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1.
Radiol Med ; 128(8): 978-988, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37402026

RESUMO

PURPOSE: To assess the diagnostic accuracy of double inversion recovery (DIR) magnetic resonance imaging (MRI) sequences for synovitis of the wrist joints in patients with rheumatoid arthritis (RA). MATERIAL AND METHODS: Participants with newly diagnosed RA were enrolled between November 2019 and November 2020. MRI examinations of the wrist joints were performed using a contrast-enhanced T1-weighted imaging sequence (CE-T1WI) and DIR sequence. We measured synovitis score, number of synovial areas, synovial volume, mean synovium-to-bone signal ratio (SBR), and synovial contrast-to-noise ratio (SNR). The inter-reviewer agreement rated on a four-point scale was evaluated by calculating the weighted k statistics. Two MRI sequences were assessed using Bland-Altman analyses, and the diagnostic performance of DIR images was calculated using the chi-square test. RESULTS: A total of 47 participants were evaluated, and 282 joint regions in 5076 images were reviewed by two readers. There was no significant difference in synovitis scores (P = 0.67), number of synovial areas (P = 0.89), and synovial volume (P = 0.086) between the two MRI sequences. DIR images showed better SBR and SNR (all P < 0.01). There was good agreement between the two reviewers in terms of synovitis distribution (κ = 0.79). The synovitis was well agreed upon by the two readers according to Bland-Altman analyses. Using CE-T1WI as the reference standard, DIR imaging demonstrated a sensitivity of 94.1% and a specificity of 84.6% at the patient level. CONCLUSION: The non-contrast DIR sequence showed good consistency with CE-T1WI and potential for evaluating synovitis in patients with RA.


Assuntos
Artrite Reumatoide , Sinovite , Humanos , Sinovite/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/patologia , Articulação do Punho/diagnóstico por imagem , Osso e Ossos
2.
BMC Neurosci ; 21(1): 46, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33218307

RESUMO

BACKGROUND: As a noninvasive perfusion-weighted MRI technique, arterial spin-labeling (ASL) was becoming increasingly used to evaluate cerebral hemodynamics in many studies. The relation between ASL-MRI and crossed cerebellar diaschisis (CCD) was rarely discussed. In this study, the aim of our study was to assess the performance of ASL-MRI in the detection of crossed cerebellar diaschisis after stroke in compared with single-photon emission CT (SPECT). RESULTS: 17 of 51(33.3%) patients revealed CCD phenomenon by the SPECT method. In CCD-positive group, CBFASL of ipsilateral cerebellar were significantly increased compared with contralateral cerebellar (p < 0.0001) while no significant differences (p = 0.063, > 0.001) in the CCD-negative group. Positive correlation was detected between admission National institute of health stroke scale (NIHSS) and asymmetry index of SPECT (AISPECT) (r = 0.351, p = 0.011), AIASL (r = 0.372, p = 0.007); infract volume and AISPECT (r = 0.443, p = 0.001), AIASL (r = 0.426, p = 0.002). Significant correlation was also found between cerebral blood flow of SPECT (CBFSPECT) and CBFASL, AISPECT and AIASL (r = 0.204, p = 0.04; r = 0.467, p = 0.001, respectively). Furthermore, the area under the receiver operating characteristic (ROC) curve value of AIASL was 0.829. CONCLUSIONS: CBF derived from ASL-MRI could be valuable for assessment of CCD in supratentorial stroke patients. Additionally, CCD was significantly associated with larger ischemic volume and higher initial NIHSS score.


Assuntos
Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/etiologia , AVC Isquêmico/complicações , Angiografia por Ressonância Magnética/métodos , Idoso , Circulação Cerebrovascular , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade , Marcadores de Spin , Tomografia Computadorizada de Emissão de Fóton Único
3.
J Magn Reson Imaging ; 45(3): 722-730, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27527072

RESUMO

PURPOSE: To compare four methods of region-of-interest (ROI) placement for apparent diffusion coefficient (ADC) measurements in distinguishing low-grade gliomas (LGGs) from high-grade gliomas (HGGs). MATERIALS AND METHODS: Two independent readers measured ADC parameters using four ROI methods (single-slice [single-round, five-round and freehand] and whole-volume) on 43 patients (20 LGGs, 23 HGGs) who had undergone 3.0 Tesla diffusion-weighted imaging and time required for each method of ADC measurements was recorded. Intraclass correlation coefficients (ICCs) were used to assess interobserver variability of ADC measurements. Mean and minimum ADC values and time required were compared using paired Student's t-tests. All ADC parameters (mean/minimum ADC values of three single-slice methods, mean/minimum/standard deviation/skewness/kurtosis/the10th and 25th percentiles/median/maximum of whole-volume method) were correlated with tumor grade (low versus high) by unpaired Student's t-tests. Discriminative ability was determined by receiver operating characteristic curves. RESULTS: All ADC measurements except minimum, skewness, and kurtosis of whole-volume ROI differed significantly between LGGs and HGGs (all P < 0.05). Mean ADC value of single-round ROI had the highest effect size (0.72) and the greatest areas under the curve (0.872). Three single-slice methods had good to excellent ICCs (0.67-0.89) and the whole-volume method fair to excellent ICCs (0.32-0.96). Minimum ADC values differed significantly between whole-volume and single-round ROI (P = 0.003) and, between whole-volume and five-round ROI (P = 0.001). The whole-volume method took significantly longer than all single-slice methods (all P < 0.001). CONCLUSION: ADC measurements are influenced by ROI determination methods. Whole-volume histogram analysis did not yield better results than single-slice methods and took longer. Mean ADC value derived from single-round ROI is the most optimal parameter for differentiating LGGs from HGGs. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:722-730.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Interpretação de Imagem Assistida por Computador/métodos , Carga de Trabalho , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
4.
BMC Neurosci ; 17(1): 36, 2016 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-27287450

RESUMO

BACKGROUND: The potential adverse effect of mobile phone radiation is currently an area of great concern in the field of public health. In the present study, we aimed to investigate the effect of mobile phone radiation (900 MHz radiofrequency) during hatching on postnatal social behaviors in chicks, as well as the effect on brain size and structural maturity estimated using 3.0 T magnetic resonance imaging. At day 4 of incubation, 76 normally developing chick embryos were divided into the control group (n = 39) and the radiation group (n = 37). Eggs in the radiation group were exposed to mobile phone radiation for 10 h each day from day 4 to 19 of incubation. Behavioral tests were performed 4 days after hatching. T2-weighted MR imaging and diffusion tensor imaging (DTI) were subsequently performed. The size of different brain subdivisions (telencephalon, optic lobe, brain stem, and cerebellum) and corresponding DTI parameters were measured. The Chi-square test and the student's t test were used for statistical analysis. P < 0.05 was considered statistically significant. RESULTS: Compared with controls, chicks in the radiation group showed significantly slower aggregation responses (14.87 ± 10.06 vs. 7.48 ± 4.31 s, respectively; P < 0.05), lower belongingness (23.71 ± 8.72 vs. 11.45 ± 6.53 s, respectively; P < 0.05), and weaker vocalization (53.23 ± 8.60 vs. 60.01 ± 10.45 dB/30 s, respectively; P < 0.05). No significant differences were found between the radiation and control group for brain size and structural maturity, except for cerebellum size, which was significantly smaller in the radiation group (28.40 ± 1.95 vs. 29.95 ± 1.41 cm(2), P < 0.05). The hatching and heteroplasia rates were also calculated and no significant difference was found between the two groups. CONCLUSIONS: Mobile phone radiation exposure during chick embryogenesis impaired social behaviors after hatching and possibly induced cerebellar retardation. This indicates potential adverse effects of mobile phone radiation on brain development.


Assuntos
Anormalidades Induzidas por Radiação/etiologia , Encéfalo/embriologia , Encéfalo/efeitos da radiação , Telefone Celular , Lesões Experimentais por Radiação/etiologia , Comportamento Social , Anormalidades Induzidas por Radiação/diagnóstico por imagem , Anormalidades Induzidas por Radiação/psicologia , Animais , Encéfalo/diagnóstico por imagem , Galinhas , Radiação Eletromagnética , Imageamento por Ressonância Magnética , Tamanho do Órgão , Testes Psicológicos , Lesões Experimentais por Radiação/diagnóstico por imagem , Lesões Experimentais por Radiação/psicologia , Distribuição Aleatória , Vocalização Animal/efeitos da radiação
5.
NMR Biomed ; 29(3): 320-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26748572

RESUMO

Intravoxel incoherent motion (IVIM) diffusion-weighted MRI can simultaneously measure diffusion and perfusion characteristics in a non-invasive way. This study aimed to determine the potential utility of IVIM in characterizing brain diffusion and perfusion properties for clinical stroke. The multi-b-value diffusion-weighted images of 101 patients diagnosed with acute/subacute ischemic stroke were retrospectively evaluated. The diffusion coefficient D, representing the water apparent diffusivity, was obtained by fitting the diffusion data with increasing high b-values to a simple mono-exponential model. The IVIM-derived perfusion parameters, pseudodiffusion coefficient D*, vascular volume fraction f and blood flow-related parameter fD*, were calculated with the bi-exponential model. Additionally, the apparent diffusion coefficient (ADC) was fitted according to the mono-exponential model using all b-values. The diffusion parameters for the ischemic lesion and normal contralateral region were measured in each patient. Statistical analysis was performed using the paired Student t-test and Pearson correlation test. Diffusion data in both the ischemic lesion and normal contralateral region followed the IVIM bi-exponential behavior, and the IVIM model showed better goodness of fit than the mono-exponential model with lower Akaike information criterion values. The paired Student t-test revealed significant differences for all diffusion parameters (all P < 0.001) except D* (P = 0.218) between ischemic and normal areas. For all patients in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001) and f (r = 0.541, P < 0.001; r = 0.262, P = 0.008); significant correlation was also found between ADC and fD* in the ischemic region (r = 0.254, P = 0.010). For all pixels within the region of interest from a representative subject in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001), f (r = 0.823, P < 0.001; r = 0.652, P < 0.001) and fD* (r = 0.294, P < 0.001; r = 0.340, P < 0.001). These findings may have clinical implications for the use of IVIM imaging in the assessment and management of acute/subacute stroke patients. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Movimento (Física) , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos
6.
BMC Dev Biol ; 15: 29, 2015 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-26208519

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) has many advantages in the research of in vivo embryonic brain development, specifically its noninvasive aspects and ability to avoid skeletal interference. However, few studies have focused on brain development in chick, which is a traditional animal model in developmental biology. We aimed to serially monitor chick embryo brain development in vivo using 3.0 T MRI. METHODS: Ten fertile Hy-line white eggs were incubated and seven chick embryo brains were monitored in vivo and analyzed serially from 5 to 20 days during incubation using 3.0 T MRI. A fast positioning sequence was pre-scanned to obtain sagittal and coronal brain planes corresponding to the established atlas. T2-weighted imaging (T2WI) was performed for volume estimation of the whole brain and subdivision (telencephalon, cerebellum, brainstem, and lateral ventricle [LV]); diffusion tensor imaging (DTI) was used to reflect the evolution of neural bundle structures. RESULTS: The chick embryos' whole brain and subdivision grew non-linearly over time; the DTI fractional anisotropy (FA) value within the telencephalon increased non-linearly as well. All seven scanned eggs hatched successfully. CONCLUSIONS: MRI avoids embryonic sacrifice in a way that allows serial monitoring of longitudinal developmental processes of a single embryo. Feasibility for analyzing subdivision of the brain during development, and adding structural information related to neural bundles, makes MRI a powerful tool for exploring brain development.


Assuntos
Encéfalo/embriologia , Imagem de Tensor de Difusão/métodos , Imageamento por Ressonância Magnética/métodos , Animais , Embrião de Galinha
7.
Radiol Med ; 119(9): 681-93, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24531890

RESUMO

PURPOSE: The aim of this study was to investigate the characteristic imaging features of giant cell tumours (GCTs) of the mobile spine. MATERIALS AND METHODS: Thirty pathologically proven GCTs of the mobile spine were reviewed. X-ray (n = 18), computed tomography (CT) (n = 24) and magnetic resonance (MR) (n = 21) images were retrospectively evaluated. RESULTS: Five tumours were located in the cervical spine, 15 tumours were located in the thoracic spine and 10 tumours in the lumbar spine. The characteristic X-ray findings included an osteolytic and expansile lesion with a "soap bubble" or purely lytic appearance. Cortical destruction was commonly seen. Margin sclerosis was seen in two lesions. No mineralised tumour matrix or periosteal reaction appeared. The CT findings were similar but outlined the cortical alterations in a more accurate way. The characteristic MR findings included a well-defined and expansile mass with heterogeneous low-to-iso signal intensity on T2-weighted images. Cystic areas were commonly seen in 17 cases. Five cases presented fluid-fluid levels, suggesting the development of aneurysmal bone cyst. The solid portions of the tumours were enhanced with a very heterogeneous signal pattern reflecting high blood supply after contrast-enhanced scan. Tumour involvement in the epidural space occurred in 12 cases, causing spinal cord and/or nerve root compression. Involvement of intervertebral discs and/or adjacent vertebrae appeared in two cases. CONCLUSIONS: Although rare, GCT can occur in the mobile spine as a kind of benign but locally aggressive tumour. Radiologists should be familiar with its characteristic imaging features in order to make a correct diagnosis and to help preoperative evaluations.


Assuntos
Diagnóstico Diferencial , Tumor de Células Gigantes do Osso/diagnóstico , Neoplasias da Coluna Vertebral/diagnóstico , Adolescente , Adulto , Vértebras Cervicais , Feminino , Tumor de Células Gigantes do Osso/diagnóstico por imagem , Humanos , Vértebras Lombares , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas , Tomografia Computadorizada por Raios X
8.
Artigo em Zh | MEDLINE | ID: mdl-37640998

RESUMO

Objective:By analyzing the clinical phenotypic characteristics and gene sequences of two patients with Treacher Collins syndrome(TCS), the biological causes of the disease were determined. Then discuss the therapeutic effect of hearing intervention after bone bridge implantation. Methods:All clinical data of the two family members were collected, and the patients signed the informed consent. The peripheral blood of the proband and family members was extracted, DNA was extracted for whole exome sequencing, and Sanger sequencing was performed on the family members for the mutation site.TCOF1genetic mutations analysis was performed on the paitents. Then, the hearing threshold and speech recognition rate of family 2 proband were evaluated and compared under the sound field between bare ear and wearing bone bridge. Results:In the two pedigrees, the probands of both families presented with auricle deformity, zygomatic and mandibular hypoplasia, micrognathia, hypotropia of the eye fissure, and hypoplasia of the medial eyelashes. The proband of Family 1 also presents with specific features including right-sided narrow anterior nasal aperture and dental hypoplasia, which were consistent with the clinical diagnosis of Treacher Collins syndrome. Genetic testing was conducted on both families, and two heterozygous mutations were identified in the TCOF1 gene: c. 1350_1351dupGG(p. A451Gfs*43) and c. 4362_4366del(p. K1457Efs*12), resulting in frameshift mutations in the amino acid sequence. Sanger sequencing validation of the TCOF1 gene in the parents of the proband in Family 1 did not detect any mutations. Proband 1 TCOF1 c. 1350_1351dupGG heterozygous variants have not been reported previously. The postoperative monosyllabic speech recognition rate of family 2 proband was 76%, the Categories of Auditory Performance(CAP) score was 6, and the Speech Intelligibility Rating(SIR) score was 4. Assessment using the Meaningful Auditory Integration Scale(MAIS) showed notable improvement in the patient's auditory perception, comprehension, and usage of hearing aids. Evaluation using the Glasgow Children's Benefit Inventory and quality of life assessment revealed significant improvements in the child's self care abilities, daily living and learning, social interactions, and psychological well being, as perceived by the parents. Conclusion:This study has elucidated the biological cause of Treacher Collins syndrome, enriched the spectrum of TCOF1 gene mutations in the Chinese population, and demonstrated that bone bridge implantation can improve the auditory and speech recognition rates in TCS patients.


Assuntos
Disostose Mandibulofacial , Criança , Humanos , Disostose Mandibulofacial/genética , Qualidade de Vida , Fala , Pais , Mutação , Proteínas Nucleares/genética , Fosfoproteínas/genética
9.
Artigo em Zh | MEDLINE | ID: mdl-35193344

RESUMO

Objective:To detect genetic mutations in a case of laryngo-onycho-cutaneous syndrome, and to explore the possible molecular biological pathogenic causes. Methods:With informed consent, the family clinical data of the child with laryngo-onycho-cutaneous syndrome were collected, peripheral blood of the protester and his parents was collected and DNA was extracted, and gene detection was performed by high-throughput sequencing method. Sanger sequencing was used to verify and analyze the mutation sites of the probs and their families. Results:Genetic testing of the proband revealed homozygous mutation of LAMA3 gene c.171+1G>A site, which is splicing mutation. There was no report in the literature, which was a new mutation site. The parents of the proband had normal phenotype and heterozygous mutation at this locus was detected. Conclusion:Homozygous mutation of LAMA3 c.171+1G>A is the likely pathogenic of the proband, and this study expands the mutant spectrum of LAMA3. The clinical phenotype of laryngo-onycho-cutaneous syndrome is highly variable, and the multidisciplinary diagnosis and treatment can effectively avoid missed diagnosis and misdiagnosis.


Assuntos
Doenças da Túnica Conjuntiva/genética , Laminina/genética , Doenças da Laringe/genética , Heterozigoto , Homozigoto , Humanos , Masculino , Mutação , Linhagem
10.
J Appl Genet ; 63(2): 327-337, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35000142

RESUMO

Congenital sensorineural hearing loss (CSHL) and microtia are development-related diseases, sharing some factors and affecting children's hearing. However, genetic tests only focus on CSHL. We try to identify the common molecular mechanism of CSHL and microtia as candidates combining gene diagnosis biomarkers. Whole-exon sequencing (WES), Sanger sequencing, qPCR, and bioinformatics analyses were performed in microtia family (F1), family two, whose proband suffered from microtia and CSHL (F2), five microtia, and four CSHL individuals, respectively. We found that 40% microtia and 40% CSHL relevant genes were detected in F1 and a sharing pathway: the sensory perception of sound was identified. Moreover, the copy number variation in proband F2 was identified in one gene of the sharing pathway: EYA1. Meanwhile, two variants of BUB3 were identified in F1 data. BUB3 is related to development, dog ear type, direct and indirect interaction with microtia, and CSHL relevant genes. Notably, although the allele frequency of two variants of BUB3 showed significant differences between microtia and CSHL, the special microtia-relevant genotype also could be detected in one CSHL sample. These results suggest that the sensory perception of sound and the development of relevant pathways may be the common pathways of microtia and CSHL. Genes of these pathways can be used as candidates combining gene diagnosis biomarkers.


Assuntos
Percepção Auditiva , Microtia Congênita , Perda Auditiva Neurossensorial , Percepção Auditiva/genética , Proteínas de Ciclo Celular/genética , Microtia Congênita/genética , Variações do Número de Cópias de DNA , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Nucleares/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas Tirosina Fosfatases/genética
11.
Cell Transplant ; 28(8): 1062-1070, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31198047

RESUMO

Intravoxel incoherent motion has received extensive attention in brain studies for its potential as a non-invasive magnetic resonance perfusion method. However, studies on intravoxel incoherent motion imaging and crossed cerebellar diaschisis detection are relatively scarce. The aim of our study was to evaluate the feasibility of using intravoxel incoherent motion imaging in crossed cerebellar diaschisis diagnosis in subacute ischemic stroke patients by comparing results from intravoxel incoherent motion imaging, single-photon emission computed tomography, and arterial spin-labeling perfusion methods. In total, 39 patients with subacute ischemic stroke who underwent intravoxel incoherent motion, arterial spin-labeling, and single-photon emission computed tomography scanning were enrolled. Intravoxel incoherent motion-derived perfusion-related parameters including fast diffusion coefficient, vascular volume fraction, arterial spin-labeling-derived cerebral blood flow as well as single-photon emission computed tomography-derived cerebral blood flow of bilateral cerebellum were measured. A crossed cerebellar diaschisis-positive result was considered present with an asymmetry index ≥10% of single-photon emission computed tomography. In the crossed cerebellar diaschisis-positive group, fast diffusion coefficient, arterial spin-labeling-derived cerebral blood flow, and computed tomography-derived cerebral blood flow of the contralateral cerebellum decreased compared with those of the ipsilesional cerebellum; whereas vascular volume fraction significantly increased. The National Institutes of Health Stroke Scale score and infarct volume in the crossed cerebellar diaschisis-positive group were significantly higher than those in the crossed cerebellar diaschisis-negative group. A positive correlation was detected between the fast diffusion coefficient-based asymmetry index and the single-photon emission computed tomography-based asymmetry index, fast diffusion coefficient-based asymmetry, and arterial spin-labeling based asymmetry index; whereas the vascular volume fraction-based asymmetry index value had a negative correlation with the single-photon emission computed tomography-based asymmetry index and arterial spin-labeling based asymmetry index. Furthermore, the area under the receiver operating characteristic curve value of the arterial spin-labeling-based asymmetry index was 0.923. The fast diffusion coefficient derived from the intravoxel incoherent motion could be valuable for the assessment of crossed cerebellar diaschisis in supratentorial stroke patients.


Assuntos
Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Cerebelo/diagnóstico por imagem , Cerebelo/patologia , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC
12.
Eur J Radiol Open ; 4: 84-88, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28725661

RESUMO

INTRODUCTION: To investigate the clinical predictive values of the apparent diffusion coefficient (ADC) as a biomarker in radiation response of brain metastases. METHOD: Forty-one patients with brain metastases treated with stereotactic radiosurgery (SRS) were imaged at baseline, one month post SRS, and six months post SRS using diffusion weighted MRI. The mean of ADC for metastases and tumor volume was calculated. A diffusion index (DI) was generated using the sum of 1/ADC among all the voxels in a tumor. Tumor response status was determined by lesion volume measured at six month post-SRS, or the last available follow-up MRI. Logistic regression analysis was used to account for factors associated with tumor response at baseline and one month post SRS. RESULTS: A higher ADC mean distinguished responders from non-responders only at six month post SRS (p < 0.05). However, a lower DI distinguished a responder from non-responders on the baseline, one month post SRS and six months post SRS, indicating better diagnostic performance of the DI with regard to a non-invasive biomarker in monitoring SRS treatment response. A multivariate logistic regression analysis identified the DI as a predictor of tumor response at baseline and one month post SRS (p = 0.002 and p = 0.001, respectively). However, logistic regression analysis identified the ADC mean as a predictor of tumor response only at six months post SRS (p = 0.019). CONCLUSION: Our results support the hypothesis that ADC and tumor volume generated DT at baseline, one month and six months post SRS may be a promising biomarker predicting brain metastases' response. Specifically, a lower DI at baseline and one month distinguished responders from non-responders.

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