Optimizing twin-beam dual-energy CT reconstruction: Quantitative consistency and stability assessment in reference to 120 kV: An observational study.

The split filter CT can filter X-ray beam. Theoretically, the split filter CT not only provides a good low-energy beam, but also provides a more robust CT value. The aim of this study was to compare conventional single-energy computed tomography (SECT) and twin-beam dual-energy (TBDE) CT regarding the quantitative consistency and stabilities of HU measurements at different abdominal organs. Forty-four patients were prospectively enrolled to randomly receive SECT and TBDE protocols at either body part of a thorax-abdominal examination. Their overlapping scan coverage was subjected to further image analysis. For TBDE scans, composed images(c-images) and virtual monoenergetic images (VMIs) at 60, 70, 80, and 90 kiloelectron volt (keV) were reconstructed. The attenuations were measured at 5 abdominal organs and compared between SECT and TBDE to characterize quantitative consistency by intraclass correlation coefficients (ICCs), whereas their standard deviations were used to assess the Hounsfield Unit (HU) stability. The c-images, 70 keV and 80 keV VMIs from TBDE provided consistent HU values (all ICCs > 0.8) with the SECT measurements; moreover, these TBDE images had superior HU stability over SECT images in all abdominal measurements except for fat tissue. The best HU stability can be achieved in 80 keV VMIs with the lowest noise level. The c-images and VMIs derived from TBDE can produce consistent values as SECT. The 80 keV images displayed better HU stability and a lower noise level across various abdominal organs.

The effects of flip angle and gadolinium contrast agent on single breath-hold compressed sensing cardiac magnetic resonance cine for biventricular global strain assessment.

Background: Due to its potential to significantly reduce scanning time while delivering accurate results for cardiac volume function, compressed sensing (CS) has gained traction in cardiovascular magnetic resonance (CMR) cine. However, further investigation is necessary to explore its feasibility and impact on myocardial strain results. Materials and methods: A total of 102 participants [75 men, 46.5 ± 17.1 (SD) years] were included in this study. Each patient underwent four consecutive cine sequences with the same slice localization, including the reference multi-breath-hold balanced steady-state free precession (bSSFPref) cine, the CS cine with the same flip angle as bSSFPref before (CS45) and after (eCS45) contrast enhancement, and the CS cine (eCS70) with a 70-degree flip angle after contrast enhancement. Biventricular strain parameters were derived from cine images. Two-tailed paired t-tests were used for data analysis. Results: Global radial strain (GRS), global circumferential strain (GCS), and global longitudinal strain (GLS) were observed to be significantly lower in comparison to those obtained from bSSFPref sequences for both the right and left ventricles (all p < 0.001). No significant difference was observed on biventricular GRS-LAX (long-axis) and GLS values derived from enhanced and unenhanced CS cine sequences with the same flip angle, but remarkable reductions were noted in GRS-SAX (short-axis) and GCS values (p < 0.001). After contrast injection, a larger flip angle caused a significant elevation in left ventricular strain results (p < 0.001) but did not affect the right ventricle. The increase in flip angle appeared to compensate for contrast agent affection on left ventricular GRS-SAX, GCS values, and right ventricular GRS-LAX, GLS values. Conclusion: Despite incorporating gadolinium contrast agents and applying larger flip angles, single breath-hold CS cine sequences consistently yielded diminished strain values for both ventricles when compared with conventional cine sequences. Prior to employing this single breath-hold CS cine sequence to refine the clinical CMR examination procedure, it is crucial to consider its impact on myocardial strain results.

Optimizing Clinical Cardiac MRI Workflow through Single Breath-Hold Compressed Sensing Cine: An Evaluation of Feasibility and Efficiency.

BACKGROUND: Although compressed sensing (CS) accelerated cine holds immense potential to replace conventional cardiovascular magnetic resonance (CMR) cine, how to use CS-based cine appropriately during clinical CMR examinations still needs exploring. METHODS: A total of 104 patients (46.5 ± 17.1 years) participated in this prospective study. For each participant, a balanced steady state free precession (bSSFP) cine was acquired as a reference, followed by two CS accelerated cine sequences with identical parameters before and after contrast injection. Lastly, a CS accelerated cine sequence with an increased flip angle was obtained. We subsequently compared scanning time, image quality, and biventricular function parameters between these sequences. RESULTS: All CS cine sequences demonstrated significantly shorter acquisition times compared to bSSFPref cine (p < 0.001). The bSSFPref cine showed higher left ventricular ejection fraction (LVEF) than all CS cine sequences (all p < 0.001), but no significant differences in LVEF were observed among the three CS cine sequences. Additionally, CS cine sequences displayed superior global image quality (p < 0.05) and fewer artifacts than bSSFPref cine (p < 0.005). Unenhanced CS cine and enhanced CS cine with increased flip angle showed higher global image quality than other cine sequences (p < 0.005). CONCLUSION: Single breath-hold CS cine delivers precise biventricular function parameters and offers a range of benefits including shorter scan time, better global image quality, and diminished motion artifacts. This innovative approach holds great promise in replacing conventional bSSFP cine and optimizing the CMR examination workflow.

Mononuclear myeloid-derived suppressor cells expansion is associated with progression of liver failure in patients with acute decompensation of cirrhosis.

Patients with acute decompensation (AD) of cirrhosis have different clinical courses. Immune dysfunction affects disease outcomes. The profile of myeloid-derived suppressor cells (MDSCs), polymorphonuclear- (PMN-MDSCs) and mononuclear- (M-MDSCs) subsets in AD and their associations with different clinical courses are still unclear. This study included 36 healthy controls (HC), 20 patients with compensated cirrhosis (CC) and 107 patients with AD. Based on the condition at enrollment and 90 days of follow-up, the patients with AD were divided into AD-acute-on-chronic liver failure (AD-ACLF), stable decompensated cirrhosis (SDC), unstable decompensated cirrhosis (UDC) and pre-acute-on-chronic liver failure (Pre-ACLF) groups. The percentages of MDSCs, PMN-MDSCs, and M-MDSCs in the peripheral blood of patients with AD were significantly higher than those in HC and CC. Lactate levels, Child-Pugh score, and MDSCs were risk factors for the occurrence of AD. A positive correlation exists between MDSCs and indices of systemic inflammation and liver failure. In the AD cohort, the percentages of M-MDSCs in the Pre-ACLF and AD-ACLF groups were significantly higher than those in the UDC and SDC groups. The percentages of MDSCs and PMN-MDSCs in the AD groups increased; however, the difference was not statistically significant. MDSCs and M-MDSCs positively correlated with the incidence of liver failure. Sex, alcoholic etiology, bacterial infection, and M-MDSCs were independent risk factors for liver failure in patients with AD. Our data indicate that M-MDSCs expansion, rather than PMN-MDSCs expansion, might predict poor prognosis in patients with AD. Reducing the suppressive activity and number of MDSCs and M-MDSCs are promising strategies for immunotherapy in patients with AD.

Novel manganese and polyester dendrimer-based theranostic nanoparticles for MRI and breast cancer therapy.

Therapeutic nanoplatforms are widely used in the diagnosis and treatment of breast cancer due to the merits of enabling high soft-tissue resolution and the availability of numerous therapeutic nanoparticles. It is thus vital to develop multifunctional theranostic nanoparticles for the visualization and dynamic monitoring of tumor therapy. In this study, we designed a manganese-based and hypericin-loaded polyester dendrimer nanoparticle (MHD) for magnetic resonance imaging (MRI) and hypericin-based photodynamic therapy (PDT) enhancement. We found that MHD could greatly enhance MRI contrast with a longitudinal relaxivity of 5.8 mM-1 s-1 due to the Mn-based paramagnetic dendrimer carrier. Meanwhile, the MRI-guided PDT inhibition of breast tumors could be achieved by the hypericin-carrying MHD and further improved by Mn2+-mediated alleviation of the hypoxic microenvironment and the enhancement of cellular ROS. Besides, MHD showed excellent biocompatibility and biosafety with liver and kidney clearance mechanisms. Thus, the high efficiency in MRI contrast enhancement and excellent tumor-inhibiting effects indicate MHD's potential as a novel, stable, and multifunctional nanotheranostic agent for breast cancer.

Identification of fibrosis in hypertrophic cardiomyopathy: a radiomic study on cardiac magnetic resonance cine imaging.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) often requires repeated enhanced cardiac magnetic resonance (CMR) imaging to detect fibrosis. We aimed to develop a practical model based on cine imaging to help identify patients with high risk of fibrosis and screen out patients without fibrosis to avoid unnecessary injection of contrast. METHODS: A total of 273 patients with HCM were divided into training and test sets at a ratio of 7:3. Logistic regression analysis was used to find predictive image features to construct CMR model. Radiomic features were derived from the maximal wall thickness (MWT) slice and entire left ventricular (LV) myocardium. Extreme gradient boosting was used to build radiomic models. Integrated models were established by fusing image features and radiomic models. The model performance was validated in the test set and assessed by ROC and calibration curve and decision curve analysis (DCA). RESULTS: We established five prediction models, including CMR, R1 (based on the MWT slice), R2 (based on the entire LV myocardium), and two integrated models (ICMR+R1 and ICMR+R2). In the test set, ICMR+R2 model had an excellent AUC value (0.898), diagnostic accuracy (89.02%), sensitivity (92.54%), and F1 score (93.23%) in identifying patients with positive late gadolinium enhancement. The calibration plots and DCA indicated that ICMR+R2 model was well-calibrated and presented a better net benefit than other models. CONCLUSIONS: A predictive model that fused image and radiomic features from the entire LV myocardium had good diagnostic performance, robustness, and clinical utility. KEY POINTS: • Hypertrophic cardiomyopathy is prone to fibrosis, requiring patients to undergo repeated enhanced cardiac magnetic resonance imaging to detect fibrosis over their lifetime follow-up. • A predictive model based on the entire left ventricular myocardium outperformed a model based on a slice of the maximal wall thickness. • A predictive model that fused image and radiomic features from the entire left ventricular myocardium had excellent diagnostic performance, robustness, and clinical utility.

Mean Scar Entropy by Late Gadolinium Enhancement Cardiac Magnetic Resonance Is Associated With Ventricular Arrhythmias Events in Hypertrophic Cardiomyopathy.

Background: Ventricular arrhythmias are associated with sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). Previous studies have found the late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) was independently associated with ventricular arrhythmia (VA) in HCM. The risk stratification of VA remains complex and LGE is present in the majority of HCM patients. This study was conducted to determine whether the scar heterogeneity from LGE-derived entropy is associated with the VAs in HCM patients. Materials and Methods: Sixty-eight HCM patients with scarring were retrospectively enrolled and divided into VA (31 patients) and non-VA (37 patients) groups. The left ventricular ejection fraction (LVEF) and percentage of the LGE (% LGE) were evaluated. The scar heterogeneity was quantified by the entropy within the scar and left ventricular (LV) myocardium. Results: Multivariate analyses showed that a higher scar [hazard ratio (HR) 2.682; 95% CI: 1.022-7.037; p = 0.039] was independently associated with VA, after the adjustment for the LVEF, %LGE, LV maximal wall thickness (MWT), and left atrium (LA) diameter. Conclusion: Scar entropy and %LGE are both independent risk indicators of VA. A high scar entropy may indicate an arrhythmogenic scar, an identification of which may have value for the clinical status assessment of VAs in HCM patients.

An MRI-trackable therapeutic nanovaccine preventing cancer liver metastasis.

Cancer vaccines consisting of tumor-associated antigens (TAAs) can initiate a powerful antitumor immune response through antigen-presenting cells, such as dendritic cells (DCs) and macrophages, and have shown great potential in cancer prevention and therapy. However, poor anticancer efficacy and an uncertain immunization process have hitherto limited the application of cancer vaccines. Herein, a multifunctional nanovaccine comprising ovalbumin (OVA), MnO2, and polydopamine (OMPN) was prepared by a facile one-pot method. OMPN displayed excellent anticancer efficacy against an orthotopic melanoma and could also prevent liver metastasis in a tumor re-challenge mice model. Additionally, the migration behavior of DCs in the inguinal lymph node after vaccination was tracked by MRI contrasted with OMPN, indicating successful DC activation and immune response. The superior anticancer efficacy, especially the high efficiency against tumor metastasis, and the capability of tracking the immunization process make OMPN a very promising multifunctional nanovaccine for cancer therapy.

Epithelioid angiomyolipoma of the pancreas: A case report and review of the literature.

BACKGROUND: Angiomyolipomas (AMLs), belonging to the family of mesenchymal tumors, are considered benign lesions that occur mostly in the kidney or as a part of tuberous sclerosis. Epithelioid AML (EAML) is a rare type of AML that appears to have malignant potential. Extrarenal AMLs usually occur in the liver according to the retrieved literature reports. There have been only two previous reports of monofocal primary AML of the pancreas; however, no cases of primary monotypic EAML of the pancreas have been reported. CASE SUMMARY: An asymptomatic 59-year-old woman incidentally revealed a tumor during abdominal ultrasound examination. Routine blood tests and physical examination were within normal limits. Abdominal ultrasound revealed a 1.9-cm hypoechogenic mass in the tail of the pancreas, clearly visualized by endoscopic ultrasound. However, contrast-enhanced abdominal computed tomography scans did not demonstrate the lesion. A subsequent gadolinium-enhanced magnetic resonance imaging scan showed that the lesion had some characteristic manifestations. The lesion was initially thought to be a neuroendocrine tumor (asymptomatic PanNET). After surgical resection, histopathology and immunohistochemistry confirmed the diagnosis of EAML. At the 6-mo follow-up, no recurrence, spread, or metastasis was identified on computed tomography or magnetic resonance imaging. CONCLUSION: The preoperative diagnosis of pancreatic AML is extremely difficult. Imaging techniques are essential for providing valuable morphological features for differential diagnosis.

Self-assembly of hyaluronic acid-mediated tumor-targeting theranostic nanoparticles.

Theranostic nanoparticles (NPs) have emerged as promising candidates for cancer diagnosis and treatment. Manganese dioxide (MnO2)-based NPs are potential contrast agents with excellent paramagnetic property and biocompatibility, exhibiting satisfactory magnetic resonance imaging (MRI) effects and biological safety. Recently, hyaluronic acid (HA) has gained increasing interest due to its tumor-targeting ability, which can improve the tumor affinity of manganese dioxide (MnO2)-based NPs. In this study, HA-coated and albumin (BSA)-templated MnO2 and polydopamine hybrid nanoparticles (HMDNs) with tumor-targeting and superior imaging capability were fabricated via modifying the nanoparticles prepared by integrating dopamine polymerization and MnO2 biomineralization. The modification was found to enhance the cellular uptake of HMDNs by cancer cells. The prepared HMDN had high MRI contrasting capability with a longitudinal relaxivity of 22.2 mM-1 s-1 and strong photothermal therapy (PTT) effects with nearly complete tumor ablation under laser irradiation in vivo. HMDNs also showed effective clearance through kidneys, with no toxicity to important tissues. Therefore, HMDNs with superior imaging and PTT capability presented a new method to prepare tumor-targeting multifunctional nanotheranostics.

On/off switchable epicatechin-based ultra-sensitive MRI-visible nanotheranostics - see it and treat it.

Nanotechnology has a remarkable impact on the preclinical development of future medicines. However, the complicated preparation and systemic toxicity to living systems prevent them from translation to clinical applications. In the present report, we developed a polyepicatechin-based on/off switchable ultra-sensitive magnetic resonance imaging (MRI) visible theranostic nanoparticle (PEMN) for image-guided photothermal therapy (PTT) using our strategy of integrating polymerization and biomineralization into the protein template. We have exploited natural polyphenols as the near infra-red (NIR) switchable photothermal source and MnO2 for the MRI-guided theranostics. PEMN demonstrates excellent MRI contrast ability with a longitudinal relaxivity value up to 30.01 mM-1 s-1. PEMN has shown great tumor inhibition on orthotopic breast tumors and the treatment could be made switchable with an on/off interchangeable mode as needed. PEMN was found to be excretable mainly through the kidneys, avoiding potential systemic toxicity. Thus, PEMN could be extremely useful for developing on-demand therapeutics via'see it and treat it' means with distinguished MRI capability and on/off switchable photothermal properties.

Osteoblastoma of the frontal bone invading the orbital roof: A case report.

RATIONALE: Osteoblastoma is an uncommon primary bone tumor that involves any part of the skeleton. But its occurrence in the skull is extremely rare. PATIENTS CONCERNS: A 30-year-old female was admitted to our hospital, because of the mass in the right frontal region with the history of headache for 3 years without nausea or vomiting. DIAGNOSIS: Initial differential diagnoses included hemangiopericytoma, atypical intraosseous meningioma, calvarial osteosarcoma, fibrous dysplasia, and histiocytosis, based on the results of enhanced CT and MRI. INTERVENTIONS: A total surgical resection of the mass was performed. OUTCOMES: Postoperative histopathologic analysis demonstrated the typical features of osteoblastoma, the benign bone neoplasm. Serial radiologic examination did not show recurrence in the 6 months follow-up. LESSONS: The radiologic appearance of the osteoblastoma is always confusing and makes the diagnosis difficult. We hope our case can give some clinical clues for the diagnosis and management of the disease.