Case report: Pulmonary artery sarcoma diagnosed through rare brain metastases.

We present the case of a 33-year-old male referred across several hospitals because of suspected chronic thromboembolic pulmonary hypertension (CTEPH). Initially admitted in October 2022 for a recurrent, severe cough and diagnosed with CTEPH, he received anticoagulant therapy. However, his symptoms worsened, necessitating a transfer to another facility for thrombolysis treatment. Following an episode of syncope, an MRI scan revealed a metastatic brain tumor. Subsequently, he experienced a third transfer to our hospital, emergency surgery was performed to alleviate cerebral edema and excise a lesion in the left frontal lobe. Postoperative pathology was inconclusive, but a multidisciplinary team meeting, aided by experienced radiologists, eventually confirmed a diagnosis of pulmonary artery sarcoma (PAS) with systemic metastases. This case underscores the necessity of promptly ruling out PAS in patients presenting with significant emboli in the central pulmonary arteries and suggests early referral to specialized centers for suspected cases.

Multiparametric MRI-based radiomics combined with pathomics features for prediction of the efficacy of neoadjuvant chemotherapy in breast cancer.

Purpose: The aim of this study is to investigate a new method that combines radiological and pathological breast cancer information to predict discrepancies in pathological responses for individualized treatment planning. We used baseline multiparametric magnetic resonance imaging and hematoxylin and eosin-stained biopsy slides to extract quantitative feature information and predict the pathological response to neoadjuvant chemotherapy in breast cancer patients. Methods: We retrospectively collected data from breast cancer patients who received neoadjuvant chemotherapy in our hospital from August 2016 to January 2018; multiparametric magnetic resonance imaging (contrast-enhanced T1-weighted imaging and diffusion-weighted imaging) and whole slide image of hematoxylin and eosin-stained biopsy sections were collected. Quantitative imaging features were extracted from the multiparametric magnetic resonance imaging and the whole slide image were used to construct a radiopathomics signature model powered by machine learning methods. Models based on multiparametric magnetic resonance imaging or whole slide image alone were also constructed for comparison and referred to as the radiomics signature and pathomics signature models, respectively. Four modeling methods were used to establish prediction models. Model performances were evaluated using receiver operating characteristic curve analysis and the area under the curve, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value. Results: The radiopathomics signature model had favourable performance for the prediction of pathological complete response in the training set (the best value: area under the curve 0.83, accuracy 0.84, and sensitivity 0.87), and in the test set (the best value: area under the curve 0.91, accuracy 0.90, and sensitivity 0.88). In the test set, the radiopathomics signature model also significantly outperformed the radiomics signature (the best value: area under the curve 0.83, accuracy 0.64, and sensitivity 0.62), pathomics signature (the best value: area under the curve 0.60, accuracy 0.74, and sensitivity 0.62) (p > 0.05). Decision curve analysis and calibration curves confirmed the excellent performance of these prediction models in discrimination, calibration, and clinical usefulness. Conclusions: The results of this study suggest that radiopathomics, the combination of both radiological information regarding the whole tumor and pathological information at the cellular level, could potentially predict discrepancies in pathological response and provide evidence for rational treatment plans.

Factors associated with overdiagnosis of benign pulmonary nodules as malignancy: a retrospective cohort study.

OBJECTIVE: To establish a preoperative model for the differential diagnosis of benign and malignant pulmonary nodules (PNs), and to evaluate the related factors of overdiagnosis of benign PNs at the time of imaging assessments. MATERIALS AND METHODS: In this retrospective study, 357 patients (median age, 52 years; interquartile range, 46-59 years) with 407 PNs were included, who underwent surgical histopathologic evaluation between January 2020 and December 2020. Patients were divided into a training set (n = 285) and a validation set (n = 122) to develop a preoperative model to identify benign PNs. CT scan features were reviewed by two chest radiologists, and imaging findings were categorized. The overdiagnosis rate of benign PNs was calculated, and bivariate and multivariable logistic regression analyses were used to evaluate factors associated with benign PNs that were over-diagnosed as malignant PNs. RESULTS: The preoperative model identified features such as the absence of part-solid and non-solid nodules, absence of spiculation, absence of vascular convergence, larger lesion size, and CYFRA21-1 positivity as features for identifying benign PNs on imaging, with a high area under the receiver operating characteristic curve of 0.88 in the validation set. The overdiagnosis rate of benign PNs was found to be 50%. Independent risk factors for overdiagnosis included diagnosis as non-solid nodules, pleural retraction, vascular convergence, and larger lesion size at imaging. CONCLUSION: We developed a preoperative model for identifying benign and malignant PNs and evaluating factors that led to the overdiagnosis of benign PNs. This preoperative model and result may help clinicians and imaging physicians reduce unnecessary surgery.

The effect of tumor vascular remodeling and immune microenvironment activation induced by radiotherapy: quantitative evaluation with magnetic resonance/photoacoustic dual-modality imaging.

Background: Tumor radiotherapy combined with immunotherapy for solid tumors has been proposed, but tumor vascular structure abnormalities and immune microenvironment often affect the therapeutic effect of tumor, and multimodal imaging technology can provide more accurate and comprehensive information in tumor research. The purpose of this study was to evaluate the dynamic monitoring of tumor blood vessels and microenvironment induced by radiotherapy by magnetic resonance/photoacoustic (MR/PA) imaging, and to explore its application value in radiotherapy combined with immunotherapy. Methods: The tumor-bearing mice were randomly allocated into six groups, which received different doses of radiation therapy (2 Gy ×14 or 8 Gy ×3) and anti-programmed death ligand-1 (PD-L1) antibody for two consecutive weeks. MR/PA imaging was used to noninvasively evaluate the response of tumor to different doses of radiotherapy, combined with histopathological techniques to observe the tumor vessels and microenvironment. Results: The inhibitory effect of high-dose radiotherapy on tumors was significantly greater than that of low-dose radiotherapy, with the MR images revealing that the signal intensity decreased significantly (P<0.05). Compared with those in the other groups, the tumor vascular density decreased significantly (P<0.01), and the vascular maturity index increased significantly in the low-dose group (P<0.05). The PA images showed that the deoxyhemoglobin and total hemoglobin levels decreased and the SO2 level increased after radiation treatment (P<0.05). In addition, the high-dose group had an increased number of tumor-infiltrating lymphocytes (CD4+ T and CD8+ T cells) (P<0.01, P<0.05) and natural killer cells (P<0.001) and increased PD-L1 expression in the tumors (P<0.05). The combination of radiotherapy and immunotherapy increased the survival rate of the mice (P<0.05), and a regimen of an 8 Gy dose of radiation combined with immunotherapy inhibited tumor growth and increased the survival rate of the mice to a greater degree than the 2 Gy radiation dose with immunotherapy combination (P=0.002). Conclusions: Differential fractionation radiotherapy doses exert biological effects on tumor vascular and the immune microenvironment, and MR/PA can be used to evaluate tumor vascular remodeling after radiotherapy, which has certain value for the clinical applications of radiotherapy combined with immunotherapy.

Diagnostic accuracy of glioma pseudoprogression identification with positron emission tomography imaging: a systematic review and meta-analysis.

Background: Positron emission tomography (PET) imaging is a promising molecular neuroimaging technique and has been proposed as one of the criteria for glioma management. However, there is some controversy concerning the diagnostic accuracy of PET using different radiotracers to differentiate between glioma pseudoprogression (PsP) and true progression (TPR). The purpose of this meta-analysis was to systematically evaluate the methodological quality and clinical value of original studies for distinguishing PsP from TPR in glioma. Methods: The Medline, Web of Science, Embase, Cochrane Library, and ClinicalTrials.gov were searched from inception until September 1, 2022. Retrieved clinical studies only investigated the PsP cases but did not include the cases of radiation necrosis or other treatment-related changes. Eligible studies were screened for data extraction and evaluated by 2 independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. A random effects model was used to describe summary receiver operating characteristics. Meta-regression and subgroup analyses were applied to identify any sources of heterogeneity. Results: The meta-analysis included 20 studies, comprising 317 (30.9%) patients with PsP and 708 (69.1%) with TPR. The summary sensitivity and specificity of general PET for identifying PsP were 0.86 [95% confidence interval (CI): 0.77-0.91] and 0.84 (95% CI: 0.79-0.88), respectively. The statistical heterogeneity was explained by sample size, study design, World Health Organization (WHO) grade, gold standard, and radiotracer type. The summary sensitivity and specificity of O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET PET) were 0.80 (95% CI: 0.68-0.88) and 0.81 (95% CI: 0.75-0.85), respectively. The maximum tumor-to-brain ratio (TBRmax) and the mean tumor-to-brain ratio (TBRmean) both showed excellent diagnostic performance in 18F-FET studies, the summary sensitivity was 0.83 (95% CI: 0.72-0.91) and 0.79 (95% CI: 0.65-0.98), respectively, and the specificity was 0.76 (95% CI: 0.68-0.84) and 0.78 (95% CI: 0.64-0.88), respectively. Conclusions: PET imaging is generally accurate in identifying glioma PsP. Considering the credibility of meta-evidence and the practicability of using radiotracer, 18F-FET PET holds the highest clinical value, while TBRmax and TBRmean should be regarded as reliable parameters. PET used with the radiotracers and multiple-parameter combinations of PET with magnetic resonance imaging (MRI) and radiomics analysis have broad research and application prospects, whose diagnostic values for identifying glioma PsP warrant further investigation.

Case report: A novel reciprocal ROS1-CD74 fusion in a NSCLC patient partially benefited from sequential tyrosine kinase inhibitors treatment.

Background: The clinical significance of majority oncogenic novel fusions is still unknown due to scarcity. Reciprocal ROS1 translocation is a rare form of ROS1 fusion and has not yet been clearly analyzed. Case presentation: A 44-year-old Chinese woman with a large dimension in the left lobe of the lung was admitted to the hospital with IVB lung adenocarcinoma. It was discovered that intron 28 of ROS1 and intron 6 of CD74 produced a unique reciprocal ROS1 rearrangement. In addition, the dual CD74-ROS1 fusions were discovered using the RNA next-generation sequencing (NGS) findings. Although benefiting from crizotinib and lorlatinib sequential treatment, the overall prognosis of the patient was relatively poor, whose progression-free survival was 4 and 5 months for crizotinib treatment and lorlatinib treatment, respectively. Conclusion: In summary, a novel ROS1-CD74 fusion identified by DNA NGS was translated into dual CD74-ROS1 transcripts. Furthermore, this patient with non-small cell lung cancer benefited from consecutive tyrosine kinase inhibitor therapy. Our discovery broadened the range of targetable ROS1 fusions and underlined the importance of sequential DNA and RNA sequencing in identifying uncommon but beneficial fusions, which eventually bring benefits to the patients.

CT and MRI findings of intracranial extraskeletal mesenchymal chondrosarcoma-a case report and literature review.

Background: Intracranial extraskeletal mesenchymal chondrosarcoma (EMCS) is a rare neoplasm and often misdiagnosed before histopathological examination due to its rarity. There were few reports previously on the radiological features of intracranial EMCS. We described a 20-year-old male patient with intracranial EMCS focusing on the imaging characteristics. Case Description: The patient was admitted to our hospital due to headache and dizziness for two months, without nausea, vomiting, limb convulsions and loss of consciousness during the illness. Pre-contrast computed tomography (CT) revealed a large slightly hyperdense mass with irregularly lobulated margins in the right parietal and occipital region and multiple patchy calcifications in peripheral of the lesion. The inner table of right parietal bone adjacent to the mass was compressed, thickened, and eroded. Magnetic resonance imaging (MRI) exhibited intermediate and hypo-intensity on T1-weighted images (T1WI) and slight hyper-intensity on T2-weighted images (T2WI) with extremely high intensity rim of cerebral spinal fluid (CSF) and low intensity flow-void vessel. The mass demonstrated heterogeneous remarkable enhancement and "dural tail" sign also was noted. The important imaging signs of this case are irregular calcifications of soft tissue on CT and "dural tail" sign on MRI. The patient underwent tumor resection and was followed up postoperatively with serial MRI every three months. He was alive without obvious clinical symptoms and evidence of recurrence for 9 months. EMCS is a highly invasive tumor and it is difficult to differentiate EMCS from the other intracranial malignant tumors only by clinical characteristics or findings of CT and conventional MR imaging. Radiotherapy and chemotherapy after radical resection are the best treatment choice. Therefore, postoperative patients should be reviewed routinely. Conclusions: A knowledge of the imaging features could facilitate differentiation of intracranial EMCS, but the final diagnosis depends on pathological examinations. This paper focuses on the imaging characteristics of EMCS and fully describes the details of lesions in order to provide clinicians with effective differential diagnosis information and improve clinical decision-making.

Focused Ultrasound Promotes the Delivery of Gastrodin and Enhances the Protective Effect on Dopaminergic Neurons in a Mouse Model of Parkinson's Disease.

Parkinson's disease (PD) is the second most common chronic neurodegenerative disease globally; however, it lacks effective treatment at present. Focused ultrasound (FUS) combined with microbubbles could increase the efficacy of drug delivery to specific brain regions and is becoming a promising technology for the treatment of central nervous system diseases. In this study, we explored the therapeutic potential of FUS-mediated blood-brain barrier (BBB) opening of the left striatum to deliver gastrodin (GAS) in a subacute PD mouse model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The concentration of GAS in the left hemisphere was detected by ultra-high performance liquid chromatography electrospray Q-Orbitrap mass spectrometry (UHPLC/ESI Q-Orbitrap) and the distribution of tyrosine hydroxylase (TH) neurons was detected by immunohistochemical staining. The expression of TH, Dopamine transporter (DAT), cleaved-caspase-3, B-cell lymphoma 2 (Bcl-2), brain-derived neurotrophic factor (BDNF), postsynaptic density protein 95 (PSD-95), and synaptophysin (SYN) protein were detected by western blotting. Analysis showed that the concentration of GAS in the left hemisphere of PD mice increased by approximately 1.8-fold after the BBB was opened. FUS-mediated GAS delivery provided optimal neuroprotective effects and was superior to the GAS or FUS control group. In addition, FUS enhanced GAS delivery significantly increased the expression of Bcl-2, BDNF, PSD-95, and SYN protein in the left striatum (P < 0.05) and reduced the levels of cleaved-caspase-3 remarkably (P = 0.001). In conclusion, the enhanced delivery by FUS effectively strengthened the protective effect of GAS on dopaminergic neurons which may be related to the reinforcement of the anti-apoptotic activity and the expression of synaptic-related proteins in the striatum. Data suggests that FUS-enhanced GAS delivery may represent a new strategy for PD treatment.

Heroin Addiction Induces Axonal Transport Dysfunction in the Brain Detected by In Vivo MRI.

Heroin is a highly addictive drug that causes axonal damage. Here, manganese-enhanced magnetic resonance imaging (MEMRI) was used to dynamically monitor axonal transport at different stages of heroin addiction. Rat models of heroin addiction (HA) and prolonged heroin addiction (PHA) were established by injecting rats with heroin at different stages. Heroin-induced learning and memory deficits were evaluated in the Morris water maze (MWM), and MEMRI was used to dynamically evaluate axonal transport in the olfactory pathway. The expression of proteins related to axonal structure and function was also assessed by Western blotting. Transmission electron microscopy (TEM) was used to observe ultrastructural changes, and protein levels of neurofilament heavy chain (NF-H) were analyzed by immunofluorescence staining. HA rats, especially PHA rats, exhibited worse spatial learning and memory than control rats. Compared with HA rats and control rats, PHA rats exhibited significantly longer escape latencies, significantly fewer platform-location crossings, and significantly more time in the target quadrant during the MWM test. Mn2+ transport was accelerated in HA rats. PHA rats exhibited severely reduced Mn2+ transport, and the axonal transport rate (ATR) was significantly lower in these rats than in control rats (P < 0.001). The levels of cytoplasmic dynein and kinesin-1 were significantly decreased in the PHA group than in the control group (P < 0.001); additionally, the levels of energy-related proteins, including cytochrome c oxidase (COX) IV and ATP synthase subunit beta (ATPB), were lower in the PHA group (P < 0.001). The brains of heroin-exposed rats displayed an abnormal ultrastructure, with neuronal apoptosis and mitochondrial dysfunction. Heroin exposure decreased the expression of NF-H, as indicated by significantly reduced staining intensities in tissues from HA and PHA rats (P < 0.05). MEMRI detected axonal transport dysfunction caused by long-term repeated exposure to heroin. The main causes of axonal transport impairment may be decreases in the levels of motor proteins and mitochondrial dysfunction. This study shows that MEMRI is a potential tool for visualizing axonal transport in individuals with drug addictions, providing a new way to evaluate addictive encephalopathy.

Cranial irradiation-induced impairment of axonal transport and sexual function in male rats and imaging of the olfactory pathway by MRI.

PURPOSE: The aim of this study was to evaluate the effect of radiation-induced brain injury (RIBI) on axonal transport (AT) and sexual function. METHODS AND MATERIALS: Adult male rats received whole-brain radiation with a total dose of 30 Gy (15 Gy with 2 fractions) to build a RIBI model. Foraging behavior and sexual function were assessed, and MRI was performed 8 weeks after brain irradiation. MRI was performed in the early and delayed phases after perfusion of MnCl2 into the rat nostril. The levels of motor proteins and proteins involved in energy metabolism and AT were determined by Western blotting. The levels of sex hormones in the blood were measured by ELISA. Ultrastructural analysis was performed with a transmission electron microscope. RESULTS: The foraging ability of rats was reduced after brain irradiation, and the foraging time of the radiation group was longer than that of the control group (P < 0.05). The sexual function of rats in the radiation group was markedly decreased. Compared with control rats, radiation-treated rats showed significant decreases in serum testosterone, FSH, LH, and GnRH levels (P < 0.001). Mn2+ uptake in the olfactory bulb (OB) in the early phase and delayed phase was lower in the radiation group than in the control group (P < 0.05). The AT rate in the lateral olfactory tracts (LOT) and the transsynaptic AT rate were significantly lower in the irradiated rats than in the control rats (P < 0.05). The levels of the motor proteins kinesin-1 and cytoplasmic dynein were significantly decreased in the irradiation group (P < 0.05). The expression of the energy metabolism-related proteins ATPB and COX IV was significantly lower in the irradiated rats than in the control rats (P < 0.05). Apoptosis and synaptic damage were observed after irradiation. CONCLUSION: MRI of the olfactory pathway can be used to assess AT impairment in RIBI models. AT deficits secondary to radiation damage are the result of multiple factors, including declines in motor protein levels, neuronal apoptosis, synaptic damage and energy metabolism dysfunction. Cranial irradiation-induced sexual dysfunction was associated with decreased sex hormone levels secondary to hypothalamic-pituitary-gonadal axis injury.

Multiparameter MRI Model With DCE-MRI, DWI, and Synthetic MRI Improves the Diagnostic Performance of BI-RADS 4 Lesions.

OBJECTIVES: To evaluate the value of synthetic magnetic resonance imaging (syMRI), diffusion-weighted imaging (DWI), DCE-MRI, and clinical features in breast imaging-reporting and data system (BI-RADS) 4 lesions, and develop an efficient method to help patients avoid unnecessary biopsy. METHODS: A total of 75 patients with breast diseases classified as BI-RADS 4 (45 with malignant lesions and 30 with benign lesions) were prospectively enrolled in this study. T1-weighted imaging (T1WI), T2WI, DWI, and syMRI were performed at 3.0 T. Relaxation time (T1 and T2), apparent diffusion coefficient (ADC), conventional MRI features, and clinical features were assessed. "T" represents the relaxation time value of the region of interest pre-contrast scanning, and "T+" represents the value post-contrast scanning. The rate of change in the T value between pre- and post-contrast scanning was represented by ΔT%. RESULTS: ΔT1%, T2, ADC, age, body mass index (BMI), menopause, irregular margins, and heterogeneous internal enhancement pattern were significantly associated with a breast cancer diagnosis in the multivariable logistic regression analysis. Based on the above parameters, four models were established: model 1 (BI-RADS model, including all conventional MRI features recommended by BI-RADS lexicon), model 2 (relaxation time model, including ΔT1% and T2), model 3 [multi-parameter (mp)MRI model, including ΔT1%, T2, ADC, margin, and internal enhancement pattern], and model 4 (combined image and clinical model, including ΔT1%, T2, ADC, margin, internal enhancement pattern, age, BMI, and menopausal state). Among these, model 4 has the best diagnostic performance, followed by models 3, 2, and 1. CONCLUSIONS: The mpMRI model with DCE-MRI, DWI, and syMRI is a robust tool for evaluating the malignancies in BI-RADS 4 lesions. The clinical features could further improve the diagnostic performance of the model.

Photoacoustic imaging in evaluating early intestinal ischemia injury and reperfusion injury in rat models.

BACKGROUND: It remains a challenge to distinguish whether the damaged intestine is viable in treating acute mesenteric ischemia. In this study, photoacoustic imaging (PAI) was used to observe intestinal tissue viability after ischemia and reperfusion injury in rats. METHODS: An in vivo study was conducted using forty male SD rats, which were randomly divided into a sham-operated (SO) group, a 1 h ischemia group, a 2 h ischemia group, and an ischemia-reperfusion (I/R) group with 10 rats in each group. In the ischemia group, the superior mesenteric artery (SMA) was isolated and clamped for 1 and 2 h, respectively, and in the I/R group, after ischemia for 1 h, the clamp was removed and reperfused for 1 h. The same time interval was used in the SO group. Immediately after establishing the animal model, a PAI examination was performed, and the small intestine was collected for histopathology. RESULTS: The levels of PAI parameters Hb, HbR, MAP 760, and MAP 840 were increased to different degrees in the ischemia groups, especially in the 2 h ischemia group, compared with the SO group (P<0.05), and with prolongation of the ischemia time, the injury was aggravated. All PAI signal levels except HbO in the I/R group were higher than those in the control group, and the increased range differed, especially in Hb and MAP 840. Using western blot, compared with the SO group, the BAX increased significantly in the 2 h ischemia group (P<0.05), and Caspase-3 in the experimental group was significantly higher than in the SO group (P<0.05). The level of HIF-1α increased in the 2 h ischemia group and I/R group (P<0.05), and TUNEL staining showed that the number of positive apoptotic nuclei in the 2 h ischemia group was significantly higher than in the SO group (P<0.05). Hematoxylin-eosin (HE) staining showed that ischemia for 2 hours was the most serious, with obvious mucosal damage, extensive epithelial injury, and bleeding. CONCLUSIONS: PAI can be used as an effective tool to detect acute intestinal ischemia injury and quantitatively evaluate tissue viability.

Assessment of the Clinical Usefulness of Preoperative Computed Tomography in Colorectal Cancer Patients Who Received Unplanned Reoperation.

BACKGROUND: In the unplanned reoperation of colorectal cancer patients, computed tomography (CT) is increasingly utilized to locate postoperative complications and previously unlocalized lesions. The purpose of this study is to explore the application of CT in the mortality and complications of the reoperation of colorectal cancer. Patients and Methods. We performed a retrospective review of collected data from the colorectal surgeries of 90 identified colorectal cancer patients who received an unplanned reoperation from 2010 to 2018. Patients were stratified according to those with preoperative CT imaging (CT group, n = 36) and those without preoperative CT imaging (NCT group, n = 54). Twenty-four statistical indicators of each patient were studied, including their preoperative risk, surgical characteristics, and postoperative outcomes, and satisfaction was evaluated. All data were statistically analysed for predicting postoperative complications by univariate and multivariate logistic regression analyses. RESULTS: Ninety patients received an unplanned reoperation in the study, and 40% (36/90) of these patients underwent preoperative CT examination. Patients' risk factors were similar between CT and NCT groups. Preoperative imaging was more commonly performed for reoperative new anastomosis + ileostomy but less common for reoperative Dixon's procedure. The operative duration of the NCT group was longer (139 vs. 104 min, respectively, P = 0.01). Preoperative NCT examination (OR 1.24; 95% CI = 1.09-1.42; P = 0.01) was an independent predictor of postoperative complications. Importantly, three patients died after an unplanned reoperation for colorectal cancer, which occurred only in the NCT group (5.6% vs. 0.0%, P = 0.01). CONCLUSION: The use of conventional preoperative CT optimizes the choice of the surgical site and the strategy of laparotomy, so as to reduce the length of operation. Preoperative imaging evaluation should be performed for patients undergoing repeat abdominal surgery.

Hippocampal changes in inflammasomes, apoptosis, and MEMRI after radiation-induced brain injury in juvenile rats.

PURPOSE: The aim of this study was to characterize changes in hippocampal inflammasomes, pyroptosis and apoptosis in juvenile rats after brain irradiation and to assess whether manganese-enhanced magnetic resonance imaging (MEMRI) reflected those changes. MATERIALS AND METHODS: Four-week-old male Sprague-Dawley rats received a whole-brain radiation dose of 15 Gy or 25 Gy. Hippocampal inflammasomes and apoptosis were measured using Western blot analysis at 4 days and 8 weeks after irradiation. MEMRI and magnetic resonance spectroscopy (MRS) were performed at the same time points. RESULTS: Neither the 15 Gy nor 25 Gy group showed changes in the expression of inflammasome proteins absent in melanoma 2 (AIM2), gasdermin-D (GSDMD), nucleotide oligomerization domain-like receptor protein 1 (NLRP1) and NLRP3 at 4 days or 8 weeks after radiation injury (P > 0.05). Furthermore, the expression levels of the inflammatory cytokines interleukin-1ß (IL-1ß) and IL-18 were not significantly different among the groups (P > 0.05). The expression levels of cleaved caspase-1 and -3, indicators of apoptosis, were higher in the irradiation groups than in the control group at 4 days post irradiation, especially for caspase-3 (P < 0.05), but this increase was slightly attenuated at 8 weeks after radiation injury. Four days post irradiation, the MEMRI signal intensity (SI) in the irradiation groups, especially the 25 Gy group, was significantly lower than that in the control group (P < 0.05). Eight weeks after radiation injury, the SI of the 15 Gy group and the 25 Gy group recovered by different degrees, but the SI of the 25 Gy group was still significantly lower than that of the control group (P < 0.05). On day 4 post irradiation, the metabolic ratio of N-acetylaspartate (NAA) to creatine (Cr) in the 15 Gy group and 25 Gy group was significantly lower than that in the control group (P < 0.05). The NAA/Cr ratio in the 15 Gy group recovered to control levels at 8 weeks (P > 0.05), but the NAA/Cr ratio in the 25 Gy group remained significantly lower than that in the control group (P < 0.05). CONCLUSION: Radiation-induced brain injury is dose-dependently associated with apoptosis but not inflammasomes or pyroptosis, and the change in apoptosis can be detected by MEMRI.

Effects of Non-invasive, Targeted, Neuronal Lesions on Seizures in a Mouse Model of Temporal Lobe Epilepsy.

Surgery to treat drug-resistant epilepsy can be quite effective but remains substantially underutilized. A pilot study was undertaken to test the feasibility of using a non-invasive, non-ablative, approach to produce focal neuronal loss to treat seizures in a rodent model of temporal lobe epilepsy. In this study, spontaneous, recurrent seizures were established in a mouse model of pilocarpine-induced status epilepticus. After post-status epilepticus stabilization, baseline behavioral seizures were monitored for 30 d. Non-invasive opening of the blood-brain barrier targeting the hippocampus was then produced by using magnetic resonance-guided, low-intensity focused ultrasound, through which a neurotoxin (quinolinic acid) administered intraperitoneally gained access to the brain parenchyma to produce focal neuronal loss. Behavioral seizures were then monitored for 30 d after this procedure, and brains were subsequently prepared for histologic analysis of the sites of neuronal loss. The average frequency of behavioral seizures in all animals (n = 11) was reduced by 21.2%. Histologic analyses along the longitudinal axis of the hippocampus revealed that most of the animals (n = 8) exhibited neuronal loss located primarily in the intermediate aspect of the hippocampus, while sparing the septal aspect. Two other animals with damage to the intermediate hippocampus also exhibited prominent bilateral damage to the septal aspect of the hippocampus. A final animal had negligible neuronal loss overall. Notably, the site of neuronal loss along the longitudinal axis of the hippocampus influenced seizure outcomes. Animals that did not have bilateral damage to the septal hippocampus displayed a mean decrease in seizure frequency of 27.7%, while those with bilateral damage to the septal hippocampus actually increased seizure frequency by 18.7%. The animal without neuronal loss exhibited an increase in seizure frequency of 19.6%. The findings indicate an overall decrease in seizure frequency in treated animals. And, the site of neuronal loss along the longitudinal axis of the hippocampus appears to play a key role in reducing seizure activity. These pilot data are promising, and they encourage additional and more comprehensive studies examining the effects of targeted, non-invasive, neuronal lesions for the treatment of epilepsy.

Multislice spiral CT images combined with CEA and lymphocyte-to-neutrophil ratio predict recurrence and post-operative metastasis of rectal cancer.

To explore the early predictors of post-operative recurrence and metastasis of rectal cancer, analyse the associated risk, and construct a model. Retrospective collection. Four hundred patients with rectal cancer underwent surgical resection and pathological diagnosis from September 2013 to September 2014. During the post-operative period, the patients were tested by imaging examination, serum tumour markers, and routine blood follow-up for at least 3 years. Preoperative CT examination of tumour size, lymphocyte-to-neutrophil ratio, and CEA were significant biomarkers for predicting recurrence and/or metastasis of post-operative rectal cancer. The stratified threshold of the lesion size cut-off point in CT images of patients with rectal cancer was 18.75 cm3, the cut-off point value of the lymphocyte-to-neutrophil ratio was 0.33, and the CEA cut-off point value was 16.97 ng/ml. We used the cut-off point to perform stratified survival analysis to obtain two K-M curves and conduct a log-rank test. The Cox multivariate risk regression results were as follows: preoperative CT images of lesion size, lymphocyte-to-neutrophil ratio, and CEA. The AUC of the normogram model for the prediction of post-operative recurrence and metastasis of rectal cancer is 0.939. Preoperative CT examination of tumour size can predict post-operative recurrence and metastasis of rectal cancer and can be used to analyse its risk. The lymphocyte-to-neutrophil ratio and CEA can also predict post-operative tumour recurrence and metastasis risk.

Radiation-induced impairment of optic nerve axonal transport in tree shrews and rats monitored by longitudinal manganese-enhanced MRI.

PURPOSE: Radiation-induced optic neuropathy (RION) is a serious complication that occurs after radiation therapy of tumors in the vicinity of the optic nerve, yet its mechanism and imaging features are poorly understood. In this study, we employed manganese-enhanced MRI (MEMRI) to assess optic nerve axonal transport in tree shrews and rats after irradiation. MATERIALS AND METHODS: A comparison of normal visual projections in tree shrews and rats was conducted by intravitreal MnCl2 injection followed by MRI. Adult male tree shrews and rats received a total dose of 20 Gy delivered in two fractions (10 Gy per fraction) within 5 days. Longitudinal MEMRI was conducted 5, 10, 20 and 30 weeks after radiation. At the end of observation, motor proteins involved in axonal transport were detected by western blotting, and the axon cytoskeleton was assessed by immunofluorescence. RESULTS: The eyeballs, lens sizes, vitreous volumes, optic nerves and superior colliculi of tree shrews were significantly larger than those of rats on MEMRI (P < 0.05). The Mn2+-enhancement of the optic nerve showed no significant changes at 5 and 10 weeks (P > 0.05) but decreased gradually from 20 to 30 weeks postirradiation (P < 0.05). The enhancement of the superior colliculus gradually decreased from 5 weeks to 30 weeks, and the decrease was most significant at 30 weeks (P < 0.05). The levels of the motor proteins cytoplasmic dynein-1, kinesin-1 and kinesin-2 in the experimental group were significantly decreased (P < 0.05). The immunofluorescence results showed that the α-tubulin, ß-tubulin and SMI 31 levels in the experimental groups and control groups were not significantly different (P > 0.05). CONCLUSION: Tree shrews show great advantages in visual neuroscience research involving MEMRI. The main cause of the decline in axonal transport in RION is an insufficient level of motor protein rather than damage to the axonal cytoskeletal structure. Longitudinal MEMRI can be used to detect changes in axonal transport function and to observe the relatively intact axon structure from the early to late stages after radiation administration.

Combined dynamic DCE-MRI and diffusion-weighted imaging to evaluate the effect of neoadjuvant chemotherapy in cervical cancer.

PURPOSE: To prospectively investigate changes in quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and the apparent diffusion coefficient (ADC) of diffusion-weighted imaging (DWI) in patients with cervical cancer before and after neoadjuvant chemotherapy (NACT). METHODS: Thirty-eight patients with cervical cancer underwent DCE-MRI and DWI 1 week before and 4 weeks after NACT. The patients were classified into 2 groups: significant reaction (sCR) group and the non-sCR group. DCE-MRI parameters and ADC values were measured and compared between the 2 groups. RESULTS: Before NACT, the mean Ktrans value was higher, but the mean Ve was lower, in the sCR group compared with the non-sCR group; these differences were statistically significant (p<0.05). After NACT, the mean Ktrans value and the delta (i.e., changed) value of Ktrans were significantly lower in the sCR group compared with the non-sCR group (p<0.05). However, the mean ADC and the delta value of the mean ADC between the 2 groups were slightly higher in the sCR group compared with the non-sCR group (p<0.05). The area under the curve of pre-mean Ktrans, DKtrans, and pre-mean Ktrans combined with post-mean ADC values were 0.801, 0.955, and 0.878, respectively (p<0.05). The optimal cutoff values for distinguishing sCR from non-sCR were pretreatment Ktrans (0.7020 min-1) and DKtrans (0.0437 min-1). CONCLUSIONS: Quantitative parameters (pre-mean Ktrans, DKtrans, and pre-mean Ktrans) combined with post-mean ADC could predict treatment efficacy more precisely. However, quantitative DCE-MRI combined with DWI could not significantly improve prognostic efficacy.