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PURPOSE: To investigate the feasibility and clinical utility of a compressed-sensing-accelerated subtractionless whole-body MRA (CS-WBMRA) protocol with only contrast injection for suspected arterial diseases, by comparison to conventional dual-pass subtraction-based whole-body MRA (conventional-WBMRA) and available computed tomography angiography (CTA). MATERIALS AND METHODS: This prospective study assessed 86 patients (mean age, 56 years ± 16.4 [standard deviation]; 25 women) with suspected arterial diseases from May 2021 to December 2022, who underwent CS-WBMRA (n = 48, mean age, 55.9 years ± 16.4 [standard deviation]; 25 women) and conventional-WBMRA (n = 38, mean age, 48 years ± 17.4 [standard deviation]; 20 women) on a 3.0 T MRI after random group assignment based on the chronological order of enrolment. Of all enrolled patients administered the CS-WBMRA protocol, 35% (17/48) underwent CTA as required by clinical demands. Two experienced radiologists independently scored the qualitative image quality and venous enhancement contamination. Quantitative image assessment was carried out by determining and comparing the apparent signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of four representative arterial segments. The total examination time and contrast-dose were also recorded. The independent samples t-test or the Wilcoxon rank sum test was used for statistical analysis. RESULTS: The overall scores of CS-WBMRA outperformed those of conventional-WMBRA (3.40 ± 0.60 vs 3.22 ± 0.55, P < 0.001). In total, 1776 and 1406 arterial segments in the CS-WBMRA and conventional-WBMRA group were evaluated. Qualitative image scores for 7 (of 15) vessel segments in the CS-WMBRA group had statistically significantly increased values compared to those of the conventional-WBMRA groups (P < 0.05). Scores from the other 8 segments showed similar image quality (P > 0.05) between the two protocols. In the quantitative analysis, overall apparent SNRs were significantly higher in the conventional-WBMRA group than in the CS-WBMRA group (214.98 ± 136.05 vs 164.90 ± 118.05; P < 0.001), while overall apparent CNRs were not significantly different in these two groups (CS vs conventional: 107.13 ± 72.323 vs 161.24 ± 118.64; P > 0.05). In the CS-WBMRA group, 7 of 1776 (0.4%) vessel segments were contaminated severely by venous enhancement, while in the convention-WBMRA group, 317 of 1406 (23%) were rated as severe contamination. In the CS-WBMRA group, total examination and reconstruction times were only 7 min and 10 min, respectively, vs 20 min and < 30 s for the conventional WBMRA group, respectively. The contrast agent dose used in the CS-WBMRA protocol was reduced by half compared to conventional-WBMRA protocol (18.7 ± 3.5 ml vs 37.2 ± 5.4 ml, P = 0.008). CONCLUSION: The CS-WBMRA protocol provides excellent image quality and sufficient diagnostic accuracy for whole-body arterial disease, with relatively faster workflow and half-dose reduction of contrast agent, which has greater potential in clinical practice compared with conventional-WBMRA.
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Meios de Contraste , Imageamento por Ressonância Magnética , Humanos , Feminino , Pessoa de Meia-Idade , Estudos de Viabilidade , Estudos Prospectivos , Valor Preditivo dos Testes , Angiografia por Ressonância Magnética/métodosRESUMO
PURPOSE: To investigate the clinical utility of pointwise encoding time reduction with radial acquisition in subtraction-based magnetic resonance angiography (PETRA-MRA) and time-of-flight magnetic resonance angiography (TOF-MRA) to evaluate saccular unruptured intracranial aneurysms (UIAs). METHODS: A total of 49 patients with 54 TOF-MRA-identified saccular UIAs were enrolled. The morphologic parameters, contrast-to-noise-ratios (CNRs), and sharpness of aneurysms were measured using PETRA-MRA and TOF-MRA. Two radiologists independently evaluated subjective image scores, focusing on aneurysm signal homogeneities and sharpness depictions using a 4-point scale: 4, excellent; 3, good; 2, poor; 1, not assessable. PETRA-MRA and TOF-MRA acoustic noises were measured. RESULTS: All aneurysms were detected with PETRA-MRA. The morphologic parameters of 15 patients evaluated with PETRA-MRA were more closely correlated with those receiving computed tomography angiography over those receiving TOF-MRA. No significant differences between PETRA-MRA and TOF-MRA parameters were seen in the 54 UIAs (p > 0.10), excluding those with inflow angles (p < 0.05). In four patients with inflow angles on PETRA-MRA, the angles were more closely related to those of digital subtraction angiography than those of TOF-MRA. CNRs between TOF-MRA and PETRA-MRA were comparable (p = 0.068), and PETRA-MRA sharpness values and subjective image scores were significantly higher than those of TOF-MRA (p < 0.001). Inter-observer agreements were excellent for both PETRA-MRA and TOF-MRA (intraclass correlation coefficients were 0.90 and 0.97, respectively). The acoustic noise levels of PETRA-MRA were much lower than those of TOF-MRA (59 vs.73 dB, p < 0.01). CONCLUSIONS: PETRA-MRA, with better visualization of aneurysms and lower acoustic noise levels than TOF-MRA, showed a superior diagnostic performance for depicting saccular UIAs.
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Aneurisma Intracraniano , Angiografia por Ressonância Magnética , Angiografia Digital , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios XRESUMO
E. sinensis is an animal model for studying the reproduction and development of crustaceans. In this study, we knocked down the Es-Kif2a gene by injecting dsRNA into E. sinensis and inhibited Es-Plk1 gene expression by injecting PLK1 inhibitor BI6727 into E. sinensis. Then, the cell proliferation level, apoptosis level, and PI3K/AKT signaling expression level were detected. Our results showed that the proliferation level of spermatogenic cells decreased, while the apoptosis level increased after Es-Kif2a knockdown or Es-Plk1 inhibition. In order to verify whether these changes are caused by regulating the PI3K/AKT pathway, we detected the expression of PI3K and AKT proteins after Es-Kif2a knockdown or Es-Plk1 inhibition. Western Blot showed that in both the Es-Kif2a knockdown group and the Es-Plk1 inhibition group, the expression of PI3K and AKT proteins decreased. In addition, immunofluorescence showed that Es-KIF2A and Es-PLK1 proteins were co-localized during E. sinensis spermatogenesis. To further explore the upstream and downstream relationship between Es-KIF2A and Es-PLK1, we detected the expression level of Es-PLK1 after Es-Kif2a knockdown as well as the expression level of Es-KIF2A after Es-Plk1 inhibition. Western Blot showed that the expression of Es-PLK1 decreased after Es-Kif2a knockdown, while there was no significant change of Es-KIF2A after Es-Plk1 inhibition, indicating that Es-PLK1 may be a downstream factor of Es-KIF2A. Taken together, these results suggest that Es-KIF2A upregulates the PI3K/AKT signaling pathway through Es-PLK1 during the spermatogenesis of E. sinensis, thereby affecting the proliferation and apoptosis levels of spermatogenic cells.
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Cell adhesion and stable signaling regulation are fundamental ways of maintaining homeostasis. Among them, the Wnt/ß-CATENIN signaling plays a key role in embryonic development and maintenance of body dynamic homeostasis. At the same time, the key signaling molecule ß-CATENIN in the Wnt signaling can also function as a cytoskeletal linker protein to regulate tissue barriers, cell migration, and morphogenesis. Dysregulation of the balance between Wnt signaling and adherens junctions can lead to disease. How ß-CATENIN maintains the independence of these two functions, or mediates the interaction and balance of these two functions, has been explored and debated for a long time. In this study, we will focus on five aspects of ß-CATENIN chaperone molecules, phosphorylation of ß-CATENIN and related proteins, epithelial mesenchymal transition, ß-CATENIN homolog protein γ-CATENIN and disease, thus deepening the understanding of the Wnt/ß-CATENIN signaling and the homeostasis between cell adhesion and further addressing related disease problems.
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Via de Sinalização Wnt , beta Catenina , beta Catenina/metabolismo , Adesão Celular , Via de Sinalização Wnt/fisiologia , Movimento Celular , FosforilaçãoRESUMO
ß-CATENIN is an evolutionarily conserved multifunctional molecule that maintains cell adhesion as a cell junction protein to safeguard the integrity of the mammalian blood-testes barrier, and also regulates cell proliferation and apoptosis as a key signaling molecule in the WNT/ß-CATENIN signaling pathway. In the crustacean Eriocheir sinensis, Es-ß-CATENIN has been shown to be involved in spermatogenesis, but the testes of E. sinensis have large and well-defined structural differences from those of mammals, and the impact of Es-ß-CATENIN in them is still unknown. In the present study, we found that Es-ß-CATENIN, Es-α-CATENIN and Es-ZO-1 interact differently in the testes of the crab compared to mammals. In addition, defective Es-ß-CATENIN resulted in increased Es-α-CATENIN protein expression levels, distorted and deformed F-ACTIN, and disturbed localization of Es-α-CATENIN and Es-ZO-1, leading to loss of hemolymph-testes barrier integrity and impaired sperm release. In addition to this, we also performed the first molecular cloning and bioinformatics analysis of Es-AXIN in the WNT/ß-CATENIN pathway to exclude the effect of the WNT/ß-CATENIN pathway on the cytoskeleton. In conclusion, Es-ß-CATENIN participates in maintaining the hemolymph-testes barrier in the spermatogenesis of E. sinensis.
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Braquiúros , Testículo , Animais , Masculino , Testículo/metabolismo , beta Catenina/genética , beta Catenina/metabolismo , alfa Catenina/metabolismo , Braquiúros/metabolismo , Hemolinfa/metabolismo , Sêmen/metabolismo , Espermatogênese , Citoesqueleto/metabolismo , Junções Intercelulares/metabolismo , Mamíferos/metabolismoRESUMO
Recent findings found that TiO2 nanoparticles (TiO2-NPs) have male reproductive toxicity. However, few reports have studied the toxicity of TiO2-NPs in crustaceans. In this study, we first chose the freshwater crustacean Eriocheir sinensis (E. sinensis) to explore the male toxicity of TiO2-NP exposure and the underlying mechanisms. Three nm and 25 nm TiO2-NPs at a dose of 30 mg/kg bw induced apoptosis and damaged the integrity of the haemolymph-testis-barrier (HTB, a structure similar to the blood-testis-barrier) and the structure of the seminiferous tubule. The 3-nm TiO2-NPs caused more severe spermatogenesis dysfunction than the 25-nm TiO2-NPs. We initially confirmed that TiO2-NP exposure affected the expression patterns of adherens junctions (α-catenin and ß-catenin) and induced tubulin disorganization in the testis of E. sinensis. TiO2-NP exposure caused reactive oxygen species (ROS) generation and an imbalance of mTORC1-mTORC2 (mTORC1/rps6/Akt levels were increased, while mTORC2 activity was not changed). After using the ROS scavenger NAC to inhibit ROS generation, both the mTORC1-mTORC2 imbalance and alterations in AJs were rescued. More importantly, the mTORC1 inhibitor rapamycin abolished mTORC1/rps6/Akt hyperactivation and partially restored the alterations in AJs and tubulin. Collectively, the mTORC1-mTORC2 imbalance induced by TiO2-NPs was involved in the mechanism of AJ and HTB disruption, resulting in spermatogenesis in E. sinensis.
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Nanopartículas , Testículo , Masculino , Humanos , Testículo/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tubulina (Proteína)/metabolismo , Junções Aderentes/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espermatogênese/fisiologia , Titânio/toxicidade , Titânio/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Nanopartículas/toxicidade , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismoRESUMO
BACKGROUND: We aimed to compare the performance of three contrast-enhanced T1-weighted three-dimensional (3D) magnetic resonance (MR) sequences to detect brain tumors at 3 Tesla. The three sequences were: (I) delay alternating with nutation for tailored excitation sampling perfection with application-optimized contrasts using different flip angle evolution (DANTE-SPACE), (II) pointwise encoding time reduction with radial acquisition (PETRA), and (III) magnetization-prepared rapid acquisition with gradient echo (MPRAGE). METHODS: This study involved 77 consecutive patients, including 34 patients with known primary brain tumors and 43 patients suspected of intracranial metastases. All patients underwent each of the three sequences with comparable spatial resolution and acquisition time post-injection. Signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM), contrast-to-noise ratios (CNRs) for lesion/GM, lesion/WM, and GM/WM were quantitatively compared. Two radiologists determined the total number of enhancing lesions by consensus. Intraclass correlation coefficients (ICCs) between the two radiologists for metastases presence, qualitative ratings for image quality, and acoustic noise level of each sequence were assessed. RESULTS: Among the three sequences, SNRs and CNRs between lesions and surrounding parenchyma were highest using DANTE-SPACE, but CNRWM/GM was the lowest with DANTE-SPACE. SNRs for PETRA images were significantly higher than those for MPRAGE (P<0.001). CNRs between lesions and surrounding parenchyma were similar for PETRA and MPRAGE (P>0.05). Significantly more brain metastases were detected with DANTE-SPACE (n=94) compared with MPRAGE (n=71) and PETRA (n=72). The ICCs were 0.964 for MPRAGE, 0.975 for PETRA, and 0.973 for DANTE-SPACE. Qualitative scores for lesion imaging using DANTE-SPACE were significantly higher than those obtained with PETRA and MPRAGE (P=0.002 and P=0.004, respectively). The acoustic noise level for PETRA (64.45 dB) was significantly lower than that for MPRAGE (78.27 dB, P<0.01) and DANTE-SPACE (80.18 dB, P<0.01). CONCLUSIONS: PETRA achieves comparable detection of brain tumors with MPRAGE and is preferred for depicting osseous metastases and meningeal enhancement. DANTE-SPACE with blood vessel suppression showed improved detection of cerebral metastases compared with MPRAGE and PETRA, which could be helpful for the differential diagnosis of tumors.
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OBJECTIVE: To investigate the clinical application, feasibility and value of 3 T whole-heart contrast enhanced free-breathing navigator-gated three-dimensional coronary magnetic resonance angiography (CE-CMRA). METHODS: 3 T CE-CMRA was used to examine patients with suspected coronary heart disease (CAD). Gd-BOPTA (0.2 mmol/kg) was injected intravenously with slow infusion rate (0.3 ml/s) to perform enhancement. Data were post-processed to obtain principal branches of coronary artery and picture quality was evaluated. According to results of selective coronary arteriography (SCAG), the diagnostic accuracy of CE-CMRA for diagnosing CAD was judged by means of detecting significant stenosis (> 50%) of the principal branches based on the 9 segments of coronary artery. RESULTS: Twenty-three out of 26 patients successfully completed the examination. The mean scanning time was (10.4 ± 2.1) minutes, 178 out of 202 (88.1%) SCAG demonstrated segments could be evaluated by CE-CMRA. The imaging quality was superior in proximal and middle segments of coronary artery principal branches than in distal segments. Based on patient-level, there were 9 positive cases and 14 negative cases examined by CE-CMRA compared with 11 positive cases and 12 negative cases examined by SCAG, respectively. The whole diagnose accordance rate of CE-CMRA was 91.3% (21/23) compared with SCAG. The sensitivity, specificity and negative predictive values were 81.8% (9/11), 88.5% (169/191) and 98.8% (9/31) respectively. CONCLUSIONS: 3 T CE-CMRA is a feasible non-invasive imaging modality for diagnosing CAD, especially to detect significant stenosis in proximal and middle segments of coronary artery principal branches. However, the detecting efficacy is limited in assessing stenosis of distal segment and small branches of coronary artery.
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Angiografia Coronária/métodos , Vasos Coronários/patologia , Angiografia por Ressonância Magnética/métodos , Idoso , Feminino , Coração/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-IdadeRESUMO
Purpose: To qualitatively and quantitatively compare the image quality and diagnostic performance of turbo gradient and spin echo PROPELLER diffusion-weighted imaging (TGSE-PROPELLER-DWI) vs. readout-segmented echo-planar imaging (rs-EPI) in the evaluation of orbital tumors. Materials and Methods: A total of 43 patients with suspected orbital tumors were enrolled to perform the two DWIs with comparable spatial resolution on 3T. The overall image qualities, geometric distortions, susceptibility artifacts, and lesion conspicuities were scored by using a four-point scale (1, poor; 4, excellent). Quantitative measurements, including contrast-to-noise ratios (CNRs), apparent diffusion coefficients (ADCs), geometric distortion rates (GDRs), and lesion sizes, were calculated and compared. The two ADCs for differentiating malignant from benign orbital tumors were evaluated. Wilcoxon signed-rank test, Kappa statistic, and receiver operating characteristics (ROC) curves were used. Results: TGSE-PROPELLER-DWI performed superior in all subjective scores and quantitative GDR evaluation than rs-EPI (p < 0.001), and excellent interobserver agreement was obtained for Kappa value ranging from 0.876 to 1.000. ADC lesion of TGSE-PROPELLER-DWI was significantly higher than those of rs-EPI (p < 0.001). Mean ADC of malignant tumors was significantly lower than that of benign tumors both in two DWIs. However, the AUC for differentiating malignant and benign tumors showed no significant difference in the two DWIs (0.860 vs. 0.854, p = 0.7448). Sensitivity and specificity could achieve 92.86% and 72.73% for TGSE-PROPELLER-DWI with a cutoff value of 1.23 × 10-3 mm2/s, and 85.71% and 81.82% for rs-EPI with a cutoff value of 0.99 × 10-3 mm2/s. Conclusion: Compared with rs-EPI, TGSE-PROPELLER-DWI showed minimized geometric distortion and susceptibility artifacts significantly improved the image quality for orbital tumors and achieved comparable diagnostic performance in differentiating malignant and benign orbital tumors.
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OBJECTIVE: The complex anatomical structures of cerebellopontine angle (CPA) pose a unique challenge to diffusion weighted imaging (DWI). This study aimed to compare the clinical utility of the prototypic 2D turbo gradient- and spin echo-BLADE-DWI (TGSE-BLADE-DWI) with that of readout-segmented echo-planar DWI (RESOLVE-DWI) and single-shot echo-planar DWI (SS-EPI-DWI) to visualize CPA anatomic structures and identify CPA tumors. METHODS: A total of 8 volunteers and 36 patients with pathological CPA tumors were enrolled to perform the three DWI sequences at 3 T. Scan time of TGSE-BLADE-DWI, RESOLVE-DWI and SS-EPI-DWI was 5 min 51 s, 5 min 15 s and 1 min 22 s, respectively. Subjective analysis, including visualization of anatomical structures, geometric distortion, ghosting artifacts, lesion conspicuity, diagnostic confidence, and overall image quality of the three DWI sequences were scored and assessed. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) of CPA tumors were measured and compared. RESULTS: A total of 39 lesions were identified, TGSE-BLADE-DWI detected all of them, RESOLVE-DWI 36 and SS-EPI-DWI 27. Significant differences were found in all the subjective parameters among the three DWI sequences (all p < 0.001). TGSE-BLADE-DWI was significantly better than RESOLVE-DWI in visualization of CPA anatomical structures, geometric distortion, ghosting artifacts, lesion conspicuity, diagnostic confidence, and overall image quality (all p < 0.01), and RESOLVE-DWI showed significantly superior performance than SS-EPI-DWI in all parameters (all p < 0.001). CNRs and ADCs were not significantly different among the three DWI sequences (p = 0.355, p = 0.590, respectively). No significant differences were detected between TGSE-BLADE-DWI SNR and RESOLVE-DWI SNR (p = 0.058), or TGSE-BLADE-DWI SNR and SS-EPI-DWI SNR (p = 0.155). CONCLUSION: Compared with RESOLVE-DWI and SS-EPI-DWI, TGSE-BLADE-DWI minimized geometric distortions and ghosting artifacts and demonstrated an improved ability for depicting CPA tumors with better lesion conspicuity. SUMMARY: Geometric distortions and ghosting artifacts are found at bone-air interfaces using conventional diffusion-weighted imaging (DWI), which is a challenge for imaging cerebellopontine angle (CPA) tumors. Our study validated that geometric distortions and ghosting artifacts were not present on 2D turbo gradient- and spin-echo-BLADE-DWI scans, making this technique useful for visualizing CPA anatomic structures and diagnosing CPA tumors.
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Neuroma Acústico , Artefatos , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Humanos , Neuroma Acústico/diagnóstico por imagem , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: to observe the association between myocardial fibrosis, detected by delayed-enhancement (DE) cardiac magnetic resonance imaging (MRI) and arrhythmia in patients with hypertrophic cardiomyopathy (HCM). METHODS: forty-eight untreated HCM patients who underwent Cine MR, DE-MRI, 24 h ambulatory Holter electrocardiogram and ECG examinations were recruited. Extent of myocardial fibrosis (fibrosis mass/total LV mass) was assessed using DE imaging. Association between arrhythmias including premature ventricular complexes (PVCS ≥ 200), supra-ventricular tachycardia (SVT), non-sustained ventricular tachycardia (NSVT), atrio-ventricular block (AVB) and intra-ventricular block (IVB) detected by Holter monitoring and ECG with regard to delayed enhancement (DE) on contrast enhanced CMR was analyzed. RESULTS: myocardial fibrosis was detected in 35 patients. Incidence of arrhythmia was significantly higher in patients with DE than in patients without DE (P < 0.05). Extent of myocardial fibrosis was significantly associated with the QRS duration (r = 0.33, P < 0.001). CONCLUSION: myocardial fibrosis detected by DE-CMR was associated with arrhythmia in patients with HCM. DE-CMR might be helpful to detect high-risk HCM patients prone to arrhythmia.
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Arritmias Cardíacas/etiologia , Cardiomiopatia Hipertrófica/patologia , Cardiomiopatia Hipertrófica/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Cardiomiopatia Hipertrófica/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
MR pulmonary angiography (MRPA) combined with indirect MR venography (MRV) was attempted by using 3D contrast-enhanced MR volume interpolated body examination (VIBE) sequence. Agreement rate for deep venous thrombosis (DVT) detection between MRV and duplex sonography (DUS) was evaluated; the potential of this method for venous thromoembolism (VTE) was also investigated. Thirty-four patients with DUS-identified DVT were enrolled in this study. MRI was performed after a single administration of Gadopentetate dimeglumine. Fat-suppressed 3D VIBE was applied for visualizing pulmonary arteries, abdominal veins, pelvic and leg veins, ranging from lung apex to ankle level. Two radiologists observed the MR images in consensus, recorded the location and number of emboli. MRV images were assessed based on per-vein segment. The agreement rate between MRV and DUS for venous segment-to-segment comparison was analyzed by Wilcoxon rank sum test. All the patients were diagnosed as having DVT by MRV. MRV detected 55 more venous segments with thrombi than DUS based on per-vein segment analysis. Twenty-three patients with pulmonary embolism (PE) were detected by MRPA. Twenty-one patients underwent both pulmonary CT angiography and MRPA, and consistency for PE detection was 100%. Total examination time of the combined MR protocol was 7 min for each patient. The contrast-enhanced VIBE sequence proves to be a feasible and reliable method for VTE diagnosis in one-stop MR scanning procedure, and contrast-enhanced VIBE performs better to depict DVT than DUS on per-vein segment basis.
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Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Angiografia por Ressonância Magnética/métodos , Flebografia/métodos , Embolia Pulmonar/diagnóstico por imagem , Trombose Venosa/diagnóstico por imagem , Adolescente , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Variações Dependentes do Observador , Exame Físico , Interpretação de Imagem Radiográfica Assistida por Computador , Sensibilidade e Especificidade , Ultrassonografia Doppler Dupla , Adulto JovemRESUMO
OBJECTIVE: Flow dephasing artifacts within intracranial internal carotid artery (ICA) have been problematic for 3D time-of-flight magnetic resonance angiography (3D-TOF-MRA). This study aimed to evaluate pointwise encoding time reduction with radial acquisition subtraction-based MR angiography (PETRA-MRA) for decreasing flow dephasing artifacts compared to 3D-TOF-MRA in intracranial segments of ICA at 3 T. METHODS: Sixty healthy participants and seven patients with intracranial ICA aneurysms were enrolled to undergo 3D-TOF-MRA and PETRA-MRA. Two radiologists each evaluated the image quality of healthy participants using a 4-point scale (1: the best and 4: the worst). Quantitative analysis of the extent of homogeneity in signal intensity within the ICA and intracranial aneurysms was conducted using a parameter d: the higher the d value, the greater the signal homogeneity. Wilcoxon signed rank test, Chi-square test and the weighted kappa (κ) statistic were used for statistical analyses. RESULTS: The image quality of PETRA-MRA with an overall score of 1.35 ± 0.53 was significantly better than that obtained with 3D-TOF-MRA, with an overall score of 3.50 ± 0.62 (Z = -9.56, p < 0.001). The parameter d of PETRA-MRA was higher than that of 3D-TOF-MRA for both 60 healthy participants (0.97 ± 0.05, 0.87 ± 0.11; z = -13.21, p < 0.001) and 7 patients with intracranial aneurysms (0.81 ± 0.18, 0.74 ± 0.16; z = -2.37, p = 0.018). CONCLUSION: Compared with conventional 3D-TOF-MRA, PETRA-MRA remarkably improved the image quality with reduced flow dephasing artifacts in segments of intracranial ICA.
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Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética , Adulto , Idoso , Artefatos , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To investigate the clinical value of different magnetic resonance (MR) pulse sequences in diagnosis of spinal metastatic tumor. METHODS: Fifteen patients with clinically suspected spinal metastatic tumor were included in this study. These patients were with documented primary tumors. Four MR pulse sequences, T1-weighted spin echo (T1WI SE), T2-weighted fast spin echo (T2WI FSE), short time inversion recovery (STIR), and gradient echo 2-D multi echo data imaging combination (GE Me-2D) were used to detect spinal metastasis. RESULTS: Fifteen vertebral bodies were entire involvement, 38 vertebral bodies were section involvement, and totally 53 vertebral bodies were involved. There were 19 focal infections in pedicle of vertebral arch, 15 metastases in spinous process and transverse process. Fifty-three vertebral bodies were abnormal in T1 WI SE and GE Me-2D, 35 vertebral bodies were found abnormal in T2WI FSE, and 50 vertebral bodies were found abnormal in STIR. The verges of focal signal of involved vertebral bodies were comparatively clear in T1WI SE, comparatively clear or vague in T2WI FSE, vague in STIR, and clear in GE Me-2D. CONCLUSIONS: GE Me-2D may be the most sensitive technique to detect metastases. So three sequences (T1WI SE, T2WI FSE, GE Me-2D) can demonstrate the early changes of spinal metastasis roundly.
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Imageamento por Ressonância Magnética/métodos , Metástase Neoplásica/patologia , Neoplasias da Coluna Vertebral/patologia , Neoplasias da Coluna Vertebral/secundário , Vértebras Cervicais/diagnóstico por imagem , Cóccix/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Radiografia , Sacro/diagnóstico por imagem , Sensibilidade e Especificidade , Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagemRESUMO
OBJECTIVE: To study, through blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI), the cerebral activated areas evoked by electro-acupuncturing (EA) the right Hegu point (L14) or non-acupoint points on the face, and through comparing their similarities and differences, to speculate on the specific cerebral areas activated by stimulating L14, for exploring the mechanism of its effect in potential clinical application. METHODS: EA was applied at volunteers' right L14 (of 9 subjects in the L14 group) and facial non-acupoint points (of 5 subjects in the control group), and whole brain 3-dimensional T1 anatomical imaging of high resolution 1 x 1 x 1 mm(3) used was performed with clustered stimulatory mode adopted by BOLD fMRI. Pretreatment and statistical t-test were conducted on the data by SPM2 software, then the statistical parameters were superimposed to the 3-dimensional anatomical imaging. RESULTS: Data from 3 testees of the 9 subjects in the L14 group were given up eventually because they were unfit to the demand due to different causes such as movement of patients' location or machinery factors. Statistical analysis showed that signal activation or deactivation was found in multiple cerebral areas in 6 subjects of L14 group and 5 subjects of the control group (P<0.01). In the L14 group, the areas which showed signal activation were: midline nuclear group of thalamus, left supra marginal gyrus, left supra temporal gyrus, right precuneous lobe, bilateral temporal pole, left precentral gyrus and left cerebellum; those which showed signal deactivation were: bilateral hippocampus, parahippocampal gyrus, amygdala body area, rostral side/ audal side of cingulate gyrus, prefrontal lobe and occipital lobe as well as left infratemporal gyrus. In the control group, areas which showed signal activation were: bilateral frontal lobe, postcentral gyrus, Reil's island lobe, primary somato-sensory cortex, cingulate gyrus, superior temporal gyrus, occipital cuneiform gyrus and/or precuneus gyrus and right brainstem; and the area that showed deactivation was left median frontal lobe. CONCLUSION: The effects of EA L14 in regulating cerebral activities could be displayed and recorded through BOLD fMRI, the distribution of signally deactivated area evoked by EA L14 was similar to the known distribution of anatomical orientation of pain in brain, and closely related to the anatomic structure of limbic system, which areas are possibly the acupuncture analgesic effect's cerebral regulating area. Furthermore, activated portion of left central anterior gyrus, which represent the movement of oral facial muscles, and the activated portion of cerebellum are possibly related with the effect of using EA L14 in treating facial palsy and facial muscle spasm. As for the mechanism of signal deactivation of cerebral activities exhibited in the present study that is unable to be elucidated, it awaits for further research.
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Pontos de Acupuntura , Encéfalo/fisiologia , Eletroacupuntura , Imageamento por Ressonância Magnética , Adulto , Encéfalo/irrigação sanguínea , Feminino , Humanos , Masculino , Oxigênio/sangue , Valores de ReferênciaRESUMO
OBJECTIVE: To explore the clinical value of magnetic resonance (MR) imaging in the diagnosis of the complications after breast augmentation with polyacrylamide hydrogel injection. METHODS: MRI was performed in 16 patients who had breast augmentation with polyacrylamide hydrogel injection. The results of magnetic resonance imaging were compared with the clinical symptoms. RESULTS: MRI examinations of the 16 patients showed that (1) 4 breasts in 2 patients were comparatively natural; (2) a large lacteal cyst was detected in one patients in lactation; (3) breast asymmetry occurred in 3 patients (6 sides); (4) in 10 patients (20 sides), the injected gel was in irregular form. The results of MRI were in accord with the clinical symptoms. CONCLUSION: MRI is of great diagnostic value for the complications after breast augmentation with polyacrylamide hydrogel injection.