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1.
J Comput Assist Tomogr ; 43(5): 755-761, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31609294

RESUMO

OBJECTIVES: This study aimed to evaluate the feasibility of intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (DW-MRI) in detecting bowel inflammation in patients with Crohn disease (CD). METHODS: Sixteen patients who underwent intravoxel incoherent motion DW-MRI for CD and colonoscopy were recruited. Seventy-nine bowel segments were selected, and their mean D, D*, f, and apparent diffusion coefficient (ADC) values were measured. The receiver operating characteristic curve was performed to distinguish inflamed from normal bowel. RESULTS: The mean D, D*, f, and ADC values of inflamed bowel were significantly lower than those of normal bowel (P < 0.05). The area under the receiver operating characteristic curve for f (0.906) and ADC values (0.924) was greater than that for D (0.709) or D* values (0.686) for differentiating inflamed bowel from normal bowel (P < 0.05). CONCLUSIONS: Intravoxel incoherent motion DW-MRI is a feasible technique for detecting inflammation in CD patients. The ADC and f values have more potential than the D and D* values.


Assuntos
Doença de Crohn/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Adulto , Colonoscopia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Inflamação/diagnóstico por imagem , Masculino , Estudos Prospectivos
2.
Medicine (Baltimore) ; 98(33): e16608, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31415354

RESUMO

The utility of multimodality molecular imaging for predicting treatment response and survival of patients with hypopharyngeal carcinoma remains unclear. Here, we sought to investigate whether the combination of different molecular imaging parameters may improve outcome prediction in this patient group.Patients with pathologically proven hypopharyngeal carcinoma scheduled to undergo chemoradiotherapy (CRT) were deemed eligible. Besides clinical data, parameters obtained from pretreatment 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography (F-FDG PET/CT), dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), and diffusion-weighted MRI were analyzed in relation to treatment response, recurrence-free survival (RFS), and overall survival (OS).A total of 61 patients with advanced-stage disease were examined. After CRT, 36% of the patients did not achieve a complete response. Total lesion glycolysis (TLG) and texture feature entropy were found to predict treatment response. The transfer constant (K), TLG, and entropy were associated with RFS, whereas K, blood plasma volume (Vp), standardized uptake value (SUV), and entropy were predictors of OS. Different scoring systems based on the sum of PET- or MRI-derived prognosticators enabled patient stratification into distinct prognostic groups (P <.0001). The complete response rate of patients with a score of 2 was significantly lower than those of patients with a score 1 or 0 (14.7% vs 58.9% vs 75.7%, respectively, P = .007, respectively). The combination of PET- and DCE-MRI-derived independent risk factors allowed a better survival stratification than the TNM staging system (P <.0001 vs .691, respectively).Texture features on F-FDG PET/CT and DCE-MRI are clinically useful to predict treatment response and survival in patients with hypopharyngeal carcinoma. Their combined use in prognostic scoring systems may help these patients benefit from tailored treatment and obtain better oncological results.


Assuntos
Carcinoma/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/estatística & dados numéricos , Neoplasias Hipofaríngeas/diagnóstico por imagem , Imagem por Ressonância Magnética/estatística & dados numéricos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Adulto , Carcinoma/mortalidade , Carcinoma/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Fluordesoxiglucose F18 , Humanos , Neoplasias Hipofaríngeas/mortalidade , Neoplasias Hipofaríngeas/patologia , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Imagem Multimodal/estatística & dados numéricos , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Compostos Radiofarmacêuticos , Taxa de Sobrevida
3.
J Comput Assist Tomogr ; 43(5): 780-785, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31268879

RESUMO

OBJECTIVE: To evaluate the relationship between the apparent diffusion coefficient (ADC) values of renal parenchyma and estimated glomerular filtration rates (eGFR). METHODS: Data on 216 patients examined by 3-T magnetic resonance imaging for various reasons were retrospectively collected. RESULTS: There was a significant linear correlation between the ADC values and eGFRs (r = 0.254, P < 0.001). The ADC values in patients with an eGFR of less than 60 mL/min per 1.73 m were significantly lower than those with an eGFR of 60 mL/min per 1.73 m or greater. The mean ADC value of patients with grouped stage 2 disease was significantly higher than those with grouped stage 3 of chronic kidney disease (P < 0.01). CONCLUSIONS: The ADC value of renal parenchyma may be a promising marker for the determination of patients with normal to mild reduction in renal function (eGFR ≥60 mL/min per 1.73 m) versus those with a moderate to severe reduction in renal function (eGFR <60 mL/min per 1.73 m).


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Taxa de Filtração Glomerular , Falência Renal Crônica/diagnóstico por imagem , Falência Renal Crônica/fisiopatologia , Meios de Contraste , Imagem Ecoplanar , Feminino , Gadolínio DTPA , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
4.
Br J Radiol ; 92(1102): 20181051, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31322913

RESUMO

OBJECTIVE: To determine whether the apparent diffusion coefficient (ADC) on 3T MR imaging including diffusion-weighted MR imaging (DWI) correlate with the standardized uptake value (SUV) on 18F-FDG PET/CT in musculoskeletal tumours. METHODS: This retrospective cohort study included 57 patients (36 males, 21 females, mean age 54 years, range 12-90 years) with pathologically confirmed soft tissue (n = 32) and bone (n = 25) tumours who underwent 3T MR imaging including DWI and whole-body 18F-FDG PET/CT before treatment. 14 patients had follow-up MR imaging and 18F-FDG PET/CT after treatment. The minimum (ADCmin) and mean (ADCmean) ADCs of musculoskeletal tumour, ADC of normal skeletal muscle (ADCmus), SUVmax and SUVmean of musculoskeletal tumour were obtained. Correlation between ADCs and SUVs was assessed using Pearson correlation coefficients (r). ADCmin and SUVmax were compared between pretreatment and posttreatment by t-test. RESULTS: There was inverse correlation between SUVmax and the ratio ADCmin/ADCmus (r = - 0.505 to - 0.495, p ≤ 0.001) and between SUVmean and the ratio ADCmean/ADCmus (r = - 0.501 to - 0.493, p = 0.001). After treatment ADC was significantly increased whereas SUV was significantly decreased (p = 0.001). There was significant correlation in percent change between the initial and follow-up values of ADCmin and SUVmax (r = 0.750 to 0.773, p ≤ 0.005). The ADCmin was increased by 163% and SUVmax was decreased by 61% in 11 patients with treatment response. CONCLUSION: ADC at 3T MR DWI and SUV at 18F-FDG PET/CT have an inverse correlation in musculoskeletal tumours. ADVANCES IN KNOWLEDGE: Our study showed that ADC at 3T DWI and SUV at 18F-FDG PET/CT had an inverse correlation in musculoskeletal tumours.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/metabolismo , Imagem de Difusão por Ressonância Magnética/métodos , Fluordesoxiglucose F18/metabolismo , Neoplasias Musculares/diagnóstico por imagem , Neoplasias Musculares/metabolismo , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/patologia , Criança , Feminino , Glucose/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/patologia , Variações Dependentes do Observador , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
5.
Einstein (Sao Paulo) ; 17(3): eAO4615, 2019 Jul 18.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31340245

RESUMO

OBJECTIVE: To compare qualitatively and quantitatively, in terms of image quality, a new biexponential diffusion sequence protocol with the standard monoexponential diffusion protocol on multiparametric prostate magnetic resonance imaging. METHODS: This study had a prospective data collection and cross-sectional analysis. Between August and November 2017, a total of 70 patients who underwent multiparametric prostate magnetic resonance imaging due to clinical suspicion of prostatic neoplasia were recruited. The images obtained were evaluated by two independent readers regarding subjective/qualitative criteria (six criteria) and objective/quantitative criteria (three criteria), always comparing the monoexponential to biexponential acquisition protocols. The results were compared by statistical analysis (interobserver agreement - Gwet coefficient; analysis of the qualitative variables - Stuart-Maxwell test; and analysis of the quantitative variables - Wilcoxon test). RESULTS: After exclusion of four patients, the final sample consisted of 66 patients. A good/excellent inter observer agreement was stablished for subjective criteria (except in one criteria). For the qualitative analysis the amount of good or excellent evaluations was higher for the monoexponential protocol (except in one category), with evidence of significant differences for three criteria (diffusion weighted imaging global quality; diffusion weighted imaging signal-to-noise ratio; and apparent diffusion coefficient signal-to-noise ratio). For the quantitative data analysis, the monoexponential protocol showed less variability of the anteroposterior diameters, meaning less distortion of the images, and better estimated signal-to-noise ratio. CONCLUSION: In our data, the quality of the images of the monoexponential standard diffusion sequence was qualitatively and quantitatively superior to those of the biexponential diffusion weighted imaging sequence.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/normas , Neoplasias da Próstata/diagnóstico por imagem , Estudos Transversais , Humanos , Masculino , Variações Dependentes do Observador , Estudos Prospectivos , Padrões de Referência , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Estatísticas não Paramétricas
6.
Br J Radiol ; 92(1100): 20180978, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31291125

RESUMO

OBJECTIVES: To assess the value of computed diffusion-weighted imaging (cDWI) and voxelwise computed diffusion-weighted imaging (vcDWI) in breast cancer. METHODS: This retrospective study involved 130 patients (age range, 25-70 years; mean age ± standard deviation, 48.6 ± 10.5 years) with 130 malignant lesions, who underwent MRI examinations, including a DWI sequence, prior to needle biopsy or surgery. cDWIs with higher b-values of 1500, 2000, 2500, 3000, 3500, and 4000 s/mm2, and vcDWI were generated from measured (m) DWI with two lower b-values of 0/600, 0/800, or 0/1000 s/mm2. The signal-to-noise ratio (SNR) and contrast ratio (CR) of all image sets were computed and compared among different DWIs by two experienced radiologists independently. To better compare the CR with the SNR, the CR value was multiplied by 100 (CR100). RESULTS: The CR of vcDWI, and cDWIs, except for cDWI1000, differed significantly from that of measured diffusion-weighted imaging (mDWI) (cDWI1000: CR = 0.4904, p = 0.394; cDWI1500: CR = 0.5503, p = 0.006; cDWI2000: CR = 0.5889, p < 0.001; cDWI2500: CR = 0.6109, p < 0.001; cDWI3000: mean = 0.6214, p < 0.001; cDWI3500: CR = 0.6245, p < 0.001; cDWI4000: CR = 0.6228, p < 0.001). The vcDWI provided the highest CR, while the CRs of all cDWI image sets improved with increased b-values. The SNR of neither cDWI1000 nor vcDWI differed significantly from that of mDWI, but the mean SNRs of the remaining cDWIs were significantly lower than that of mDWI. The SNRs of cDWIs declined with increasing b-values, and the initial decrease at low b-values was steeper than the gradual attenuation at higher b-values; the CR100 rose gradually, and the two converged on the b-value interval of 1500-2000 s/mm2 . CONCLUSIONS: The highest CR was achieved with vcDWI; this could be a promising approach easier detection of breast cancer. ADVANCES IN KNOWLEDGE: This study comprehensively compared and evaluated the value of the emerging post-processing DWI techniques (including a set of cDWIs and vcDWI) in breast cancer.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Adulto , Idoso , Mama/diagnóstico por imagem , Estudos de Avaliação como Assunto , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Razão Sinal-Ruído
7.
Medicine (Baltimore) ; 98(27): e16089, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31277105

RESUMO

To establish magnetic resonance imaging (MRI) features that differentiate residual tumors from postoperative surgical changes following the transsphenoidal approach of a pituitary adenoma.We analyzed residual enhancements at the tumor bed in 52 patients who underwent dynamic contrast-enhanced sella MRI within 48 hours after surgery and at 6 to 28 months. Patients were divided into 2 groups defined by either peripheral or nodular enhancement patterns. For each group, we measured the maximum thickness of the residual enhancing portion and compared differences in the residual tumor and postoperative changes.Among the tumors examined in the 52 patients, 19 residual tumors showed nodular (n = 16) and peripheral (n = 3) enhancement patterns, and 33 postoperative changes showed nodular (n = 3) and peripheral (n = 30) enhancement patterns. The mean residual tumor thickness was 7.1 mm (range, 2.9-16.8 mm) and 1.9 mm (range, 1.0-7.4 mm) in the postoperative change. Receiver operating characteristic curve analysis revealed that a 3.9-mm thickness was associated with 89% sensitivity, 97% specificity, and 94% accuracy for diagnosis of residual tumor.On immediate postoperative MRI, residual enhancement with greater than 3.9-mm thickness and nodular pattern suggest residual pituitary adenoma tumor.


Assuntos
Adenoma/patologia , Neoplasia Residual/patologia , Neoplasias Hipofisárias/patologia , Adenoma/diagnóstico por imagem , Adenoma/cirurgia , Adolescente , Adulto , Idoso , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasia Residual/diagnóstico por imagem , Neoplasias Hipofisárias/diagnóstico por imagem , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Sela Túrcica/diagnóstico por imagem , Adulto Jovem
8.
Medicine (Baltimore) ; 98(29): e16313, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31335678

RESUMO

We evaluated the relationships among functional imaging modality such as PET-CT and DW-MRI and lung adenocarcinoma pathologic heterogeneity, extent of invasion depth, and tumor cellularity as a marker of tumor microenvironment.In total, 74 lung adenocarcinomas were prospectively included. All patients underwent 18F-fluorodeoxyglucose (FDG) PET-CT and MRI before curative surgery. Pathology revealed 68 stage I tumors, 3 stage II tumors, and 3 stage IIIA tumors. Comprehensive histologic subtyping was performed for all surgically resected tumors. Maximum standardized uptake value (SUVmax) and ADC values were correlated with pathologic grade, extent of invasion, solid tumor size, and tumor cellularity.Mean solid tumor size (low: 1.7 ±â€Š3.0 mm, indeterminate: 13.9 ±â€Š14.2 mm, and high grade: 30.3 ±â€Š13.5 mm) and SUVmax (low: 1.5 ±â€Š0.2, indeterminate: 3.5 ±â€Š2.5, and high grade: 15.3 ±â€Š0) had a significant relationship with pathologic grade based on 95% confidence intervals (P = .01 and P < .01, respectively). SUVmax showed a strong correlation with tumor cellularity (R = 0.713, P < .001), but was not correlated with extent of invasion (R = 0.387, P = .148). A significant and strong positive correlation was observed among SUVmax values and higher cellularity and pathologic grade. ADC did not exhibit a significant relationship with tumor cellularity.Intratumor heterogeneity quantification using a multimodal-multiparametric approach might be effective when tumor volume consists of a real tumor component as well as a non-tumorous stromal component.


Assuntos
Adenocarcinoma de Pulmão , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Pulmonares , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Microambiente Tumoral , Adenocarcinoma de Pulmão/diagnóstico por imagem , Adenocarcinoma de Pulmão/patologia , Adulto , Idoso , Correlação de Dados , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Reprodutibilidade dos Testes , República da Coreia , Carga Tumoral
9.
Medicine (Baltimore) ; 98(29): e16447, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31335699

RESUMO

To evaluate readout-segmented echoplanar (rsEPI) diffusion weighted imaging (DWI) for multiparametric (mp) magnetic resonance imaging (MRI) of the prostate compared to the established single-shot echoplanar imaging (ssEPI) sequence.One hundred ten consecutive patients with clinical suspicion of prostate cancer underwent mp prostate MRI using both, the ssEPI and the rsEPI DWI sequence. For an objective assessment, delineation of the prostate shape on both DWI sequences was compared to T2-weighted images by measuring organ diameters. Apparent diffusion coefficient (ADC) values, image contrast and contrast-to-noise ratio (CNR) were compared between the 2 sequences on a region-of-interest-based analysis. Diagnostic accuracy for quantitative ADC-values was calculated. Histopathology from MRI/ultrasound fusion-guided biopsy was used as reference standard. For a subjective assessment, 2 independent readers visually assessed image quality of both sequences using Likert-scales.Delineation of the prostate shape was more accurate with rsEPI compared to ssEPI. ADC values in target lesions were not significantly different but significantly higher in the surrounding normal prostatic tissue of the transition zone. CNR was comparable between ssEPI and rsEPI. Sensitivity and specificity were good for both sequences with 84/84% and 82/73% with a Youden selected cut-off of ADC = 0.971*10 mm/s for rsEPI and 1.017*10 mm/s for ssEPI. Anatomic artifacts were significantly less and SNR was lower on rsEPI compared to ssEPI in the subjective analysis.Delineation of the prostate shape was more accurate with rsEPI DWI than with ssEPI DWI with less anatomic artifacts and higher subjective SNR and image quality on rsEPI DW images. Diagnostic ability of quantitative ADC-values was not significantly different between the 2 sequences. Thus, rsEPI DWI might be more suitable for prostate MRI with regard to MRI-guided targeted biopsy and therapy planning.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Próstata , Neoplasias da Próstata , Idoso , Pesquisa Comparativa da Efetividade , Precisão da Medição Dimensional , Humanos , Biópsia Guiada por Imagem/métodos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Planejamento de Assistência ao Paciente , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes
10.
Medicine (Baltimore) ; 98(30): e16360, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31348236

RESUMO

BACKGROUND AND OBJECTIVE: Ischemic stroke is a foremost cause for disability and death worldwide. This study is conducted in order to compare the diagnostic values between transcranial Doppler ultrasound (ultrasonography), computed tomography (CT), and magnetic resonance imaging (MRI) in patients suffering from ischemic stroke by performing a network meta-analysis. METHODS: We made use of Cochrane Library, PubMed, and Embase in order to obtain literature and papers. The combination analysis of both direct and indirect evidence in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was conducted so as to assess the odds ratios (ORs) and surface under the cumulative ranking curve (SUCRA) values of the seven different imaging methods. These imaging techniques include ultrasonography, computed tomography (traditional CT, computed tomography angiography [CTA], computed tomography perfusion [CTP]), and MRI (traditional MRI, diffusion-weighted imaging [DWI], magnetic resonance angiography), in order to properly diagnose ischemic stroke patients. RESULTS: Thirteen eligible diagnostic trials were enrolled into this network meta-analysis. The results of the traditional meta-analysis showed that among CT methods, CTP showed higher sensitivity, NPV, and accuracy; among MRI methods, DWI had relatively higher sensitivity, NPV, and accuracy. The results of network meta-analysis showed that DWI had relatively higher sensitivity, NPV, and accuracy when compared with traditional CT, CTA, magnetic resonance angiography and traditional MRI. CTP showed higher SUCRA among CT methods while DWI showed higher SUCRA among MRI methods. A cluster analysis revealed that DWI had the highest diagnostic value in terms of sensitivity, PPV, NPV, and accuracy amongst the aforementioned seven imaging techniques. CONCLUSION: This network meta-analysis provides supporting evidence to the idea that DWI has a higher diagnostic value regarding ischemic stroke among MRI methods, and CTP has a poor diagnostic value among CT methods, which provide therapeutic considerations for Ischemic stroke intervention.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia Doppler Transcraniana/métodos , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/normas , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/normas , Humanos , Angiografia por Ressonância Magnética/métodos , Angiografia por Ressonância Magnética/normas , Imagem por Ressonância Magnética/normas , Meta-Análise em Rede , Valor Preditivo dos Testes , Tomografia Computadorizada por Raios X/normas , Ultrassonografia Doppler Transcraniana/normas
11.
Br J Radiol ; 92(1100): 20190119, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31204855

RESUMO

OBJECTIVES: To investigate the feasibility of intravoxel incoherent motion (IVIM) diffusion MR and diffusion kurtosis imaging (DKI) in discriminating atypical bone metastasis from benign bone lesion in patients with tumors. METHODS: Patients with bone lesions in lower extremity suspected of metastases were enrolled in this prospective study. IVIM diffusion MR and DKI were performed before biopsy. Apparent diffusion coefficient (ADC), true diffusion (D), perfusion fraction (f) and perfusion-related pseudodiffusion (D*) were generated with IVIM, while mean kurtosis (MK) and mean diffusion (MD) generated with DKI. Two radiologists blinded to pathology results separately measured these parameters for each lesion through drawing region of interest. Intraclass correlation coefficient was used to determine the inter-reader viability in measurement. The patients with pathology-confirmed metastasis or benign lesion were analyzed. The Mann-Whitney test was used to compare IVIM and DKI parameters between metastasis group and benign lesion group. Receiver operating characteristic curves were constructed to evaluate the ability of discrimination. RESULTS: Bone lesions from 28 patients (metastasis, n = 15; benign lesion, n = 13; mean age = 55 years; age range, 34~77) were analyzed with IVIM and DKI. Intraclass correlation coefficient was greater than 0.8 for all parameters. ADC, D and MD were significantly lower in metastases versus benign lesions (p <0.05). MK and f value were significantly higher in metastases versus benign lesions (p<0.05). D* was not significantly different between the two groups (p>0.05). Areas under curve for ADC, D, f, MK and MD were 0.935, 0.939, 0.891, 0.840 and 0.844 respectively. CONCLUSIONS: IVIM and DKI derived parameters distinguish between atypical bone metastasis and benign bone lesion in selected patients with tumors. ADVANCES IN KNOWLEDGE: Bone metastasis and benign bone lesion differ in water molecular diffusion. Intravoxel incoherent motion derived true diffusion distinguishes between atypical bone metastasis and benign lesion.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Imagem de Difusão por Ressonância Magnética/métodos , Adulto , Idoso , Osso e Ossos/diagnóstico por imagem , Diagnóstico Diferencial , Imagem de Tensor de Difusão/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
J Comput Assist Tomogr ; 43(4): 563-567, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31162233

RESUMO

OBJECTIVE: The objective of this study was to determine whether apparent diffusion coefficient (ADC) values obtained from diffusion-weighted imaging allow differentiation between infantile hemangiomas (IHs) and malignant soft tissue tumors. METHODS: A retrospective review was performed on magnetic resonance images of pediatric patients with IHs and malignant soft tissue tumors from January 2014 to December 2016, which comprised 7 patients with 8 IHs and 6 patients with 6 malignant soft tissue tumors. We calculated and compared the ADC values of each lesion. Receiver operating characteristic curve analysis was performed to determine a cutoff value for the ADC. RESULTS: There was a statistically significant difference between the ADC values of IHs and those of malignant soft tissue tumors (1.32 [1.27-1.72] × 10 mm/s vs 0.67 [0.57-0.79] × 10 mm/s; P < 0.001), with no overlap between the 2 groups. CONCLUSIONS: The ADC values obtained from diffusion-weighted imaging were useful in differentiating IHs from malignant soft tissue tumors in pediatric patients.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Hemangioma/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Sarcoma/diagnóstico por imagem
13.
Zhonghua Zhong Liu Za Zhi ; 41(6): 421-428, 2019 Jun 23.
Artigo em Chinês | MEDLINE | ID: mdl-31216827

RESUMO

Objective: To evaluate the feasibility of intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DWI MRI) in the evaluation of tumor vascular normalization in a mouse model of colorectal cancer induced by recombinant human endostatin (rhES). Methods: The CT26 colorectal cancer xenograft model of BALB/c mice were established and divided into rhES group and control group, with 20 mice in each group. The mice of rhES group were intravenously injected with rhES 5 mg·kg(-1)·d(-1) once daily for 12 days, while the mice of the control group were intravenously injected with the same volume of 0.9% saline. 5 mice of rhES group and control group were randomly selected to perform IVIM-DWI MRI as following times: before treatment and four, eight, twelve days after treatment. The parameters of IVIM-DWI were recorded, including true diffusion coefficient(D), pseudo-diffusion coefficient (D(*)) and perfusion fraction (f). Meanwhile, microvessel density (MVD), pericyte coverage and tumor perfusion in tumor tissues were detected by immunofluorescence, respectively. Results: The tumor volumes of control group and rhES group before treatment were (154.42±24.65) mm(3) and (174.24±28.27)mm(3,) respectively, without statistically significant difference (P=0.440). From day 2 to day 12 after treatment, the tumor volume of rhES group was significantly smaller than that of control group (all P<0.05). There were no statistical significances of D value between the rhES group and control group before and after treatment (all P>0.05). The D(*) values of the rhES group were (10.940±2.834)×10(-3)mm(2)/s and (12.940±2.801)×10(-3)mm(2)/s in day 4 and 8 after treatment respectively, significantly higher than (6.980±1.554)×10(-3)mm(2)/s and (7.898±1.603)×10(-3)mm(2)/s of control group (P<0.05). Moreover, compared with control group, the D(*) value of rhES group was significantly lower in day 12 (6.848±1.460)×10(-3)mm(2)/s vs (9.950±2.596)×10(-3)mm(2)/s, (P<0.05). The f value of rhES group in day 8 was (0.226±0.021)%, significantly higher than (0.178±0.016)% of control group (P<0.01). The MVD of rhES group was significantly lower than that of control group (P<0.05), while the pericyte coverage and tumor perfusion of rhES group were significantly higher than those of control group in day 4 and 8 after treatment (all P<0.05). In addition, we found D(*) value of IVIM-DWI in rhES group was significantly related with MVD, pericyte coverage and tumor perfusion (r=-0.354, r=0.555, r=0.559, all P<0.05). Meanwhile, the f value in rhES group was also significantly related with MVD, pericyte coverage and tumor perfusion (r=-0.391, r=0.538, r=0.315, all P<0.05). Conclusions: IVIM-DWI MRI can effectively evaluate the vascular normalization in rhES-induced CT26 colorectal tumor.The parameters D(*) and f are closely related to intratumorally microvessel density, pericyte coverage and perfusion, which can effectively monitor the occurrence of tumor vascular normalization time.


Assuntos
Neoplasias Colorretais/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Neovascularização Patológica/diagnóstico por imagem , Animais , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/induzido quimicamente , Modelos Animais de Doenças , Endostatinas/toxicidade , Estudos de Viabilidade , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/toxicidade
14.
Cancer Imaging ; 19(1): 39, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217036

RESUMO

BACKGROUND: Preoperative chemotherapy is becoming standard therapy for liver metastasis from colorectal cancer, so early assessment of treatment response is crucial to make a reasonable therapeutic regimen and avoid overtreatment, especially for patients with severe side effects. The role of three non-mono-exponential diffusion models, such as the kurtosis model, the stretched exponential model and the statistical model, were explored in this study to early assess the response to chemotherapy in patients with liver metastasis from colorectal cancer. METHODS: Thirty-three patients diagnosed as colorectal liver metastasis were evaluated in this study. Diffusion-weighted images with b values (0, 200, 500, 1000, 1500, 2000 s/mm2) were acquired at 3.0 T. The parameters (ADCk, K, DDC,α, Ds and σ) were derived from three non-mono-exponential models (the kurtosis, stretched exponential and statistical models) as well as their corresponding percentage changes before and after chemotherapy. The difference in above parameters between the response and non-response groups were analyzed with independent-samples T-test (normality) and Mann-Whitney U-test (non-normality). Meanwhile, receiver operating characteristic curve (ROC) analyses were performed to assess the response to chemotherapy. RESULTS: Significantly lower values of K (the kurtosis coefficient derived from the kurtosis model) and σ (the width of diffusion coefficient distribution in the statistical model) (P < 0.05) were observed in the respond group before treatment, as well as higher ΔK and Δσ values (P < 0.05) after the first cycle of chemotherapy were also found compared with the non-respond group. ROC analyses showed the K value acquired before treatment had the highest diagnostic performance (0.746) in distinguishing responders from non-responders. Furthermore, the high sensitivity (100%) and accuracy (76.3%) from the K value before treatment was found in assessing the response of colorectal liver metastasis to chemotherapy. CONCLUSIONS: The non-mono-exponential diffusion models may be able to predict early response to chemotherapy in patients with colorectal liver metastasis.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Hepáticas/tratamento farmacológico , Idoso , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/patologia , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida
15.
Top Magn Reson Imaging ; 28(3): 145-158, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31188273

RESUMO

Radiofrequency (RF) coils are an essential part of the magnetic resonance (MR) system. To exploit the inherently higher signal-to-noise ratio at ultrahigh magnetic fields (UHF), research sites were forced to build up expertise in RF coil development, as the number of commercially available RF coils were limited. In addition, an integrated transmit body RF coil, which is well-established at MR systems of lower field strength, is still missing at UHF due to technical and physical constraints. This review article provides a brief recapitulation of RF characteristics and RF coils in general to introduce terminology and RF-related parameters, and will then provide an extensive overview of current state-of-the-art RF coils used for MRI from head to toe at 7 Tesla. Finally, a section on RF safety will briefly discuss challenges in performing a safety assessment for custom-designed RF coils, and issues arising from the interaction of the RF field and potentially implanted medical devices.


Assuntos
Encéfalo/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/instrumentação , Imagem de Difusão por Ressonância Magnética/métodos , Desenho de Equipamento , Humanos , Imagem por Ressonância Magnética/instrumentação , Imagem por Ressonância Magnética/tendências , Ondas de Rádio
16.
Medicine (Baltimore) ; 98(20): e15227, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31096431

RESUMO

The study aimed to demonstrate the clinical application value of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing a clinical curative effect of early ankylosing spondylitis (AS).Forty-eight patients with early AS who were already treated combinations by traditional Chinese and Western medicine were involved in this study. All subjects underwent the conventional MRI, DWI, and DCE-MRI scanning of bilateral sacroiliac joints before and after treatment. The relevant data, such as the mean apparent diffusion coefficient (ADC) value, time-intensity curve of subarticular surface bone marrow, and the relationship between ADC value and enhancement factor (Fenh), enhancement slope (Senh), and time to peak (TTP), were obtained.1. The mean ADC value of the subarticular surface bone marrow of patients and after clinical treatment was (5.05 ±â€Š1.10) × 10 and (4.34 ±â€Š0.55) × 10 mm/s in ilium and (4.63 ±â€Š0.79) × 10 and (3.96 ±â€Š0.23) × 10 mm/s in sacrum, respectively. 2. In the DCE-MRI follow-up treatment imaging of 48 patients with AS (192 parts), the TIC curve type recorded was as follows: 43.75% (84/192) of type II, 56.25% (108/192) of type III, and type I curve was not seen. The number of type II curve was significantly reduced for pre treatment group (84 cases) compared with that post treatment group (124 cases). The Fenh, Senh, and TTP values were respective (113.38 ±â€Š44.71)%, (60.94 ±â€Š38.56)% min, (129.52 ±â€Š42.66) s in ilium and (83.03 ±â€Š20.39)%, (44.91 ±â€Š15.19)% min, (123.44 ±â€Š28.50) s in sacrum before clinical treatment. After the treatment, the Fenh, Senh, and TTP values were respective (75.90 ±â€Š17.97)%, (33.96 ±â€Š11.36)% min, (138.67 ±â€Š26.60) s in ilium and (73.28 ±â€Š15.67)%, (31.92 ±â€Š8.15)% min, (140.19 ±â€Š19.88) s in sacrum. The Fenh, Senh, and TTP values of semiquantitative indexes before and after clinical treatment were significantly different.DWI and DCE-MRI sequences can help evaluate the degree of active changes in AS inflammation and treatment effect in patients with early AS, and provide reliable imaging evidence.


Assuntos
Meios de Contraste/administração & dosagem , Imagem de Difusão por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/métodos , Articulação Sacroilíaca/diagnóstico por imagem , Espondilite Anquilosante/diagnóstico por imagem , Adolescente , Adulto , Criança , Feminino , Humanos , Inflamação/patologia , Masculino , Articulação Sacroilíaca/efeitos dos fármacos , Articulação Sacroilíaca/patologia , Espondilite Anquilosante/tratamento farmacológico , Espondilite Anquilosante/patologia , Espondilite Anquilosante/terapia , Adulto Jovem
17.
J Comput Assist Tomogr ; 43(3): 434-442, 2019 May/Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31082949

RESUMO

OBJECTIVES: Motivated by the similar appearance of malignant breast lesions in high b-value diffusion-weighted imaging (DWI) and positron emission tomography, the purpose of this work was to evaluate the applicability of a threshold isocontouring approach commonly used in positron emission tomography to analyze DWI data acquired from female human breasts with minimal interobserver variability. METHODS: Twenty-three female participants (59.4 ± 10.0 years) with 23 lesions initially classified as suggestive of cancers in x-ray mammography screening were subsequently imaged on a 1.5-T magnetic resonance imaging scanner. Diffusion-weighted imaging was performed prior to biopsy with b values of 0, 100, 750, and 1500 s/mm. Isocontouring with different threshold levels was performed on the highest b-value image to determine the voxels used for subsequent evaluation of diffusion metrics. The coefficient of variation was computed by specifying 4 different regions of interest drawn around the lesion. Additionally, a receiver operating statistical analysis was performed. RESULTS: Using a relative threshold level greater than or equal to 0.85 almost completely suppresses the intra-individual and inter-individual variability. Among 4 studied diffusion metrics, the diffusion coefficients from the intravoxel incoherent motion model returned the highest area under curve value of 0.9. The optimal cut-off diffusivity was found to be 0.85 µm/ms with a sensitivity of 87.5% and specificity of 90.9%. CONCLUSION: Threshold isocontouring on high b-value maps is a viable approach to reliably evaluate DWI data of suspicious focal lesions in magnetic resonance mammography.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Mamografia/métodos , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Modelos Teóricos , Variações Dependentes do Observador , Tomografia por Emissão de Pósitrons , Intensificação de Imagem Radiográfica , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
J Stroke Cerebrovasc Dis ; 28(7): 1824-1831, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078388

RESUMO

OBJECTIVE: To assess the reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of atherosclerotic plaques in the middle cerebral artery. METHODS: Sixty-nine consecutive patients with ischemic stroke or asymptomatic stenosis (>30%) of the middle cerebral artery underwent 3.0T high-resolution magnetic resonance imaging examinations. Two independent investigators reviewed all images with 1 investigator re-evaluating all images 4 weeks later. Wall characteristics of the middle cerebral artery, including plaque surface morphology, plaque location, plaque components, and burden were identified and measured. RESULTS: Intraobserver and interobserver agreement were all substantial in identifying plaque surface irregularity (k = 0.741, 0.555-0.897; k = 0.685, 0.490-0.843; respectively) and intraplaque hemorrhage (k = 0.654, 0.446-0.838; k = 0.605, 0.369-0.792; respectively). Intraobserver agreement was substantial (k = 0.654) and interobserver agreement was moderate (k = 0.553) for the identification of plaque fibrous caps. The total intraobserver and interobserver reproducibility was almost excellent for the identification of plaque position. With regards to vessel area measurement at the site of maximal lumen narrowing, intraobserver and interobserver reproducibility was excellent (intraclass correlation coefficient was 0.886 and 0.885, respectively) and moderate for lumen area at the site of maximal lumen narrowing (intraclass correlation coefficient was 0.695 and 0.558, respectively). In addition, intraobserver and interobserver reproducibility was excellent for vessel area and lumen area measurements at the reference sites. CONCLUSIONS: The reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of artery wall characteristics was overall acceptable. However, the reliability for lumen area measurement at the maximum narrowing site and identification of the fibrous cap needs to be improved.


Assuntos
Angiografia Cerebral/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Arteriosclerose Intracraniana/diagnóstico por imagem , Ataque Isquêmico Transitório/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Artéria Cerebral Média/diagnóstico por imagem , Placa Aterosclerótica , Idoso , Feminino , Fibrose , Humanos , Infarto da Artéria Cerebral Média/patologia , Arteriosclerose Intracraniana/patologia , Ataque Isquêmico Transitório/patologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/patologia , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
19.
Medicine (Baltimore) ; 98(21): e15520, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31124932

RESUMO

Diffusion-weighted imaging (DWI) is a functional imaging technique sensitive to microstructure in tissues. It is widely acknowledged to reflect cellularity in tumors. A small part of DWI is also sensitive to perfusion-related information and might therefore be also be able to reflect microvessel density in tumor tissues. Aim of the present study was to elucidate possible correlations between microvessel density and apparent diffusion coefficient (ADC) values in head and neck squamous cell carcinoma (HNSCC).Thirty-four patients with histologically proven primary HNSCC were included in the study. DWI was performed with a 3 T magnetic resonance imaging (MRI) (b-values 0 and 800 s/mm) and histogram analysis was calculated with a whole lesion measurement. In every case, microvessel density was estimated with CD105-stained specimens.There were no statistically significant correlations between ADC histogram parameters and microvessel density. The calculated correlation coefficients ranged from r = -0.27, P = .13 for entropy and vessel area to r = 0.16, P = .40 for ADCmin and vessel count.Whole-lesion histogram analysis of ADC values cannot reflect microvessel density in HNSCC.


Assuntos
Imagem de Difusão por Ressonância Magnética/estatística & dados numéricos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Microvasos/diagnóstico por imagem , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Adulto , Idoso , Imagem de Difusão por Ressonância Magnética/métodos , Endoglina , Entropia , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Microvasos/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Coloração e Rotulagem , Carga Tumoral
20.
Br J Radiol ; 92(1101): 20181016, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30933548

RESUMO

Quantitative Susceptibility Mapping (QSM) and Susceptibility Weighted Imaging (SWI) are MRI techniques that measure and display differences in the magnetization that is induced in tissues, i.e. their magnetic susceptibility, when placed in the strong external magnetic field of an MRI system. SWI produces images in which the contrast is heavily weighted by the intrinsic tissue magnetic susceptibility. It has been applied in a wide range of clinical applications. QSM is a further advancement of this technique that requires sophisticated post-processing in order to provide quantitative maps of tissue susceptibility. This review explains the steps involved in both SWI and QSM as well as describing some of their uses in both clinical and research applications.


Assuntos
Imagem por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Magnetismo
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