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Introduction: Image quality reduction due to metallic artefacts is a significant challenge during vascular computed tomography (CT) imaging of the lower extremities in patients with hip prostheses. This study aims to analyse various reconstruction algorithms' ability to reduce metal artefacts due to two types of hip prostheses during lower extremity CT angiography examinations., Methods: A pelvis phantom was fabricated with the insertion of a tube filled with contrast media to simulate the femoral artery, and the phantom was then CT scanned with and without hip prostheses. Multimodal images were acquired using different kilovoltage peak (kVp) settings and reconstructed with different algorithms, such as filtered back projection (FBP), iterative reconstruction (iDose 4 ), iterative model-based reconstruction (IMR) and orthopaedic metal artefact reduction (O-MAR). Image quality was assessed based on image noise, signal-to-noise ratio (SNR) and Hounsfield unit (HU) deviation., Results: The IMR approach significantly improved image quality compared to iDose 4 and FBP. For the vascular region, O-MAR improves SNR by 5 ± 1, 23 ± 5 and 42 ± 9 for FBP, iDose 4 and IMR respectively, and improves HU precision towards the baseline values by 49% and 83% for FBP and IMR, respectively. The noise reduction was 71% and 89% for FBP and IMR, and 57% for iDose 4 . O-MAR greatly enhances SNR corrections among the most severe artefacts, with 29 ± 1 and 43 ± 4 for FBP and IMR, compared to iDose 4 by 37 ± 7., Conclusion: IMR combined with O-MAR could improve the CT angiography of the lower extremities of patients with a hip prosthesis., (© 2024 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.)

Contrast agents is used in magnetic resonance imaging (MRI) to improve the visibility of the details of the organ structures. Gadolinium-based contrast agent (GBCA) has been used since 1988 in MRI for diagnostic and follow-up of patients, the gadolinium good properties make it an effective choice for enhance the signal in MRI by increase its intensity and shortening the relaxation time of the proton. Recently, many studies show a gadolinium deposition in different human organs due to release of free gadolinium various body organs or tissue, which led to increased concern about the use of gadolinium agents, in this study, the potential diseases that may affect the patient and side effects that appear on the patient and related to accumulation of gadolinium were clarified, the study focused on the organs such as brain and bones in which gadolinium deposition was found and the lesions associated with it, and the diseases associated with gadolinium retention includes Nephrogenic Systemic Fibrosis (NSF) and Gadolinium deposition disease (GDD). Some studies tended to improve the contrast agents by developing a new non-gadolinium agents or development of next-generation gadolinium agents. In this review article the latest knowledge about MRI contrast agent., Competing Interests: Nebal Iyad, Sanaa G. Alkhatib, Osama Makhamrah, and Muntaser S. Ahmad declare that they have no conflict of interest., (© 2023 The Authors.)

Background and Aims: Micronutrient supplements such as vitamin D, vitamin C, and zinc have been used in managing viral illnesses. However, the clinical significance of these individual micronutrients in patients with Coronavirus disease 2019 (COVID-19) remains unclear. We conducted this meta-analysis to provide a quantitative assessment of the clinical significance of these individual micronutrients in COVID-19., Methods: We performed a comprehensive literature search using MEDLINE, Embase, and Cochrane databases through December 5th, 2021. All individual micronutrients reported by ≥ 3 studies and compared with standard-of-care (SOC) were included. The primary outcome was mortality. The secondary outcomes were intubation rate and length of hospital stay (LOS). Pooled risk ratios (RR) and mean difference (MD) with corresponding 95% confidence intervals (CI) were calculated using the random-effects model., Results: We identified 26 studies (10 randomized controlled trials and 16 observational studies) involving 5633 COVID-19 patients that compared three individual micronutrient supplements (vitamin C, vitamin D, and zinc) with SOC. Nine studies evaluated vitamin C in 1488 patients (605 in vitamin C and 883 in SOC). Vitamin C supplementation had no significant effect on mortality (RR 1.00, 95% CI 0.62-1.62, P = 1.00), intubation rate (RR 1.77, 95% CI 0.56-5.56, P = 0.33), or LOS (MD 0.64; 95% CI -1.70, 2.99; P = 0.59). Fourteen studies assessed the impact of vitamin D on mortality among 3497 patients (927 in vitamin D and 2570 in SOC). Vitamin D did not reduce mortality (RR 0.75, 95% CI 0.49-1.17, P = 0.21) but reduced intubation rate (RR 0.55, 95% CI 0.32-0.97, P = 0.04) and LOS (MD -1.26; 95% CI -2.27, -0.25; P = 0.01). Subgroup analysis showed that vitamin D supplementation was not associated with a mortality benefit in patients receiving vitamin D pre or post COVID-19 diagnosis. Five studies, including 738 patients, compared zinc intake with SOC (447 in zinc and 291 in SOC). Zinc supplementation was not associated with a significant reduction of mortality (RR 0.79, 95% CI 0.60-1.03, P = 0.08)., Conclusions: Individual micronutrient supplementations, including vitamin C, vitamin D, and zinc, were not associated with a mortality benefit in COVID-19. Vitamin D may be associated with lower intubation rate and shorter LOS, but vitamin C did not reduce intubation rate or LOS. Further research is needed to validate our findings., Competing Interests: Declaration of competing interest All authors declare no conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Choriocarcinoma syndrome is a rare complication of metastatic germ cell tumors. The hallmark of the condition is metastatic tumor hemorrhage. We describe the case of a 28-year-old man with metastatic testicular choriocarcinoma who presented with dyspnea on exertion and lightheadedness. Symptoms started two days after completing cycle one of fractionated bleomycin, etoposide, and cisplatin (BEP) chemotherapy. Laboratory investigations showed severe anemia, with a hemoglobin of 5.4 mg/dL (normal: 13-17 mg/dL). His baseline hemoglobin was 15.1 mg/dL before chemotherapy initiation. Coagulation and hemolysis workup showed no significant evidence of disseminated intravascular coagulopathy or autoimmune hemolysis. Imaging showed a significant increase in the size of previous metastatic liver lesions with surrounding hypodensity representing hemorrhage. He was admitted to the intensive care unit and started on massive transfusion protocol. On the same day, he developed a maroon-colored stool. Urgent upper endoscopy showed blood in the entire stomach and the second part of the duodenum spurting out through the ampulla, which suggested bleeding from metastatic liver lesions into the biliary tree. No defined culprit vessel was identified on visceral angiography. Endoscopic and surgical interventions were unlikely to be successful in controlling the bleeding due to the diffuse nature. He underwent one dose of radiation therapy to the abdomen, which was successful in controlling the bleeding. He survived, and his chemotherapy was switched to etoposide, ifosfamide, and cisplatin (VIP) with no further episodes of bleeding., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Abuhelwa et al.)

The present study is part of an ongoing effort to develop a simple diagnostic technology for detecting internal bleeding in the brain, which can be used in lieu or in support of medical imaging and thereby reduce the cost of diagnostics in general, and in particular, would make diagnostics accessible to economically disadvantaged populations. The study deals with a single coil inductive device to be used for detecting cerebral hemorrhage. It presents a first-order experimental study that examines the predictions of our recently published theoretical study. The experimental model employs a homogeneous cylindrical phantom in which internal head bleeding was simulated by way of a fluid inclusion. We measured the changes in amplitude and phase across the coil with a network vector analyzer as a function of frequency (100-1,000 MHz), volume of blood simulating fluid, and the site of the fluid injection. We have developed a new mathematical model to statistically analyze the complex data produced in this experiment. We determined that the resolution for the fluid volume increase following fluid injection is strongly dependent on frequency as well as the location of liquid accumulation. The experimental data obtained in this study supports the predictions of our previous theoretical study, and the statistical analysis shows that the simple single coil device is sensitive enough to detect changes due to fluid volume alteration of two milliliters. Bioelectromagnetics. 2020;41:21-33 © 2019 Bioelectromagnetics Society., (© 2019 Bioelectromagnetics Society.)

BACKGROUND: Catheter based treatment of atrial fibrillation (AFib) involves ablation of groups of cells near the pulmonary vein., Objective: The goal of this study was to evaluate the technological feasability of a new technology for catheter-based ablation for treatment of AFib that combines freezing with electrolysis., Materials and Methods: The study was performed on a pH dye stained gel phantom of the pulmonary vein. Freezing was induced with a cryosurgical probe inserted in the vein and electrolysis was delivered through the probe with a DC power supply., Results: Visual recording of colorimetric changes in pH demonstrate that electrolytic products can propagate through the frozen tissue phantom. For example, a voltage of 9 V and a current of 40 mA delivered through a -15 degree C cryosurgical probe produced an electrolysis impacted rim of over 7 mm width in 2 min., Conclusion: This early stage experimental work suggests that cryoelectrolysis may have potential for treatment of AFib.

Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural and economically underdeveloped parts of the world. A group of nine subjects participated in this pilot clinical evaluation of the technology. Substantial research remains to be done on correlating the measurements with physiology and anatomy.

This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research.

To generate an understanding of the physiological significance of MR images of Non-Thermal Irreversible Electroporation (NTIRE) we compared the following MR imaging sequences: T1W, T2W, PD, GE, and T2 SPAIR acquired after NTIRE treatment in a rodent liver model. The parameters that were studied included the presence or absence of a Gd-based contrast agent, and in vivo and ex-vivo NTIRE treatments in the same liver. NTIRE is a new minimally invasive tissue ablation modality in which pulsed electric fields cause molecularly selective cell death while, the extracellular matrix and large blood vessels remain patent. This attribute of NTIRE is of major clinical importance as it allows treatment of undesirable tissues near critical blood vessels. The presented study results suggest that MR images acquired following NTIRE treatment are all directly related to the unique pattern of blood flow after NTIRE treatment and are not produced in the absence of blood flow.

Electroporation, is known to induce cell membrane permeabilization in the reversible (RE) mode and cell death in the irreversible (IRE) mode. Using an experimental system designed to produce a continuum of IRE followed by RE around a single electrode we used MRI to study the effects of electroporation on the brain. Fifty-four rats were injected with Gd-DOTA and treated with a G25 electrode implanted 5.5 mm deep into the striata. MRI was acquired immediately after treatment, 10 min, 20 min, 30 min, and up to three weeks following the treatment using: T1W, T2W, Gradient echo (GE), serial SPGR (DCE-MRI) with flip angles ranging over 5-25°, and diffusion-weighted MRI (DWMRI). Blood brain barrier (BBB) disruption was depicted as clear enhancement on T1W images. The average signal intensity in the regions of T1-enhancement, representing BBB disruption, increased from 1887±83 (arbitrary units) immediately post treatment to 2246±94 20 min post treatment, then reached a plateau towards the 30 min scan where it reached 2289±87. DWMRI at 30 min showed no significant effects. Early treatment effects and late irreversible damage were clearly depicted on T2W. The enhancing volume on T2W has increased by an average of 2.27±0.27 in the first 24-48 hours post treatment, suggesting an inflammatory tissue response. The permanent tissue damage, depicted as an enhancing region on T2W, 3 weeks post treatment, decreased to an average of 50±10% of the T2W enhancing volumes on the day of the treatment which was 33±5% of the BBB disruption volume. Permanent tissue damage was significantly smaller than the volume of BBB disruption, suggesting, that BBB disruption is associated with RE while tissue damage with IRE. These results demonstrate the feasibility of applying reversible and irreversible electroporation for transient BBB disruption or permanent damage, respectively, and applying MRI for planning/monitoring disruption volume/shape by optimizing electrode positions and treatment parameters.

We introduce and characterize the use of MRI for studying nonthermal irreversible electroporation (NTIRE) in a vegetative tissue model. NTIRE is a new minimally invasive surgical technique for tissue ablation in which microsecond, high electric-field pulses form nanoscale defects in the cell membrane that lead to cell death. Clinical NTIRE sequences were applied to a potato tuber tissue model. The potato is used for NTIRE studies because cell damage is readily visible with optical means through a natural oxidation process of released intracellular enzymes (polyphenol oxidase) and the formation of brown-black melanins. MRI sequences of the treated area were taken at various times before and after NTIRE and compared with photographic images. A comparison was made between T1W, T2W, FLAIR and STIR MRIs of NTIRE and photographic images. Some MRI sequences show changes in areas treated by irreversible electroporation. T1W and FLAIR produce brighter images of the treated areas. In contrast, the signal was lost from the treated area when a suppression technique, STIR, was used. There was similarity between optical photographic images of the treated tissue and MRIs of the same areas. This is the first study to characterize MRI of NTIRE in vegetative tissue. We find that NTIRE produces changes in vegetative tissue that can be imaged by certain MRI sequences. This could make MRI an effective tool to study the fundamentals of NTIRE in nonanimal tissue.