Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 2.199
Filter
1.
Journal of Sun Yat-sen University(Medical Sciences) ; (6): 114-120, 2024.
Article in Chinese | WPRIM | ID: wpr-1007282

ABSTRACT

ObjectiveTo assess the microstructural involvement of gray matter in recovered COVID-19 patients using Synthetic MRI. MethodsThis study was conducted in 29 recovered COVID-19 patients, including severe group (SG, n=11) and ordinary group (OG, n=18). Healthy volunteers matched by age, sex, BMI and years of education were selected as a healthy control group (HC=23 cases). Each subject underwent synthetic MRI to generate quantitative T1 and T2 maps, and the T1 and T2 maps were segmented into 90 regions of interest (ROIs) using automatic anatomical labeling (AAL) mapping. T1 and T2 values for each ROI were obtained by averaging all voxels within the ROIs. The T1 and T2 values of the 90 brain regions between the three groups were compared. ResultsRelative to HC, the SG had significantly higher T2 values in bilateral orbital superior frontal gyrus, bilateral parahippocampal gyrus, bilateral putamen, bilateral middle temporal gyrus, bilateral Inferior temporal gyrus, left orbital superior frontal gyrus, left orbital inferior frontal gyrus, left gyrus rectus, left anterior cingulate and paracingulate gyri, right median cingulate and paracingulate gyri, left posterior cingulate gyrus, and left supramarginal gyrus (P<0.05); Relative to OG, SG showed significantly increased T2 values in the left rectus gyrus, left parahippocampal gyrus, bilateral middle temporal gyrus, and bilateral inferior temporal gyrus (P<0.05). Relative to HC, the T1 values of SG were significantly increased in bilateral orbital superior frontal gyrus, left rectus gyrus, left anterior cingulate and paracingulate gyri, right posterior cingulate gyrus, left parahippocampal gyrus, left lingual gyrus, left putamen, left thalamus(P<0.05); Relative to OG, the T1 values of SG were significantly higher in the right posterior cingulate gyrus, right calcarine fissure and surrounding cortex, and left putamen (P<0.05). ConclusionsEven after recovering from COVID-19, patients may still have persistent or delayed damage to their brain gray matter structure, which is correlated with the severity of the condition. SyMRI can serve as a sensitive tool to assess the extent of microstructural damage to the central nervous system, aiding in early diagnosis of the disease.

2.
Journal of Sun Yat-sen University(Medical Sciences) ; (6): 100-107, 2024.
Article in Chinese | WPRIM | ID: wpr-1007280

ABSTRACT

ObjectivesTo explore the effect of diffuse glioma with precentral-gyrus invasion on fMRI activation maps by grasping T-fMRI. MethodsA total of 56 diffuse glioma patients were divided into precentral-gyrus invasion (PGI: n=21) and precentral-gyrus non-invasion (PGNI: n=35) groups. Three statistical thresholds (P value: 10-4, P1; 10-6, P2; 10-8, P3) were set to obtain the activation maps accordingly (V1, V2 and V3). The interhemispheric and bilateral precentral gyrus activation volumes ratios (IAVR and PAVR) were calculated, respectively. The activation volumes [△V1=V1-V2; △V2=V2-V3; △Vn (ipsilateral)/△Vn’ (contralateral), n=1, 2] within two statistical thresholds and the corresponding interhemispheric ratio was further compared. In addition, the associations of tumor characteristics with IAVR and PAVR were analyzed. ResultsCompared with PGNI, PGI showed significantly decreased IAVR at p1, and the same trends of PAVR in PGI at P1 and P2 (P<0.05). However, neither IAVR nor PAVR showed significant differences at P3. PGI showed significantly lower ratios of △V1/△V1’ than PGNI (P=0.02), except for △V2/△V2’. Additionally, within PGI, PAVR was negatively correlated with tumor volume (P=0.043), and the distance from the tumor to the hand-knob was positively correlated with the IAVR and PAVR (P<0.05). ConclusionDiffuse glioma invading eloquent areas tended to affect interhemispheric asymmetry of activation at relatively lower statistical thresholds than diffuse glioma without invasion, rather than stricter statistical thresholds. Multiple ranges of statistical thresholds were recommended to analyze T-fMRI.

3.
Int. j. morphol ; 41(4): 1166-1170, ago. 2023. ilus, tab
Article in English | LILACS | ID: biblio-1514353

ABSTRACT

SUMMARY: Sex determination of unknown persons plays an important role in forensic science. As most bones used for sex determination are recovered in incomplete state, it is often necessary to use bones that are recovered intact e.g., the sphenoid sinus. This study aimed to evaluate the diagnostic value of sphenoid sinuses dimensions for sex determination using Magnetic Resonance Imaging (MRI) images in Chinese adults. MRI images of 79 sphenoid sinuses (from 44 men and 35 women) were retrospectively selected. The height, anterior-posterior diameter, area, and perimeter were measured in the midsagittal view of the sphenoid sinuses. All data were subjected to descriptive and discriminative functional analysis with unpaired t-test and canonical discriminant. Comparison between male and female groups showed significant statistical differences regarding the height, anterior-posterior diameter, area, and perimeter of sphenoid sinuses. The predictive accuracy rate of the sphenoid sinus to identify sex was 63.6 % in males and 62.9 % in females with an overall accuracy of 63.3 %. This study proposed the importance of sexual dimorphism of sphenoid sinus dimensions, especially if other methods are not available. It suggested using MRI in forensics science thus obviating the complete dependence on the usage of conventional computed tomography (CT) and facilitating the study of forensic anatomy at the level of soft tissue.


La determinación del sexo de personas desconocidas juega un papel importante en la ciencia forense. Como la mayoría de los huesos utilizados para la determinación del sexo se recuperan en un estado incompleto, a menudo es necesario utilizar huesos recuperados intactos, por ejemplo, el seno esfenoidal. Este estudio tuvo como objetivo evaluar el valor diagnóstico de las dimensiones de los senos esfenoidales para la determinación del sexo utilizando imágenes de resonancia magnética en individuos adultos chinos. Se seleccionaron retrospectivamente imágenes de resonancia magnética de 79 senos esfenoidales (de 44 hombres y 35 mujeres). La altura, el diámetro anteroposterior, el área y el perímetro de los senos esfenoidales, se midieron en vista mediana sagital. Todos los datos se sometieron a análisis funcional descriptivo y discriminativo con prueba t no pareada y discriminante canónico. La comparación entre los grupos de hombres y mujeres mostró diferencias estadísticas significativas en cuanto a la altura, el diámetro anteroposterior, el área y el perímetro de los senos esfenoidales. La tasa de precisión predictiva del seno esfenoidal para identificar el sexo fue del 63,6 % en hombres y del 62,9 % en mujeres, con una precisión general del 63,3 %. Este estudio propuso la importancia del dimorfismo sexual de las dimensiones del seno esfenoidal, especialmente si no se dispone de otros métodos. Se sugiere utilizar la resonancia magnética en la ciencia forense, obviando así la dependencia total del uso de la tomografía computarizada convencional y facilitando con esto el estudio de la anatomía forense a nivel de los tejidos blandos.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Sphenoid Sinus/diagnostic imaging , Magnetic Resonance Imaging , Sex Determination by Skeleton/methods , Sphenoid Sinus/anatomy & histology , Discriminant Analysis , Prospective Studies , Sex Characteristics , Forensic Sciences
4.
Indian J Ophthalmol ; 2023 Jul; 71(7): 2926
Article | IMSEAR | ID: sea-225158

ABSTRACT

Background: In 1978, the advent of magnetic resonance imaging (MRI) was a remarkable volte-face in the world of diagnostics. Employing the phenomenon of nuclear resonance enables us to exploit the properties of differential protons in living tissues. The ability of providing higher and variable contrast and the absence of ionizing radiations make it superior to computed tomography. Being the diagnostic tool of choice, it is an indispensable part of assessment of the location and characteristics of different ocular and orbital pathologies (vascular, inflammatory, and neoplastic). Purpose: The intrinsic and extrinsic properties of MRI provide multi-parametric imaging, making it of paramount importance in ophthalmological evaluation. Also, MRI-dynamic color mapping provides non-invasive and quantitative assessment of soft tissues in motion. An in-depth knowledge of the basic principle and technique of MRI aids in diagnosing as well optimal planning of surgical interventions. Synopsis: In this video, we shall be displaying the anatomical, clinical, and radiological aspects of MRI with an overlap to make it easier to understand the implications of this miraculous invention. Highlights: A good understanding of MRI analysis makes the ophthalmologists independent and helps in ruling out the differential diagnoses, exact extent and invasion, precise surgical planning and therefore, avoiding tragic outcomes. This video is an attempt to simplify and emphasize on the importance of MRI interpretation for an ophthalmologist.

5.
Article | IMSEAR | ID: sea-220320

ABSTRACT

AA amyloidosis is a classic and serious complication of many chronic inflammatory processes, whether of infectious, autoimmune, or neoplastic origin. It is frequently complicated by kidney damage, often in the form of a nephrotic syndrome. Giant cell arteritis is a common inflammatory arteritis in the elderly; however, it rarely causes AA amyloidosis. We report a rare case of Horton disease causing AA amyloidosis in an elderly patient with history of myopericarditis and repeated episodes of congestive heart failure. Patient was treated initially with dual therapy based on corticosteroids and anti TNF therapy (Tocilizumab) associated with heart failure therapy recommended by the European society of cardiology (ESC 2021 guidelines on Heart Failure). The initial outcome was favorable but later complicated by the involvement of the lungs; pulmonary fibrosis, responsible for repeated episodes of pleural effusion non controlled in spite of high dose of loop diuretics and repeated pleural punction. Patient died shortly after her second hospitalization due to respiratory insufficiency.

6.
Article | IMSEAR | ID: sea-220146

ABSTRACT

Background: Stroke is a prevalent and potentially fatal medical condition that affects individuals worldwide. Ischemic strokes, caused by arterial blockages, are the most common type, accounting for about 80% of all cases. Hemorrhagic strokes, on the other hand, are less frequent but can have more severe consequences. Accurate and timely diagnosis of stroke is critical for effective treatment and optimal patient outcomes. In this context, diffusion-weighted imaging (DWI) has emerged as a valuable tool for identifying and monitoring ischemic stroke. This article provides an overview of the role of DWI in stroke assessment and management, with a focus on early detection and intervention. The aim of this study is to investigate the reliability of diffusion-weighted MRI (DWI) as an imaging modality in the evaluation of acute ischemic stroke. Material & Methods: This prospective cross-sectional study was conducted at the Department of Radiology and Imaging at the Combined Military Hospital (CMH) in Dhaka, Bangladesh, between June 2020 and June 2021. The study aimed to examine 120 patients clinically diagnosed with acute ischemic stroke. Prior to the study, verbal consent was obtained from all patients. The Study subjects were identified in the emergency and casualty department and had undergone an MRI of the brain in the Department of Radiology and Imaging at CMH, Dhaka. . Data were collected on pre-designed forms, and the relevant information was compiled on a master chart for statistical analysis using SPSS software. Descriptive analysis and frequency of results were presented in the form of tables, pie charts, and bar graphs. The ethical clearance of this study was obtained from the Institutional Ethics Committee of CMH, Dhaka, Bangladesh. Results: The study included 64 males and 56 females with a mean age of 65.2 ± 7.83 years. The majority of patients had an acute ischemic lesion (88.30%) in the MCA (50.0%) with small-sized lesions (41.7%) and low ADC values (90.0%). The most common clinical presentation was hemiplegia (100%), and diffusion-weighted MRI had a high diagnostic accuracy in detecting acute ischaemic lesions (96.3%). Overall, these findings highlight the importance of MRI in the evaluation of stroke patients and can guide clinical decision-making. Conclusion: The present study concluded that DWI in conjunction with ADC map MR imaging is a gold standard diagnostic modality in the evaluation and management of acute ischaemic stroke.

7.
Indian J Ophthalmol ; 2023 May; 71(5): 2279-2281
Article | IMSEAR | ID: sea-225072

ABSTRACT

We report two adult cases of abducens nerve palsy presenting immediately (within weeks) after they received the first dose of Covishield vaccination. Magnetic resonance imaging (MRI) of the brain obtained after the onset of diplopia demonstrated demyelinating changes. The patients had associated systemic symptoms. Post-vaccination demyelination typically known as acute disseminated encephalomyelitis (ADEM) associated with several vaccines is more common in children. Although the mechanism of the nerve palsy remains unclear, it is suspected to be related to the post-vaccine neuroinflammatory syndrome. Cranial nerve palsies and ADEM-like presentations may represent part of the neurologic spectrum following COVID-vaccination in adults, and ophthalmologists should be aware of these sequelae. Although cases of sixth nerve palsy following COVID vaccination are already reported, associated MRI changes have not been reported from India.

8.
Article | IMSEAR | ID: sea-220334

ABSTRACT

Hypertrophic cardiomyopathy (HCM) is the most common non-ischemic cardiomyopathy with a prevalence of 1:500 in the general population, based on the recognition of the phenotype. HCM is defined by the presence of increased left ventricular (LV) wall thickness that is not solely explained by abnormal loading conditions and the phenotype also includes disorganized myocyte arrangement, fibrosis, small-vessel disease, and abnormalities of the mitral valve apparatus. In particular to this pathology, we have conducted a one-year prospective study to determine clinical, echocardiographic features and etiopathogenic aspects of hypertrophic cardiomyopathy in the Casablanca university hospital. The results concluded that 50% of the causes was due to amyloidosis 35%, sarcomeric HCM and 15% Fabry disease in which 2 cases were related with pregnancy. Transthoracic echocardiography and cardia MRI plays an important role in HCM diagnosis and prognosis.

9.
Article | IMSEAR | ID: sea-222318

ABSTRACT

In a country like India, oral metronidazole is the commonly prescribed drug of choice for entities such as amebiasis and visceral abscesses. Oral such cases, it is usually well tolerated and safe but can cause serious neurological adverse events. Peripheral neuropathy commonly encounters in practice but central nervous system toxicity is also well documented as it crosses the blood–brain barrier easily. Neurological toxicity of metronidazole may be due to prolonged administration, high doses, or high cumulative doses. Magnetic resonance imaging (MRI) of brain is the modality of choice to evaluate brain involvement. In the brain, the splenium of the corpus callosum, dentate nucleus of the cerebellum, and posterior pons involvement are commonly seen and diagnostic. Here, we have an interesting case report of a patient who was on oral metronidazole treatment for his large liver abscess, presenting with a complaint of neurological symptoms of unsteady gait, vertigo, dysdiadochokinesia, and difficulty in speech. Moreover, thus suspected as metronidazole drug toxicity and further investigated for the same, and MRI typically shows cerebellar and posterior corpus callosal involvement

10.
Indian J Cancer ; 2023 Mar; 60(1): 52-58
Article | IMSEAR | ID: sea-221754

ABSTRACT

Background: We aimed to evaluate the role of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography朿omputed tomography (PET-CT) in determining the correct stage and predicting the pathological response. Methods: Seventy one patients with pathologic proven rectal adenocarcinoma, clinical stage IIA-IVA, and neoadjuvant chemoradiotherapy (CRT) were evaluated retrospectively. Radiotherapy was delivered 45� Gy in 25 fractions with concomitant oral capecitabine. Pelvic MRI, colonoscopy, and 18F-FDG PET-CT were performed before the neoadjuvant treatment (NAT). After NAT, MRI and PET-CT were performed for re-evaluation. Results: The median follow-up time was 25 months (range: 3� months). Of the 71 patients who underwent NAT, 57 patients underwent surgery. Downstaging was recorded in 48 (84.2%) of 57 patients who underwent surgery. There was no statistically significant difference between both MRI and PET-CT with pathology results in terms of response evaluation. As a result of the comparison of MRI and PET-CT with pathological results; sensitivity and specificity were 91.6% (44/48) and 22.2% (2/9) for MRI, and 100% (47/47) and 12.5% (1/8) for PET-CT, respectively. Conclusion: PET-CT and MRI are effective in predicting response to NAT and predictive for the pathological response. A more accurate response can be judged when both PET-CT and MRI are executed together in restaging after NAT

11.
Indian J Pediatr ; 2023 Feb; 90(2): 146–152
Article | IMSEAR | ID: sea-223745

ABSTRACT

Objectives To evaluate the relationship between TGFBR3 rs284875 single nucleotide polymorphism (SNP) state and silent cerebral infarction (SCI) in asymptomatic patients with sickle cell disease (SCD). Methods A cross-sectional study was conducted on 50 children with SCD above 2 y of age followed up at the hematology outpatient clinic of Alexandria University Children's Hospital in Egypt. Twenty-four healthy children were included as a control group. All patients included in the study were subjected to complete history and clinical examination. Real-time polymerase chain reaction was performed on patients and controls for identifcation of SNP rs284875 of the TGFBR3 gene. A magnetic resonance imaging (MRI) of the brain were performed only on patients for detection of SCI. Results Fifty SCD patients were enrolled (26 males and 24 females), with a median age of 10.9 y (2.3–17.8 y), and 24 children as healthy control for the studied SNP. Thirty-fve (70%) patients had homozygous SCD, while 30% had sickle ?-thalassemia. The brain MRI was normal in all the patients except for 2 patients who had features of SCI. The TGFBR3 rs284875 SNP was detected in 15 (30%) patients in the homozygous state (GG) versus only 1 (4.2%) child from the control group (p=0.003). The prevalence of SCI was low in the study population and there was no statistically signifcant relationship between the TGFBR3 rs284875 SNP status and the presence of SCI in the brain MRI (p=0.621). Conclusions This study confrmed a low prevalence of SCI in the SCD patient included in the study. The TGFBR3 rs284875 SNP did not signifcantly increase SCI among those patients.

12.
Rev. argent. radiol ; 87(1): 11-22, ene. 2023. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1422989

ABSTRACT

Resumen El ataque cerebrovascular (ACV) es la primera causa de discapacidad y la tercera causa de muerte en la Argentina y en el mundo. La etiología del stroke es isquémica en su mayoría (más del 80% de los casos), siendo las causas más frecuentes las lesiones isquémicas de pequeños vasos de tipo lacunar y las tromboembólicas debido a ateroesclerosis de grandes arterias o cardioembolia. Las secuencias utilizadas en nuestro protocolo de estudio incluyen DWI, FLAIR, angio-RM 3D-TOF, SWI y FSE-T1 (tiempo aproximado de exploración de 13 minutos). Pueden observarse diferentes hallazgos en cada una de estas secuencias que son orientativos para determinar la etiología subyacente y estimar el tiempo de evolución de la lesión. En la actualidad, la trombectomía mecánica se ha convertido en el tratamiento de elección en pacientes seleccionados con accidente cerebral isquémico agudo. La transformación hemorrágica es la complicación más temida luego de la terapia de reperfusión intraarterial. La técnica de difusión de la resonancia magnética (RM) posee una mayor sensibilidad para detectar lesiones isquémicas, permite sospechar la etiología según el patrón lesional y aporta información valiosa para la selección de los pacientes candidatos a la reperfusión arterial.


Abstract Stroke or cerebrovascular attack (CVA) is the first cause of disability and the third cause of death in Argentina and in the world. The etiology of strokes is mostly ischemic (more than 80% of cases), with the most frequent causes being lacunar-type ischemic lesions of small vessels and thromboembolic lesions due to atherosclerosis of large arteries or cardioembolism. The sequences used in our study protocol include DWI, FLAIR, angio-RM 3D-TOF, SWI, and FSE-T1 (approximate scan time of 13 minutes). Different findings can be observed in each of these sequences that are indicative to determine the underlying etiology and estimate the time of evolution of the lesion. Currently, mechanical thrombectomy has become the treatment of choice in selected patients with acute ischemic stroke. Hemorrhagic transformation is the most feared complication after intra-arterial reperfusion therapy. The diffusion magnetic resonance technique is more sensitive for detecting ischemic lesions, allows one to suspect the etiology based on the lesion pattern, and provides valuable information for the selection of patients who are candidates for arterial reperfusion.

13.
Journal of Sun Yat-sen University(Medical Sciences) ; (6): 1008-1015, 2023.
Article in Chinese | WPRIM | ID: wpr-998993

ABSTRACT

ObjectiveTo investigate the feasibility of multiparametric MRI (mpMRI) combined with histogram analysis of apparent diffusion coefficient (ADC) in the assessment of patients with variant histology (VH) of urothelial carcinoma (UC). MethodWe retrospectively analyzed the data of patients pathologically diagnosed with UC who underwent mpMRI in the First Affiliated Hospital of Sun Yat-sen University between March 2015 and March 2023. The patients were divided into VH group (urothelial carcinoma mixed with other histologies) and non-VH group (pure urothelial carcinoma) according to pathological results. We performed propensity score 1:1 nearest-neighbor matching on the two groups based on age and gender and 49 patients were included in each group. The regions of interest (ROIs) of the whole tumor were delineated manually by using ITK-SNAP software and Pyradiomics was applied to extract ADC histogram parameters. We compared the clinicopathological data, MRI morphological features and ADC histogram parameters between the groups. Multivariate logistic regression was used to identify independent risk factors and construct the prediction model. Receiver operating characteristic (ROC) curve analyses were performed to evaluate the diagnostic performance of these parameters for determining VH of UC. ResultsMRI morphological features including the lesion shape, vesical imaging-reporting and data system (Ⅵ-RADS)score, enhancement pattern and suspicious lymph node metastasis were markedly different between the two groups (all P < 0.05). ADC mean, ADC median, ADC25th, ADC75th, ADC10th and ADC90th were significantly lower in patients with VH than those in non-VH group (all P<0.05). Multivariate logistic regression analysis showed enhancement pattern, ADC25th, ADC75th and ADC mean were independent predictors (P < 0.05). The combined model yielded the best predictive performance, with an area under the ROC curve (AUC) of 0.91 (95% CI: 0.83-0.96). ConclusionsMpMRI combined with whole-tumor histogram analysis of ADC can serve as a reliable method for evaluating the presence of VH in UC, further to assist the clinical decision making.

14.
Malaysian Journal of Medicine and Health Sciences ; : 441-443, 2023.
Article in English | WPRIM | ID: wpr-998651

ABSTRACT

@#Currently, ASL is widely used as an additional breakthrough sequence in MRI due to acquiring reliable results. The case report aims to prove the efficacy and effectiveness of a quantitative method of ASL sequence through the calculation of the cerebral blood flow (CBF) on CBF maps in different cases. ASL sequence has been done on four patients with different cases. Then, the authors put 2 regions of interest (ROI) for measurement in normal and different regions on CBF maps and then calculated the average value result from CBF maps. ASL has been proven as a reliable and breakthrough sequence in MRI for detecting brain disease with a non-invasive method through the calculation of CBF value. ASL should be used as an additional protocol in brain examinations because it allows radiologists to assess the significance of CBF values using a quantitative method that is more reliable and non-invasiv

15.
Malaysian Journal of Medicine and Health Sciences ; : 389-398, 2023.
Article in English | WPRIM | ID: wpr-998624

ABSTRACT

@#Alar ligament is one of the most important craniocervical junction (CCJ) ligaments; acting as stabilizer of CCJ and limiting axial rotation. It may be involved in various pathological processes including trauma. Magnetic resonance imaging (MRI) is increasingly being used in cervical spine trauma as a supplement to conventional radiography and computed tomography (CT) to detect a wide range of severe cervical spine injuries. MR depiction of alar ligament requires special sequences despite no known established MR sequence is available. However, the role of MRI in minor or moderate trauma, including whiplash injuries, has long been debated, particularly when neurological dysfunction is absent, because no anatomical disruption other than degenerative disc disease have been reported. In this review, we provide detailed account on the current knowledge of MR visualization of normal alar ligament; outlining the variations in its signal intensity, dimension, shape and orientation.

16.
Sichuan Mental Health ; (6): 402-408, 2023.
Article in Chinese | WPRIM | ID: wpr-998145

ABSTRACT

BackgroundCompared with adult-onset schizophrenia, patients with adolescent-onset schizophrenia experience a high genetic susceptibility, severe negative symptoms, high recurrence rate, poor prognosis and social function recovery. And clarifying the brain functional alterations in adolescent-onset schizophrenia is of great significance for further elucidating the pathogenesis of the disease and exploring personalized and precise treatment. ObjectiveTo investigate the altered functional and effective connectivity of bilateral precuneus in first-episode patients with adolescent-onset schizophrenia based on resting-state functional magnetic resonance imaging (rs-fMRI), thus providing reliable imaging evidence in guiding the study on mechanism involved in adolescent-onset schizophrenia. MethodsTwenty-one drugnaïve first-episode patients with adolescent-onset schizophrenia who met the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria for schizophrenia were enrolled, and another 21 psychiatrially healthy controls matched on age, educational background and gender were concurrently selected. The schizophrenic subjects were evaluated using the Psychotic Symptom Rating Scales (PSYRATS) and Positive and Negative Symptom Scale (PANSS). All participants underwent rs-fMRI scans, and the whole-brain seed-based functional and effective connectivity analyses were conducted in bilateral cuneus region. Then the correlation between functional connectivity strength and clinical symptoms of patients was discussed. ResultsIn terms of functional connectivity, the functional connectivity of bilateral precuneus and left middle temporal gyrus was increased in patient group compared with healthy control group [P<0.01, family-wise error (FWE) correction at cluster level, P<0.05]. In terms of effective connectivity, patient group responded to negative feedback with greater activation of seed region and left middle frontal gyrus than healthy control group. Correlation analysis within patient group denoted that the decreased effective connectivity of bilateral precuneus and left middle frontal gyrus was positively correlated with the total PANSS score (r=0.450, P<0.05). ConclusionThe resting-state functional and effective connectivity of bilateral precuneus is abnormally alerted in drugnaïve first-episode patients with adolescent-onset schizophrenia, and the decreased effective connectivity of bilateral precuneus and left middle frontal gyrus may be related to the development of clinical symptoms. [Funded by National Key Research and Development Program of China (number, 2022YFC2009901, 2022YFC2009900)]

17.
Chinese Journal of Medical Instrumentation ; (6): 497-501, 2023.
Article in Chinese | WPRIM | ID: wpr-1010227

ABSTRACT

In MRI examination, RF heating of implants will affect the safety of implant wearers. The conductivity of various tissues in the human body is significantly different, and the medium conductivity will affect the distribution of the RF electric field. Therefore, it is necessary to study the RF heating of different medium conductivity. Based on the analysis of the principle of MRI RF heating, this study build the model of the bird cage coil, ASTM standard phantom and lead, and the conductivity of several typical human tissues is selected as the conductivity in the experiment. Then calculate the power deposition of the lead at 64 MHz. The results show that the medium conductivity has no effect on the distribution of electric field and power deposition, and the hot spot distribution remains unchanged under different conductivity; The smaller the conductivity is, the larger the power deposition of the lead is, and the greater the temperature rise of the lead caused by RF heating is; The change of conductivity and power deposition is approximately linear. At the limit of 2 W/kg whole body specific absorption rate(SAR), the conductivity decreases, and the wire power deposition increases sharply.

18.
Asian Journal of Andrology ; (6): 410-415, 2023.
Article in English | WPRIM | ID: wpr-981956

ABSTRACT

The purpose of this study was to explore transrectal ultrasound (TRUS) findings of prostate cancer (PCa) guided by multiparametric magnetic resonance imaging (mpMRI) and to improve the Prostate Imaging Reporting and Data System (PI-RADS) system for avoiding unnecessary mpMRI-guided targeted biopsy (TB). From January 2018 to October 2019, fusion mpMRI and TRUS-guided biopsies were performed in 162 consecutive patients. The study included 188 suspicious lesions on mpMRI in 156 patients, all of whom underwent mpMRI-TRUS fusion imaging-guided TB and 12-core transperineal systematic biopsy (SB). Univariate analyses were performed to investigate the relationship between TRUS features and PCa. Then, logistic regression analysis with generalized estimating equations was performed to determine the independent predictors of PCa and obtain the fitted probability of PCa. The detection rates of PCa based on TB alone, SB alone, and combined SB and TB were 55.9% (105 of 188), 52.6% (82 of 156), and 62.8% (98 of 156), respectively. The significant predictors of PCa on TRUS were hypoechogenicity (odds ratio [OR]: 9.595, P = 0.002), taller-than-wide shape (OR: 3.539, P = 0.022), asymmetric vascular structures (OR: 3.728, P = 0.031), close proximity to capsule (OR: 3.473, P = 0.040), and irregular margins (OR: 3.843, P = 0.041). We propose subgrouping PI-RADS score 3 into categories 3a, 3b, 3c, and 3d based on different numbers of TRUS predictors, as the creation of PI-RADS 3a (no suspicious ultrasound features) could avoid 16.7% of mpMRI-guided TBs. Risk stratification of PCa with mpMRI-TRUS fusion imaging-directed ultrasound features could avoid unnecessary mpMRI-TBs.


Subject(s)
Male , Humans , Prostatic Neoplasms/pathology , Multiparametric Magnetic Resonance Imaging , Magnetic Resonance Imaging/methods , Prostate/pathology , Image-Guided Biopsy/methods
19.
Journal of Sun Yat-sen University(Medical Sciences) ; (6): 271-276, 2023.
Article in Chinese | WPRIM | ID: wpr-965842

ABSTRACT

ObjectiveCentral nervous system (CNS) infiltration commonly occurs in children with acute lymphoblastic leukemia (ALL). Early subclinical CNS infiltration in pediatric ALL is hard to detect with conventional methods. This study aimed to investigate the changes of brain structure volume parameters based on Synthetic MRI (SyMRI) in pediatric ALL without clinically diagnosed CNS infiltration. MethodsThirty-six ALL and twenty-nine typically developing (TD) children were prospectively collected and all underwent SyMRI. The Synthetic MR software was used to obtain brain volumetric parameters including total white matter volume (WMV), gray matter volume (GMV), cerebrospinal fluid (CSF) volume, etc. and their within-group differences were assessed by analysis of covariance. The Spearman correlation analysis was used to examine the correlation between biological characteristics and statistically significant brain volume parameters. ResultsALL children showed increased CSF volume (PFDR-corrected = 0.009) and decreased GMV (PFDR-corrected = 0.027) when compared to TD children. We also found a moderately negative association between GMV/intracranial volume and risk classification in pediatric ALL (rs = -0.380, P = 0.022). ConclusionsPediatric ALL without clinically diagnosed CNS infiltration presented with accumulation of CSF and reduction of gray matter. The brain volumetric changes in subclinical CNS infiltration of pediatric ALL provides a new attempt for exploring the underlying mechanism and early detection of CNS infiltration in pediatric ALL.

20.
Chinese Journal of Radiological Health ; (6): 70-74, 2023.
Article in Chinese | WPRIM | ID: wpr-965376

ABSTRACT

@#Stenosis and occlusion caused by carotid atherosclerosis is an important cause of ischemic stroke. In recent years, with the continuous development of magnetic resonance imaging (MRI) technology and the introduction of complex network theory, brain network analysis can be used not only to explain the clinical symptoms and cognitive dysfunction in patients with carotid stenosis caused by changes in network topological properties of different brain regions, but also to explore the imaging markers of carotid stenosis, thus providing important reference data for the diagnosis of early asymptomatic carotid stenosis, the selection of individualized intervention programs, and the assessment of efficacy. Brain network analysis has been used as a powerful tool. In this paper, we review the studies of structural and functional brain networks in patients with carotid stenosis, and introduce the definitions of brain network nodes and edges and important topological properties of complex networks. We also analyze the current research on brain network in patients with carotid stenosis, and discuss the challenges and outlook of existing imaging techniques and network construction methodologies in this field.

SELECTION OF CITATIONS
SEARCH DETAIL