitative CT assessment of iodinated aerosol nasal deposition using a 3D-printed nasal replica.

Computed tomography can provide high-resolution details on nasal anatomy being potentially useful for the assessment of nasal spray deposition. The purpose of this technical note was to present a method based on CT imaging to assess qualitatively and quantitatively the in vitro spray deposition patterns within the sinonasal cavities of a nasal replica obtained by three-dimensional (3D) printing, using iodinated contrast agent labelled solutions with high spatial and temporal resolution. Using a third generation dual-source CT scanner in single energy mode, scans of a nasal replica were acquired following application of iodinated contrast agent labelled aerosols with an iodine concentration of 92.5 mgl/mL. Two software programmes were then utilised (Osirix MD v.9.0, Pixmeo, Geneva, Switzerland; 3mensio, Pie Medical Imaging, Bilthoven, Netherlands) to generate three-dimensional reconstructions of the scans, thus enabling the rapid detection and visualisation of administered single droplets and their voxel-by-voxel localisation. Using this approach, we achieved recovery rates between 84-98% and 89-109% (depending on the software programme) of the total applied aerosol volume.

Nephrotoxicity of iodinated contrast media: From pathophysiology to prevention strategies.

Iodinated contrast media (ICM) induced acute kidney injury (AKI) accounts for 11% of cases of AKI and is its third most common cause in hospitalized patients. However, the pathophysiological mechanisms are not yet completely understood. The nephrotoxicity of ICM is partly the consequence of a direct cytotoxic effect on renal tubular epithelial and endothelial cells. It is also the consequence of impaired intrarenal hemodynamics, these two mechanisms being closely linked. The rheological properties of ICM, the volume infused, and the route of administration increase the intrinsic toxicity generated by the contrast media used. Furthermore, various clinical situations increase the risk of developing AKI. There is no specific treatment. Hydration is the cornerstone of prevention. Preventive measures have reduced the incidence of AKI over the last ten years. After an overview of the pathophysiology of the renal toxicity of ICM, we review risk factors and scores, diagnosis, and means of prevention in the light of the 2018 European Society of Urogenital Radiology and the 2018 American College of Radiology guidelines and recent studies on the subject. In addition, a side-by-side comparison of the updated and less conservative guidelines from the Radiology community and the more cautionary attitude from the Nephrology community are also presented.

The administration of contrast media: is there a risk of acute kidney injury? / Administración de medios de contraste. ¿Existe riesgo de daño renal agudo?

OBJECTIVE: To determine whether the intravenous administration of iodinated contrast material for computed tomography (CT) is associated with an increase in creatinine levels and acute kidney injury. MATERIAL AND METHODS: This retrospective cohort study included all patients who presented at the emergency department between 2010 and 2015 with baseline creatinine measurement (C1) and follow-up creatinine measurement (C2) between 24 and 72hours later. The clinical research ethics committee approved the study. The exclusion criteria were age <18 years, creatinine ≤ 0.4mg/dl or ≥4.0mg/dl, and the administration of contrast media within the previous 6 months. The mean number of patients presenting at the emergency department was 105,435.6 per year. Patients who met the inclusion criteria were classified into three groups: those who underwent contrast-enhanced CT (n=6,642), those who underwent noncontrast CT (n=6,193), and those who did not undergo CT (n=33,802). We used the Acute Kidney Injury Network's (AKIN) and the Contrast-induced Nephropathy Consensus Working Panel's (CIN) criteria. Statistical analyses included bivariate statistics and logistic regression. Stata 15 was used for all statistical analyses. RESULTS: We analyzed 52,411 patients; after data cleansing: 46,637; mean age: 67.95 years; C1: mean 1.16mg/dl (SD: 0.61); C2: 1.14mg/dl (SD: 0.66). With AKIN and CIN criteria: contrast-enhanced CT was not associated with a greater probability of developing nephropathy (odds ratio [OR: 0.90; 95% CI: 0.83-0.99] and [OR 0.89, 95% CI: 0.81-0.98], respectively). The propensity score matching study using both sets of criteria (AKIN+CIN) yielded OR 0.80 [95% CI: 0.77-0.84]. Glomerular filtration rates less than 30ml/min were not associated with increased kidney damage [OR: 0.66, 95% CI: 0.47-0.91]. CONCLUSION: The administration of intravenous contrast material in the patients studied is not associated with increased acute kidney injury.

Virtual Monochromatic Dual-Energy Aortoiliac CT Angiography With Reduced Iodine Dose: A Prospective Randomized Study.

OBJECTIVE: The purpose of this study was to assess the feasibility of performing abdominopelvic aortoiliac CT angiography (CTA) with 16.0 g of iodine contrast medium acquired with low-energy (40 and 50 keV) virtual monochromatic (VMC) images with rapid-kilovoltage-switching dual-energy CT. SUBJECTS AND METHODS: A total of 52 adults with abdominal aortoiliac aneurysm and prior 120-kVp single-energy CTA (SECTA) with 33 g iodine (standard dose) underwent follow-up dual-energy CTA (DECTA) with a 52% reduced iodine dose. Subjects were randomly assigned to a contrast medium protocol for DECTA examinations: one group (n = 26) received 16.2 g (270 mg I/mL) and the other (n = 26) received 16.0 g (320 mg I/mL). Two readers independently assessed SECTA and VMC DECTA datasets for image quality using a 5-point scale. Aortoiliac intravascular attenuation was measured, and ANOVA was used to compare measurements between VMC DECTA and SECTA images. In a subset of patients with DECTA after endovascular aortic repair, endoleak detection was evaluated on VMC images. Volume CT dose index, dose-length product, and size-specific dose estimate were compared between DECTA and SECTA. RESULTS: All DECTA examinations (n = 52) were rated diagnostic with image quality scores comparable to those of 120-kVp single-energy CTA (40 keV, 4.2-4.4; 50 keV, 4.6-4.8; SECTA, 4.4-4.5). Intravascular attenuation was uniform in all reduced-iodine DECTA examinations and was significantly higher on 40- and 50-keV images than on standard-iodine-dose SECTA images (720 ± 125 HU and 482 ± 82 HU vs 303 ± 65 HU) (p < 0.01). There was no difference in intravascular attenuation between the 16.2-g and the 16.0-g doses (p = 0.82). Sensitivity and specificity for endoleak detection were 78.9-94.7% and 100%. Total dose-length product was lower for DECTA (788 ± 166 mGy · cm) than for SECTA (1114 ± 468 mGy · cm). CONCLUSION: Low-energy VMC DECTA images (40 and 50 keV) acquired with two contrast protocols at approximately 50% reduced iodine dose (16.0 and 16.2 g) provide adequate intravascular attenuation and diagnostic quality for aortoiliac evaluation.

Impacto de la angiografía coronaria rotacional en la cantidad total de contraste administrado y la exposición a las radiaciones ionizantes en pacientes en los que se realizan procedimientos coronarios invasivos: revisión sistemática y metaanálisis / Impact of rotational coronary angiography in the amount of iodinated contrast and the exposure to ionising radiations in patients undergoing invasive coronary procedures: A systematic review and meta-analysis

Resumen Antecedentes: Los procedimientos coronarios invasivos conllevan la administración de contraste y la exposición a radiaciones ionizantes, comportando un incremento de la morbimortalidad. La angiografía coronaria rotacional (ACR) permite adquirir múltiples proyecciones con una inyección de contraste. Hasta la fecha, no hay metaanálisis específicos comparando la ACR y la angiografía coronaria convencional (ACC) en pacientes en los que se realizan procedimientos coronarios invasivos, tanto diagnósticos como diagnósticos y terapéuticos. El objetivo de este metaanálisis es evaluar el impacto de la ACR en la cantidad de contraste, y la radiación ionizante en procedimientos coronarios invasivos. Métodos: Se realizó una búsqueda en las bases de datos PubMed y Ovid para identificar estudios tanto diagnósticos como diagnósticos y terapéuticos que comparasen ACR y ACC. Los estudios fueron evaluados sobre la calidad y los sesgos, y fueron incluidos si contemplaban alguna de las siguientes variables de valoración: volumen de contraste, radiación ionizante medida como producto dosis-área, Kerma-aire o tiempo de fluoroscopia. Resultados: Dieciséis estudios, totalizando 2,327 pacientes, fueron incluidos en el análisis final (1,146 pacientes recibieron ACR y 1,181, ACC), objetivándose diferencias significativas en volumen de contraste (diferencia estándar de medias (intervalo de confianza al 95%) −1.887 (−2.472 a −1.302); p < 0.001), producto dosis-área (−0.726 (−1.034 a −0.418); p < 0.001), Kerma-aire (−0.842 (−1.104 a −0.581); p < 0.001) y tiempo de fluoroscopia (0.263 (−0.496 a −0.030); p = 0.027). Conclusiones: La ACR permite reducir el volumen de contraste y la radiación, evaluada como producto dosis-área, Kerma-aire y tiempo de fluoroscopia en pacientes a los que se les realizan procedimientos coronarios invasivos.

Abstract Background: Invasive coronary procedures involve the administration of iodinated contrast and the exposure to ionising radiations, increasing morbidity and mortality. The rotational coronary angiography (RCA) allows acquiring multiple projections with a unique injection of iodinated contrast. To date, there are no meta-analyses specifically comparing RCA and conventional coronary angiography (CCA) in patients undergoing invasive coronary procedures, whether diagnostic or diagnostic and therapeutic. The aim of this meta-analysis is to assess the impact of RCA on the amount of iodinated contrast and the exposure to ionising radiations during invasive coronary procedures. Methods: A search in PubMed and Ovid databases was conducted to identify studies, including diagnostic and diagnostic and therapeutic studies, comparing RCA and CCA. The manuscripts were evaluated on quality and biases, and were included if they analysed any of the following endpoints: volume of contrast and exposure to ionising radiations measured as dose-area product, and Kerma-air or fluoroscopy time. Results: Sixteen studies, with a total of 2,327 patients, were included in the final analysis (1,146 patients underwent RCA and 1,181 patients underwent CCA), with significant differences being detected in volume of contrast (standard difference in means (95% confidence interval) −1.887 (−2.472 to −1.302); P < .001), dose-area product (−0.726 (−1.034 to −0.418); P < .001), Kerma-air (−0.842 (−1.104 to −0.581); P < .001), and fluoroscopy time (0.263 (−0.496 to −0.030); P = .027). Conclusions: RCA reduces the volume of contrast and the exposure to radiation, evaluated as dose-area product, Kerma-air, and fluoroscopy time, in patients undergoing invasive coronary procedures.

[Impact of rotational coronary angiography in the amount of iodinated contrast and the exposure to ionising radiations in patients undergoing invasive coronary procedures: A systematic review and meta-analysis]. / Impacto de la angiografía coronaria rotacional en la cantidad total de contraste administrado y la exposición a las radiaciones ionizantes en pacientes en los que se realizan procedimientos coronarios invasivos: revisión sistemática y metaanálisis.

BACKGROUND: Invasive coronary procedures involve the administration of iodinated contrast and the exposure to ionising radiations, increasing morbidity and mortality. The rotational coronary angiography (RCA) allows acquiring multiple projections with a unique injection of iodinated contrast. To date, there are no meta-analyses specifically comparing RCA and conventional coronary angiography (CCA) in patients undergoing invasive coronary procedures, whether diagnostic or diagnostic and therapeutic. The aim of this meta-analysis is to assess the impact of RCA on the amount of iodinated contrast and the exposure to ionising radiations during invasive coronary procedures. METHODS: A search in PubMed and Ovid databases was conducted to identify studies, including diagnostic and diagnostic and therapeutic studies, comparing RCA and CCA. The manuscripts were evaluated on quality and biases, and were included if they analysed any of the following endpoints: volume of contrast and exposure to ionising radiations measured as dose-area product, and Kerma-air or fluoroscopy time. RESULTS: Sixteen studies, with a total of 2,327 patients, were included in the final analysis (1,146 patients underwent RCA and 1,181 patients underwent CCA), with significant differences being detected in volume of contrast (standard difference in means [95% confidence interval] -1.887 [-2.472 to -1.302]; P<.001), dose-area product (-0.726 [-1.034 to -0.418]; P<.001), Kerma-air (-0.842 [-1.104 to -0.581]; P<.001), and fluoroscopy time (0.263 [-0.496 to -0.030]; P=.027). CONCLUSIONS: RCA reduces the volume of contrast and the exposure to radiation, evaluated as dose-area product, Kerma-air, and fluoroscopy time, in patients undergoing invasive coronary procedures.

Contrast induced-acute kidney injury following peripheral angiography with carbon dioxide versus iodinated contrast media: A meta-analysis and systematic review of current literature.

OBJECTIVE: We conducted a meta-analysis to compare the incidence of acute kidney injury (AKI) with carbon dioxide (CO2 ) versus iodinated contrast media (ICM). BACKGROUND: Contrast induced-acute kidney injury (CI-AKI) is a known complication following endovascular procedures with ICM. CO2 has been employed as an alternative imaging medium as it is nontoxic to the kidneys. METHODS: Search of indexed databases was performed and 1,732 references were retrieved. Eight studies (7 observational, 1 Randomized Controlled Trial) formed the meta-analysis. Primary outcome was AKI. Fixed effect model was used when possible in addition to analysis of publication bias. RESULTS: In this meta-analysis, 677 patients underwent 754 peripheral angiographic procedures. Compared with ICM, CO2 was associated with a decreased incidence of AKI (4.3% vs. 11.1%; OR 0.465, 95% CI: 0.218-0.992; P = 0.048). Subgroup analysis of four studies that included granular data for patients with chronic kidney disease (CKD) did not demonstrate a decreased incidence of AKI with CO2 (4.1% vs. 10.0%; OR 0.449, 95% CI: 0.165-1.221, P = 0.117). Patients undergoing CO2 angiography experienced a higher number of nonrenal events including limb/abdominal pain (11 vs. 0; P = 0.001) and nausea/vomiting (9 vs. 1; P = 0.006). CONCLUSIONS: In comparison to ICM, CO2 use is associated with a modestly reduced rate of AKI with more frequent adverse nonrenal events. In studies that use CO2 as the primary imaging agent, the average incidence of AKI remained high at 6.2%-supporting the concept that factors other than renal toxicity from ICM may contribute to renal impairment following peripheral angiography. © 2017 Wiley Periodicals, Inc.

Photodynamic therapeutic efficacy of symmetrical diiodinated squaraine in in vivo skin cancer models.

BACKGROUND: Photodynamic therapy (PDT) has clinical approval for use as a minimally invasive therapeutic procedure that is able to exert selective cytotoxic activity toward malignant cells. The dye selected for our study, symmetrical diiodinated squaraine, is one of the newly developed photosensitizers. The study is designed to determine the efficacy of PDT mediated by symmetrical diiodinated squaraine in skin tumor induced Swiss albino mice. METHODS: Skin tumor was induced in mice with dimethyl benzanthracene (DMBA) and croton oil. After squaraine administration to the tumor mice, photodynamic treatment of tumors was performed using a 1000W halogen lamp corresponding to the light dose of 100J/cm2. The mice were euthanized and skin flaps and tumor tissues from the back of mice were excised for biochemical studies. The biochemical parameters analyzed include some relevant tumor markers for epithelial tissues, inflammatory markers and markers of apoptosis. The gene expression studies were done by RT-PCR. RESULTS: After two weeks of the treatment, there was significant inflammation. However at 90days after PDT, the parameters reverted to near-normal values. All marker parameters of tumor progression brought back to normal levels by PDT. Increased caspase-3 activity in PDT treated group shows that cell death might have occurred by apoptosis. The gene expression profile confirms the results. CONCLUSIONS: The results of the whole study show the therapeutic efficacy and apoptosis mediated tumor destruction by squaraine PDT.

The effects of combining fusion imaging, low-frequency pulsed fluoroscopy, and low-concentration contrast agent during endovascular aneurysm repair.

OBJECTIVE: This study evaluated the effects of a combined imaging protocol using low-frequency pulsed fluoroscopy, fusion imaging, and low-concentration iodine contrast for endovascular aneurysm repair (EVAR) of aortic aneurysms of varying complexity. METHODS: The study retrospectively reviewed the data of 103 patients treated between May 2013 and November 2014 with the combined imaging protocol (group A) with low-dose fluoroscopy at 3.75 frames/s, fusion imaging, and iodine contrast of 140 mg iodine/mL. A control group (group B) consisted of 123 consecutive patients who underwent EVAR before the combined imaging protocol was introduced by matching the type of procedure. In group B, low-dose 7.5 frames/s fluoroscopy, no fusion imaging, and 200 mg iodine/mL contrast were used. All patients were reviewed for preoperative, intraoperative, and postoperative variables, with emphasis on intraoperative radiation (dose area product) and iodine exposure, fluoroscopy, and operation times, as well as technical success. Values are presented as median and interquartile range (IQR) when not stated otherwise. RESULTS: Group A included 22 infrarenal EVARs, 17 iliac branch devices, 10 thoracic endovascular aortic repairs, 21 fenestrated EVARs, and 33 thoracoabdominal branched/fenestrated EVARs. Groups A and B were similar in types of procedure, body mass index (P > .05), and intraoperative technical success (92% and 92%, respectively; P > .05). Operation time (230 [IQR, 138-331] minutes vs 235 [IQR, 158-364] minutes) and fluoroscopy time (66 [IQR, 33-101] minutes vs 72 [IQR, 42-102] minutes) were similar in both groups (P > .05), but radiation exposure (19,934 [IQR, 11,340-30,615] µGym(2) vs 32,856 [IQR, 19,562-55,677] µGym(2); P < .0001), contrast volume usage (63 [IQR, 103-145] mL vs 215 [IQR, 166-280] mL; P < .0001), and iodine dose (14.5 [IQR, 8.8-20.4] g iodine vs 43.0 [IQR, 32.2-56.0] g iodine; P < .0001) were lower in group A than in group B. The differences were uniform throughout the different procedure types, with the exception of fenestrated grafts, where radiation exposure was similar between group A and B; however, group A had a much higher involvement of the superior mesenteric artery in the repairs (81% vs 17%; P < .0001) explaining this finding. Fluoroscopic frame rate reduction contributed to a median reduction of the dose area product by 22%. Only four of the group A patients (3.9%) showed a decrease in the glomerular filtration rate ≥30% after EVAR, although 32% of the entire group had at least moderately impaired renal function preoperatively. CONCLUSIONS: Combining low-frequency pulsed fluoroscopy, fusion imaging, low-concentration, and iodine contrast medium during EVAR reduces the exposure to radiation and iodine.