Macrophage ablation significantly reduces uptake of imaging probe into organs of the reticuloendothelial system

2020 ◽  
pp. 028418512094304
Author(s):  
Bastian O Sabel ◽  
Karsten Brand ◽  
Johannes Rueckel ◽  
Boj Hoppe ◽  
Nicola Fink ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Animal Model ◽  
Contrast Media ◽  
Reticuloendothelial System ◽  
Ct Scans ◽  
The Third ◽  
Imaging Probes ◽  
Kinetics Of ◽  
Over Time ◽  
Ct Contrast

Background Macrophages engulf particulate contrast media, which is pivotal for biomedical imaging. Purpose To introduce a macrophage ablation animal model by showing its power to manipulate the kinetics of imaging probes. Material and Methods The kinetics of a particulate computed tomography (CT) contrast media was compared in macrophage ablative mice and normal mice. Liposomes (size 220 µg), loaded with clodronate, were injected into the peritoneum of three C57BL/6 mice. On the third day, 200 µL of the particulate agent ExiTron nano 6000 were injected into three macrophage-ablative mice and three control mice. CT scans were acquired before and 3 min, 1 h, 6 h, and 24 h after the ExiTron application. The animals were sacrificed, and their spleens and livers removed. Relative CT values (CTV) were measured and analyzed. Results Liver and spleen enhancement of treated mice and controls were increasing over time. The median peak values were different with 225 CTV for treated mice and 582 CTV for controls in the liver ( P = 0.032) and 431 CTV for treated and 974 CTV in controls in the spleen ( P = 0.016). Conclusion Macrophage ablation leads to a decrease of enhancement in organs containing high numbers of macrophages, but only marginal changes in macrophage-poor organs. Macrophage ablation can influence the phagocytic activity and thus opens new potentials to investigate and manipulate the uptake of imaging probes.

scholarly journals The Effect of Contrast-enhanced Computed Tomography (CT) Scans on the Calculated Dose of Radiotherapy in a Thorax Phantom

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Athar Ehtiati ◽  
Payman Hejazi ◽  
Mohsen Bakhshandeh ◽  
Ali Jabbary Arfaee ◽  
Eftekhar Rajab Bolookat ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Media ◽  
Ct Scan ◽  
Treatment Planning ◽  
Tumor Volume ◽  
Ct Scans ◽  
Contrast Enhanced ◽  
Enhanced Ct ◽  
Enhanced Computed Tomography ◽  
Contrast Enhanced Computed Tomography

Background: Despite the benefits of contrast-enhanced computed tomography (CT) scans in better tumor volume delineation, it can affect the accuracy of dose calculation in radiation therapy. This study examined this effect on a thorax phantom. Objectives: The influence of different variables including the concentrations of the Visipaque contrast media, tumor sizes, and CT scan energies on the dose measurement was examined. Methods: Transparent cylinders containing the contrast media were inserted in the lung area of the phantom and the CT scans were made. Non-enhanced CT scans were also acquired. Treatment planning using 2 opposite fields was performed on the CT scans and the doses were calculated in the treatment planning system. The results of the 2 sets of enhanced and non-enhanced CT scans were compared. Results: The correlation between concentration and the percentage of mean dose of the tumor volume was significant in 2 of the tumor sizes. The differences in the mean doses of the 2 plans were examined and more than 3% increase was observed in higher concentrations of the contrast media. Conclusions: According to this study, the suitable concentration of the contrast media administered and the CT scan energy should be considered. This would help to decrease the discrepancies between the calculated and delivered dose in radiotherapy treatments to a clinically acceptable level. The importance of time delays for CT scans after administration of the contrast media is emphasized.

MO419THE ROLE OF SHORT-TERM, HIGH-DOSE ATORVASTATIN FOR PREVENTION OF CONTRAST-INDUCED ACUTE KIDNEY INJURY (CI-AKI) IN PATIENTS WITH CARDIOVASCULAR DISEASES UNDERGOING COMPUTED TOMOGRAPHY WITH INTRAVENOUS CONTRAST ADMINISTRATION

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Andrey Vasin ◽  
Olga Mironova ◽  
Viktor Fomin
Keyword(s):  
Computed Tomography ◽  
Acute Kidney Injury ◽  
Cardiovascular Diseases ◽  
Contrast Media ◽  
Kidney Injury ◽  
Ct Scans ◽  
Intravenous Contrast ◽  
Dosing Regimens ◽  
Intravenous Contrast Media ◽  
Contrast Media Administration

Abstract Background and Aims Computed tomography with intravenous contrast media is widely used in hospitals. The incidence of CI-AKI due to intravenous contrast media administration in high-risk patients remains not studied as well as CI-AKI after intraarterial contrast media administration is. According to other researchers, the use of statins in the prevention of AKI after intra-arterial administration of a contrast agent is currently considered an efficient preventive measure. The aim of our study is to assess the incidence of contrast-induced acute kidney injury in patients with cardiovascular diseases during CT scan with intravenous contrast media and analyze the efficacy and safety of various statin dosing regimens for prevention of CI-AKI. Method A randomized controlled open prospective study is planned. Statin naive patients with cardiovascular diseases will be divided into 3 groups. Patients in the first group will receive atorvastatin 80mg 24 hours and 40mg 2 hours before CT scans and 40 mg after. The second group – 40 mg 2 hours before CT scans and 40 mg after. A third group is a control group. Exclusion criteria were current or previous statin treatment, contraindications to statins, severe renal failure, acute coronary syndrome, administration of nephrotoxic drugs. The primary endpoint will the development of CI-AKI, defined as an increase in serum Cr concentration 0.5 mg/dl (44.2 mmol/l) or 25% above baseline at 72 h after exposure to the contrast media. Results We assume a higher incidence of contrast-induced acute kidney injury in the group of patients not receiving statin therapy (about 5-10%). At the same time, it is unlikely to get a significant difference between statin dosing regimens. Risk factors such as age over 75 years, the presence of chronic kidney disease, diabetes mellitus, and chronic heart failure increase the risk of contrast-induced acute kidney injury. Conclusion Despite the significantly lower incidence of CI-AKI with intravenous contrast compared to intra-arterial, patients with CVD have a greater risk of this complication even with intravenous contrast. Therefore, the development of prevention methods and scales for assessing the likelihood of CI-AKI is an important problem. As a result of the study, we expect to conclude the benefits of statins in CI-AKI prevention and the optimal dosage regimen. This information will help us to reduce the burden of CI-AKI after CT scanning in statin naive patients with cardiovascular diseases in everyday clinical practice. ClinicalTrials.gov ID: NCT04666389

scholarly journals Iodine-induced Nephropathy in Patients with Oncological Disorders Treated with Chemotherapy

2020 ◽  
Vol 70 (12) ◽  
pp. 4537-4544
Keyword(s):  
Computed Tomography ◽  
Observational Study ◽  
Serum Creatinine ◽  
Contrast Media ◽  
Cytotoxic Effect ◽  
Diagnostic Value ◽  
Iodinated Contrast Media ◽  
Iodinated Contrast ◽  
Contrast Enhanced ◽  
Ct Contrast

Cancer represents the second most important cause of death and morbidity in Europe, with more than 3.7 million new cases and 1.9 million deaths reported each year. Computed tomography plays a fundamental role in the management of oncology patients, and the superior diagnostic value that contrast-enhanced images offer is frequently critical. It is well recognized that iodinated contrast media have a cytotoxic effect, and this is felt to be one of the mechanisms responsible for contrast-induced nephrotoxicity. The study aims to analyze the correlation between administration of iodinated contrast substance (namely, Iohexol) and serum creatinine values 48 hours afterwards in patients with oncological conditions undergoing chemotherapy, which perform CT examinations (observational study). Keywords: CT, contrast media induced nephropathy, chemotherapy

scholarly journals Monitoring vitamin E pools in sheep tissue and plasma after intravenous dosing of radiotocopherol

1990 ◽  
Vol 63 (2) ◽  
pp. 375-386 ◽  
Author(s):  
K. Karpinski ◽  
M. Hidiroglou
Keyword(s):  
Principal Component ◽  
Rapid Decrease ◽  
Plasma Samples ◽  
Tissue Concentrations ◽  
Fourth Group ◽  
The Third ◽  
Gluteus Muscle ◽  
Specific Activities ◽  
Kinetics Of ◽  
Over Time

The fate of radiotocopherol was studied in plasma and tissues of sheep at various intervals after injection of single intravenous doses of 3H-labelled D-α-tocopherol. Plasma samples were taken at regular intervals after dosing and selected tissues were taken from all sheep after slaughter and assayed for radioactivity and D-α-tocopherol. Sheep were killed in groups of five at 24, 72, 96, 272 and 432 h post-dosing. Plasma profiles were characterized as a sum of three exponential terms. A principal component analysis of tissue concentrations was carried out to identify tissues with parallel profiles of log (disintegrations/min per μg) over time. Five groups of tissues with distinct uptake and elimination processes were identified. The D-α-tocopherol in the liver and heart appeared to be consistent with the post-distributive kinetics of a highly perfused shallow compartment, while lung kinetics appeared to reflect a non-linear kinetic process. The third group, which included the spleen, neck brachiocephalicus muscle and pancreas, had depletion rates parallel to those of plasma for 24–272 h, but slower decreases than plasma over 272–432 h. Hip gluteus muscle and kidney comprised a fourth group, with depletion parallel to plasma rates for 24–96 h but progressively slower than plasma decreases over 96–272 h. Adrenal kinetics resembled the fourth group, but had a more rapid decrease in specific activities over 24–72 h.

“CBCT-THE THIRD AND THE MOST DIAGNOSTIC DIMENSION”: A CASE REPORT

2021 ◽  
pp. 85-87
Author(s):  
Rudrax Jindal ◽  
Rekha Gupta ◽  
Divyajoti Das ◽  
Abhishek Kumar Gupta
Keyword(s):  
Computed Tomography ◽  
Case Report ◽  
Cone Beam ◽  
Root Fracture ◽  
Vertical Root Fracture ◽  
Naked Eye ◽  
The Third ◽  
Diagnostic Modalities ◽  
Cause Of Pain ◽  
Over Time

Radiology is an essential tool in the dental clinical practice as most structures harbouring disease are not visible to the naked eye. There are various entities that are generally not noticed until periapical pathology occurs. Under such circumstances, the diagnosis is difcult, as they mimic various other conditions. One of such condition is root fracture after an endodontic treatment of tooth. Vertical root fracture (VRF) usually starts from an internal dentinal crack and develops over time, due to masticatory forces and occlusal loads. Here in this paper we will discuss how we stepwise diagnostic radiographic modalities are used to see the actual cause of pain in a 60 year old male patient. Cone Beam Computed Tomography (CBCT) was done to view in 3D which revealed VRF of tooth. Throughout the paper the edge of CBCT over other diagnostic modalities is discussed till we get our diagnosis.

Computed Tomography for Acute Appendicitis Diagnosis and Confirmation in Men

2020 ◽  
pp. 000313482095148
Author(s):  
Kristen M. Westfall ◽  
Laura N. Purcell ◽  
Anthony G. Charles
Keyword(s):  
Computed Tomography ◽  
Acute Appendicitis ◽  
Clinical Laboratory ◽  
Ct Scans ◽  
Male Population ◽  
Lower Quadrant Pain ◽  
Lower Quadrant ◽  
Right Lower Quadrant Pain ◽  
Male Patients ◽  
Over Time

Introduction The classic findings of acute appendicitis—right lower quadrant pain, anorexia, and leukocytosis—have been well known. However, emergency medicine and surgical providers continue to rely on imaging to confirm the diagnosis. We aimed to evaluate the increase in reliance on computed tomography (CT) scans for acute appendicitis diagnosis over time. Methods We conducted a retrospective study of patients ≥18 years presenting to UNC Hospitals with signs and symptoms of acute appendicitis who subsequently underwent appendectomy from 2011 to 2015. Demographic, clinical, laboratory, and pathologic data were reviewed. We evaluated the incidence of CT scans stratified by year, age, and sex. Results Within our male population, 55.2% (278/504) had classic appendicitis symptoms. Of the 278 male patients with classic appendicitis symptoms, 248 underwent CT imaging. Male patients <45 years of age were more likely to present with classic appendicitis symptoms (216/357, 60.5%) compared with patients aged 46-65 (52/108, 48.1%) or >65 (10/39, 25.6%). Of the male patients <45 years with classic appendicitis symptoms, the incidence of CT scans increased over time (68.3% in 2011, 84.2% in 2012, 92.3% in 2013, 93.9% in 2014, 92.3% in 2015). When considering the 216 CT scans that could have been avoided in our population, we calculate an approximate savings of $173 998.80 over 5 years. Conclusion The incidence of CT scans for acute appendicitis confirmation has increased over time even in men. CT scans for the diagnosis or confirmation of acute appendicitis should rarely be indicated in men aged <45 years with classic appendicitis symptoms.

SPECIFIC CHARACTERISTICS OF BONE STRUCTURES ON CT-SCANS OF PATIENTS WITH SINONASAL INVERTED PAPILLOMAS

2019 ◽  
Vol 65 (4) ◽  
pp. 590-595
Author(s):  
Arkadiy Naumenko ◽  
Kseniya Sapova ◽  
Oleg Konoplev ◽  
Svetlana Astashchenko ◽  
Igor Chernushevich
Keyword(s):  
Computed Tomography ◽  
Tumor Recurrence ◽  
Inverted Papilloma ◽  
Ct Scans ◽  
Precise Localization ◽  
Sinonasal Inverted Papilloma ◽  
Bone Structures ◽  
Inverted Papillomas

Precise localization and excision of the originating site of a sinonasal inverted papilloma is essential for decreasing tumor recurrence. In this study we evaluated the use of preoperative computed tomography (CT) to pinpoint the attachment/origi-nating sites of the tumor.

The Stabilization Process Then and Now

2018 ◽  
Author(s):  
Ben Epstein
Keyword(s):  
Political Communication ◽  
Status Quo ◽  
The Political ◽  
The Internet ◽  
Stabilization Process ◽  
The Third ◽  
Stabilization Phase ◽  
Over Time

This chapter shifts the focus to the third and final stabilization phase of the political communication cycle (PCC). During the stabilization phase, a new political communication order (PCO) takes shape through the building of norms, institutions, and regulations that serve to fix the newly established status quo in place. This status quo occurs when formerly innovative political communication activities become mundane, yet remain powerful. Much of the chapter details the pattern of communication regulation and institution construction over time. In particular, this chapter explores the instructive similarities and key differences between the regulation of radio and the internet, which offers important perspectives on the significance of our current place in the PCC and the consequences of choices that will be made over the next few years.

Coping with longitudinal data in research on developmental psychopathology

2006 ◽  
Vol 30 (1) ◽  
pp. 20-25 ◽  
Author(s):  
David A. Cole
Keyword(s):  
Data Collection ◽  
Longitudinal Data ◽  
Developmental Psychopathology ◽  
Careful Consideration ◽  
Two Dimensions ◽  
The Other ◽  
Outcome Variable ◽  
The Third ◽  
Data Analytic ◽  
Over Time

Many outcome variables in developmental psychopathology research are highly stable over time. In conventional longitudinal data analytic approaches such as multiple regression, controlling for prior levels of the outcome variable often yields little (if any) reliable variance in the dependent variable for putative predictors to explain. Three strategies for coping with this problem are described. One involves focusing on developmental periods of transition, in which the outcome of interest may be less stable. A second is to give careful consideration to the amount of time allowed to elapse between waves of data collection. The third is to consider trait-state-occasion models that partition the outcome variable into two dimensions: one entirely stable and trait-like, the other less stable and subject to occasion-specific fluctuations.

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