Dynamic contrast-enhanced MR imaging in identifying active anal fistula after surgery.

BACKGROUND: It is challenging to identify residual or recurrent fistulas from the surgical region, while MR imaging is feasible. The aim was to use dynamic contrast-enhanced MR imaging (DCE-MRI) technology to distinguish between active anal fistula and postoperative healing (granulation) tissue. METHODS: Thirty-six patients following idiopathic anal fistula underwent DCE-MRI. Subjects were divided into Group I (active fistula) and Group IV (postoperative healing tissue), with the latter divided into Group II (≤ 75 days) and Group III (> 75 days) according to the 75-day interval from surgery to postoperative MRI reexamination. MRI classification and quantitative analysis were performed. Correlation between postoperative time intervals and parameters was analyzed. The difference of parameters between the four groups was analyzed, and diagnostic efficiency was tested by receiver operating characteristic curve. RESULTS: Wash-in rate (WI) and peak enhancement intensity (PEI) were significantly higher in Group I than in Group II (p = 0.003, p = 0.040), while wash-out rate (WO), time to peak (TTP), and normalized signal intensity (NSI) were opposite (p = 0.031, p = 0.007, p = 0.010). Area under curves for discriminating active fistula from healing tissue within 75 days were 0.810 in WI, 0.708 in PEI, 0.719 in WO, 0.783 in TTP, 0.779 in NSI. All MRI parameters were significantly different between Group I and Group IV, but not between Group II and Group III, and not related to time intervals. CONCLUSION: In early postoperative period, DCE-MRI can be used to identify active anal fistula in the surgical area. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000033072.

M-MSSEU: source-free domain adaptation for multi-modal stroke lesion segmentation using shadowed sets and evidential uncertainty.

Due to the unavailability of source domain data encountered in unsupervised domain adaptation, there has been an increasing number of studies on source-free domain adaptation (SFDA) in recent years. To better solve the SFDA problem and effectively leverage the multi-modal information in medical images, this paper presents a novel SFDA method for multi-modal stroke lesion segmentation in which evidential deep learning instead of convolutional neural network. Specifically, for multi-modal stroke images, we design a multi-modal opinion fusion module which uses Dempster-Shafer evidence theory for decision fusion of different modalities. Besides, for the SFDA problem, we use the pseudo label learning method, which obtains pseudo labels from the pre-trained source model to perform the adaptation process. To solve the unreliability of pseudo label caused by domain shift, we propose a pseudo label filtering scheme using shadowed sets theory and a pseudo label refining scheme using evidential uncertainty. These two schemes can automatically extract unreliable parts in pseudo labels and jointly improve the quality of pseudo labels with low computational costs. Experiments on two multi-modal stroke lesion datasets demonstrate the superiority of our method over other state-of-the-art SFDA methods.

Analysis of magnetic resonance splectroscopy characteristics in patients with type 2 diabetes complicated with stroke.

In this study, we investigated the metabolism of white matter by magnetic resonance spectroscopy (MRS) in stroke complicated with diabetes mellitus in combination with glycosylated hemoglobin (HbAlc) detection and clinical neurological deficit score (NIHSS). Fifty-three patients with stroke within 24 h after onset were collected and scanned by MRS. The biochemical, clinical and imaging characteristics of patients were analyzed. Patients were divided into three groups according to HbAlc levels: Good glycemic control (A): < 6.5%; satisfactory glycemic control (B): 6.5-7.5% and poor glycemic control (C): > 7.5%. The results showed that HbA1c levels were positively correlated with NIHSS in patients with acute ischemic stroke (AIS). There is significant difference in NAA/Cr between the infarcted site of the three groups and the mirror site. HbA1C level was negatively correlated with NAA/Cr in patients with AIS, and there was no significant correlation between NIHSS score and NAA/Cr. The data above demonstrated that the MRS imaging can be used to explain the adverse effects of hyperglycated hemoglobin on brain parenchyma from the perspective of imaging. This imaging technique and clinical NIHSS score have a high consistency in evaluating stroke.

Using Deep Learning Radiomics to Distinguish Cognitively Normal Adults at Risk of Alzheimer's Disease From Normal Control: An Exploratory Study Based on Structural MRI.

Objectives: We proposed a novel deep learning radiomics (DLR) method to distinguish cognitively normal adults at risk of Alzheimer's disease (AD) from normal control based on T1-weighted structural MRI images. Methods: In this study, we selected MRI data from the Alzheimer's Disease Neuroimaging Initiative Database (ADNI), which included 417 cognitively normal adults. These subjects were divided into 181 individuals at risk of Alzheimer's disease (preAD group) and 236 normal control individuals (NC group) according to standard uptake ratio >1.18 calculated by amyloid Positron Emission Tomography (PET). We further divided the preaAD group into APOE+ and APOE- subgroups according to whether APOE ε4 was positive or not. All data sets were divided into one training/validation group and one independent test group. The proposed DLR method included three steps: (1) the pre-training of basic deep learning (DL) models, (2) the extraction, selection and fusion of DLR features, and (3) classification. The support vector machine (SVM) was used as the classifier. In the comparative experiments, we compared our proposed DLR method with three existing models: hippocampal model, clinical model, and traditional radiomics model. Ten-fold cross-validation was performed with 100 time repetitions. Results: The DLR method achieved the best classification performance between preAD and NC than other models with an accuracy of 89.85% ± 1.12%. In comparison, the accuracies of the other three models were 72.44% ± 1.37%, 82.00% ± 4.09% and 79.65% ± 2.21%. In addition, the DLR model also showed the best classification performance (85.45% ± 9.04% and 92.80% ± 2.61%) in the subgroup experiment. Conclusion: The results showed that the DLR method provided a potentially clinical value to distinguish preAD from NC.

Biomedical engineering of two-dimensional MXenes.

The emergence of two-dimensional (2D) transition metal carbides, carbonitrides and nitrides, referred to MXenes, with a general chemical formula of Mn+1XnTx have aroused considerable interest and shown remarkable potential applications in diverse fields. The unique ultrathin lamellar structure accompanied with charming electronic, optical, magnetic, mechanical and biological properties make MXenes as a kind of promising alternative biomaterials for versatile biomedical applications, as well as uncovering many new fundamental scientific discoveries. Herein, the current state-of-the-art advances of MXenes-related biomaterials are systematically summarized in this comprehensive review, especially focusing on the synthetic methodologies, design and surface engineering strategies, unique properties, biological effects, and particularly the property-activity-effect relationship of MXenes at the nano-bio interface. Furthermore, the elaborated MXenes for varied biomedical applications, such as biosensors and biodevices, antibacteria, bioimaging, therapeutics, theranostics, tissue engineering and regenerative medicine, are illustrated in detail. Finally, we discuss the current challenges and opportunities for future advancement of MXene-based biomaterials in-depth on the basis of the present situation, aiming to facilitate their early realization of practical biomedical applications.

Study on collateral circulation level and prognosis of acute ischemic stroke by 4D CTA-CTP integrated technology and serum S100B.

OBJECTIVE: To evaluate the cerebral collateral circulation in patients with acute ischemic stroke (AIS) by Four-dimensional CT angiography-CT perfusion (4D CTA-CTP)-integrated technology, and to explore the feasibility of predicting the prognosis of patients with AIS by using cerebral collateral circulation and serum S100B protein concentration. METHODS: Thirty-two patients with anterior circulation AIS who underwent 4D CTA-CTP were retrospectively analysed. The level of cerebral collateral circulation was assessed by multi-phase CT angiography (mCTA) scores and regional leptomeningeal collateral (rLMC) scores. Combined with serum S100B protein concentration, multivariate binary logistic regression was used to explore the indicators that can independently predict the prognosis of AIS neurological function. RESULTS: Univariate analysis showed that the baseline National Institutes of Health stroke scale score, rLMC score, and mCTA score were correlated with the neurological prognosis of patients with AIS; multivariate analysis showed that mCTA cerebral collateral circulation score was the only indicator that could independently predict the neurological prognosis of AIS patients (OR = 0.065, P = 0.030). The baseline serum S100B protein concentration could not independently predict the neurological prognosis of AIS patients. CONCLUSION: mCTA cerebral collateral circulation scores can independently predict the neurological prognosis of patients with AIS. For the assessment of neurological prognosis of AIS patients, the cerebral collateral circulation phase score is better than the regional score.

Quantitative CT for detecting COVID­19 pneumonia in suspected cases.

BACKGROUND: Corona Virus Disease 2019 (COVID-19) is currently a worldwide pandemic and has a huge impact on public health and socio-economic development. The purpose of this study is to explore the diagnostic value of the quantitative computed tomography (CT) method by using different threshold segmentation techniques to distinguish between patients with or without COVID-19 pneumonia. METHODS: A total of 47 patients with suspected COVID-19 were retrospectively analyzed, including nine patients with positive real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR) test (confirmed case group) and 38 patients with negative RT-PCR test (excluded case group). An improved 3D convolutional neural network (VB-Net) was used to automatically extract lung lesions. Eight different threshold segmentation methods were used to define the ground glass opacity (GGO) and consolidation. The receiver operating characteristic (ROC) curves were used to compare the performance of various parameters with different thresholds for diagnosing COVID-19 pneumonia. RESULTS: The volume of GGO (VOGGO) and GGO percentage in the whole lung (GGOPITWL) were the most effective values for diagnosing COVID-19 at a threshold of - 300 HU, with areas under the curve (AUCs) of 0.769 and 0.769, sensitivity of 66.67 and 66.67%, specificity of 94.74 and 86.84%. Compared with VOGGO or GGOPITWL at a threshold of - 300 Hounsfield units (HU), the consolidation percentage in the whole lung (CPITWL) with thresholds at - 400 HU, - 350 HU, and - 250 HU were statistically different. There were statistical differences in the infection volume and percentage of the whole lung, right lung, and lobes between the two groups. VOGGO, GGOPITWL, and volume of consolidation (VOC) were also statistically different at the threshold of - 300 HU. CONCLUSIONS: Quantitative CT provides an image quantification method for the auxiliary diagnosis of COVID-19 and is expected to assist in confirming patients with COVID-19 pneumonia in suspected cases.

Preoperative CT feature of incomplete overlying enhancing mucosa as a high-risk predictor in gastrointestinal stromal tumors of the stomach.

OBJECTIVES: To determine whether the CT finding of overlying enhancing gastric mucosa (OEGM) can be used to predict risk stratifications by observing CT features of gastrointestinal stromal tumors (GISTs) of the stomach. METHODS: Clinical characteristics and CT features within pathologically demonstrated GISTs were retrospectively reviewed. Risk stratifications were classified into non-high group and high-risk group according to the modified National Institutes of Health criteria. Univariate analysis and multivariate logistic regression analysis were performed in order to determine significant predictors for high-risk stratification. Receiver operating characteristic (ROC) curve analysis, subgroup analysis, and pathologic-radiologic correlation analysis were all executed. RESULTS: A total of 147 patients were finally enrolled as test subjects. Within the univariate analysis, high-risk tumors tended to have a larger diameter, irregular shape, exophytic growth pattern, present necrosis, incomplete OEGM, tumor vessels, heterogeneous enhancement, and present rupture. According to ROC curve analysis, incomplete OEGM showed the largest area under curve values for diagnosing lesions (0.835; 95% CI, 0.766-0.904; p < 0.001). Multivariate analysis showed that the incomplete OEGM was the strongest independent predictor for high-risk stratification of gastric GISTs (OR = 21.944; 95% CI, 4.344-110.863; p < 0.001). Within the subgroup analysis, incomplete OEGM was more frequently associated with tumors size > 10 cm, irregular shape, exophytic growth pattern, high mitotic count, and disrupted mucosa on pathology. CONCLUSIONS: The CT feature of incomplete OEGM is an independent predictive factor for high-risk stratification of gastric GISTs and strongly correlated with pathological mucosal changes. KEY POINTS: • Preoperative CT features can be helpful in assessment of risk stratifications of gastric GISTs. • OEGM is an independent predictor for high-risk stratification of gastric GISTs. • Incomplete OEGM likely indicates high-risk stratification of gastric GISTs.

Sclerostin Antibody Mitigates Estrogen Deficiency-Inducted Marrow Lipid Accumulation Assessed by Proton MR Spectroscopy.

Sclerostin knock-out mice or sclerostin antibody (Scl-Ab) treated wild-type mice displayed decreased marrow adiposity. But the effects of Scl-Ab on estrogen deficiency-induced marrow fat expansion remain elusive. In this work, 45 female New Zealand rabbits were equally divided into sham-operation, ovariectomy controls, and ovariectomy treated with Scl-Ab for 5 months. MR spectroscopy was performed to longitudinally assess marrow fat fraction at baseline conditions, 2.5 and 5 months post-operatively, respectively. We evaluated bone mineral density (BMD), bone structural parameters, serum bone biomarkers, and quantitative parameters of marrow adipocytes. Ovariectomized rabbits markedly exhibited expansion of marrow fat in a time-dependent manner, with a variation of marrow fat fraction (+17.8%) at 2.5 months relative to baseline and it was maintained until 5 months (+30.4%, all P < 0.001), which was accompanied by diminished BMD and deterioration of trabecular microstructure. Compared to sham controls, adipocyte mean diameter, adipocyte density and adipocytes area percentage was increased by 42.9, 68.3, and 108.6% in ovariectomized rabbits, respectively. Scl-Ab treatment increased serum bone formation marker and alleviated the ovariectomy escalation of serum bone resorption marker. It remarkably lessened the ovariectomy-mediated deterioration of BMD, and morphometric characteristics of trabecular bone. Marrow fat fraction was decreased significantly with Scl-Ab to levels matching that of sham-operated controls and correlated positively with reductions in adipocyte mean diameter, percentage adipocyte volume per marrow volume, and adipocyte density. Taken together, early Scl-Ab treatment reverts marrow fat expansion seen in ovariectomized rabbits in addition to having a beneficial effect on bone mass and microstructural properties.

Malignant solitary fibrous tumor of the kidney with liver metastasis: A case report and literature review.

Solitary fibrous tumor (SFT) is a rare spindle cell soft tissue tumor which is rarely encountered in the clinical setting and imaging findings are nonspecific, mainly occurring in the tissue structure of the serosa. However, there is very little report on SFT originating in the kidney in the medical literature. We report a case of SFT with liver metastasis in an adult female and discuss the pathological features as it appears in our case.

[Analysis of mutations of 4 common genes among 216 patients with non-syndromic hearing impairment].

OBJECTIVE: To explore the characteristics of mutations 4 common deafness-related genes among 216 patients from Shanghai area with non-syndromic hearing impairment (NSHI). METHODS: Thirteen mutation sites in the four genes, namely GJB2 (c.35delG, c.176del16, c.235delC, c.299delAT, and c.155delTCTG), SLC26A4 (c.IVS7-2A>G, c.2168A>G, and c.1229C>T), mtDNA 12SrRNA (m.1494C>T, m.1555A>G, m.7445A>G, and m.12201T>C) and GJB3 (c.538C>T) were detected among the 216 patients and 41 individuals with normal hearing. The frequency and types of mutations were compared between the two groups. RESULTS: Among the 216 NSHI patients, the total detection rate was 16.20% (35/216). GJB2 mutations were found in 17(7.87%) of the 216 patients, which included 5 cases with homozygous c.235delC mutation, 5 with homozygous c.235delC mutation, 1 with homozygous c.299delAT mutation, and 1 with homozygous c.299delAT mutation. c.235delC and 299delAT mutations were found in 5 cases. SLC26A4 mutation was found in 12(5.56%) of the 216 patients, which included 2 cases with homozygous c.IVS7-2A>G mutation, 9 with homozygous c.IVS7-2A>G mutation, and 1 with homozygous c.2168A>G mutation. Homogeneous mtDNA 12SrRNA m.1555A>G mutation was found in 6(2.78%) of the 216 patients. No GJB3 gene mutation was detected. No mutation of the 4 genes were detected in the 41 individuals with normal hearing. In 2 cases of the 12 patients with SLC26A4 gene mutation, CT scan of the temporal bone has confirmed expansion of vestibular aqueduct. CONCLUSION: Above results indicated that GJB2 and SLC26A4 were the major genes involved with hearing loss in Shanghai area.

The Value of Performing Early Non-enhanced CT in Developing Strategies for Treating Acute Gallstone Pancreatitis.

BACKGROUND: The purpose of this study is to assess the value of early abdominal non-enhanced computed tomography (NECT) in developing strategies for treating acute gallstone pancreatitis (AGP). METHODS: AGP patients underwent NECT within 48 h after symptom onset to determine the presence of peripancreatic fluid collection, gallstones, and common bile duct stones. Patients with mild AGP who had neither organ failure by clinical data nor peripancreatic fluid collection by NECT (classified as grade A, B, or C based on the Balthazar CT grading system) were randomized to undergo an early laparoscopic cholecystomy (ELC; LC performed within 7 days after a pancreatitis attack, without waiting for symptom resolution) or late laparoscopic cholecystomy (LLC; LC performed ≥ 7 days following an attack, with the patient being completely free of AGP symptoms). RESULTS: The study enrolled 102 patients with mild AGP defined by clinical data and NECT. NECT was 89.2 % and 87.8 % accurate in detecting gallbladder stones and CBD stones, respectively. Totals of 49 and 53 patients were assigned to an ELC and LLC group, respectively. All patients in both groups were cured, no LC-related complications occurred, and no case of AGP increased in severity following LC. The mean lengths of hospital stay and LC operation time were significantly shorter in the ELC group than the LLC group (P < 0.05). CONCLUSIONS: NECT can accurately detect peripancreatic fluid collection and biliary obstructions; thus, early abdominal NECT is valuable when developing strategies for treating AGP. Patients with mild AGP without organ failure or peripancreatic fluid collection can safely undergo ELC without waiting for complete resolution of their pancreatitis.

Magnetic resonance imaging characteristics of hepatocyte apoptosis (induced by right portal vein ligation) and necrosis (induced by combined right portal vein and right hepatic artery ligation) in rats.

OBJECTIVE: Using magnetic resonance imaging (MRI), this study aimed to demonstrate the appearance of hepatocytes following ligation of the right portal vein or combined ligation of the right portal vein and right hepatic artery, in a rat model. METHODS: Ninety adult Sprague-Dawley rats (body weight 250-300 g) were divided into three groups (n = 30 per group): ligation of the right portal vein (Group A); combined ligation of the right portal vein and right hepatic artery (Group B); no intervention to obstruct blood supply (control group). Rats were then randomly subdivided into five groups that underwent examination at 3 h and 1, 3, 7 and 14 days postprocedure (n = 6 per group). Livers were examined by routine MRI, diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS). After examination, each group of rats was sacrificed. Right hepatic lobes were removed and examined by pathology in six rats per timepoint; transmission electron microscopy (TEM) was undertaken in up to three rats per timepoint. RESULTS: Hepatocyte apoptosis and necrosis, by right portal vein ligation and combined right portal vein and right hepatic artery ligation respectively, were confirmed by pathology and TEM. In Group A, there were slight increases in intensity of T1- and T2-weighted images and in the apparent diffusion coefficient (ADC). In addition there were larger areas under the lactic acid and lipid peaks on MRS. In Group B, there were increased T1 and T2 signals, a decrease in the ADC and an increase of the area under the lactic acid peaks on MRS. CONCLUSIONS: Hepatocyte apoptosis and necrosis induced by ligation procedures exhibited specific changes that were evident on MRI, DWI and MRS, and could be detected in vivo by MRI, in a rat model.

[Association between clinical ischemic events and carotid calcification evaluated by 64 slices CT angiography].

OBJECTIVE: To explore the relationship between clinical ischemic events and carotid calcification detected by 64 slices CT angiography. METHODS: We retrospectively analyzed the carotid calcified plaques in 116 patients underwent the 64 slices CT angiography. The relationship between the carotid calcification and the clinical ischemic events was analyzed. RESULTS: A total of 377 plaques were detected and the incidence of carotid plaque calcification was 63.40%. Incidence of plaque calcification was significantly lower in patients with ages < 50 years than that in patients with ages 51 - 59 years, 60 - 69 years and higher than 70 years (P = 0.003, P = 0.002, P = 0.000, respectively). The incidence of plaque calcification in the common carotid artery was significantly lower than the carotid bifurcation (P = 0.000) and the internal carotid artery (P = 0.000). The incidences of calcification in the mild, moderate and severe degree of stenosis and occlusion were 46.54%, 33.33%, 26.67% and 0% respectively. The distribution of intraplaque calcium was similar between patients with ischemic event and non-ischemic event group. However, the incidence of calcification was significantly lower patients with ischemic event than that in patients without ischemic event (30.34% vs. 43.10%, P = 0.013). Calcified plaque was negatively associated with ischemic event (beta = -0.688, P = 0.006). CONCLUSION: 64 slices CT angiography can analyze the characterization of carotid plaque calcium.