Seguridad del paciente en Resonancia Magnética / Patient safety in magnetic resonance imaging

El uso de campos magnéticos estáticos, gradientes de campo y ondas de radiofrecuencia suponen un reto de seguridad diferente a otras modalidades de imagen. Cada vez más centros trabajan con equipos de 3,0T que presentan mayores riesgos para el paciente frente a los de 1,5T. Hay una necesidad de actualización para el personal de radiología que le permita entender los riesgos y disminuirlos, pues pueden producirse incidentes graves e incluso mortales. El objetivo de este trabajo es presentar una revisión y actualización de los riesgos a los que se ven sometidos los pacientes durante la realización de un estudio de resonancia magnética.(AU)

Image acquisition involves the use of static magnetic fields, field gradients and radiofrequency waves. These elements make the MRI a different modality. More and more centers work with 3.0 T equipment that present higher risks for the patient, compared to those of 1.5 T. Therefore, there is a need for updating for radiology staff that allows them to understand the risks and reduce them, since serious and even fatal incidents can occur. The objective of this work is to present a review and update of the risks to which patients are subjected during the performance of a magnetic resonance imaging study.(AU)

[Conditions for performing CT and MRI scans in pregnant and lactating patients]. / Att tänka på vid neuroradiologisk diagnostik av gravida och ammande.

Many women are pregnant during several percent of their lives. Occasionally, there is a need for neuroradiological examinations during pregnancy or lactation. In our clinical work, we regularly see that female patients are being withheld relevant diagnostic scans during pregnancy, due to insufficient knowledge or an unbalanced comparison between benefits and risks. This article describes the current knowledge regarding conditions for performing CT and MRI scans in pregnant and lactating patients, including the use of contrast media. PET scans and reactions to contrast media are briefly mentioned, but interventional radiology is not discussed.

Impact of a reduced iodine load with deep learning reconstruction on abdominal MDCT.

To evaluate the impact of a reduced iodine load using deep learning reconstruction (DLR) on the hepatic parenchyma compared to conventional iterative reconstruction (hybrid IR) and its consequence on the radiation dose and image quality. This retrospective monocentric intraindividual comparison study included 66 patients explored at the portal phase using different multidetector computed tomography parameters: Group A, hybrid IR algorithm (hybrid IR) and a nonionic low-osmolality contrast agent (350 mgI/mL); Group B, DLR algorithm (DLR) and a nonionic iso-osmolality contrast agent (270 mgI/mL). We recorded the attenuation of the liver parenchyma, image quality, and radiation dose parameters. The mean hounsfield units (HU) value of the liver parenchyma was significantly lower in group B, at 105.9 ± 10.9 HU versus 118.5 ± 14.6 HU in group A. However, the 90%IC of mean liver attenuation in the group B (DLR) was between 100.8 HU and 109.3 HU. The signal-to-noise ratio of the liver parenchyma was significantly higher on DLR images, increasing by 56%. However, for both the contrast-to-noise ratio (CNR) and CNR liver/PV no statistical difference was found, even if the CNR liver/PV ratio was slightly higher for group A. The mean dose-length product and computed tomography dose index volume values were significantly lower with DLR, corresponding to a radiation dose reduction of 36% for the DLR. Using a DLR algorithm for abdominal multidetector computed tomography with a low iodine load can provide sufficient enhancement of the liver parenchyma up to 100 HU in addition to the advantages of a higher image quality, a better signal-to-noise ratio and a lower radiation dose.

Clinical profile and outcomes of pediatric hypertrophic cardiomyopathy in a South Indian tertiary care cardiac center: a three decade experience.

INTRODUCTION: Although much research has been done on adult hypertrophic cardiomyopathy, data on pediatric hypertrophic cardiomyopathy is still limited. METHODS AND RESULTS: The study enrolled all patients with cardiomyopathy who presented to us between 1990 to 2020 and were younger than 18 yrs. During the thirty-year study period, we identified 233 cases of pediatric cardiomyopathy. Sixty-three cases (27%) had hypertrophic cardiomyopathy. Out of the 63 HCM cases, 12% presented in the neonatal period and 37% presented in the first year of life. The median age of presentation was 7 yrs (Range 0.1-18 yrs). Sixteen patients had proven syndromic, metabolic, or genetic disease (25%). LV outflow obstruction was present in 30 patients (47%). Noonan syndrome was present in 9 of the 63 patients (14%). Dyspnea on exertion was the most common mode of presentation. Cardiac MRI was done in 28 patients, out of which 17 had late gadolinium enhancement (LGE). Mid myocardial enhancement was the most common pattern. Four patients had LGE of more than 15%. Over a mean follow-up period of 5.6 years (0.1-30 years), twenty-one were lost to follow-up (33%). Among the patients whose outcome was known, eleven died (26%), and thirty-one (73%) were alive. The 5-year survival rate of HCM patients was 82%, and the 10-year survival rate was 78%. Seven died of sudden cardiac death, three from heart failure, and one from ventricular arrhythmias. Sustained ventricular arrhythmias were seen in three patients and atrial arrhythmias in two. First-degree AV block was seen in 10 patients (15%) and bundle branch blocks (BBB) in five (8%). Eight patients required ICD or transplant (12.7%). Two patients underwent ICD for primary prevention, and one underwent PPI for distal AV conduction disease. Among the various clinical, echocardiographic, and radiological risk factors studied, only consanguinity showed a trend towards higher events of death or ventricular arrhythmias (P-value 0.08). CONCLUSION: More than one-third of our HCM cohort presented in infancy. LV outflow tract obstruction is common (47%). Mid myocardial enhancement was the most common pattern of late gadolinium enhancement. SCD was the most common cause of death. The outcome in our HCM cohort is good and similar to other population cohorts. Only Consanguinity showed a trend towards higher events of death or ventricular arrhythmias.

Myocardial native T1 mapping and extracellular volume quantification in asymptomatic female carriers of Duchenne muscular dystrophy gene mutations.

BACKGROUND: Female carriers of dystrophin gene mutations (DMD-FC) were previously considered non-manifesting, but in recent decades, cardiomyopathy associated with muscular dystrophy and myocardial fibrosis has been described. Our study aimed to assess prospectively myocardial fibrosis in asymptomatic DMD-FC compared to a sex-matched control group (CG) with similar age distribution using native T1 mapping and extracellular volume (ECV) quantification by cardiovascular magnetic resonance (CMR) imaging. MATERIALS AND METHODS: 38 DMD-FC with verified genetic mutation and 22 healthy volunteers were included. Using CMR, native T1 relaxation time and ECV quantification were determined in each group. Late gadolinium enhancement (LGE) was assessed in all cases. RESULTS: There were 38 DMD-FC (mean age 39.1 ± 8.8 years) and 22 healthy volunteers (mean age 39.9 ± 12.6 years) imagined by CMR. The mean global native T1 relaxation time was similar for DMD-FC and CG (1005.1 ± 26.3 ms vs. 1003.5 ± 25.0 ms; p-value = 0.81). Likewise, the mean global ECV value was also similar between the groups (27.92 ± 2.02% vs. 27.10 ± 2.89%; p-value = 0.20). The segmental analysis of mean ECV values according to the American Heart Association classification did not show any differences between DMD-FC and CG. There was a non-significant trend towards higher mean ECV values of DMD-FC in the inferior and inferolateral segments of the myocardium (p-value = 0.075 and 0.070 respectively). CONCLUSION: There were no statistically significant differences in the mean global and segmental native T1 relaxation times and the mean global or segmental ECV values. There was a trend towards higher segmental mean ECV values of DMD-FC in the inferior and inferolateral walls of the myocardium.

[How I explore an hypersensitivity to iodinated contrast media]. / Comment j'explore... une hypersensibilité aux produits de contraste iodés.

Immediate or delayed hypersensitivity reactions to iodinated contrast media (ICM) occur in 0.5-3 % of patients receiving radiological examinations using the last generation ICM. Although the majority of the reactions are mild to moderate, severe and potentially lethal reactions may occasionally be observed. In the last few years, there has been an increase of patients referred to the dermato-allergology department for the work-up of a hypersensitivity reaction to ICM. In this article, the allergological investigations and their indications are described in the case of a suspicion of ICM hypersensitivity.

Les réactions d'hypersensibilités immédiates ou retardées aux produits de contraste iodés (PCI) surviennent chez 0,5-3 % des patients bénéficiant d'un examen d'imagerie radiologique utilisant les PCI de dernière génération. Bien que la plupart des réactions soient d'intensité faible à modérée, des réactions sévères, parfois mortelles, sont possibles. Depuis quelques années, on note une nette augmentation du nombre de patients adressés en consultation de dermato-allergologie pour mise au point de réaction d'hypersensibilité aux PCI. Dans cet article, l'exploration allergologique devant une suspicion d'hypersensibilité aux PCI est décrite avec ses indications.

Lumped element models of sound conduction in the human ear: A systematic review.

Lumped element models facilitate investigating the fundamental mechanisms of human ear sound conduction. This systematic review aims to guide researchers to the optimal model for the investigated parameters. For this purpose, the literature was reviewed up to 12 July 2023, according to the PRISMA guidelines. Seven models are included via database searching, and another 19 via cross-referencing. The quality of the models is assessed by comparing the predicted middle ear transfer function, the tympanic membrane impedance, the energy reflectance, and the intracochlear pressures (ICPs) (scala vestibuli, scala tympani, and differential) with experimental data. Regarding air conduction (AC), the models characterize the pathway from the outer to the inner ear and accurately predict all six aforementioned parameters. This contrasts with the few existing bone conduction (BC) models that simulate only a part of the ear. In addition, these models excel at predicting one observable parameter, namely, ICP. Thus, a model that simulates BC from the coupling site to the inner ear is still lacking and would increase insights into the human ear sound conduction. Last, this review provides insights and recommendations to determine the appropriate model for AC and BC implants, which is highly relevant for future clinical applications.

Evaluation and Management of Cardiac Sarcoidosis with Advanced Imaging.

A high clinical suspicion in the setting of appropriate history, physical exam, laboratory, and imaging parameters is often required to set the groundwork for diagnosis and management. Echocardiography may show septal thinning, evidence of systolic and diastolic dysfunction, along with impaired global longitudinal strain. Cardiac MRI reveals late gadolinium enhancement along with evidence of myocardial edema and inflammation on T2 weighted imaging and parametric mapping. 18F-FDG PET detects the presence of active inflammation and the presence of scar. Involvement of the right ventricle on MRI or PET confers a high risk for adverse cardiac events and mortality.

[Research on magneto-acoustic-electrical tomography method based on liquid metal contrast agent and M sequence coded excitation].

Magneto-acoustic-electric tomography (MAET) boasts high resolution in ultrasound imaging and high contrast in electrical impedance imaging, making it of significant research value in the fields of early tumor diagnosis and bioelectrical monitoring. In this study, a method was proposed that combined high conductivity liquid metal and maximum length sequence (M sequence) coded excitation to improve the signal-to-noise ratio. It was shown that, under rotational scanning, the liquid metal significantly improved the signal-to-noise ratio of the inter-tissue magneto-acoustic-electric signal and enhanced the quality of the reconstructed image. The signal-to-noise ratio of the signal was increased by 5.6, 11.1, 21.7, and 45.7 times under the excitation of 7-, 15-, 31-, and 63-bit M sequence code, respectively. The total usage time of 31-bit M sequence coded excitation imaging was shortened by 75.6% compared with single-pulse excitation when the same signal-to-noise ratio was improved. In conclusion, the imaging method combining liquid metal and M-sequence coding excitation has positive significance for improving MAET image quality.

Optofluidic Sensor Based on Polymer Optical Microresonators for the Specific, Sensitive and Fast Detection of Chemical and Biochemical Species.

The accurate, rapid, and specific detection of DNA strands in solution is becoming increasingly important, especially in biomedical applications such as the trace detection of COVID-19 or cancer diagnosis. In this work we present the design, elaboration and characterization of an optofluidic sensor based on a polymer-based microresonator which shows a quick response time, a low detection limit and good sensitivity. The device is composed of a micro-racetrack waveguide vertically coupled to a bus waveguide and embedded within a microfluidic circuit. The spectral response of the microresonator, in air or immersed in deionised water, shows quality factors up to 72,900 and contrasts up to 0.9. The concentration of DNA strands in water is related to the spectral shift of the microresonator transmission function, as measured at the inflection points of resonance peaks in order to optimize the signal-over-noise ratio. After functionalization by a DNA probe strand on the surface of the microresonator, a specific and real time measurement of the complementary DNA strands in the solution is realized. Additionally, we have inferred the dissociation constant value of the binding equilibrium of the two complementary DNA strands and evidenced a sensitivity of 16.0 pm/µM and a detection limit of 121 nM.

Tannic acid-mediated synthesis of flower-like mesoporous MnO2 nanostructures as T1-T2 dual-modal MRI contrast agents and dual-enzyme mimetic agents.

This study introduces a simple method for preparing a new generation of MnO2 nanomaterials (MNMs) using tannic acid as a template. Two shapes of MnO2 NMs, flower-like M1-MnO2 and near-spherical M2-MnO2, were prepared and compared as dual-active nanozymes and contrast agents in magnetic resonance imaging (MRI). Various parameters, including the crystallinity, morphology, magnetic saturation (Ms), surface functionality, surface area, and porosity of the MNMs were investigated. Flower-like M1-MnO2 NMs were biocompatible and exhibited pH-sensitive oxidase and peroxidase mimetic activity, more potent than near-spherical M2-MnO2. Furthermore, the signal intensity and r1 relaxivity strongly depended on the crystallinity, morphology, pore size, and specific surface area of the synthesized MNMs. Our findings suggest that flower-like M1-MnO2 NM with acceptable dual-enzyme mimetic (oxidase-like and peroxidase-like) and T1 MRI contrast activities could be employed as a promising theranostic system for future purposes.

Identification of non-ischaemic fibrosis in male veteran endurance athletes, mechanisms and association with premature ventricular beats.

Left ventricular fibrosis can be identified by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in some veteran athletes. We aimed to investigate prevalence of ventricular fibrosis in veteran athletes and associations with cardiac arrhythmia. 50 asymptomatic male endurance athletes were recruited. They underwent CMR imaging including volumetric analysis, bright blood (BB) and dark blood (DB) LGE, motion corrected (MOCO) quantitative stress and rest perfusion and T1/T2/extracellular volume mapping. Athletes underwent 12-lead electrocardiogram (ECG) and 24-h ECG. Myocardial fibrosis was identified in 24/50 (48%) athletes. All fibrosis was mid-myocardial in the basal-lateral left ventricular wall. Blood pressure was reduced in athletes without fibrosis compared to controls, but not athletes with fibrosis. Fibrotic areas had longer T2 time (44 ± 4 vs. 40 ± 2 ms, p < 0.0001) and lower rest myocardial blood flow (MBF, 0.5 ± 0.1 vs. 0.6 ± 0.1 ml/g/min, p < 0.0001). On 24-h ECG, athletes with fibrosis had greater burden of premature ventricular beats (0.3 ± 0.6 vs. 0.05 ± 0.2%, p = 0.03), with higher prevalence of ventricular couplets and triplets (33 vs. 8%, p = 0.02). In veteran endurance athletes, myocardial fibrosis is common and associated with an increased burden of ventricular ectopy. Possible mechanisms include inflammation and blood pressure. Further studies are needed to establish whether fibrosis increases risk of malignant arrhythmic events.

[A Dual-Aware deep learning framework for identification of glioma isocitrate dehydrogenase genotype using magnetic resonance amide proton transfer modalities].

OBJECTIVE: To propose a Dual-Aware deep learning framework for genotyping of isocitrate dehydrogenase (IDH) in gliomas based on magnetic resonance amide proton transfer (APT) modality data as a means to assist non-invasive diagnosis of gliomas. METHODS: We collected multimodal magnetic resonance imaging (MRI) imaging data of the brain from 118 cases of gliomas, including 68 wild-type and 50 mutant type cases. The delineation of the ROI of brain glioma was completed in all the cases. APT modality imaging does not require contrast agents, and its signal intensity on tumors is positively correlated with tumor malignancy, and the signal intensity on wild-type IDH is higher than that on mutant IDH. For APT modalities, tumor imaging and derived areas are morphologically variable and lack prominent edge contour characteristics compared with other modalities. Based on these characteristics, we propose the Dual-Aware framework, which introduces the Multi-Aware framework to mine multi-scale features, and the Edge Aware module mines the edge features for automatic genotype identification. RESULTS: The introduction of two types of Aware mechanisms effectively improved the identification rate of the model for glioma IDH genotyping. The accuracy and AUC for each modality data were enhanced, and the best performance was achieved on the APT modality with a prediction accuracy of 83.1% and an AUC of 0.822, suggesting its advantages and effectiveness for identifying glioma IDH genotypes. CONCLUSION: The proposed deep learning algorithm model constructed based on the image characteristics of the APT modality is effective for glioma IDH genotyping and identification task and may potentially replace the commonly used T1CE modality to avoid contrast agent injection and achieve non- invasive IDH genotyping.

Investigation of optimizing indocyanine green solution for in vivo lymphatic research using near-infrared fluorescence indocyanine green lymphangiography.

Despite the tireless efforts of many researchers in lymphatic research, indocyanine green (ICG) solution conditions suitable for lymphatic circulation tests have not been perfectly established yet. We aimed to investigate the optimal in vivo conditions of ICG solution to avoid photobleaching and quenching effects, which may affect the accuracy of lymphatic circulation evaluation. After ICG fluorescence intensity (or ICG intensity) was assessed under different in vitro conditions, the image quality of brachial lymph nodes (LNs) and collecting lymphatic vessels (LVs) in eight rats was investigated. The in vitro results showed that ICG intensity depends on concentration and time in various solvents; however, the brightest intensity was observed at a concentration of 8-30 µg/mL in all solvents. ICG concentration in the albumin (bovine serum albumin; BSA) solution and rat's plasma showed more than two times higher fluorescence intensity than in distilled water (DW) in the same range. However, saline reduced the intensity by almost half compared to DW. In the in vivo experiment, we obtained relatively high-quality images of the LNs and LVs using ICG in the BSA solution. Even at low concentrations, the result in the BSA solution was comparable to those obtained from high-concentration solutions commonly used in conventional circulation tests. This study provides valuable information about the conditions for optimal ICG intensity in near infrared fluorescence indocyanine green (NIRF-ICG) lymphangiography, which may be useful not only for the diagnosis of lymphatic circulation diseases such as lymphedema but also for preclinical research for the lymphatic system.

Differences between CEUS LI-RADS and CECT LI-RADS in the diagnosis of focal liver lesions in patients at risk for HCC.

OBJECTIVES: To compare the inter-modality consistency and diagnostic performances of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and contrast-enhanced computed tomography (CECT) LI-RADS in patients at risk for hepatocellular carcinoma (HCC), so as to help clinicians to select a more appropriate modality to follow the focal liver lesions (FLLs). METHODS: This retrospective study included untreated 277 FLLs from 247 patients who underwent both CEUS and CECT within 1 month. The ultrasound contrast medium used was SonoVue. FLL categories were independently assigned by two ultrasound physicians and two radiologists using CEUS LI-RADS v2017 and CECT LI-RADS v2018, respectively. The diagnostic performances of CEUS and CECT LI-RADS were evaluated using sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Cohen's Kappa was employed to evaluate the concordance of the LI-RADS category. RESULTS: The inter-modality consistency for CEUS and CECT LI-RADS was 0.31 (p < 0.001). HCC was more frequently observed in CECT LR-3 and LR-4 hepatic lesions than in CEUS (7.3% vs. 19.5%, p < 0.001). The specificity and PPV of CEUS and CECT LR-5 for the diagnosis of HCC were 89.5%, 95.0%, and 82.5%, 94.4%, respectively. The sensitivity of CEUS LR-5 + LR-M for the diagnosis of hepatic malignancies was higher than that of CECT (93.7% vs. 82.7%, p < 0.001). The specificity and PPV of CEUS LR-M for the diagnosis of non-HCC malignancies were lower than those of CECT (59.7% vs. 95.5%, p < 0.001; 23.4% vs. 70.3%, p < 0.001). CONCLUSIONS: The inter-modality consistency between the CEUS and CECT LI-RADS categories is fair. CEUS LI-RADS was more sensitive than CECT LI-RADS in terms of identifying hepatic malignancies, but weaker in terms of separating HCC from non-HCC malignancies.

Predicting Contrast-induced Renal Complications.

Chronic kidney disease is an independent risk factor for the development of coronary artery disease and overlaps with other risk factors such as hypertension and diabetes. Percutaneous coronary intervention is a cornerstone of therapy for coronary artery disease and requires contrast media, which can lead to renal injury. Identifying patients at risk for contrast-associated acute kidney injury (CA-AKI) is critical for preventing kidney damage, which is associated with both short- and long-term mortality. Determination of the potential risk for CA-AKI and a new need for dialysis using validated risk prediction tools identifies patients at high risk for this complication. Identification of patients at risk for renal injury after contrast exposure is the first critical step in prevention. Contrast media volume, age and sex of the patient, a history of chronic kidney disease and/or diabetes, clinical presentation, and hemodynamic and volume status are factors known to predict incident contrast-induced nephropathy. Recognition of at-risk patient subpopulations allows for targeted, efficient, and cost-effective strategies to reduce the risk of renal complications resulting from contrast media exposure.

Endovascular embolization with EVOH for the treatment of a Rasmussen aneurysm.

First-line treatment of pulmonary artery aneurysms/pseudoaneurysms (PAA/PAPA) is percutaneous or endovascular embolization. The present case of a Rasmussen aneurysm, a PAPA caused by Tuberculosis (TB), was successfully treated with ethylene-vinyl alcohol (EVOH), a radiopaque liquid embolic agent with favorable characteristics. A 35-year-old man presented as a new patient with hemoptysis, and CT imaging revealed multiple cavitary lesions and a 2.1 cm aneurysm in the upper right lobe. Endovascular treatment was delivered and a complete lack of filling of the lesion was noted on post-treatment angiography. The patient's history includes risk factors and past TB infection. Despite the suspicious imaging, diagnostic tests were negative for active TB in this patient. He was then found to have MRSA bacteremia and a mediastinal lymph node positive for M. avium. The etiology of this aneurysm is suspicious for the superinfection of a chronic tuberculous cavity with M. avium, MRSA, or both.

Chemotherapy-Related Cardiac Dysfunction: Quantitative Cardiac Magnetic Resonance Image Parameters and Their Prognostic Implications.

OBJECTIVE: To quantitatively analyze the cardiac magnetic resonance imaging (CMR) characteristics of chemotherapy-related cardiac dysfunction (CTRCD) and explore their prognostic value for major adverse cardiovascular events (MACE). MATERIALS AND METHODS: A total of 145 patients (male:female = 76:69, mean age = 63.0 years) with cancer and heart failure who underwent CMR between January 2015 and January 2021 were included. CMR was performed using a 3T scanner (Siemens). Biventricular functions, native T1 T2, extracellular volume fraction (ECV) values, and late gadolinium enhancement (LGE) of the left ventricle (LV) were compared between those with and without CTRCD. These were compared between patients with mild-to-moderate CTRCD and those with severe CTRCD. Cox proportional hazard regression analysis was used to evaluate the association between the CMR parameters and MACE occurrence during follow-up in the CTRCD patients. RESULTS: Among 145 patients, 61 had CTRCD and 84 did not have CTRCD. Native T1, ECV, and T2 were significantly higher in the CTRCD group (1336.9 ms, 32.5%, and 44.7 ms, respectively) than those in the non-CTRCD group (1303.4 ms, 30.5%, and 42.0 ms, respectively; P = 0.013, 0.010, and < 0.001, respectively). They were not significantly different between patients with mild-to-moderate and severe CTRCD. Indexed LV mass was significantly smaller in the CTRCD group (65.0 g/m² vs. 78.9 g/m²; P < 0.001). According to the multivariable Cox regression analysis, T2 (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.01-1.27; P = 0.028) and quantified LGE (HR: 1.07, 95% CI: 1.01-1.13; P = 0.021) were independently associated with MACE in the CTRCD patients. CONCLUSION: Quantitative parameters from CMR have the potential to evaluate myocardial changes in CTRCD. Increased T2 with reduced LV mass was demonstrated in CTRCD patients even before the development of severe cardiac dysfunction. T2 and quantified LGE may be independent prognostic factors for MACE in patients with CTRCD.

Impact of portal-phase signal intensity of dynamic gadoxetic acid-enhanced magnetic resonance imaging in hepatocellular carcinoma.

PURPOSE: To evaluate the prognostic impact of dynamic gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in patients with hepatocellular carcinoma (HCC). METHODS: We retrospectively reviewed the data of 206 patients with HCC who underwent preoperative Gd-EOB-DTPA-enhanced MRI and hepatectomy and quantitatively evaluated the signal intensity ratio of the tumor to the surrounding liver tissue in the portal phase (SIRPP). We verified the survival rates and assessed the prognostic factors associated with overall survival (OS) and recurrence-free survival (RFS) using SIRPP. RESULTS: Multivariate analysis revealed that the independent predictive factors for poorly-differentiated HCC were α-fetoprotein > 20 ng/mL (hazard ratio [HR]: 3.1909, 95% confidence interval [CI]: 1.3464-7.5622, p = .0084) and SIRPP ≤ 0.85 (HR: 3.7155, 95% CI: 1.521-9.076, p = .004). The 5-year OS and RFS rates in the high and low SIRPP groups were 83.2 and 52.1%, respectively (p < .0001) and 49.7 and 18.5%, respectively (p = .0003). Multivariate analysis revealed that SIRPP ≤ 0.68 was an independent prognostic factor related to OS (HR: 4.4537, 95% CI: 1.6581-11.9626, p = .003). CONCLUSION: The SIRPP of preoperative Gd-EOB-DTPA-enhanced MRI might predict the histological differentiation and prognosis of HCC.

Dual-Energy CT Arthrography: Advanced Muscolo-Skelatal Applications in Clinical Practice.

This paper provides a comprehensive overview of the potential applications of dual-energy CT (DECT) in improving image quality and the diagnostic capabilities of CT arthrography (CTA) in clinical practice. The paper covers the use of virtual non-contrast (VNC) images, in which the injected contrast medium is subtracted from the articular cavity in order to better analyze 2D and 3D images of the bone. Moreover, virtual monoenergetic imaging (VMI) applications and their potential use for the reduction of metal artifacts and improving image contrast are reviewed. The role of virtual non-calcium (VNCa) in detecting bone marrow edema surrounding the imaged joint will be discussed. Furthermore, the role of iodine maps in enhancing the contrast between soft tissues, optimizing the visualization of contrast material, and distinguishing contrast material from calcifications is described. Finally, a case series including different joints is provided to underline the additional advantages of high-spatial-resolution dual-energy CT reconstructed images.