Background: During computed tomography (CT) examinations, the presence of radiation material undoubtedly has a certain impact on patients, particularly children, who are more susceptible to radiation. Consequently, finding ways to minimize radiation dosage and mitigate radiation-related risks while enhancing the quality and accuracy of CT scans has become a crucial concern for medical professionals in CT equipment manufacturing companies and radiology departments to contemplate. Objectives: This study aimed to explore the feasibility of low dose and low contrast medium combined with low flow rate scanning in CT angiography (CTA) of children's liver. Patients and Methods: A total of 59 children who visited our department for liver vascular CT scans between April 2021 and December 2022 were prospectively selected and randomly divided into 2 groups: the experimental group and the control group. The experimental group consisted of 28 children who received an injection of 80 kV, automatic tube current, low contrast dose (1.5 mL/kg), and low flow rate of 20 s. The control group included 31 children who were injected with 100 kV, automatic tube current, contrast agent dose (2 mL/kg), and flow rate of 16 s. The objective and subjective image quality, radiation dose, and iodine intake in the arterial, portal, and venous phases were compared between the 2 groups. Results: During the arterial, portal, and venous phases, the experimental group exhibited lower signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) compared to the control group (P < 0.05). However, there was no significant difference in subjective quality scores between the 2 groups (P > 0.05). The effective dose (ED), volume CT dose index (CTDIvol), and dose-length product (DLP) of the experimental group were lower than those of the control group (P < 0.05). Additionally, the iodine intake in the experimental group was lower than that in the control group (P < 0.05). Conclusion: In the examination of hepatic vascular CTA in children, the use of a 3-low scanning technique can effectively decrease radiation and contrast agents while ensuring sufficient image quality for accurate clinical diagnosis.

Objectives: To investigate the control preferences of clinicians working in a regional hospital to prevent contrast agent reactions. Materials and Methods: This study investigated through a questionnaire the role preferred by 75 participant specialist physicians working in two local hospitals regarding prevention of contrast agent reactions. The questionnaire form included five different items consisting of modified forms of preferences found in control preferences scale (Degner et al., 1997). These items were as follows: A, I prefer to make a decision as a clinician; B, I prefer to make a decision as a clinician but should get radiologist’ s opinion; C, Radiologist and I should make a decision together. The ideas of the two of us are equally important; D, The radiologist should make a decision but after getting my opinion; E, I prefer the radiologist to make a decision. Participants were asked to specify their primary (the most preferred) and secondary (subsequent) preferences. Results: The results of the statistical analysis indicated that females showed more equalitarian approach when compared to males (43. 3% versus 15. 6%, P < 0. 005). Also, the physicians in internal medicine branches showed more equalitarian approach when compared to the physicians in surgical branches (37. 8% versus 15. 8%, P < 0. 01) Conclusion: Whenwe attempt to establish a clinical guideline committee towards preventing reactions to contrast agents, involvement of physicians exhibiting cooperative attitude in the committee will facilitate communication, and thereby improve group performance.

By year of 1990, second MRI revolution has hap-pened in the diagnosis of infection and tumor assessment "first revolution was made by clinical MRI invention in the early 1980's".Tumor-associated epilepsis is an important contributor to morbidity in patients with brain tumors. Perilesional tissue changes play a vital role in the generation of tumor-associated seizures.Tumor-associated seizure is usually focal with secondary generalization and often resistant to antiepileptic drugs.For studying the tumor well and diagnosis, contrast injection is a necessity and T1 pulse is used for demonstration. It needs pre-contrast T1 to compare with post contrast T1. Contrast agent "Gadolinium" changes the relaxation time of tissue in T1 pulse "shortening the time". Contrast circulation in the body is in a close circuit from vein or artery to the capillary system, interstitial tissue and contrast does not go inside the normal cells except in hepatocytes, pituicytes and damaged cells "broken blood brain barrier".For tumor diagnosis, MRI with and without Gadolinium is used more than x-ray CT techniques.Other diagnostic techniques for tumor D.D.X and epilepsis are PET, SPECT, EEG, MEG "MSI" and ultrasound. Tested Double Dose contrasted images "2 x 1mmol/kg" of Gadolinium by 1.5 Tesla machine increased the enhancement rate about 5-10% but needs double money for contrast. Using 3 Tesla machine also increases signal demonstration but today all imaging "95%" is sufficient by 1.5 Tesla and imaging by 3-Tesla is difficult and expensive. Conclusion: 1/ Please request MRI with and without GD for tumor diagnosis "pre-contrast T1and post contrast T1 is necessary to diagnosis and D.D.X of any hemorrhage inside the tumor versus enhancement". 2/ Please do not request double dose contrast for imaging "it is more expensive and less effective". 3/ Please request your patients imaging by 1.5 Tesla "3 Tesla imaging is difficult and more expensive". 4/Requesting only contrasted MRI is not exact and less scientific, for tumor diagnosis "Radiologist needs pre-contrast T1 and post contrast T1 to compare".

Developing nanoparticles with multimodal contrast agents with therapeutic and contrast effects can greatly improve disease diagnosis. Magnetic resonance imaging (MRI) and computed tomography (CT) are sophisticated medical imaging modalities utilized for visualizing internal tissues and bones, facilitating the diagnosis of organ-related ailments and diseases. In MRI, bovine serum albumin (BSA) is a well-known compound used to carry gadolinium oxide as a contrast agent. Bismuth ferrite nanoparticles (BiFeO3 NPs) have been identified as a novel multifunctional therapeutic agent suitable for applications in radiotherapy, MRI, CT, and as mediators for magnetic hyperthermia. This study presents new NPs that can serve as dual imaging contrast agents for MRI and CT. These novel nanoparticles (BiFeO3@BSA-Gd2O3) consist of BiFeO3 nanoparticles, with BSA acting as a carrier for gadolinium oxide nanoparticles. BiFeO3 was synthesized by the sol-gel method and covered with a BSA layer, then gadolinium oxide was added to the BSA layer. Synthesized nanoparticles were identified using different physicochemical methods. The Inductively Coupled Plasma Spectroscopy (ICP) confirms the existence of Gd, Bi, and Fe in the nanoparticle and the average size of nanoparticles regarding to SEM was 120 nm. The presence of BiFeO3 nanoparticles as a promising agent with multi-functional properties such as CT and MRI imaging and BSA-Gd2O3 as an MRI contrast agent, the newly synthesized nanoparticle has the potential to be used as nanomedicine for simultaneous MRI and CT as a Dual imaging contrast.

The differentiation of certain structures from nearby tissues during medical imaging requires a sufficient amount of signals from the targeted area. The limitations of conventional contrast agents prevent the possibility of quick and accurate diagnosis of some cases and cause many problems for the patients and society. However, most of these restrictions can be surpassed through the unique physico-chemical characteristic nanotechnologyology and nano structures. Nanocarriers are abled to take the role of contrast agents or even provide the efficient delivery of these agents as carriers, while the capability of nanostructures in facilitating the simultaneous transportation of diagnostic and therapeutic agents is also undeniable. Thanks to the modern application of nanotechnology, it is possible to perform the targeted distribution of diagnostic and therapeutic agents to the desired locations. The status of in vivo surveillance and targeting efficiency can be improved by exploiting the potential benefits of nanoparticles and therefore, it is quiet expected to witness interesting characteristics from nanocarrier imaging agents for the diagnosis and staging of different diseases. This work presents a summary on the most common contrast agent nanostructures in medical imaging.

accurate detection and characterization of lymph node metastases is crucial for planning therapy and determining prognosis in patients with various un-derlying primary tumors such as the breast, prostate, head and neck, urogenital, melanoma and other cancers. CT and MR imaging are of limited value because they primarily rely on the tumor size for differentiating benign from malignant lymph nodes. Ultrasmall super paramagnetic iron oxide (USPIO) (Combidex or Ferumoxtran-10; Advanced Magnetics, Sinerem; Guerbet) is an MR contrast agent that has shown improved accuracy in the staging of lymph nodes in cancer patients. Animal and recent human studies have shown that USPIO particles allow MR differentiation of benign from malignant lymph nodes based on enhancement patterns.This lecture is a review about new imaging methods in oncological imaging, especially for the lymphatic system.

Introduction: Pharmacokinetic (PK) modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is widely applied in tumor diagnosis and treatment evaluation. Precision analysis of the estimated PK parameters is essential when they are used as a measure for therapy evaluation or treatment planning. In this study, the accuracy of PK parameters in brain DCE-MRI studies was quantified in relation to two major sources of error(including pre-contrast longitudinal-relaxation time, T1, 0 and flip angle, α ). Material and Methods: 3470 dynamic contrast-enhanced-curves were simulated using a wide variation of the PK parameters. The bias of contrast concentration due to the systematic biases in α and T1, 0 was calculated and added to both contrast concentration and AIF profiles. Thereafter, the PK parameters were estimated for each simulated curve in the presence of different percentages of relative biases in α and T1, 0. The mean percentage error (MPE) of PK parameters was then calculated for all simulated curves. Results: The results indicated that plasma volume(vp) was the most sensitive parameter to bias of contrast concentration, which may overestimate up to 700% in 10% coincidence relative bias in α and T1, 0. The lowest MPE was related to the backward transfer constant (kep), which was ~2%-15% in 10% coincidence relative bias in each α and T1, 0. Conclusion: Utilization of a nested model selection technique, along with an accurate estimator, such as maximum-likelihood estimation, created a unique approach for investigating the effect of the bias in the concentration measurement to the estimated PK parameters without the addition of any extra biases to the parameters during the estimation.

Glucose mediated imaging tools have recently be-come an area of research interest in the field of nuclear medicine, especially Positron Emission Tomography (PET) imaging. The difficulties in the use, preparation and cost of radioactively-labeled glycosylated compounds led to the research and development in this present study of a new gadolinium-labeled glucose that does not have a radioactive half-life or difficulties in its synthesis and utilization. Based on the structure of fluorodeoxyglucose (18FDG), a new compound consisting of a D-glucose conjugated to a well-known chelator DTPA was synthesized, labeled with Gd3+ and examined in vitro and in vivo. The results showed a good anti-cancer potency for the prepared complex. Gd3+ -DTPA-DG did not produce any significant alteration in the blood glucose level and was also phosphorylated by hexokinase enzyme. In vitro relaxation times T1 and T2 were determined and compared with a standard compound Magnevist®. Finally, imaging studies were performed in tumor-bearing mice and the tumor areas were shown successfully. This compound may have great potential in the future in radio-oncology.