Enhanced MR Imaging Research Articles

Revolutionizing MRI Brain Tumor Detection Through GAN Augmentation and Smart Algorithms.

The accurate detection and classification of brain tumors in Magnetic Resonance Technology is critical to accurate diagnosis and therapy planning. However, the absence of annotated MR imaging datasets presents a significant challenge for advanced machine learning models, which require a range of data to achieve high accuracy and generalizability. This study provides a novel data augmentation method to enhance MR images for improved tumor identification by combining noise-to-image and image-to-image Generative Adversarial Networks (GANs). Noise-to-image GANs generate synthetic MR images from random noise, expanding the dataset with a range of anatomical variations, whereas image-to-image GANs refine and enhance existing MR images, highlighting important features relevant to tumor detection. The enlarged set of input data was taken to teach CNN, which was then correlated to a baseline model built solely on the original dataset. The GAN-augmented model beat the baseline cancer sorting and division tasks, as measured by parameters such as accuracy, recall, F1-score, and Dice coefficient. An ablation study verified the independent contributions of noise-to-image and image-to-image GANs, demonstrating that both types of augmentation operate together to improve model performance. This work illustrates the promise of GAN-based augmentation in medical imaging by giving a realistic solution to data restrictions and improving the robustness of deep learning models in brain tumor detection. This technology provides the way for more accurate and reliable based on artificial intelligence tools for diagnosis that can help medical practitioners make clinical decisions by integrating alternative GAN techniques. Key Words: GAN-based augmentation, Deep learning, Image augmentation techniques, Generative adversarial networks (GANs)

The Capabilities of Machine Learning Radiomics Based Models in the MRI Diagnosis of Early HCC

Purpose: To evaluate machine-learning radiomics based models on enhanced MR images in diagnostics of early HCC.Material and methods: Data from 72 patients with 93 masses who underwent Gadoxetic acid-enhanced MRI scans was retrospectively analyzed.Results: Binary classification models were produced for the differential diagnosis of regenerative and dysplastic nodes, early HCC and HCC nodes with an atypical enhancement with high discriminatory capabilities; the area under the ROC-curve ranged from 0.89 to 0.95 in various models.Conclusion: The performed radiomic models can be used as an effective method for differential diagnostics of HCC with typical and atypical enhancement, dysplastic and regenerative nodes.

Current Practice: Rationale for Screening Children with Hereditary Hemorrhagic Telangiectasia for Brain Vascular Malformations.

Hereditary hemorrhagic telangiectasia is an autosomal dominant vascular dysplasia characterized by mucocutaneous telangiectasias, recurrent epistaxis, and organ vascular malformations including in the brain, which occur in about 10% of patients. These brain vascular malformations include high-flow AVMs and AVFs as well as low-flow capillary malformations. High-flow lesions can rupture, causing neurologic morbidity and mortality. International guidelines for the diagnosis and management of hereditary hemorrhagic telangiectasia recommend screening children for brain vascular malformations with contrast enhanced MR imaging at hereditary hemorrhagic telangiectasia diagnosis. Screening has not been uniformly adopted by some practitioners who contend that screening is not justified. Arguments against screening include application of short-term data from the adult A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial of unruptured sporadic brain AVMs to children with hereditary hemorrhagic telangiectasia as well as concerns about administration of sedation or IV contrast and causing patients or families increased anxiety. In this article, a multidisciplinary group of experts on hereditary hemorrhagic telangiectasia reviewed data that support screening guidelines and counter arguments against screening. Children with hereditary hemorrhagic telangiectasia have a preponderance of high-flow lesions including AVFs, which have the highest rupture risk. The rupture risk among children is estimated at about 0.7% per lesion per year and is additive across lesions and during a lifetime. ARUBA, an adult clinical trial of expectant medical management versus treatment of unruptured brain AVMs, favored medical management at 5 years but is not applicable to pediatric patients with hereditary hemorrhagic telangiectasia given the life expectancy of a child. Additionally, interventional, radiosurgical, and surgical techniques have improved with time. Experienced neurovascular experts can prospectively determine the best treatment for each child on the basis of local resources. The "watch and wait" approach to imaging means that children with brain vascular malformations will not be identified until a potentially life-threatening and deficit-producing intracerebral hemorrhage occurs. This expert group does not deem this to be an acceptable trade-off.

Noninvasive assessment of Ki-67 labeling index in glioma patients based on multi-parameters derived from advanced MR imaging.

To investigate the predictive value of multi-parameters derived from advanced MR imaging for Ki-67 labeling index (LI) in glioma patients. One hundred and nine patients with histologically confirmed gliomas were evaluated retrospectively. These patients underwent advanced MR imaging, including dynamic susceptibility-weighted contrast enhanced MR imaging (DSC), MR spectroscopy imaging (MRS), diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI), before treatment. Twenty-one parameters were extracted, including the maximum, minimum and mean values of relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transit time (rMTT), relative apparent diffusion coefficient (rADC), relative fractional anisotropy (rFA) and relative mean diffusivity (rMD) respectively, and ration of choline (Cho)/creatine (Cr), Cho/N-acetylaspartate (NAA) and NAA/Cr. Stepwise multivariate regression was performed to build multivariate models to predict Ki-67 LI. Pearson correlation analysis was used to investigate the correlation between imaging parameters and the grade of glioma. One-way analysis of variance (ANOVA) was used to explore the differences of the imaging parameters among the gliomas of grade II, III, and IV. The multivariate regression showed that the model of five parameters, including rCBVmax (RC=0.282), rCBFmax (RC=0.151), rADCmin (RC= -0.14), rFAmax (RC=0.325) and Cho/Cr ratio (RC=0.157) predicted the Ki-67 LI with a root mean square (RMS) error of 0. 0679 (R2 = 0.8025).The regression check of this model showed that there were no multicollinearity problem (variance inflation factor: rCBVmax, 3.22; rCBFmax, 3.14; rADCmin, 1.96; rFAmax, 2.51; Cho/Cr ratio, 1.64), and the functional form of this model was appropriate (F test: p=0.682). The results of Pearson correlation analysis showed that the rCBVmax, rCBFmax, rFAmax, the ratio of Cho/Cr and Cho/NAA were positively correlated with Ki-67 LI and the grade of glioma, while the rADCmin and rMDmin were negatively correlated with Ki-67 LI and the grade of glioma. Combining multiple parameters derived from DSC, DTI, DWI and MRS can precisely predict the Ki-67 LI in glioma patients.

Ultrasmall iron oxide nanoparticles with MRgFUS for enhanced magnetic resonance imaging of orthotopic glioblastoma.

Ultrasmall iron oxide nanoparticles (USIO NPs) are expected to become the next generation T1 contrast agents; however, their diagnostic and therapeutic potential for primary brain tumors (such as glioblastoma multiforme, GBM) is yet to be explored. At present, the main challenge is the effective hindering of biological barriers, including the blood-brain barrier (BBB) and the blood-brain tumor barrier (BBTB). Herein, we aimed to investigate whether the USIO NPs, in combination with MR-guided focused ultrasound (MRgFUS), could intensify MR imaging of GBM. In this study, we presented zwitterionic USIO NPs for enhanced MR imaging of both xenografted and orthotopic GBM mouse models. We first synthesized citric-stabilized USIO NPs with a size of 3.19 ± 0.76 nm, modified with ethylenediamine, and decorated with 1,3-propanesultone (1,3-PS) to form USIO NPs-1,3-PS. The obtained USIO NPs-1,3-PS exhibited good cytocompatibility and cellular uptake efficiency. MRgFUS, in combination with microbubbles, provided a non-invasive and safe technique for BBB opening, which, in turn, promoted the delivery of USIO NPs-1,3-PS in orthotopic GBM. This developed USIO NP nanoplatform may improve the precision imaging of solid tumors and therapeutic efficacy in the central nervous system.

NCOG-13. OUTCOMES OF CNS WHO GRADE 2 OLIGODENDROGLIOMA IN ADULT PATIENTS ; IMPACT OF ADJUVANT TREATMENT ON OVERALL RESULTS

Abstract OBJECTIVE Patients with oligodendroglioma (ODG), isocitrate dehydrogenase (IDH)-mutant, 1p19q codeleted, CNS WHO grade 2 have a median overall survival of longer than 10 years. Patients with ODG who are high-risk by RTOG criteria are offered radiation in combination with procarbazine, lomustine, and vincristine (PCV). The study aims to analyze the patient’s outcomes and assess the efficacy of postoperative treatment. METHODS A total of 138 adult patients who underwent resection for newly diagnosed grade 2 ODG between 1994 and 2021 were enrolled. Sixty-three (45.7%) were observed after gross total resection (GTR) or near total resection (NTR), 5 (0.4%) received adjuvant treatment after GTR or NTR, 37 (26.8%) were observed after subtotal resection (STR) or biopsy, and 33 (24.0%) received adjuvant treatment after STR or biopsy. The study analyzed progression-free survival (PFS), overall survival (OS), and risk variables. RESULTS Out of the 138 patients, 38 (27%) patients received adjuvant treatment, with 30 of them (78.9%) underwent radiotherapy only, 6 (15.8%) underwent radiochemotherapy, and 2 (5.3%) received chemotherapy alone. The median PFS was 6.8 years. Multivariate analysis revealed STR or biopsy (p=0.04), initial MR imaging enhancement (p=0.002), and postoperative observation(p=0.006) were associated with poorer PFS outcomes. The 5-year overall survival rate was 95.5% and the 10-year overall survival was 76.1%. Poor OS prognosis was associated with STR or biopsy (p=0.03), preoperative seizure (p=0.002), and initial MR imaging enhancement (p< 0.001). CONCLUSIONS : GTR and NTR is essential for achieving prolonged PFS and OS in ODG patients. Postoperative treatment is associated with favorable PFS outcomes but does not significantly affect OS. For an accurate diagnosis and appropriate treatment, the utmost care should be taken to avoid underestimating the results of the biopsy.

T1Gd is reduced in bone marrow lesions overlying cartilage in the hip

Bone Marrow Lesions (BMLs) are areas in bone with high fluid signal on MRI associated with painful and progressive OA. While cartilage near BMLs in the knee has been shown to be degenerated, this relationship has not been investigated in the hip. is T1Gd lower in areas of cartilage overlying BMLs in the hip? 128 participants were recruited from a population-based study of hip pain in 20-49-year-olds. Proton-density weighted fat-suppressed and delayed Gadolinium Enhanced MR Imaging of Cartilage (dGEMRIC) images were acquired to locate BMLs and quantify hip cartilage health. BML and cartilage images were registered and cartilage was separated into BML overlying and surrounding regions. Mean T1Gd was measured in 32 participants with BMLs in both cartilage regions and in matched regions in 32 age- and sex-matched controls. Mean T1Gd in the overlying cartilage was compared using linear mixed-effects models between BML and control groups for acetabular and femoral BMLs, and between cystic and non-cystic BML groups. Mean T1Gd of overlying cartilage was lower in the BML group compared to the control group (acetabular: -105ms; 95% CI: -175, -35; femoral: -8ms; 95% CI: -141, 124). Mean T1Gd in overlying cartilage was lower in cystic compared to non-cystic BML subjects, but the confidence interval is too large to provide certainty in this difference (-3 [95% CI: -126, 121]). T1Gd is reduced in overlying cartilage in hips from a population-based sample of adults aged 20-49, which suggests BMLs are associated with local cartilage degeneration in hips.

Weakly Supervised Breast Lesion Detection in Dynamic Contrast-Enhanced MRI.

Currently, obtaining accurate medical annotations requires high labor and time effort, which largely limits the development of supervised learning-based tumor detection tasks. In this work, we investigated a weakly supervised learning model for detecting breast lesions in dynamic contrast-enhanced MRI (DCE-MRI) with only image-level labels. Two hundred fifty-four normal and 398 abnormal cases with pathologically confirmed lesions were retrospectively enrolled into the breast dataset, which was divided into the training set (80%), validation set (10%), and testing set (10%) at the patient level. First, the second image series S2 after the injection of a contrast agent was acquired from the 3.0-T, T1-weighted dynamic enhanced MR imaging sequences. Second, a feature pyramid network (FPN) with convolutional block attention module (CBAM) was proposed to extract multi-scale feature maps of the modified classification network VGG16. Then, initial location information was obtained from the heatmaps generated using the layer class activation mapping algorithm (Layer-CAM). Finally, the detection results of breast lesion were refined by the conditional random field (CRF). Accuracy, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC) were utilized for evaluation of image-level classification. Average precision (AP) was estimated for breast lesion localization. Delong's test was used to compare the AUCs of different models for significance. The proposed model was effective with accuracy of 95.2%, sensitivity of 91.6%, specificity of 99.2%, and AUC of 0.986. The AP for breast lesion detection was 84.1% using weakly supervised learning. Weakly supervised learning based on FPN combined with Layer-CAM facilitated automatic detection of breast lesion.

Novel topological method to define scar heterogeneity relates to arrhythmia vulnerability

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): KU Leuven BOF, C14/18/079 Background Healing of myocardial infarction (MI) can result in heterogeneous scar structures, resulting in border zone conduction channels with altered electrophysiological properties, that lead to arrhythmia vulnerability. Identification of scar heterogeneity and potential conduction channels based on contrast enhanced MRI has shown to be viable. However, current methods rely on manual identification and systematic approaches are lacking. Objective To provide a systematic methodology to annotate scar heterogeneity on contrast enhanced MRI and to correlate it to arrhythmia vulnerability. Methods Antero-septal MI was induced in 10 domestic pigs by 120-minute occlusion of the left anterior descending artery followed by reperfusion. Late gadolinium enhanced MR imaging was performed one month after infarction. The endocardium and epicardium of the left ventricle were segmented and the voxels inside the left ventricle (LV) were extracted. All LV voxels with signal intensity above the middle of the myocardial signal intensity range were defined to be infarct voxels and otherwise intact voxels. The infarct voxel structure and intact voxel structure were analyzed using a novel computational cubical homology approach that automatically identifies "holes" in the respective structures. The so called topological "holes" were annotated using a minimal length cycle encircling the hole (see Figure 1). This cycle annotation corresponds with scar heterogeneity as it pinpoints regions of intertwined fibrosis and viable myocardium which can potentially act as functional arrhythmia substrate. Scar heterogeneity, annotated as cycles, was compared against two measures of arrhythmia vulnerability. On one hand, the number of premature ventricular complexes (PVCs) were determined during an incremental isoproterenol infusion protocol (ranging from no infusion to 0.04 µg/kg with increments of 0.01µg/kg each 5 minutes). And on the other hand, the ease of induction is defined as the complementary percentage of the steps of the programmed electrical stimulation (PES) protocol needed to induce a ventricular tachycardia. Results Scar heterogeneity cycles were automatically annotated in all animals. In 7 of the 9 animals a ventricular tachycardia was successfully induced during the PES protocol. The ease of induction correlated with the circumference of the myocardial infarct (r = 0.69, p = 0.040). Furthermore, the ease of induction tended to correlate with the circumference of the largest heterogeneity cycle (r = 0.61, p = 0.083). The total number of PVCs throughout the isoproterenol infusion protocol correlated with the circumference of the heterogeneity cycle (r = 0.72, p = 0.031). Conclusion A novel automated and systematic method to identify scar heterogeneity on contrast enhanced MR imaging is introduced. Furthermore, the presence of large heterogeneous scar structures, potentially adding an arrhythmia substrate, correlated with arrhythmia vulnerability.

PO-02-216 SEGMENTAL INCREASE IN HETEROGENEITY OF REPOLARIZATION CORRESPONDS TO REGIONS OF DECREASED INNERVATION AFTER MYOCARDIAL INFARCTION

Myocardial infarction (MI) results in a dense scar region surrounded by a heterogeneous remodeled border zone. In this region denervation and nerve regeneration during healing could be region dependent and contribute to segmental differences in the functional substrate for arrhythmias. To examine regional electrophysiological remodeling in relation to perfusion and innervation changes after myocardial infarction. Anterio-septal MI was induced in 6 domestic pigs by a 120-minute occlusion of the left anterior descending artery (LAD) followed by reperfusion. After one month, PET-MR imaging was performed to evaluate myocardial perfusion (13N-ammonia) and innervation (11C-epinephrine), together with late gadolinium enhanced MR imaging for scar quantification. The next day electro-anatomical mapping was performed. The BZ was defined using contact mapping as the region with bipolar voltage between 0.5 and 1.5 mV. A non-contact recording of a 64-electrode array was translated to 2048 non-contact electrograms distributed over the LV (EnSite PrecisionTM, St. Jude/Abbott Medical). In each of the 2048 points non-contact electrograms over 25 consecutive beats were processed to determine the beat-to-beat variability of repolarization (BVR). Spatial heterogeneity of repolarization was quantified in each point as the repolarization time variability within a 1cm radius neighborhood. MI size was 14.2±3.2% of the left ventricle on gadolinium enhanced MR imaging. The perfusion and innervation defects were significantly larger (22.3±3.2%, P<0.01 and 28.1±4.3%, P<0.01 respectively). The innervation defect was also significantly larger than the perfusion defect (P=0.03). Regional analysis revealed less innervation in the anterior versus the septal border zone (14.2±2.9 %/min vs 18.6+3.1 %/min, P<0.01). In one animal the electrophysiology study was unsuccessful due to a high baseline heart rate (>120 BPM). In the remaining animals, the average spatial heterogeneity was higher in the anterior than septal border zone (5.8±3.0 ms vs 3.8±2.6 ms, P<0.01). Additionally, the maximum BVR tended to be higher in the anterior than septal border zone (2.6±1.3 ms vs 2.02±0.77 ms, P=0.08). MI resulting from LAD occlusion/reperfusion leads to increased denervation on the anterior side of the infarct, correlating with increased repolarization heterogeneity in this region.

346 Development of Deuterium Magnetic Resonance Imaging for Cerebrospinal Fluid Studies

INTRODUCTION: Over the past ten years, the role of the glymphatic system has been defined and explored using various cerebrospinal fluid (CSF) tracers to track the movement of CSF through the perivascular spaces and into the brain interstitium. Glymphatic studies most commonly use gadolinium as a CSF tracer, which is not blood-brain-barrier (BBB) soluble. The primary component of CSF is water, however, which is BBB permeable. Cerebrospinal fluid may behave differently than large molecule tracers. Heavy water (D2O) is an isotope of water often used in physiology studies. We hypothesized that D2O would provide a traceable MR signal in the brain, allowing for more physiologically realistic models of CSF flow within the glymphatic system. METHODS: Two adult male rats underwent deuterium enhanced MR imaging. Images were obtained using a custom-made RF transmit/receive coil from Rapid MR International that is dual tuned to both proton (1H, 300.3 MHz) and deuterium (2H, 46.1 MHz) resonant frequencies for use in a 7 Tesla Bruker MRI system. After appropriate system calibration for optimization of deuterium MR signal with intravenous D2O infusion, the rats underwent spinal catheter implantation for intrathecal infusion. Images were taken during and after D2O infusion to evaluate uptake and clearance. RESULTS: Deuterium produced a imageable MR signal in the brain with intravenous and intrathecal infusion. Complete signal washout was noted within 10 minutes of stopping the intrathecal infusion. CONCLUSIONS: Deuterium MRI holds promise as a physiologic CSF tracer. As the technique is refined, it can be used for further CSF physiology studies. The rapid clearance of intrathecal D2O as compared to previous models using gadolinium supports our theory that CSF behaves differently than the large molecule tracers historically used to characterize its flow.

Enhancement in the Round Window Niche: A Potential Pitfall in High-Resolution MR Imaging of the Internal Auditory Canal.

There is limited discussion in current literature about the normal imaging appearance of the round window. The purpose of this study was to assess the prevalence and imaging characteristics of gadolinium enhancement in the round window niche on MR imaging to the internal auditory canal. The presence or absence and laterality of enhancement in the round window niche on MR imaging was retrospectively reviewed in 95 patients from 1 institution. All studies included high-resolution (≤0.5-mm section thickness) pre- and postgadolinium 3D FSE T1 with fat-saturation and postgadolinium 3D FLAIR image sequences. T1 and T2 acquisitions were viewed as coregistered overlays to confirm that enhancement was lateral to the round window membrane within the round window niche. CT was reviewed when available to assess the presence and laterality of soft tissue in the round window niche. Ninety-five patients with internal auditory canal MRIs were included. Enhancement was present in the round window of 15 of 95 patients (15.8%). Of the 27 patients who underwent CT, 4 (14.8%) had concordant soft tissue on CT and MR imaging enhancement in the round window niche. One patient had MR imaging enhancement within the round window niche without a corresponding abnormality on CT. The absence of soft tissue on CT and the corresponding lack of MR imaging enhancement were present in 22 (81.5%) patients. Enhancement can be visualized within the round window niche on MR imaging as an incidental finding. This enhancement probably represents postinflammatory granulation tissue and does not require further intervention. However, the potential for this enhancement to be misdiagnosed as a pathologic process can be a pitfall in MR imaging.

A Large Facial Nerve Schwannoma Presenting as a Swelling in Parotid Region-A Rare Case Report.

Extratemporal facial nerve schwannomas are rare entity. Pre-operative assessment is mostly inconclusive with differential diagnosis of parotid tumors. We hereby report a case of 28years female who presented with painless swelling in right parotid region with normal facial nerve function. Ultrasonography was suggestive well circumscribed and homogenous mass arising from the deep lobe of parotid gland. The Fine-needle aspiration cytology came out to be inconclusive. For further characterization of the tumor contrast enhanced MR imaging was performed. The MR imaging revealed well-defined cystic, heterogeneous, pear-shaped mass lesion situated near the stylomastoid foramen. Post operatively the mass came out to be schwannoma on histopathological examination.

Magnetic nanoparticle loaded biodegradable vascular stents for magnetic resonance imaging and long-term visualization.

Benefiting from their good biosafety and bioabsorbability, polymeric biodegradable stents (BDSs) have promising application prospects in the treatment of cardiovascular diseases. However, due to the low density of the polymer itself, it is difficult to visualize with medical imaging techniques such as CT and MRI, which leads to difficulties in accurate BDS localization and subsequent non-invasive evaluation. Therefore, modification of BDSs to adapt to monitoring techniques for clinical use without affecting their biocompatibility and mechanical properties is a promising strategy to support the clinical translation of BDSs. In this study, Fe3O4 superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized to modify the BDS by ultrasonic spraying. Due to the T2-weighted MR imaging enhancement capability of SPIONs, the fabricated SPION-BDS can be entirely visualized and long-term monitored under MR imaging. Further, a stent degradation assessment method based on the analysis of image gray value changes was established. In conclusion, the constructed SPION-BDS provides a possible solution for precise localization of BDSs after implantation, and furthermore, opens up opportunities for long-term non-invasive monitoring of in vivo BDS degradation and multimodal imaging assessment of vascular endothelial remodeling.

MSE-Fusion: Weakly supervised medical image fusion with modal synthesis and enhancement

Existing multi-modal image fusion methods utilize multi-modal images as input that require multiple imaging of patients causing harm to patients’ bodies and large costs, moreover, image fusion needs a large number of registered images which is time-consuming and difficult to get, and has unclear texture and structure of the fused images. Therefore, a weakly supervised medical image fusion method with modal synthesis and enhancement is proposed. In modal synthesis, a weakly supervised approach is used to train the model to decrease the requirements of registered images, and MR images are used as input to synthesize CT images through a deep-structure and shallow-detail generator by training to reduce the required input modal and make the texture and structure clearer. In image enhancement, MR images are passed through a trained generator to generate enhanced MR images which enhance the texture and structure of the MR images. And then using the synthesized CT and enhanced MR images together with the original PET images as input to achieve tri-modal image fusion. Compared with 13 state-of-the-art modal synthesis and image fusion methods on the same datasets, the performance of the proposed method on 7 objective evaluation metrics is significantly improved. The subjective visual effect and objective evaluation metrics of our method are better than those of the compared image fusion methods.

Comparison of imaging findings on three-dimensional black-blood enhanced MR imaging between intracranial atherosclerotic occlusion and thrombotic occlusion

PurposeThe purpose of this study was to compare the imaging findings on three-dimensional (3D) black-blood (BB) contrast-enhanced MR imaging between intracranial atherosclerotic occlusion (IAO) and thrombotic occlusion (TO) of the middle cerebral artery (MCA) territory. Materials and methodsFrom August 2020 to September 2021, we retrospectively reviewed the BB contrast-enhanced MR imaging of patients visiting the emergency room for evaluation of acute ischemic stroke. In total, 77 patients with complete occlusion of the MCA territory on 3D BB contrast-enhanced MR imaging and cerebral angiography were enrolled in this study. We divided the IAO and TO groups according to occlusion causes based on angiography findings. ResultsOf 77 patients, 44 (57.1%) had an IAO in the M1 and M2 and 33 had a TO. Lesion length contrast enhancement (CE) in patients with a TO was significantly longer than that in patients with an IAO (18.95 mm [IQR: 20.91] vs. 7.1 mm [8.92], p <0.001). Overall, 38 (39.4%) patients showed a disconnection of CE on 3D BB contrast-enhanced MR imaging, and 35 showed CE before and after the stenotic or thrombotic lesion. Symptomatic lesions on diffusion-weighted imaging in the TO group were significantly higher than that of the IAO group (97.0% vs, 70.5%, p = 0.003). ConclusionThe long segment CE on 3D BB contrast-enhanced MR imaging was related to TO of MCA. CE before and after a stenotic or thrombotic lesion is a common finding on 3D BB contrast-enhanced MR imaging.

Analysis of Tumor Burden as a Biomarker for Patient Survival with Neuroendocrine Tumor Liver Metastases Undergoing Intra-Arterial Therapies: A Single-Center Retrospective Analysis.

To assess the value of quantitative analysis of tumor burden on baseline MRI for prediction of survival in patients with neuroendocrine tumor liver metastases (NELM) undergoing intra-arterial therapies. This retrospective single-center analysis included 122 patients with NELM who received conventional (n = 74) or drug-eluting beads, (n = 20) chemoembolization and radioembolization (n = 28) from 2000 to 2014. Overall tumor diameter (1D) and area (2D) of up to 3 largest liver lesions were measured on baseline arterially contrast enhanced MR images. Three-dimensional quantitative analysis was performed using the qEASL tool (IntelliSpace Portal Version 8, Philips) to calculate enhancing tumor burden (the ratio between enhancing tumor volume and total liver volume). Based on Q-statistics, patients were stratified into low tumor burden (TB) or high TB. The survival curves were significantly separated between low TB and high TB groups for 1D (p < 0.001), 2D (p < 0.001) and enhancing TB (p = 0.008) measurements, with, respectively, 2.7, 2.6 and 2.2 times longer median overall survival (MOS) in the low TB group (p < 0.001, p < 0.001 and p = 0.008). Multivariate analysis showed that 1D, 2D, and enhancing TB were independent prognostic factors for MOS, with respective hazard ratios of 0.4 (95%CI: 0.2-0.6, p < 0.001), 0.4 (95%CI: 0.3-0.7, p < 0.001) and 0.5 (95%CI: 0.3-0.8, p = 0.003). The overall tumor diameter, overall tumor area, and enhancing tumor burden are strong prognostic factors of overall survival in patients withneuroendocrine tumor liver metastases undergoing intra-arterial therapies.

A double DNAzyme-loaded MnO2 versatile nanodevice for precise cancer diagnosis and Self-Sufficient synergistic gene therapy

Tumors progression is usually characterized by proliferation, migration, and angiogenesis, and it leads to uncontrolled tissue growth and blocks the mechanism of apoptosis. Therefore, targeted angiogenesis and anti-apoptosis is considered promising therapeutic strategy for cancer prevention and treatment. Herein, we report a versatile and intelligent MnO2-PEI-DNAzymes (MnPDs) nanodevice for self-sufficient anti-tumor angiogenesis and pro-apoptosis synergistic gene silencing, coupling multi-target bimodal in situ imaging. Intracellularly, the multifunctional charge-reversal MnPDs undergo reduction and lysis by the overexpressed GSH, actualizing enhanced MR imaging and sufficient DNAzyme cofactors in tumor tissue, and enabling miRNA-155 and telomerase biomarkers dual-fluorescence imaging. Under the precise multimodal imaging, the dual DNAzymes enable self-sufficient Early growth response-1 (EGR1) and Survivin (SUR) mRNAs synergistic silencing, effectively inhibiting tumor angiogenesis and anti-apoptotic. Considering that accurate and efficient therapy has become a trend in cancer therapy, our proposed self-sustaining multifunctional nanodevice is promising for broad clinical applications.

Fully automatic quantification of transient severe respiratory motion artifact of gadoxetate disodium-enhanced MRI during arterial phase.

It is important to fully automate the evaluation of gadoxetate disodium-enhanced arterial phase images because the efficient quantification of transient severe motion artifacts can be used in a variety of applications. Our study proposes a fully automatic evaluation method of motion artifacts during the arterial phase of gadoxetate disodium-enhanced MR imaging. The proposed method was based on the construction of quality-aware features to represent the motion artifact using MR image statistics and multidirectional filtered coefficients. Using the quality-aware features, the method calculated quantitative quality scores of gadoxetate disodium-enhanced images fully automatically. The performance of our proposed method, as well as two other methods, was acquired by correlating scores against subjective scores from radiologists based on the 5-point scale and binary evaluation. The subjective scores evaluated by two radiologists were severity scores of motion artifacts in the evaluation set on a scale of 1 (no motion artifacts) to 5 (severe motion artifacts). Pearson's linear correlation coefficient (PLCC) and Spearman's rank-ordered correlation coefficient (SROCC) values of our proposed method against the subjective scores were 0.9036 and 0.9057, respectively, whereas the PLCC values of two other methods were 0.6525 and 0.8243, and the SROCC values were 0.6070 and 0.8348. Also, in terms of binary quantification of transient severe respiratory motion, the proposed method achieved 0.9310 sensitivity, 0.9048 specificity, and 0.9200 accuracy, whereas the other two methods achieved 0.7586, 0.8996 sensitivities, 0.8098, 0.8905 specificities, and 0.9200, 0.9048 accuracies CONCLUSIONS: This study demonstrated the high performance of the proposed automatic quantification method in evaluating transient severe motion artifacts in arterial phase images.

Long-term outcomes of staged Gamma Knife radiosurgery for giant cavernous sinus hemangiomas: a single-center retrospective study.

Cavernous sinus hemangiomas (CSHs) are rare benign tumors originating from the cavernous sinus. Gamma Knife radiosurgery (GKRS) has been recommended as a primary treatment for small- to medium-sized CSHs. The optimal treatment for giant CSHs is still controversial. In this study, the authors retrospectively reviewed the effectiveness and safety of staged GKRS treatment for giant CSHs. Twenty-two patients with giant CSH who received staged GKRS treatment in the Gamma Knife Treatment Center of Henan Province during the period from January 1, 2011, to December 31, 2018, were enrolled in this study. Six patients had received microsurgery before GKRS, the other 16 patients were diagnosed according to clinical symptoms and MR images. All of the enrolled patients received 2-stage GKRS, and the mean interval between the two GKRS treatments was 6.5 months (range 6-12 months). For the first GKRS, the median isodose line was 48% (range 45%-50%), the median marginal dose was 13 Gy (range 11.5-14 Gy), and the median coverage of CSHs was 80% (range 70%-88%). For the second GKRS treatment, the median isodose line was 50% (range 45%-55%), the median marginal dose to the CSHs was 10.5 Gy (range 9-12.5 Gy), and the median coverage of the CSHs was 88% (range 80%-94%). All of the patients received an outpatient review of an enhanced MR image of the head and a clinical physical check every 6 months after the first GKRS treatment. The mean follow-up duration was 52 months (range 24-84 months). The tumor control rate was 100% 24 months after staged GKRS, and at the last follow-up the mean tumor shrinkage rate was 96.7% (range 90.6%-100%) and the mean residual CSH volume was 2.1 ml (range 0-8.5 ml). Twenty patients suffered central nervous system (CNS) injury symptoms to varying degrees before staged GKRS treatment. Complete symptom recovery was found in 11 (55%) patients, improved symptoms in 5 (25%) patients, and no change in 4 (20%) patients after treatment. Only 1 patient suffered temporary preexisting headache aggravation and 1 patient suffered temporary preexisting diplopia aggravation 1 week after receiving the first GKRS treatment. Subacute or chronic complications were not detected after staged GKRS. Staged GKRS is an effective treatment for giant CSHs. Because of the impressively low incidence of adverse effects, staged GKRS may be considered as a primary treatment for giant CSHs.