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1.
Medicine (Baltimore) ; 102(46): e36176, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37986292

RESUMO

To determine the relevant laboratory values for hepatobiliary phase (HBP) imaging and predictive factors for suboptimal HBP images on gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) for the evaluation of hepatocellular carcinoma (HCC) in patients with chronic liver disease (CLD). This study included 307 patients with CLD who underwent gadoxetic acid-enhanced liver MRI for HCC evaluation. The liver-portal vein contrast ratio and liver-spleen contrast ratio were calculated from the measurements of the HBP images. In this study, a suboptimal HBP image was defined as the presence of a bright portal vein or a liver-spleen contrast ratio of <1.5. Correlation, comparison, and receiver operating characteristic analyses were performed between the measured parameters on the HBP images and hepatic and renal function tests. The estimated glomerular filtration rate did not correlate with any measured or calculated values on the HBP images. On receiver operating characteristic analysis, the optimal cutoff value for the bright portal vein was an albumin level of 4.05 g/dL (area under the curve, 0.971; sensitivity, 65%; specificity, 82%). The optimal cutoff value of the suboptimal HBP image was a serum direct bilirubin level of 0.83 mg/dL (area under the curve, 0.830; sensitivity, 69%; specificity, 84%). On gadoxetic acid-enhanced MRI for the evaluation of HCC in patients with CLD, suboptimal HBP images were most strongly correlated with serum direct bilirubin levels. Renal function was not associated with suboptimal HBP imaging. Although the sensitivity is low, suboptimal HBP images can be predicted before gadoxetic acid-enhanced liver MRI can be performed.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Bilirrubina , Sensibilidade e Especificidade
2.
J Korean Soc Radiol ; 84(5): 1094-1109, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37869127

RESUMO

Purpose: To investigate whether CT-based tumor regression grade (ctTRG) can be used to predict the response to neoadjuvant chemotherapy (NAC) in colon cancer. Materials and Methods: A total of 53 patients were enrolled. Two radiologists independently assessed the ctTRG using the length, thickness, layer pattern, and luminal and extraluminal appearance of the tumor. Changes in tumor volume were also analyzed using the 3D Slicer software. We evaluated the association between pathologic TRG (pTRG) and ctTRG. Patients with Rödel's TRG of 2, 3, or 4 were classified as responders. In terms of predicting responder and pathologic complete remission (pCR), receiver operating characteristic was compared between ctTRG and tumor volume change. Results: There was a moderate correlation between ctTRG and pTRG (ρ = -0.540, p < 0.001), and the interobserver agreement was substantial (weighted κ = 0.672). In the prediction of responder, there was no significant difference between ctTRG and volumetry (Az = 0.749, criterion: ctTRG ≤ 3 for ctTRG, Az = 0.794, criterion: ≤ -27.1% for volume, p = 0.53). Moreover, there was no significant difference between the two methods in predicting pCR (p = 0.447). Conclusion: ctTRG might predict the response to NAC in colon cancer. The diagnostic performance of ctTRG was comparable to that of CT volumetry.

3.
Abdom Radiol (NY) ; 45(10): 2997-3006, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31578607

RESUMO

PURPOSE: The objective was to assess which image-based criteria can be best accurately determined at MDCT and which results in least overtreatment. MATERIALS AND METHODS: A total of 110 consecutive patients, who underwent curative surgery for colon cancer, were included in this retrospective study. Five radiologists independently assessed the longitudinal diameter of cancer as well as T- and N-categories. The five image-based criteria (T3cd/T4, T3/T4, T3/T4 or N+, T3cd/T4 or N2, and T3/T4 with ≥ 4 cm) were evaluated in terms of diagnostic accuracy, interreader agreement, and overtreatment risk using pooled receiver-operating curve and Fleiss kappa analyses. Pathologic high-risk stage II or III was used as a reference standard for assessment of overtreatment risk. RESULTS: The diagnostic accuracy of multireaders was in the acceptable range (pooled area under curve (AUC): 0.751-0.829). T3/T4 showed the highest AUC (0.829) in terms of diagnostic accuracy. T3/T4 with ≥ 4 cm showed the highest kappa value (κ = 0.695) followed by T3/T4 (κ = 0.623), indicating substantial agreement. The other three criteria revealed moderate agreement (κ = 0.558-0.577). In terms of overtreatment ratio, T3cd/T4 and T3cd/T4 or N2 showed relatively lower ratios (T3cd/T4, 2.2%; T3cd/T4 or N2, 2.9%), whereas T3/T4 and T3/T4 or N+ revealed higher ratios (T3/T4, 8.7%; T3/T4 or N+, 9.5%). CONCLUSIONS: T3/T4 was the best criterion in terms of diagnostic accuracy. However, in terms of interreader agreement and overtreatment risk, T3/T4 with ≥ 4 cm and T3cd/T4 were better as potential image-based criteria of neoadjuvant chemotherapy for colon cancer.


Assuntos
Neoplasias do Colo , Terapia Neoadjuvante , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Humanos , Estadiamento de Neoplasias , Estudos Retrospectivos , Sensibilidade e Especificidade
4.
Radiology ; 287(1): 68-75, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29315062

RESUMO

Purpose To determine the prognostic value of peritumoral edema identified at preoperative breast magnetic resonance (MR) imaging for disease recurrence in patients with invasive breast cancer. Materials and Methods Between January 2011 and December 2012, 353 women (median age, 49 years; range, 27-77 years) with invasive breast cancer who had undergone preoperative MR imaging and mastectomy or breast-conserving surgery were identified. Two radiologists independently reviewed peritumoral edema on the basis of the degree of the signal intensity surrounding the tumor on T2-weighted images. The association of disease recurrence with peritumoral edema and clinical-pathologic features was assessed by using the multivariate Cox proportional hazards model and the integrated discrimination improvement (IDI) and continuous net reclassification improvement (NRI) indexes. Results Twenty-four patients (6.8%) had disease recurrence after 27.2 months of median follow-up. At multivariate analysis, higher N stage (hazard ratio = 4.84, P = .002) and the presence of lymphovascular invasion (hazard ratio = 2.48, P = .044) and peritumoral edema (hazard ratio = 2.77, P = .022) were independent factors associated with disease recurrence. IDI and continuous NRI showed significant improvement in the accuracy of the association with disease recurrence when peritumoral edema was added to established clinical-pathologic features (IDI = 0.061, P < .001; continuous NRI = 0.334, P = .012). Conclusion Peritumoral edema identified at preoperative MR imaging is independently associated with disease recurrence. Peritumoral edema assessment may provide better prognostication in patients with invasive breast cancer. © RSNA, 2018.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Edema/complicações , Edema/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Cuidados Pré-Operatórios/métodos , Adulto , Idoso , Mama/diagnóstico por imagem , Mama/patologia , Neoplasias da Mama/complicações , Edema/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Adulto Jovem
5.
Medicine (Baltimore) ; 96(44): e8533, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29095318

RESUMO

Percutaneous transhepatic gallbladder drainage followed by laparoscopic cholecystectomy (PTGBD+LC) is one treatment option for patients with moderate to severe acute cholecystitis (AC). However, the impact of PTGBD on operative difficulties in performing LC is controversial. We designed this retrospective study to clarify the surgical outcomes after PTGBD+LC for the management of patients with moderate to severe AC.The medical records of 85 patients who underwent LC for moderate to severe AC from January 2013 to September 2016 were evaluated. They were divided into 2 groups based on the type of management: group A received PTGBD+LC, and group B received LC without drainage. We compared the patient characteristics, laboratory data which were obtained immediately before surgery or PTGBD at index admission, and surgical outcomes between the 2 groups. We also evaluated possible predictive factors associated with prolonged operative duration after PTGBD+LC.Patients in group A were older and had more comorbidities than those in group B. The laboratory tests obtained at index admission in group A showed higher serum levels of C-reactive protein (CRP) and alkaline phosphatase, and lower albumin levels than those in group B. The surgical outcomes after LC were similar between the 2 groups. However, operative duration was significantly shorter in group A (P = .012). In group A, a higher serum level of CRP was a predictive factor for a prolonged operation (hazard ratio 1.126; 95% confidence interval 1.012-1.253; P = .029). In conclusion, PTGBD+LC can shorten the operative duration in patients with moderate to severe AC, which might improve surgical outcomes in elderly patients with comorbidities, and elevated CRP values predicted a prolonged operation after PTGBD.


Assuntos
Colecistectomia Laparoscópica/métodos , Colecistite Aguda/cirurgia , Drenagem/métodos , Vesícula Biliar/cirurgia , Fígado/cirurgia , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/análise , Colecistite Aguda/sangue , Terapia Combinada , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
6.
J Med Chem ; 60(12): 4861-4868, 2017 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-28530407

RESUMO

We report the synthesis of a macrocyclic Gd chelate based on a 1,4,7,10-tetraazacyclododecane-1,4,7-trisacetic acid (DO3A) coordinationn cage bearing an ethoxybenzyl (EOB) moiety and discuss its use as a T1 hepatobiliary magnetic resonance imaging (MRI) contrast agent. The new macrocyclic liver agent shows high chelation stability and high r1 relaxivity compared with linear-type Gd chelates, which are the current clinically approved liver agents. Our macrocyclic, liver-specific Gd chelate was evaluated in vivo through biodistribution analysis and liver MRI, which demonstrated its high tumor detection sensitivity and suggested that the new Gd complex is a promising contrast agent for liver cancer imaging.


Assuntos
Meios de Contraste/química , Meios de Contraste/farmacocinética , Gadolínio/química , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Animais , Sobrevivência Celular/efeitos dos fármacos , Quelantes/química , Quelantes/farmacocinética , Células HEK293 , Compostos Heterocíclicos com 1 Anel/química , Humanos , Cinética , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Masculino , Camundongos Endogâmicos ICR , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Medicine (Baltimore) ; 96(12): e6362, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28328820

RESUMO

Recently, a few studies have raised the question of whether preoperative chemoradiotherapy (PCRT) is essential for all T3 rectal cancers. This case-matched study aimed to compare the long-term outcomes of surgery alone with those of PCRT + surgery for magnetic resonance imaging (MRI)-assessed T3ab (extramural depth of invasion ≤5 mm) and absent mesorectal fascia invasion (clear MRF) in mid/lower rectal cancer patients.From January 2006 to November 2012, 203 patients who underwent curative surgery alone (n = 118) or PCRT + surgery (n = 85) were enrolled in this retrospective study. A 1:1 propensity score-matched analysis was performed to eliminate the inherent bias. Case-matching covariates included age, sex, body mass index, histologic grade, carcinoembryonic antigen, operation method, follow-up period, tumor height, and status of lymph node metastasis. The end-points were the 5-year local recurrence (LR) rate and disease-free-survival (DFS).After propensity score matching, 140 patients in 70 pairs were included. Neither the 5-year LR rate nor the DFS was significantly different between the 2 groups (the 5-year LR rate, P = 0.93; the 5-year DFS, P = 0.94). The 5-year LR rate of the surgery alone was 2% (95% confidence interval [CI] 0.2%-10.9%) versus 2% (95% CI 0.2%-10.1%) in the PCRT + surgery group. The 5-year DFS of the surgery alone was 87% (95% CI 74.6%-93.7%) versus 88% (95% CI 77.8%-93.9%) in the PCRT + surgery group.In patients with MRI-assessed T3ab and clear MRF mid/lower rectal cancer, the long-term outcomes of surgery alone were comparable with those of the PCRT + surgery. The suggested MRI-assessed T3ab and clear MRF can be used as a highly selective indication of surgery alone in mid/lower T3 rectal cancer. Additionally, in those patients, surgery alone can be tailored to the clinical situation.


Assuntos
Quimiorradioterapia Adjuvante , Neoplasias Retais/terapia , Idoso , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Metástase Linfática , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/epidemiologia , Cuidados Pré-Operatórios , Pontuação de Propensão , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/epidemiologia , Neoplasias Retais/patologia , Reto/diagnóstico por imagem , Reto/patologia , Reto/cirurgia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
8.
J Biomed Nanotechnol ; 12(5): 894-908, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27305813

RESUMO

This work is directed toward the synthesis of two types of gadolinium oxide nanoparticles (Gd-oxide NPs), abbreviated as Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA, with diameters of 50-60 nm. The synthesis involves sequential coating of Gd-oxide NPs with tetraethyl orthosilicate (TEOS) and (3-aminopropyl) triethoxysilane (APTES), followed by functionalization of the aminopropylsilane group with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7,10-tetraazacyclododecane-1,4,7-trisacetic acid conjugates of benzothiazoles (DO3A-BTA). Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA exhibit high water solubility and colloidal stability. The r1 relaxivities of both Gd@SiO2-DO3A and Gd@SiO2-DO2A-BTA are higher than those of the corresponding low-molecular-weight magnetic resonance imaging contrast agents (MRI CAs), and their r2/r1 ratios are close to 1, indicating that both can be used as potential T1 MRI CAs. Biodistribution studies demonstrated that Gd@SiO2-DO2A-BTA was excreted via both hepatobiliary and renal pathways. Gd@SiO2-DO2A-BTA exhibits a strong intracellular uptake property in a series of tumor cell lines, and has significant anticancer characteristics against cell lines such as SK-HEP-1, MDA-MB-231, HeLa, and Hep-3B.


Assuntos
Quelantes/química , Gadolínio/química , Imageamento por Ressonância Magnética , Nanopartículas/química , Nanomedicina Teranóstica , Animais , Benzotiazóis/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Coloides , Túnica Conjuntiva/citologia , Modelos Animais de Doenças , Difusão Dinâmica da Luz , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Fígado/patologia , Camundongos , Nanopartículas/ultraestrutura , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Distribuição Tecidual/efeitos dos fármacos , Água/química
9.
Acta Radiol ; 57(10): 1205-9, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26787678

RESUMO

BACKGROUND: As a minimally invasive treatment, ethanol sclerotherapy has been used for large symptomatic hepatic cysts, but there are not many long-term reports on treatment outcomes and safety. PURPOSE: To evaluate the long-term outcomes of percutaneous ethanol sclerotherapy in patients with large symptomatic hepatic cysts. MATERIAL AND METHODS: This study included 43 symptomatic, enlarging hepatic cysts in 42 patients who had undergone ethanol sclerotherapy from 2003 to 2013 and were followed up for >1 year. The treatment outcomes were evaluated in terms of the reduction of cyst size and resolution of symptoms. The patients were followed up for a mean period of 33 months with either ultrasound or computed tomography examination. RESULTS: Thirty-nine hepatic cysts (91%) were successfully treated with ethanol sclerotherapy, showing resolution of symptoms and remarkable reduction in cyst volume. Eight hepatic cysts (19%) disappeared completely, and 31 hepatic cysts (72%) decreased in size during the follow-up period. The mean diameter of the cysts decreased from 12.5 ± 4.4 cm to 3.8 ± 3.4 cm during follow-up. There were no immediate serious complications related to the procedure. There were four cases (9%) of treatment failure requiring subsequent surgical procedures. CONCLUSION: Percutaneous ethanol sclerotherapy can be considered as an effective first-line treatment for large symptomatic hepatic cysts.


Assuntos
Cistos/terapia , Etanol/uso terapêutico , Hepatopatias/terapia , Soluções Esclerosantes/uso terapêutico , Escleroterapia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Cistos/diagnóstico por imagem , Diagnóstico por Imagem , Feminino , Seguimentos , Humanos , Hepatopatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
10.
Acta Radiol ; 56(9): 1042-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25270374

RESUMO

BACKGROUND: The value of diffusion-weighted imaging (DWI) for reliable differentiation between pathologic complete response (pCR) and residual tumor is still unclear. Recently, a few studies reported that histogram analysis can be helpful to monitor the therapeutic response in various cancer research. PURPOSE: To investigate whether post-chemoradiotherapy (CRT) apparent diffusion coefficient (ADC) histogram analysis can be helpful to predict a pCR in locally advanced rectal cancer (LARC). MATERIAL AND METHODS: Fifty patients who underwent preoperative CRT followed by surgery were enrolled in this retrospective study, non-pCR (n = 41) and pCR (n = 9), respectively. ADC histogram analysis encompassing the whole tumor was performed on two post-CRT ADC600 and ADC1000 (b factors 0, 600 vs. 0, 1000 s/mm(2)) maps. Mean, minimum, maximum, SD, mode, 10th, 25th, 50th, 75th, 90th percentile ADCs, skewness, and kurtosis were derived. Diagnostic performance for predicting pCR was evaluated and compared. RESULTS: On both maps, 10th and 25th ADCs showed better diagnostic performance than that using mean ADC. Tenth percentile ADCs revealed the best diagnostic performance on both ADC600 (AZ 0.841, sensitivity 100%, specificity 70.7%) and ADC1000 (AZ 0.821, sensitivity 77.8%, specificity 87.8%) maps. In comparison between 10th percentile and mean ADC, the specificity was significantly improved on both ADC600 (70.7% vs. 53.7%; P = 0.031) and ADC1000 (87.8% vs. 73.2%; P = 0.039) maps. CONCLUSION: Post-CRT ADC histogram analysis is helpful for predicting pCR in LARC, especially, in improving the specificity, compared with mean ADC.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Terapia Combinada , Procedimentos Cirúrgicos do Sistema Digestório , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Estudos Retrospectivos , Resultado do Tratamento
12.
PLoS One ; 9(8): e105308, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25141213

RESUMO

BACKGROUND: It is well known that lead exposure induces neurotoxic effects, which can result in a variety of neurocognitive dysfunction. Especially, occupational lead exposures in adults are associated with decreases in cognitive performance including working memory. Despite recent advances in human neuroimaging techniques, the neural correlates of lead-exposed cognitive impairment remain unclear. Therefore, this study was aimed to compare the neural activations in relation to working memory function between the lead-exposed subjects and healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-one lead-exposed subjects and 34 healthy subjects performed an n-back memory task during MRI scan. We performed fMRI using the 1-back and 2-back memory tasks differing in cognitive demand. Functional MRI data were analyzed using within- and between-group analysis. We found that the lead-exposed subjects showed poorer working memory performance during high memory loading task than the healthy subjects. In addition, between-group analyses revealed that the lead-exposed subjects showed reduced activation in the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, pre supplementary motor areas, and inferior parietal cortex. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that functional abnormalities in the frontoparietal working memory network might contribute to impairments in maintenance and manipulation of working memory in the lead-exposed subjects.


Assuntos
Intoxicação por Chumbo/psicologia , Memória de Curto Prazo/efeitos dos fármacos , Doenças Profissionais/psicologia , Idoso , Estudos de Casos e Controles , Córtex Cerebral/fisiopatologia , Feminino , Neuroimagem Funcional , Humanos , Chumbo/sangue , Intoxicação por Chumbo/fisiopatologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Doenças Profissionais/fisiopatologia
13.
Ann Hepatol ; 12(6): 926-34, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24114823

RESUMO

INTRODUCTION: Gadoxetate-disodium is a liver-specific MR contrast agent absorbed by hepatocytes via organic anion transporting polypeptide 1B3 and is excreted into the biliary system by multidrug resistance-associated protein 2. It has been suggested that relative parenchymal enhancement on hepatocyte phase image is associated with hepatic function. However, it is not clear whether gadoxetate-disodium-enhanced MRI can be used as a noninvasive fibrosis marker. Thus, the purpose of our study was to evaluate the diagnostic performance of gadoxetate-disodium-enhanced MRI in predicting the hepatic fibrosis stage. MATERIALS AND METHODS: A total of 113 patients who had fibrosis staged according to the Batts and Ludwig score were enrolled: F0 (n = 13), F1 (n = 18), F2 (n = 15), F3 (n = 32), and F4 (n = 35). All patients underwent gadoxetate-disodium-enhanced MRI before confirmation by biopsy (n = 67) or surgery (n = 46). For quantitative analysis, the contrast enhancement index (CEI) was calculated by measuring the signal intensity (SI) in liver and paraspinal muscle using a region of interest, as follows: CEI = (liver SI/paraspinal muscle SI) 20 min hepatocyte phase image/(liver SI/paraspinal muscle SI) pre-contrast T1-weighted image. The diagnostic performance was evaluated by the ROC curve, adjusted for the prevalence of each fibrosis stage. RESULTS: A significant negative correlation was observed between CEI and fibrosis stage (r = -0.545, P < 0.0001). The adjusted AUROC for CEI in the prediction of mild (≥F1), moderate (≥ F2), or severe fibrosis (≥ F3) and liver cirrhosis (F4) was 0.668, 0.703, 0.73, and 0.84, respectively. IN CONCLUSION: our results demonstrate that quantitative analysis of relative hepatic enhancement using gadoxetate-disodium-enhanced MRI can predict the hepatic fibrosis stage.


Assuntos
Meios de Contraste , Gadolínio DTPA , Cirrose Hepática/patologia , Fígado/patologia , Imageamento por Ressonância Magnética , Adulto , Idoso , Área Sob a Curva , Biomarcadores/sangue , Biópsia , Feminino , Humanos , Fígado/metabolismo , Fígado/cirurgia , Cirrose Hepática/sangue , Cirrose Hepática/cirurgia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Estudos Retrospectivos , Índice de Gravidade de Doença
14.
Behav Brain Res ; 234(1): 26-32, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22698706

RESUMO

Evidence from previous studies has suggested that motor imagery and motor action engage overlapping brain systems. As a result of this observation that motor imagery can activate brain regions associated with actual motor movement, motor imagery is expected to enhance motor skill performance and become an underlying principle for physical training in sports and physical rehabilitation. However, few studies have examined the effects of physical training on motor imagery in beginners. Also, differences in neural networks related to motor imagery before and after training have seldom been studied. In the current study, using functional magnetic resonance imaging (fMRI), we investigated the question of whether motor imagery can reflect plastic changes of neural correlates associated with intensive training. In fact, motor imagery was used in this study as a tool to assess the brain areas involved in shooting and involved in learning of shooting. We discovered that use of motor imagery resulted in recruitment of widely distributed common cortical areas, which were suggested to play a role in generation and maintenance of mental images before and after 90 h of shooting training. In addition to these common areas, brain activation before and after 90 h of shooting practice showed regionally distinct patterns of activity change in subcortical motor areas. That is, basal ganglia showed increased activity after 90 h of shooting practice, suggesting the occurrence of plastic change in association with gains in performance and reinforcement learning. Therefore, our results suggest that, in order to reach a level of expertise, the brain would change through initial reinforcement of preexistent connections during the training period and then use more focused neural correlates through formation of new connections.


Assuntos
Encéfalo/fisiologia , Atividade Motora/fisiologia , Destreza Motora/fisiologia , Plasticidade Neuronal/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Esportes , Adulto Jovem
15.
J Comput Assist Tomogr ; 36(2): 220-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22446363

RESUMO

OBJECTIVE: To investigate if there is difference in hepatic segmental volume distribution according to causes of liver cirrhosis (LC) using computed tomography volumetric analysis. METHODS: On computed tomographic scans, hepatic segmental volumes were measured in 90 patients with LC of 4 different causes (alcohol, hepatitis B virus (HBV), hepatitis C virus (HCV), and cryptogenic cirrhosis). The volumetric indices were compared. RESULTS: The volume proportion of the lateral segment in the liver in patients with HBV was significantly higher than in the patients with HCV (P = 0.038). Hepatic volume distribution in alcoholic LC showed differences: larger caudate lobe volume than HBV- and HCV-induced LC (P = 0.029 and P = 0.031), larger right lobe volume (P = 0.043) and smaller proportion of the lateral segment in the liver (P = 0.003) than in HBV-induced LC. CONCLUSIONS: Computed tomography volumetric analysis showed differences in hepatic segmental volume distribution in cirrhotic patients according to causes of LC.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/etiologia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Meios de Contraste , Feminino , Humanos , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estatísticas não Paramétricas
16.
Korean J Radiol ; 5(4): 231-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15637473

RESUMO

OBJECTIVE: Gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a newly developed MR contrast agent. After intravenous injection, Gd-EOB-DTPA is gradually taken up by the hepatocytes and eventually excreted via the biliary pathway without any change to its chemical structure. Because of these characteristics, it can be used as a tracer for quantitative liver function testing. The purpose of this study is to develop a noninvasive method of quantitation of the hepatic function using Gd-EOB-DTPA through the deconvolution analysis. MATERIALS AND METHODS: Adult New Zealand white rabbits (n = 10, average body weight = 3.5 kg) were used in the present study. Hepatic injury was induced to by the intragastric administration of carbon tetrachloride (CCl4) three times a week for three weeks. Liver enzyme (aspartate aminotransferase, AST; alanine aminotransferase, ALT) levels and the plasma indocyanine green (ICG) retention rate 15 minutes after an intravenous injection of ICG (ICG R15), was checked before and after the three-week administration of CCl4. At the end of experimental period, an observer "blinded" to the treatment given the rabbits performed the histological examination. MRI studies were performed before and after the three-week administration of CCl4 on a 1.5 T scanner using a human extremity coil. After intravenous bolus injection of Gd-EOB-DTPA (0.3 mL of Gd-EOB-DTPA freshly prepared in 2.7 mL of normal saline) through the ear vein, the 250 axial single level dynamic MR images were obtained using a fast low angle shot (FLASH, T /TE = 11/4.2 msec, flip angle = 15, acquisition time 1 second, slice thickness = 5 mm, matrix = 128x128, field of view = 120 mm) sequence with 1.5 sec time intervals. The time-intensity curves were obtained at the abdominal aorta and the liver parenchyma that was devoid of blood vessels. Deconvolution analysis of the aortic (input function) and hepatic parenchymal (output function) time-intensity curves was performed with a modified Fourier transform technique to calculate the hepatic extraction fraction (HEF). The presence and type of hepatic injury were determined by the histopathologic examination and statistical analysis of the changes of the hepatic enzyme levels, the ICG R15 and Gd-EOBDTPA HEF values between the time before and after CCl4 administration with Wicoxon signed rank test. Correlation between the Gd-EOB-DTPA HEF and the change of the ICG R15 were analyzed with Pearson's correlation coefficient. RESULTS: Histopathologic examination showed findings that were compatible with hepatic fibrosis caused by chronic liver injury. The initial blood biochemical studies before the administration of carbon tetrachloride showed that the mean AST and ALT levels were 39.8+/-5.2 IU/L and 59.1+/-11.7 IU/L, respectively. The AST and ALT levels increased to 138.4+/-50.5 IU and 172.0+/-71.6 IU/L, respectively, after the three week administration of CCl4. The ALT and AST levels were significantly increased after the three weeks of CCl4 administration (p = 0.018). The ICG R15 values were 4.47+/-2.08% and 19.43+/-3.98% before and after three-week administration of CCl4, respectively. The ICG R15 values were significantly increased after hepatic injury (p = 0.018). After normalizing the HEF as 100% in each rabbit before CCl4 administration, the deconvoluted curve after CCl4 administration revealed less hepatocyte extraction efficiency with a mean value of 77.7+/-3.6. There was a significant correlation between the HEF and changes of the ICG R15 by the Pearson correlation coefficient assessment (correlation coefficient = -0.965, p = 0.000). CONCLUSION: The Gd-EOB-DTPA HEF could be calculated from deconvolution analysis of aortic and hepatic parenchymal time-intensity curves obtained by dynamic MRI. The Gd-EOB-DTPA HEF was well correlated with changes of the ICG R15, which is the most common parameter used in the quantitative estimation of the hepatic function. The Gd-EOB-DTPA HEF is a direct, noninvasive technique for the quantitative evaluation of liver function. It could be a promising alternative for the determination of noninvasive hepatic function in those patients with liver disease.


Assuntos
Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Testes de Função Hepática/métodos , Fígado/enzimologia , Fígado/patologia , Imageamento por Ressonância Magnética , Alanina Transaminase/sangue , Alanina Transaminase/efeitos dos fármacos , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/efeitos dos fármacos , Biomarcadores/sangue , Tetracloreto de Carbono , Corantes/metabolismo , Modelos Animais de Doenças , Fibrose/induzido quimicamente , Verde de Indocianina/metabolismo , Injeções Intravenosas , Coelhos
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