The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.
Magnetic Resonance Imaging/instrumentation* ; Humans ; Image Processing, Computer-Assisted/methods* ; Nonlinear Dynamics ; Magnetic Fields ; Algorithms ; Phantoms, Imaging

Iron overload is strongly associated with heart disease. Ferroptosis is a new form of regulated cell death indicated in cardiac ischemia-reperfusion (I/R) injury. However, the specific molecular mechanism of myocardial injury caused by iron overload in the heart is still unclear, and the involvement of ferroptosis in iron overload-induced myocardial injury is not fully understood. In this study, we observed that ferroptosis participated in developing of iron overload and I/R-induced cardiomyopathy. Mechanistically, we discovered that Parkin inhibited iron overload-induced ferroptosis in cardiomyocytes by promoting the ubiquitination of long-chain acyl-CoA synthetase 4 (ACSL4), a crucial protein involved in ferroptosis-related lipid metabolism pathways. Additionally, we identified p53 as a transcription factor that transcriptionally suppressed Parkin expression in iron-overloaded cardiomyocytes, thereby regulating iron overload-induced ferroptosis. In animal studies, cardiac-specific Parkin knockout mice (Myh6-CreER ^T2 /Parkin ^fl/fl ) fed a high-iron diet presented more severe myocardial damage, and the high iron levels exacerbated myocardial I/R injury. However, the ferroptosis inhibitor Fer-1 significantly suppressed iron overload-induced ferroptosis and myocardial I/R injury. Moreover, Parkin effectively protected against impaired mitochondrial function and prevented iron overload-induced mitochondrial lipid peroxidation. These findings unveil a novel regulatory pathway involving p53-Parkin-ACSL4 in heart disease by inhibiting of ferroptosis.

Objective: To understand the attitudes and perceptions of traditional Chinese medicine (TCM) practitioners in Beijing TCM hospitals regarding the use of Ephedra sinica Stapf (E. sinica, Ma Huang). Methods: A two-stage cross-sectional study was conducted using a questionnaire survey of TCM practitioners in Beijing TCM hospitals between April 2023 and March 2024. The questionnaire included demographic information, the clinical background of TCM practitioners, and the clinical application of E. sinica. Logistic regression analysis was used to analyze the relevant influencing factors when using E. sinica. Results: Of the 465 questionnaires collected, 441 were valid. Among these, 84.81% (374/441) reported having used E. sinica in clinical practice at least once. The commonly used doses of E. sinica—excluding the pediatric department—were 10 g for high doses, 6 g for medium, and 3 g for low. The three most frequently used formulas for E. sinica included Maxing Shigan decoction, Mahuang decoction, and Xiao Qing Long decoction. The most common TCM patterns treated with a high dose of E. sinica were wind-cold exterior pattern, wind-cold invading the lung, and wind and water combat with meridians congealed by cold. The top three Western medical diagnoses when using E. sinica for treatment were common cold, pneumonia, and upper respiratory tract infections. Nearly half of the respondents reported experiencing adverse reactions from the oral administration of E. sinica, with the most common being palpitations, insomnia, and restlessness. Starting with a low dose and gradually increasing it as appropriate was identified as an effective approach. Conclusion This study investigated the attitudes and perceptions of TCM practitioners in Beijing TCM hospitals regarding the dose–efficacy–adverse reaction relationship of E. sinica, providing a reference for the safe and effective clinical use of E. sinica.

Objective To observe the feasibility of 5.0T MR for cardiac imaging.Methods Three patients with heart diseases and 17 healthy volunteers were prospectively enrolled.Cardiac MR(CMR)cine sequence and black blood sequence imaging were performed using 5.0T and 3.0T MR scanner,respectively.The image quality and artifacts degrees were compared between 5.0T and 3.0T CMR images,and the consistency of left ventricular parameters obtained using 5.0T and 3.0T scanners was analyzed.Results No significant difference of image quality nor artifacts degrees was found between 5.0T and 3.0T CMR images(all P＞0.05).The left ventricular end diastolic volume(EDV),end systolic volume(ESV),ejection fraction(EF),stroke volume(SV)and end diastolic mass(EDM)derived from cine images acquired at different fields were in a good agreement(all ICC＞0.75,all P＜0.001).Conclusion 5.0T MR could be used for cardiac imaging,with image quality of cine and black blood sequences comparable to that of 3.0T MR.

Objective To observe the value of susceptibility weighted imaging(SWI)based on 5.0T MRI for diagnosing hepatocellular carcinoma(HCC)complicated with vein tumor thrombi.Methods Totally 63 HCC patients were retrospectively enrolled,among them 17 complicated with vein tumor thrombi.The efficacy of 5.0T SWI for detecting vein tumor thrombus was observed,and the image quality were compared between 5.0T and 3.0T.Results 5.0T SWI displayed vein tumor thrombi in 16 cases,except for 1 case with vein tumor thrombi in the upper segment of the left lateral lobe of the left portal vein.The liver edge score,overall image quality score,signal-to-noise ratio and contrast-to-noise ratio of portal venous phase and hepatobiliary phase in 5.0T enhanced MRI were all higher than those in 3.0T(all P＜0.05).Conclusion 5.0T SWI was helpful for diagnosing HCC complicated with vein tumor thrombi.

Objective:To investigate the value of three-dimensional (3D) T 1WI structural images using different acceleration methods including parallel acquisition technique, joint compressed sensing (uCS) technique, and artificial intelligence-assisted compressed sensing (ACS) technique for brain region segmentation. Methods:In this cross-sectional study, fifty patients (female: n=25, age range: 13 to 87 years old) at Corning Hospital of Ningbo University from July to September 2023 were prospectively and consecutively collected. All the subjects underwent brain MRI. Six groups of 3D T 1WI structural images were obtained using different acceleration technique and parameters, including 3D T 1WI without acceleration factor (3D-T 1WI group), 3D T 1WI with parallel acquisition technique with acceleration factor 3 (3D-T 1WI-PI-3 group), 3D T 1WI with uCS technique with acceleration factor 4.5 and 6.9 (3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group), 3D T 1WI by ACS technique with acceleration factors of 3 and 5 (3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group). T 2WI fluid-attenuated inversion recovery (FLAIR) images were also acquired. Subjective scores (cerebral grey matter and white matter clarity scores, clarity scores of cerebral white matter degeneration lesions in relation to the surrounding white matter, and Gibbs artifact scores) and objective metrics [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), cerebrospinal fluid signal homogeneity, peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), and natural image quality evaluator (NIQE)] were used to evaluate image quality in different groups. Totally 109 brain regions were segmented and volumes were measured using the uAI Research Portal image analysis tool. Kappa or intraclass correlation coefficient ( ICC) was used to evaluate the agreement of subjective and objective evaluation indexes between the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group, and 3D-T 1WI group. Kappa or ICC value>0.70 was considered as good agreement. Results:The acquisition time for the 3D-T 1WI group, 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group were 527, 204, 169, 95, 133, 90 s, respectively. Subjective evaluation showed that the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups had excellent agreement with the 3D-T 1WI group in terms of the distribution of cases of cerebral grey matter and white matter clarity scores, respectively (all Kappa value=1.000); The distribution of cases of clarity score of cerebral white matter lesions and surrounding white matter in the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group were in good agreement with that of the 3D-T 1WI group ( Kappa values of 0.775, 0.701, and 0.777, respectively); the distribution of the number of cases of the Gibbs artifact score of the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups was in good agreement with the 3D-T 1WI group (all Kappa value=1.000). Objective evaluation showed the CNR of the images in the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, and 3D-T 1WI-uCS-6.9 groups were in good agreement with those of the 3D-T 1WI group ( ICC of 0.720, 0.759, and 0.752, respectively); PSNR and SSIM were in good agreement among the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group (PSNR: ICC=0.854; SSIM: ICC=0.851). NIQE of 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group images were in good agreement with the 3D-T 1WI group ( ICC value of 0.866, 0.727, 0.753, respectively). The ICC values of the volume of each segmented brain region among the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, 3D-T 1WI-uCS-6.9, 3D-T 1WI-ACS-3, 3D-T 1WI-ACS-5 group and the 3D-T 1WI group images showed decreased in order (all ICC≥0.62). Conclusions:The uCS and ACS techniques used in 3D-T 1WI show high agreement with 3D-T 1WI in terms of brain segmentation. The application of these accelerating techniques can significantly shorten the acquisition time with obtaining images with good image quality, displaying great value.

【Objective】 To investigate the efficacy and surgical technique of total laparoscopic radical cystectomy with intracorporeal ileal conduit urinary diversion, so as to provide reference for the selection of surgery for patients with bladder cancer. 【Methods】 Clinical data of 48 patients with bladder cancer who underwent laparoscopic radical cystectomy during Mar.2017 and Aug.2022 in our hospital were retrospectively analyzed, including 23 cases who received traditional laparoscopic radical cystectomy combined with extracorporeal ileal conduit, and 25 who received total laparoscopic radical cystectomy with intracorporeal ileal conduit.The operation time, blood loss, postoperative intestinal function recovery time, drainage tube removal time and hospital stay were compared between the two groups. 【Results】 All procedures were successfully performed, and no Clavien-Dindo>grade 3 complications were observed.The operation time, and amount of estimated blood loss of the traditional group and total laparoscopic radical group were (227.0±46.4) min vs. (253.6±58.9) min, and (131.7±79.8) mL vs. (154.0±93.0) mL, respectively.There were no differences in postoperative intestinal function recovery time and drainage tube removal time (P>0.05).The hospital stay was shorter in the total laparoscopic radical group than in the traditional group (P=0.035). 【Conclusion】 Total laparoscopic radical cystectomy with intracorporeal ileal conduit urinary diversion is safe and feasible.which is comparable to the traditional laparoscopic surgery, while the hospital stay in the total laparoscopic group is shorter, which is conducive to rapid postoperative recovery.

Alzheimer's disease (AD) is associated with the impairment of white matter (WM) tracts. The current study aimed to verify the utility of WM as the neuroimaging marker of AD with multisite diffusion tensor imaging datasets [321 patients with AD, 265 patients with mild cognitive impairment (MCI), 279 normal controls (NC)], a unified pipeline, and independent site cross-validation. Automated fiber quantification was used to extract diffusion profiles along tracts. Random-effects meta-analyses showed a reproducible degeneration pattern in which fractional anisotropy significantly decreased in the AD and MCI groups compared with NC. Machine learning models using tract-based features showed good generalizability among independent site cross-validation. The diffusion metrics of the altered regions and the AD probability predicted by the models were highly correlated with cognitive ability in the AD and MCI groups. We highlighted the reproducibility and generalizability of the degeneration pattern of WM tracts in AD.
Humans ; White Matter/diagnostic imaging* ; Diffusion Tensor Imaging/methods* ; Alzheimer Disease/complications* ; Reproducibility of Results ; Cognition ; Cognitive Dysfunction/complications* ; Brain/diagnostic imaging*

Basilar artery trunk aneurysms (BTAs) are relatively rare, with poor natural prognosis, high disability and mortality rates. The treatment options for BTAs includes conservative treatment, craniotomy, and endovascular treatment. Due to the deep anatomical structure, rich perforating vessels, and complex pathological structure of the basilar artery, craniotomy is more difficult. There is currently no consensus on the treatment of BTAs. This article reviews the current treatment status of BTAs, aiming to provide reference for clinical work.

Objective:To evaluate the safety and efficacy of laparoscopic nipple-inserted ureteral bladder reimplantation in the treatment of ureteral stricture in kidney recipients.Methods:Two patients with ureteral stenosis after kidney transplantation who underwent laparoscopic nipple-inserted ureteral bladder reimplantation in our hospital in November 2020 and May 2021 were retrospectively analyzed. Case 1, Female, 54 years old, the patient found mild hydronephrosis in the transplanted kidney 2 years before the operation. Ultrasound showed aggravated hydronephrosis 1 week before the operation, and the width of the renal pelvis was 2.9 cm. Nephrostomy was performed before the operation, and antegrade radiography showed that the ureteral anastomosis was narrow, about 2 cm in length, and the grade of ureteral stenosis in the transplanted kidney was grade 3. Case 2, Male, 56 years old, the patient was previously diagnosed with transplanted kidney hydronephrosis, ureterolithiasis and ureteral stricture, and had undergone percutaneous nephrolithotripsy for transplanted kidney and balloon dilatation for ureteral stricture. However, the hydronephrosis and calculus of the transplanted kidney recurred. One month before the operation, due to sudden anuria, a nephrostomy was performed in our hospital. Ultrasound indicated that the transplanted renal pelvis was dilated, and the width of the renal pelvis was 3.1 cm. The grade of ureteral stricture of the transplanted kidney was grade 3. Both patients underwent transabdominal laparoscopy to dissociate and disconnect the ureter, and performed ureteral papillaplasty outside the abdominal cavity to complete ureteral reimplantation. Data on operation time, intraoperative blood loss, intraoperative and postoperative complications, and postoperative follow-up data were collected.Results:Both operations were successfully completed. The operation time was 145 and 180 minutes respectively. The intraoperative blood loss was 30 ml and 50 ml, respectively. The patient had no postoperative complications, and the renal function recovered compared with before. The double J tube was removed 12 weeks after the operation, and ultrasound showed that the width of the renal pelvis recovered to 0.8 cm and 1.1 cm respectively. The two patients were followed up for 18 and 12 months, respectively, and no recurrence of hydronephrosis was found.Conclusions:Laparoscopic nipple-inserted ureteral bladder reimplantation is a safe and effective method for the treatment of allograft ureteral stenosis, which has the advantages of minimally invasive, faster recovery, and fewer complications.