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1.
Sci Rep ; 10(1): 403, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31942025

RESUMO

Fatal cerebrovascular events are often caused by rupture of atherosclerotic plaques. However, rupture-prone plaques are often distinguished by their internal composition rather than degree of luminal narrowing, and conventional imaging techniques might thus fail to detect such culprit lesions. In this feasibility study, we investigate the potential of ultrasound shear wave elastography (SWE) to detect vulnerable carotid plaques, evaluating group velocity and frequency-dependent phase velocities as novel biomarkers for plaque vulnerability. In total, 27 carotid plaques from 20 patients were scanned by ultrasound SWE and magnetic resonance imaging (MRI). SWE output was quantified as group velocity and frequency-dependent phase velocities, respectively, with results correlated to intraplaque constituents identified by MRI. Overall, vulnerable lesions graded as American Heart Association (AHA) type VI showed significantly higher group and phase velocity compared to any other AHA type. A selection of correlations with intraplaque components could also be identified with group and phase velocity (lipid-rich necrotic core content, fibrous cap structure, intraplaque hemorrhage), complementing the clinical lesion classification. In conclusion, we demonstrate the ability to detect vulnerable carotid plaques using combined SWE, with group velocity and frequency-dependent phase velocity providing potentially complementary information on plaque characteristics. With such, the method represents a promising non-invasive approach for refined atherosclerotic risk prediction.

3.
Intern Med ; 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31956203

RESUMO

We report a case in which diffusion-weighted magnetic resonance imaging (DWI) demonstrated renal artery stenosis-related renal ischemia and the therapeutic efficacy of revascularization. The patient was a 73-year-old man, who underwent descending thoracic aortic replacement due to DeBakey IIIb chronic aortic dissection, and who showed progressive renal dysfunction due to right renal artery stenosis caused by false lumen thrombosis. DWI demonstrated a decreased apparent diffusion coefficient (ADC) in the right kidney, indicating renal ischemia. Angioplasty with stenting restored renal perfusion and improved the renal function, resulting in the normalization of the decreased ADC in the treated kidney. Thus, DWI can be used to monitor renal ischemia in cases involving advanced renal artery stenosis.

4.
J Cardiol ; 75(1): 34-41, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31277963

RESUMO

BACKGROUND: Although recent reports showed that left ventricular ejection fraction (LVEF) is a prognostic factor in patients with cardiac sarcoidosis (CS), advances in diagnostic imaging have enabled us to detect CS patients with preserved LVEF in the early stage of the disorder. In the present study, we examined the prognosis and risk stratification in CS patients with preserved LVEF. METHODS AND RESULTS: We retrospectively examined 91 consecutive CS patients at our hospital from October 1998 to December 2015 (age, 57±11 years; male/female, 25/66) for the relationship between LVEF and major adverse cardiac events (MACE), including ventricular tachycardia and fibrillation (VT/VF), heart failure (HF) admission, complete atrioventricular block, and all-cause death. CS patients with preserved LVEF (≥50%), as compared with those with reduced LVEF (<50%), showed significantly higher survival free from total MACE or VT/VF (log-rank p<0.001) and significantly smaller LV myocardial damaged area as evaluated by magnetic resonance imaging (MRI) (p<0.001). Although CS patients with preserved LVEF had a good prognosis in general, persistent right ventricular (RV) pacing and reduced EF were significant predictors for MACE after 1 year from introduction of steroid therapy (hazard ratio, 5.25; 95% confidence interval, 1.31-22.50, p=0.020, hazard ratio, 9.01; 95% confidence interval, 2.45-72.09; p=0.001). Patients with the 2 factors (LVEF reduction rate >13.9% per year and persistent RV pacing) had significantly higher risk for MACE, compared with those without them (log-rank p<0.001). CONCLUSION: The present study demonstrates that CS patients with preserved LVEF have better long-term prognosis than those with reduced LVEF in general. However, we should carefully follow them up, since chronological reduction in LVEF and persistent RV pacing could predict worse prognosis in those patients.

5.
Medicine (Baltimore) ; 98(45): e17940, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702683

RESUMO

Venous air embolism (VAE) can be observed in the right heart system on contrast-enhanced computed tomography (CT), following injection of contrast media with a power injector system. Although most VAEs are mostly asymptomatic, they may result in paradoxical air embolism (PAE).To evaluate whether the incidence of VAE on coronary CT angiography is associated with the process of preparation of the intravenous access route.We retrospectively evaluated 692 coronary CT examinations at 3 institutions. Trained CT nurses placed an intravenous cannula in the forearm. Tubes connected to the cannula were prepared in the following ways: A, using an interposed three-way cock and a 20-mL syringe filled with normal saline to collect air contamination in the tube; B, through direct connection to the power injector system without the interposed 3-way cock; and C, using an interposed three-way cock and a 100-mL normal saline drip infusion bottle system to keep the tube patent. The incidence and location of VAE and preparation of intravenous injection were assessed.The overall incidence of VAE was 55.3% (383/692), most frequently observed in the right atrium (81.5%, 312/383). Its incidence varied significantly across the 3 techniques (A: 21.6% (35/162), B: 63.2% (237/375) and C: 71.6% (111/155); P < .001). No patient demonstrated any symptom associated with VAE.Using a 3-way cock with syringe demonstrated the lowest incidence of VAE on coronary CT angiography. It is thus recommended to reduce potential complication risks related to intravenous contrast media injection.


Assuntos
Angiografia por Tomografia Computadorizada/efeitos adversos , Embolia Aérea/etiologia , Embolia Paradoxal/etiologia , Átrios do Coração/diagnóstico por imagem , Idoso , Meios de Contraste/administração & dosagem , Embolia Aérea/complicações , Embolia Aérea/epidemiologia , Embolia Paradoxal/epidemiologia , Humanos , Injeções Intravenosas/efeitos adversos , Injeções Intravenosas/instrumentação , Injeções Intravenosas/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
6.
Artigo em Inglês | MEDLINE | ID: mdl-31323320

RESUMO

This study investigated hemodynamic changes in the thoracic aorta and aortic arch branches before and after aortic valve replacement (AVR) by 4D-flow MRI in patients with aortic valve stenosis (AS). Thoracic 4D-flow MRI was performed in 10 AS patients before and after AVR (mean 27 ± 1.9 days). Fifteen aortic planes and 3 aortic arch branches planes were set to evaluate the mean volume flow rate in each plane during a cardiac cycle and the angle between the main flow direction in a specified plane and the axial direction of the aorta. We also focused on the distribution and magnitude of helicity density to evaluate the flow complexity. A significant increase in the volume flow rate after AVR was found in the ascending aorta (before 59.2 ± 8.7 mL/s vs after 77.3 ± 6.2 mL/s, P < 0.05) and the aortic arch branches (before 26.5 ± 2.8 mL/s vs after 35.8 ± 3.3 mL/s, P < 0.001). The flow angle significantly decreased in the ascending aorta (before 39.2 ± 2.7 degree vs after 25.2 ± 1.7°, P < 0.0001) and the arch aorta (before 19.3 ± 2.0 degree vs after 13.4 ± 0.9°, P < 0.001). The volume flow rate in the ascending aorta and the arch branches increased within 1 month after AVR, showing an increased blood supply to the upper body, including to the brain. The postoperative change was accompanied with an increased blood flow in the ascending aorta and a decreased flow complexity proximal to the arch branches.

7.
Br J Radiol ; 92(1103): 20190465, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31356106

RESUMO

Increased collagen, or fibrosis, is an important marker of disease and may improve identification of patients at risk. In addition, fibrosis imaging may play an increasing role in guiding therapy and monitoring its effectiveness. MRI is the most frequently used modality to detect, visualize and quantify fibrosis non-invasively. However, standard MRI techniques used to phenotype cardiac fibrosis such as delayed enhancement and extracellular volume determination by T1 mapping, require the administration of gadolinium-based contrast and are particularly difficult to use in patients with cardiac devices such as pacemakers and automatic defibrillators. Therefore, such methods are limited in the serial evaluation of cardiovascular fibrosis as part of chronic disease monitoring. A method to directly measure collagen amount could be of great clinical benefit. In the current review we will discuss the potential of a novel MR technique, ultrashort echo time (UTE) MR, for fibrosis imaging. Although UTE imaging is successfully applied in other body areas such as musculoskeletal applications, there is very limited experience so far in the heart. We will review the established methods and currently available literature, discuss the technical considerations and challenges, show preliminary in vivo images and provide a future outlook on potential applications of cardiovascular UTE.


Assuntos
Sistema Cardiovascular/patologia , Angiografia por Ressonância Magnética/métodos , Artefatos , Meios de Contraste , Fibrose/patologia , Gadolínio , Humanos , Fatores de Tempo
9.
Endocr Connect ; 8(5): 454-461, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30959487

RESUMO

Objective: Regional differences in cardiac magnetic resonance, which can reveal catecholamine-induced myocardial injury in patients with pheochromocytoma, have not yet been assessed using 3T magnetic resonance imaging. We evaluated these differences using myocardial T1-mapping and strain analysis. Design and Methods: We retrospectively reviewed 16 patients newly diagnosed with catecholamine-producing tumors (CPT group) and 16 patients with essential hypertension (EH group), who underwent cardiac magnetic resonance imaging between May 2016 and March 2018. We acquired 3T magnetic resonance cine and native T1-mapping images and performed feature-tracking-based strain analysis in the former. Results: Global cardiac function, morphology, global strain and peak strain rate were similar, but end-diastolic wall thickness differed between groups (CPT vs EH: 10.5 ± 1.7 vs 12.6 ± 2.8 mm; P < 0.05). Basal, but not apical, circumferential strain was significantly higher in the CPT than the EH group (19.4 ± 3.2 vs 16.8 ± 3.6 %; P < 0.05). Native T1 values were significantly higher in CPT than in EH patients, in both the basal septum (1307 ± 48 vs 1241 ± 45 ms; P < 0.01) and the apical septum (1377 ± 59 vs 1265 ± 58 ms; P < 0.01) mid-walls. In the CPT, but not in the EH group, native T1 values in the apical wall were significantly higher than those in the basal wall (P < 0.01). Conclusion: 3T magnetic resonance-based T1-mapping can sensitively detect subclinical catecholamine-induced myocardial injury; the influence of catecholamines may be greater in the apical than in the basal wall.

10.
Radiol Case Rep ; 14(6): 687-691, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30976369

RESUMO

We report a case of asymptomatic iatrogenic air bubbles in the left ventricle observed by coronary computed tomographic angiography. Air bubbles are rarely found in the left ventricle and could prove fatal should they migrate to the brain or coronary arteries. We believe that the cause is micro air bubbles in the tubing system between the intravenous catheter and power injector.

11.
Int J Cancer ; 145(2): 484-493, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30628065

RESUMO

Renal cell carcinoma (RCC) is a malignant tumor that currently lacks clinically useful biomarkers indicative of early diagnosis or disease status. RCC has commonly been diagnosed based on imaging results. Metabolomics offers a potential technology for discovering biomarkers and therapeutic targets by comprehensive screening of metabolites from patients with various cancers. We aimed to identify metabolites associated with early diagnosis and clinicopathological factors in RCC using global metabolomics (G-Met). Tumor and nontumor tissues were sampled from 20 cases of surgically resected clear cell RCC. G-Met was performed by liquid chromatography mass spectrometry and important metabolites specific to RCC were analyzed by multivariate statistical analysis for cancer diagnostic ability based on area under the curve (AUC) and clinicopathological factors (tumor volume, pathological T stage, Fuhrman grade, presence of coagulation necrosis and distant metastasis). We identified 58 metabolites showing significantly increased levels in tumor tissues, 34 of which showed potential early diagnostic ability (AUC >0.8), but 24 did not discriminate between tumor and nontumor tissues (AUC ≤0.8). We recognized 6 pathways from 9 metabolites with AUC >0.8 and 7 pathways from 10 metabolites with AUC ≤0.8 about malignant status. Clinicopathological factors involving malignant status correlated significantly with metabolites showing AUC ≤0.8 (p = 0.0279). The tricarboxylic acid cycle (TCA) cycle, TCA cycle intermediates, nucleotide sugar pathway and inositol pathway were characteristic pathways for the malignant status of RCC. In conclusion, our study found that metabolites and their pathways allowed discrimination between early diagnosis and malignant status in RCC according to our G-Met protocol.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/diagnóstico , Neoplasias Renais/diagnóstico , Metabolômica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/cirurgia , Estudos de Casos e Controles , Cromatografia Líquida , Ciclo do Ácido Cítrico , Detecção Precoce de Câncer , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Nefrectomia , Transdução de Sinais , Espectrometria de Massas em Tandem
13.
J Cardiovasc Comput Tomogr ; 13(2): 134-141, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30385326

RESUMO

BACKGROUND: An optimal system for interpreting fractional flow reserve (FFR) values derived from CT (FFRCT) is lacking. We sought to evaluate performance of three FFRCT measurements in detecting ischemia by comparing them with invasive FFR. METHODS: For 73 vessels in 50 patients who underwent coronary CT angiography (CCTA) and FFRCT analysis followed by invasive FFR, the greatest diameter stenosis on CCTA, FFRCT difference between distal and proximal to the stenosis (ΔFFRCT), FFRCT 2 cm distal to the stenosis (lesion-specific FFRCT), and the lowest FFRCT in distal vessel tip were calculated. Significant obstruction (≥50% diameter stenosis) and ischemia (lesion-specific FFRCT ≤0.80, the lowest FFRCT ≤0.80, or ΔFFRCT ≥0.12 based on the greatest Youden index) were compared with invasive FFR (≤0.80). RESULTS: Forty (55%) vessels demonstrated ischemia during invasive FFR. On multivariable generalized estimating equations, ΔFFRCT (odds ratio [OR] 10.2, p < 0.01) remained a predictor of ischemia over CCTA (OR 2.9), lesion-specific FFRCT (OR 3.1), and the lowest FFRCT (OR 0.9) (p > 0.05 for all). Area under the curve (AUC) of ΔFFRCT (0.86) was higher than CCTA (0.66), lesion-specific FFRCT (0.71), and the lowest FFRCT (0.65) (p < 0.01 for all). Addition of each FFRCT measure to CCTA showed improvement of AUC and significant net reclassification improvement (NRI): ΔFFRCT (AUC 0.84, NRI 1.24); lesion-specific FFRCT (AUC 0.77, NRI 0.83); and the lowest FFRCT (AUC 0.76, NRI 0.59) (p < 0.01 for all). CONCLUSIONS: Compared with diameter stenosis, ΔFFRCT, lesion-specific FFRCT, and the lowest FFRCT improved ischemia discrimination and reclassification, with ΔFFRCT being superior in identifying and discriminating ischemia.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Tomografia Computadorizada Multidetectores/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Idoso , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Sistema de Registros , Reprodutibilidade dos Testes , Estudos Retrospectivos
14.
Heart Vessels ; 34(1): 104-113, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29942978

RESUMO

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm2) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.


Assuntos
Angina Pectoris/terapia , Tratamento por Ondas de Choque Extracorpóreas/métodos , Ondas de Choque de Alta Energia/uso terapêutico , Idoso , Angina Pectoris/diagnóstico , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Japão , Imagem Cinética por Ressonância Magnética , Masculino , Imagem de Perfusão do Miocárdio , Resultado do Tratamento
15.
Nihon Ronen Igakkai Zasshi ; 55(4): 657-662, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-30542032

RESUMO

Providing defecation care can be challenging because bowel movements cannot be directly observed in home-care settings, and the objective evaluation of constipation symptoms is difficult, particularly for elderly patients with cognitive impairment. We evaluated the use of rectal ultrasonography (US) to assess the properties and volume of feces in three cases with different fecal properties. Case 1: In a 94-year-old man with normal feces (Bristol stool score: BS type 4), rectal US revealed a crescent-shaped high-echo area without acoustic shadow that was present until the next defecation. Case 2: In a 92-year-old woman with hard stool (BS type 1), rectal US showed a crescent-shaped strong-echo area with acoustic shadow that was present until the next defecation. The length of the high-echo area gradually increased during the observation period and decreased after defecation in Cases 1 and 2. Case 3: In a 67-year-old man with watery stool (BS type 7), rectal US revealed a low-peripheral-frequency-echo area without acoustic shadow. Rectal ultrasonography was able to demonstrate the presence or absence of hard stool, which was observed as a crescent-shaped a strong, high-echo area with acoustic shadow; the presence or absence of hard stool may be evaluated based on these findings. Furthermore, the fecal volume may be able to be evaluated based on the long diameter of the crescent-shaped high-echo area. Determining the best course of defecation care based on the fecal properties/volume evaluated using rectal US will likely be possible in the future.


Assuntos
Fezes , Reto/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Constipação Intestinal , Defecação , Diarreia , Feminino , Humanos , Masculino , Ultrassonografia
16.
Circ Arrhythm Electrophysiol ; 11(11): e006234, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30571179

RESUMO

BACKGROUND: Several studies have demonstrated the importance of mechanoelectrical interaction in patients with surgically corrected tetralogy of Fallot. However, the significance of atrioventricular conduction disturbance, that is PR interval prolongation, on adverse cardiac events in those patients remains to be elucidated. METHODS: We examined electrocardiograms at baseline and their temporal change in a total of 176 patients with repaired tetralogy of Fallot (49% men; median age, 17.4 years). Then, we evaluated their correlation with right ventricular volume and function measured by cardiac magnetic resonance and the significance as a risk factor of adverse cardiac events: lethal ventricular arrhythmias, atrial arrhythmias, heart failure hospitalization, complete atrioventricular block (AVB), and all-cause death. RESULTS: First-degree AVB was noted in 25 patients (14%). During a median follow-up of 10.0 (5.0-14.2) years, there was a progressive prolongation of PR interval (2.00±3.99 ms/y). Importantly, there were significant correlations between PR interval prolongation and right ventricular enlargement or right ventricular dysfunction. In contrast, in patients who underwent pulmonary valve replacement (n=23), significant shortening of PR interval by pulmonary valve replacement was noted (204±32 versus 176±34 ms; P=0.007). Cox regression analysis showed that first-degree AVB was an independent risk factor for lethal ventricular arrhythmias (hazard ratio, 5.479; 95% CI, 1.181-25.42; P=0.030) and complete AVB (hazard ratio, 27.67; 95% CI, 4.152-184.3; P<0.001) and had a tendency for heart failure hospitalization (hazard ratio, 3.301; 95% CI, 0.864-11.80; P=0.069). In addition, PR interval prolongation >2 ms/y was also a significant risk factor for lethal ventricular arrhythmias, regardless of the presence or absence of first-degree AVB at enrollment (hazard ratio, 24.18; 95% CI, 2.080-281.1; P=0.011). CONCLUSIONS: These results indicate that progressive atrioventricular conduction disturbance is correlated with right ventricular enlargement and could be a useful predictor for increased risk of lethal ventricular arrhythmias in patients with repaired tetralogy of Fallot.


Assuntos
Bloqueio Atrioventricular/etiologia , Bloqueio Atrioventricular/fisiopatologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Sistema de Condução Cardíaco/fisiopatologia , Tetralogia de Fallot/cirurgia , Disfunção Ventricular Direita/etiologia , Disfunção Ventricular Direita/fisiopatologia , Adolescente , Adulto , Eletrocardiografia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Prognóstico , Fatores de Risco
17.
J Magn Reson Imaging ; 48(6): 1657-1667, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30325551

RESUMO

BACKGROUND: There is limited evidence of parametric MR mapping to characterize carotid plaques associated with cerebral ischemic events. PURPOSE: To explore the apparent diffusion coefficients (ADCs) and longitudinal relaxation rates (R1 ) of carotid plaques, including areas of hemorrhage, lipid-rich/necrotic core (LR/NC) without hemorrhage, and fibrous tissue (Fbr) STUDY TYPE: Prospective. SUBJECTS: Twelve patients who underwent carotid endarterectomy. FIELD STRENGTH/SEQUENCE: R1 was measured using double angle Look-Locker acquisition on 3T systems. Single-shot spin-echo echo-planar imaging with fat suppression and outer-volume suppression (OVS-DWEPI) with b values of 10 and 500 s/mm2 was used for diffusion-weighted imaging. ASSESSMENT: A phantom study using diluted gadolinium solutions and polyvinyl alcohol solutions was used to validate the two protocols. Regions of interest (ROIs) were manually outlined on MR images for areas of LR/NC, hemorrhage, and Fbr based on histological cross-sections. Pixel-based R1 and ADC values in the ROIs were plotted for each component. The probability density function of the plots determined the optimum contours to separate the three components in the ADC-R1 plane. The LR/NC, hemorrhage, and Fbr regions were mapped on MR images based on the above results and compared to histological results. STATISTICAL TESTS: The R1 values of the phantom measurements were tested using Bland-Altman analysis. The accuracies of the MRI classification were calculated. RESULTS: R1 values <8 s-1 calculated using our method agreed with those calculated using an inversion-recovery fast-spin-echo sequence (error, ≤0.1 s-1 ). ADC values obtained using OVS-DWEPI were 4.1% higher than those obtained using standard echo-planar imaging. LR/NC (R1 , 0.4-1.2 s-1 ; ADC, 0-1.5 µm2 /ms), hemorrhage (R1 ≥ 1.5 s-1 ; ADC, 0.5-1.5 µm2 /ms), and Fbr (R1 , 0.2-0.8 s-1 ; ADC, 1.5-2.9 µm2 /ms) were separated on the plots. The accuracies of MRI classification were LR/NC, 0.86; hemorrhage, 0.79; and Fbr, 0.77. CONCLUSION: The combination of ADC and R1 values measured using our method enabled differentiation among LR/NC, hemorrhage, and Fbr. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1657-1667.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Técnicas Histológicas/métodos , Processamento de Imagem Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/diagnóstico por imagem , Isquemia Encefálica/complicações , Artérias Carótidas/patologia , Estenose das Carótidas/complicações , Imagem Ecoplanar , Feminino , Gadolínio/química , Hemorragia/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Lipídeos/química , Masculino , Pessoa de Meia-Idade , Necrose , Imagens de Fantasmas , Placa Aterosclerótica/patologia , Álcool de Polivinil , Probabilidade , Estudos Prospectivos , Razão Sinal-Ruído
19.
Radiology ; 289(2): 347-354, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29989523

RESUMO

Purpose To assess changes in left ventricular function and tissue composition by using MRI after chemotherapy-radiation therapy in participants with esophageal cancer. Materials and Methods Between January 2013 and April 2015, this prospective study enrolled 24 participants (42% women; mean age, 63 years; range, 49-73 years) scheduled for chemotherapy-radiation therapy. 3.0-T MRI examinations were performed before, at 0.5 year, and at 1.5 years after chemotherapy-radiation therapy. Myocardial native T1, postcontrast T1, and extracellular volume were measured in basal septum (as irradiated areas) and apical lateral wall (as nonirradiated areas). Left ventricular function, prevalence of late gadolinium enhancement, and T1 and extracellular volume values were compared over the follow-up period by using Friedman or Cochran Q tests, followed by Dunn test. Results In 14 participants who were followed up for 1.5 years, native T1 and extracellular volume in the septum were elevated at 0.5 year compared with baseline (1183 msec ± 46 [standard deviation] vs 1257 msec ± 35; 26% ± 3 vs 32% ± 3; adjusted P < .01 for both), but not in the lateral wall. Left ventricular stroke volume index and late gadolinium enhancement changed at 1.5 years compared with baseline (41 mL/m2 ± 11 vs 36 mL/m2 ± 9; P = .046; 7% [one of 14] vs 78% [11 of 14]; P < .01). Other measures of left ventricular function did not change during the follow-up period (P > .10 for all). Conclusion Native T1 and extracellular volume could detect early changes in myocardium at 0.5 year after chemotherapy-radiation therapy, whereas left ventricular stroke volume index and late gadolinium enhancement showed abnormality at 1.5 years. © RSNA, 2018 Online supplemental material is available for this article.


Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Imagem por Ressonância Magnética/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Terapia Combinada , Neoplasias Esofágicas/complicações , Feminino , Seguimentos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Disfunção Ventricular Esquerda/complicações
20.
Artigo em Japonês | MEDLINE | ID: mdl-30033961

RESUMO

With shortening of the gantry of magnetic resonance imaging (MRI) systems, large field-of-view (FOV) imaging has become difficult because static magnetic field nonuniformity and gradient magnetic field nonlinearity exacerbate geometric distortion of MR images. However, results of earlier studies have demonstrated that view angle tilting (VAT) can reduce severe image distortion attributable to local susceptibility effects of metals. Although VAT is usually applied to local magnetic field nonuniformity, in principle VAT is expected to correct distortion also for peripheral images in large-FOV MRI. Results from this phantom experiment using VAT with large-FOV verified the effectiveness of distortion correction. The experiment using VAT showed reduction of maximum distortion from 23.6 to -1.9 mm. Furthermore, results of a volunteer study confirmed the distortion correction capability of VAT: it reduced distortion and improved visibility of the anatomical structure. In conclusion, experimentally obtained results underscore VAT effectiveness for improving distortion in large-FOV MRI.


Assuntos
Imagem por Ressonância Magnética , Imagens de Fantasmas , Artefatos , Humanos , Campos Magnéticos , Metais
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