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1.
Nanotechnology ; 32(14): 145401, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33348328

RESUMO

Coaxial type piezoelectric energy generator (C-PEG) nanofiber was fabricated by a self-designed continuous electrospinning deposition system. Piezoelectric PVDF-TrFE nanofiber as an electroactive material was electrospun at a discharge voltage of 9-12 kV onto a simultaneously rotating and transverse moving Cu metal wire at an angular velocity of ω g = 60-120 RPM. The piezoelectric coefficient d33 of the PVDF-TrFE nanofiber was approximately -20 pm V-1. The generated output voltage (V G) increased according to the relationship exp(-α P) (α = 0.41- 0.57) as the pressure (P) increased from 30 to 500 kpa. The V G values for ten and twenty pieces of C-PEG were V G = 3.9 V and 9.5 V at P = 100 kpa, respectively, relatively high output voltages compared to previously reported values. The high V G for the C-PEG stems from the fact that it can generate a fairly high V G due to the increased number of voltage collection points compared to a conventional two-dimensional (2-dim) capacitor type of piezoelectric film or fiber device. C-PEG yarn was also fabricated via the dip-coating of a PDMS polymer solution, followed by winding with Ag-coated nylon fiber as an outer electrode. The current and power density of ten pieces of C-PEG yarn were correspondingly 22 nA cm-2 and 8.6 µW cm-3 at V G = 1.97 V, higher than previously reported values of 5.54 and 6 µW cm-3. The C-PEG yarn, which can generate high voltage compared to the conventional film/nanofiber mat type, is expected to be very useful as a wearable energy generator system.

2.
Nanotechnology ; 30(3): 035207, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30452390

RESUMO

ZnO nanoparticles (NPs) of 4-5 nm, widely adopted as an electron transport layer (ETL) in quantum dot light emitting diodes (QD-LEDs), were synthesized using the solution-precipitation process. It is notable that synthesized ZnO NPs are highly degenerate intrinsic semiconductors and their donor concentration can be increased up to N D = 6.9 × 1021 cm-3 by annealing at 140 °C in air. An optical bandgap increase of as large as 0.16-0.33 eV by degeneracy is explained well by the Burstein-Moss shift. In order to investigate the influence of intrinsic defects of ZnO NP ETLs on the performance of QD-LED devices without a combined annealing temperature between ZnO NP ETLs and the emissive QD layer, pre-annealed ZnO NPs at 60 °C, 90 °C, 140 °C, and 180 °C were spin-coated on the annealed QD layer without further post-annealing. As the annealing temperature increases from 60 °C to 180 °C, the defect density related to oxygen vacancy (V O) in ZnO NPs is reduced from 34.4% to 17.8%, whereas the defect density of interstitial Zn (Zni) is increased. Increased Zni reduces the width (W) of the depletion region from 0.21 to 0.12 nm and lowers the Schottky barrier (ФB) between ZnO NPs and the Al electrode from 1.19 to 0.98 eV. We reveal for the first time that carrier conduction between ZnO NP ETLs and the Al electrode is largely affected by the concentration of Zni above the conduction band minimum, and effectively described by space charge limited current and trap charge limited current models.

3.
Sci Rep ; 3: 3253, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24247038

RESUMO

This paper reports for the first time the luminescent property of polystyrene (PS), produced by pulsed ultra violet laser irradiation. We have discovered that, in air, ultra-violet (UV) irradiated PS nanospheres emit bright white light with the dominant peak at 510 nm, while in vacuum they emit in the near-blue region. From the comparison of PS nanospheres irradiated in vacuum and air, we suggest that the white luminescence is due to the formation of carbonyl groups on the surface of PS by photochemical oxidation. Our results potentially offer a new route and strategy for white light sources.

4.
Korean Circ J ; 42(7): 492-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22870084

RESUMO

Stent migration from the delivery balloon catheter is a rare but serious complication during percutaneous coronary intervention, particularly when a part of the stent stretches into the aorta. We report an unusual case of stent migration treated with a combination of a gooseneck snare and rotablation. A part of the stent was overstretched and unrolled into the aorta and the rest of the stent remained implanted in the coronary artery. The stent was captured with a gooseneck snare but could not be retrieved because it was connected to a stent remnant implanted in the coronary artery. The stent strut was cut with rotablation, and the stent was successfully removed through the femoral sheath.

5.
J Nanosci Nanotechnol ; 12(2): 1284-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22629939

RESUMO

TiNx films were successfully deposited by DC reactive magnetron sputtering superimposed EMF system without substrate heating. In case of DCMS 400 W+ EMF 25 W, electrical property, reflectance and crystallinity of the TiN films were clearly improved by the enhancement of nitrification. The lowest sheet resistance of 2.9 Ω/⟂ (resistivity 5.8 x 10(-5) Ωcm) was observed for the film deposited at F(N)2: 16%. Mixture phases of the (111) plane and (200) plane showed lower resistivity than only (200) single phase. Therefore it is confirmed that introduction of EMF system is promising technology to deposit TiN film.

6.
Nanotechnology ; 23(11): 115603, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22370486

RESUMO

We investigate the growth procedures for achieving taper-free and kinked germanium nanowires epitaxially grown on silicon substrates by chemical vapor deposition. Singly and multiply kinked germanium nanowires consisting of <111> segments were formed by employing a reactant gas purging process. Unlike non-epitaxial kinked nanowires, a two-temperature process is necessary to maintain the taper-free nature of segments in our kinked germanium nanowires on silicon. As an application, nanobridges formed between (111) side walls of V-grooved (100) silicon substrates have been demonstrated.

7.
J Ultrasound Med ; 30(1): 3-10, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21193699

RESUMO

OBJECTIVES: The aim of study was to assess the usefulness of 3D ultrasonography (3DUS) in the diagnosis of carpal tunnel syndrome. METHODS: Fifty patients with carpal tunnel syndrome confirmed by electromyography and 37 healthy control participants underwent 3DUS of the wrists. The mean times per participant for the 3DUS examination and review of the 3D volume set were recorded. The cross-sectional area at the proximal carpal tunnel and the maximum swelling point were measured. Data from patients and controls were compared for determination of statistical significance. The accuracy of the 3DUS diagnostic criteria for carpal tunnel syndrome was evaluated using receiver operating characteristic analysis, and changes in the median nerve shape, including the maximum swelling point, were assessed by review of the 3D volume data. RESULTS: The mean times for examination of a participant and review in each wrist were 56 seconds and 5.7 minutes, respectively. Significant differences were observed in the mean cross-sectional areas of the median nerve between patients and controls. The mean cross-sectional areas ± SD were 16.7 ± 6.7 mm(2) in patients and 8.3 ± 1.9 mm(2) in controls. Using the receiver operating characteristic curve, a cutoff value of greater than 10.5 mm(2) provided diagnostic sensitivity of 84% and specificity of 86%. In 42 of 73 wrists with carpal tunnel syndrome, the median nerve showed fusiform morphologic abnormalities and maximum swelling points. CONCLUSIONS: Our results show that 3DUS could markedly decrease scanning time, and measurement of the median nerve cross-sectional area combined with morphologic analysis using 3DUS is a promising supplementary method for the diagnosis of carpal tunnel syndrome.


Assuntos
Síndrome do Túnel Carpal/diagnóstico por imagem , Imageamento Tridimensional/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Nervo Mediano/diagnóstico por imagem , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia , Articulação do Punho/diagnóstico por imagem
8.
Neuroradiology ; 53(9): 643-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21088962

RESUMO

INTRODUCTION: The aim of this study was to evaluate the correlation between carotid siphon (CS) calcification and lacunar infarction caused by small-vessel disease. METHODS: This retrospective study included 445 patients (M/F = 256:189) older than 40 years (mean age 60.0 ± 12.3 years, range 41-98 years) without large intracranial lesions who had undergone both brain CT and MRI within an interval of 6 months. The patients were classified into three groups according to the number of lacunar infarctions: group I-zero infarctions (n = 328), group II-one to three infarctions (n = 94), and group III-four or more infarctions (n = 23). The severity of CS calcification was evaluated on CT and scored on a five-point scale (0-none, 1-stippled, 2-thin continuous or thick discontinuous, 3-thick continuous, 4-double tracts), and the calcification scores on both sides were summed. An ANOVA test was used to compare calcification scores among the three groups, and a logistic regression test was used to evaluate the influence of CS calcification and known cerebrovascular risk factors on the occurrence of lacunar infarction. RESULTS: On the ANOVA test, total calcification scores were significantly different among the three groups (group I = 1.28 ± 1.99, group II = 3.31 ± 2.39, group III = 4.36 ± 2.08; P < 0.05). Higher rates of lacunar infarction were associated with higher CS calcification scores. On the logistic regression test, CS calcification, age, and hypertension were significant risk factors for lacunar infarction (P < 0.05). CONCLUSION: CS calcification was correlated with the occurrence of lacunar infarction. The degree of CS calcification may be used to predict the possibility of a future lacunar infarction.


Assuntos
Calcinose/patologia , Artéria Carótida Interna/patologia , Estenose das Carótidas/patologia , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral Lacunar/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Calcinose/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Feminino , Humanos , Hipertensão/complicações , Hipertensão/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral Lacunar/diagnóstico por imagem , Tomografia Computadorizada por Raios X
9.
Laryngoscope ; 120(6): 1120-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20513027

RESUMO

OBJECTIVES/HYPOTHESIS: The purpose of this study was to determine the appropriate cut-off value for fine needle aspiration-thyroglobulin (FNA-Tg) associated with postoperative recurrences and validate the diagnostic efficacy of FNA-Tg in patients after total thyroidectomy compared with concomitant cytology (C). STUDY DESIGN: Retrospective. METHODS: We retrospectively evaluated the results of ultrasound-guided FNAs performed for suspicious cervical lesions of 40 patients (male:female = 10:30; mean age, 44.0 years) after total thyroidectomy (mean duration, 89.1 months), to acquire the material for Tg and C analysis. After collection of the cytologic sample, we rinsed the same needle with 1 mL of normal saline for Tg radioimmunoassay. RESULTS: Of 40 lesions (mean size, 0.89 cm; range, 0.3-3.5 cm), 21 were confirmed as recurrences and 19 were nonrecurrences. The rates of nondiagnostic sampling and sensitivity and specificity of FNA-C when diagnostic sampling was obtained were 40% (16/40), 100% (14/14), and 90.0% (9/10), respectively. According to receiver operating characteristic analysis, the optimal cut-off value of FNA-Tg was 4.1 ng/mL (sensitivity, 100% [21/21]; specificity, 100% [19/19], P < .05). Furthermore, in 16 inconclusive lesions due to nondiagnostic cytologic results, the FNA-Tg results coincided with a final diagnosis (seven recurrences and nine nonrecurrences). The cases with maximum diameters <1 cm showed a significantly increased rate of nondiagnostic cytologic results, and the FNA-Tg results were more helpful than lesions > or =1 cm in diagnosing a recurrence (P < .05). CONCLUSIONS: Measurement of FNA-Tg is helpful for distinguishing recurrent from nonrecurrent lesions in the majority of patients who were previously treated for well-differentiated papillary thyroid carcinoma.


Assuntos
Carcinoma Papilar/patologia , Recidiva Local de Neoplasia/patologia , Tireoglobulina , Neoplasias da Glândula Tireoide/patologia , Adulto , Idoso , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/cirurgia , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Curva ROC , Radioimunoensaio , Estudos Retrospectivos , Sensibilidade e Especificidade , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Ultrassonografia de Intervenção
10.
Skeletal Radiol ; 38(11): 1063-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19543893

RESUMO

OBJECTIVE: The objective of the study was to compare the diagnostic reliability of 3D US with MR arthrography in diagnosing supraspinatus tendon tears, with arthroscopic findings used as the standard. MATERIALS AND METHODS: In a prospective study 50 patients who later underwent arthroscopic surgery of the rotator cuff were examined pre-operatively by 3D US with MR arthrography. The presence or absence of a full- or partial-thickness supraspinatus tendon tear and the tear size as demonstrated by each imaging and arthroscopy was recorded. The tear size was divided into three grades: small (<1 cm), medium (1-3 cm), and large (>3 cm). RESULTS: The arthroscopic diagnosis was a full-thickness tear in 40 patients, partial-thickness tears in 5, and intact supraspinatus tendon in 5. 3D US correctly diagnosed 35 out of 40 full-thickness tears and MR arthrography 39 out of 40 full-thickness tears. Regarding partial-thickness tears, 3D US underestimated 2 cases as no tear and overestimated 1 case as a full-thickness tear. MR arthrography underestimated 1 case as a partial-thickness tear and overestimated 2 cases as full-thickness and partial-thickness tears respectively. 3D US and MR arthrography yield a sensitivity for full-thickness tears of 87.5% and 97.5% with specificity of 90.0% and 90.0%. Based on the grading system, 3D US measurements correctly predicted the tear size of 23 (65.7%) of the 35 full-thickness tears and MR arthrography 30 (75.0%) of the 39 full-thickness tears. CONCLUSION: Three-dimensional ultrasound seems to be a promising imaging modality comparable to MR arthrography for the assessment of the supraspinatus tendon tears.


Assuntos
Artroscopia , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Lesões do Ombro , Traumatismos dos Tendões/diagnóstico , Ultrassonografia/métodos , Adulto , Idoso , Feminino , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/patologia
11.
Skeletal Radiol ; 38(9): 877-85, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19430778

RESUMO

OBJECTIVE: To correlate magnetic resonance (MR) image findings with pain response by provocation discography in patients with discogenic low back pain, with an emphasis on the combination analysis of a high intensity zone (HIZ) and disc contour abnormalities. MATERIALS AND METHODS: Sixty-two patients (aged 17-68 years) with axial low back pain that was likely to be disc related underwent lumbar discography (178 discs tested). The MR images were evaluated for disc degeneration, disc contour abnormalities, HIZ, and endplate abnormalities. Based on the combination of an HIZ and disc contour abnormalities, four classes were determined: (1) normal or bulging disc without HIZ; (2) normal or bulging disc with HIZ; (3) disc protrusion without HIZ; (4) disc protrusion with HIZ. These MR image findings and a new combined MR classification were analyzed in the base of concordant pain determined by discography. RESULTS: Disc protrusion with HIZ [sensitivity 45.5%; specificity 97.8%; positive predictive value (PPV), 87.0%] correlated significantly with concordant pain provocation (P < 0.01). A normal or bulging disc with HIZ was not associated with reproduction of pain. Disc degeneration (sensitivity 95.4%; specificity 38.8%; PPV 33.9%), disc protrusion (sensitivity 68.2%; specificity 80.6%; PPV 53.6%), and HIZ (sensitivity 56.8%; specificity 83.6%; PPV 53.2%) were not helpful in the identification of a disc with concordant pain. CONCLUSION: The proposed MR classification is useful to predict a disc with concordant pain. Disc protrusion with HIZ on MR imaging predicted positive discography in patients with discogenic low back pain.


Assuntos
Deslocamento do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/diagnóstico , Dor Lombar/diagnóstico , Dor Lombar/etiologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Meios de Contraste/administração & dosagem , Feminino , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
12.
Echocardiography ; 26(6): 645-50, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19392839

RESUMO

We investigated whether the echocardiographic parameters of the left atrium (LA) can predict the development of nonvalvular atrial fibrillation (AF). Among 14,062 patients (>20 years old) who underwent an echocardiographic examination were evaluated, 2,606 patients who underwent follow-up ECG with an interval of >6 months were investigated. Newly developed AF was noted in 42 (1.6%) patients with follow-up duration of 31.8 +/- 8.9 months. Cox regression analysis revealed that a higher left atrial volume index (hazard ratio [HR]=1.06; 95% confidence interval [CI] 1.03-1.09, P < 0.001), relative wall thickness (RWT) of>or=0.407 (HR=2.74, 95% CI 1.39-5.41, P=0.004), a reduced peak atrial systolic mitral annular velocity (HR=0.845, 95% CI 0.72-0.99, P=0.037), and an advanced age (HR=1.04, 95% CI 1.01-1.07, P=0.009) were independently related to the development of nonvalvular AF. Therefore, reduced A', which is parameter of LA contractile function, might be an important predictor for the development of nonvalvular AF.


Assuntos
Fibrilação Atrial/diagnóstico por imagem , Ecocardiografia/métodos , Técnicas de Imagem por Elasticidade/métodos , Átrios do Coração/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Valva Mitral/diagnóstico por imagem , Fibrilação Atrial/complicações , Feminino , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/diagnóstico por imagem , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Heart Vessels ; 24(6): 413-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20108072

RESUMO

Pulse wave velocity (PWV) and augmentation index (AI) are both indirect indicators of arterial stiffness, which is an independent predictor of morbidity and mortality in cardiovascular diseases. The aim of this study was to assess the association between carotid AI (CAI), carotid-femoral PWV (CFPWV), and Framingham risk score (FRS), and to evaluate the factors determining CAI and CFPWV. Carotid AI and CFPWV were measured by applanation tonometry in 177 consecutive subjects without evidence of significant cardiovascular disease. Correlations between CAI and FRS and CFPWV and FRS were analyzed and major determinants of CAI and CFPWV were assessed. The mean age was 60.5 +/- 11.9 years and 112 (63%) of study patients were men. There was a significant association between CFPWV and FRS (r = 0.417, P < 0.001) and a weaker but also significant relation between CAI and FRS (r = 0.267, P < 0.001). CFPWV was significantly related to FRS in both men and women (P < 0.001 in both sexes), whereas the relation between CAI and FRS was significant only in women (P < 0.001). Our results suggest that CFPWV may be associated with CVD risk irrespective of sex, whereas CAI may be associated with CVD risk in women only.


Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Artérias Carótidas/fisiopatologia , Artéria Femoral/fisiopatologia , Fluxo Pulsátil , Distribuição por Idade , Fatores Etários , Idoso , Pressão Sanguínea , Estudos Transversais , Elasticidade , Feminino , Humanos , Modelos Lineares , Masculino , Manometria , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais
14.
J Clin Ultrasound ; 36(9): 570-2, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18431747

RESUMO

A case of subcutaneous and intramuscular sparganosis was confirmed on surgical excision of a worm in a 60-year-old woman suffering from painful masses in the right thigh. Sonography and MRI revealed an ill-defined intramuscular lesion and multiple cystic lesions in the subcutaneous tissue. At the time of the excision, a sparganum larva was found in the adductor longus muscle. If an intramuscular mass with a serpiginous cystic tract is seen on imaging studies in an endemic area, musculoskeletal sparganosis should be included in the differential diagnosis of a soft tissue tumor.


Assuntos
Imageamento por Ressonância Magnética , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/parasitologia , Esparganose/diagnóstico por imagem , Tela Subcutânea/diagnóstico por imagem , Tela Subcutânea/parasitologia , Animais , Feminino , Humanos , Pessoa de Meia-Idade , Spirometra/fisiologia , Ultrassonografia
15.
J Comput Assist Tomogr ; 32(1): 124-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18303300

RESUMO

OBJECTIVE: To investigate potential risk factors for hemodynamic depression (HD) in elective carotid angioplasty with stenting (CAS) by using multidetector computed tomography (MDCT) angiographic findings and clinical data. METHODS: A retrospective study was conducted for 32 patients that underwent MDCT angiography before CAS in our hospital. We reviewed the MDCT angiographic findings to evaluate parameters including total plaque volume, composition and the composition ratio of plaque, degree of stenosis, and distance of the most stenotic portion from carotid bifurcation. Clinical data such as patient age, presence of neurological symptoms, underlying medical disease, smoking history, and previous stroke history were noted. The MDCT angiographic parameters and clinical data were then analyzed to determine a prediction for periprocedural HD (systolic blood pressure, <90 mm Hg; or heart rate, <40 beats/min). RESULTS: Periprocedural HD was observed in 9 patients (28.1%). Among the MDCT angiographic parameters, the hemodynamic unstable group of patients had a smaller total plaque volume than that of stable group of patients (P = 0.04). The other MDCT parameters and clinical data did not show statistically significant difference between 2 groups. CONCLUSIONS: In this study, only the total volume of plaque was a positive factor for predicting HD during CAS. Multidetector computed tomography angiography can be helpful for predicting HD during CAS.


Assuntos
Angioplastia/métodos , Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Hemodinâmica , Stents , Tomografia Computadorizada por Raios X/métodos , Idoso , Pressão Sanguínea , Bradicardia/diagnóstico , Bradicardia/etiologia , Estenose das Carótidas/diagnóstico , Meios de Contraste/administração & dosagem , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Frequência Cardíaca , Humanos , Hipotensão/diagnóstico , Hipotensão/etiologia , Processamento de Imagem Assistida por Computador , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
16.
J Clin Ultrasound ; 36(1): 6-11, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17924577

RESUMO

PURPOSE: To analyze the discrepancies between the cytologic results of sonographically (US)-guided fine needle aspiration (FNA) of thyroid nodules and final histopathologic results and to discuss the limitations of US-guided FNA. MATERIALS AND METHODS: The results of US-guided FNAs performed by a single experienced radiologist in 315 thyroid nodules in 292 patients (246 women, 46 men aged 12-79 years) were retrospectively correlated with their surgical pathologic results. The FNA results were classified as nondiagnostic, indeterminate, negative, or positive, whereas final pathologic diagnoses were classified as malignant or benign. RESULTS: The FNA results were nondiagnostic in 31 cases (9.8%), indeterminate in 97 cases (30.8%), and determinate in 187 cases (59.4%). Of the 187 conclusive cases, 169 (90.4%) were concordant with the final pathologic results, whereas 18 (9.6%) were discordant with 14 false-positive and 4 false-negative results. These discrepancies were caused by atypical nuclear features. Among the 97 indeterminate and 31 nondiagnostic cases, a malignancy was found in 14 (14.4%) and 8 (25.8%) cases, respectively. In addition, 10 papillary carcinomas, which were not visualized on sonograms, were detected incidentally in thyroidectomy specimens. CONCLUSION: The diagnostic accuracy of US-guided FNA of thyroid nodule has limitations that should be minimized by careful interpretation of the cytologic findings and accurate sampling.


Assuntos
Biópsia por Agulha Fina/métodos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Nódulo da Glândula Tireoide/cirurgia , Ultrassonografia
17.
Clin Anat ; 20(8): 905-14, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17879307

RESUMO

The aim of our study was to examine the locational distribution of paraspinal structures on MRI and to determine any predictable parameters that may be used for the identification of transitional vertebra (TV). We enrolled 534 patients who underwent MRI of their lumbosacral spine. The locations of the paraspinal structures, such as aortic bifurcation (AB), IVC confluence (IC), right renal artery (RRA), celiac trunk (CT), SMA root (SR), and iliolumbar ligament (ILL), were determined using "cross link" in PACS. We also assessed the morphology of the TV. The MRI showed that the most common site of the paraspinal structures in the normal group was AB at the lower L4, IC at the L4-5 disc space, RRA at the L1-2 disc space, CT at the T12-L1 disc space, SR at the upper L1, and ILL at the L5. The frequency of TV was 23.8% (lumbarization, 9.9%; sacralization, 13.9%). The paraspinal structures of the S1 lumbarization were positioned more toward the caudal location, whereas the paraspinal structures of the L5 sacralization were positioned more toward the cephalic location (P < 0.01). In conclusion, AB, IC, RRA, CT, SR, and ILL are useful landmarks for predicting the presence of TV on MRI. TV is possible when these paraspinal structures are in positions outside of the frequent locations.


Assuntos
Imageamento por Ressonância Magnética , Doenças da Coluna Vertebral/diagnóstico , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/patologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Doenças da Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem
18.
Auris Nasus Larynx ; 34(2): 213-9, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17270376

RESUMO

OBJECTIVE: To describe the sonographic features of cervical recurrence in patient with thyroid cancer and review clinical significance. MATERIALS AND METHODS: Twenty-two consecutive patients with 24 surgically confirmed recurrences undergoing preoperative ultrasonography (US) and US-guided fine needle aspiration biopsy (FNAB) were enrolled. Retrospective analysis was conducted on the sonographic features of recurrence including size, location, shape, echogenicity, multiplicity, laterality relative to initial primary tumor and presence of characteristic findings; cystic change and microcalcification. In addition, review was made on their clinical data including the time interval between the thyroidectomy and the recurrence, serum thyroglobulin (Tg), anti-thyroglobulin antibody (Tg Ab) and 131 iodine whole body scan (IWBS). RESULTS: Fifteen of 24 recurrences occurred in internal jugular lymphatic chain and 9 in the postoperative paratracheal region with mostly ipsilaterally to the initial tumor (19/24). Their mean size was 1.0 cm (range: 0.5-2.5 cm) with ovoid (n=18) or lobulated (n=6) shape. They appeared hyperechoic in nine (37.5%), hypoechoic in nine (37.5%), and mixed echoic due to cystic change in six (25.0%). Microcalcification was observed in eight (33.3%) and multiplicity in seven (29.2%). US-guided FNAB established the preoperative diagnosis of recurrence in all. The mean interval between the thyroidectomy and recurrence was 59 months (range: 15-162 months). Suspicion of recurrence was possible in 8 with Tg of 2 ng/ml or greater (8/24) during thyroxine (T4) therapy and 6 (6/8) after T4 withdrawal. All of the 8 recurrences were negative on 131 IWBS. In two patients with Tg less than 2 ng/ml after T4 withdrawal, elevated Tg Ab was observed. CONCLUSION: US and US-guided FNAB are valuable postoperative follow up modalities of thyroid cancer due to their convenience, early detection and precise localization. Therefore, it's essential to get familiar with sonographic findings of cervical recurrence.


Assuntos
Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Tireoidectomia , Adulto , Idoso , Autoanticorpos/sangue , Biomarcadores Tumorais/sangue , Biópsia por Agulha Fina , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Tireoglobulina/sangue , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Tiroxina/uso terapêutico , Ultrassonografia
19.
Korean J Hepatol ; 12(3): 404-11, 2006 Sep.
Artigo em Coreano | MEDLINE | ID: mdl-16998292

RESUMO

BACKGROUND/AIMS: Protein induced by vitamin K absence or antagonist-II (PIVKA-II), also known as des-carboxyprothrombin (DCP), can be used as an alternative tool to alpha-fetoprotein (AFP) for surveillance of hepatocellular carcinoma (HCC). The aims of the present study were to compare PIVKA-II levels between the patients with HCC and patients with non-HCC chronic liver disease, to evaluate the correlation of PIVKA-II and AFP in HCC patients, and finally to estimate the optimal cut-off value for PIVKA-II for the diagnosis of HCC with using the receiver operating characteristic (ROC) curve. METHODS: A total of 227 consecutive patients with HCC (n=42) or chronic liver disease (n=185) were enrolled in this study. HCC was diagnosed histologically or by imaging such as computed tomography, magnetic resonance imaging or angiography. The serum PIVKA-II and AFP levels were measured by electrochemiluminoimmunoassay with using the Haicatch PIVKA-II kit and by immunoradiometric assay, respectively. RESULTS: The PIVKA-II level in the HCC patients was significantly higher than the non-HCC chronic liver disease patients (903.0+/-1156.7 vs. 111.7+/-211.0 mAU/ mL, respectively, P<0.01). PIVKA-II and AFP showed a statistical correlation in HCC patients (r=0.46, P<0.01). The sensitivity and specificity of PIVKA-II for the diagnosis of HCC were 66.7% and 74.1%, respectively, and when tasted together with AFP, the sensitivity was increased by 85.7%. For the ROC curve of PIVKA-II in HCC patients, the specificity of a 250 mAU/mL level of PIVKA-II was 95%. CONCLUSIONS: PIVKA-II was as useful surveillance tool for differentiating HCC from chronic liver disease, and a PIVKA-II value of 250 mAU/ mL was proposed as a significant cut-off value for diagnosis of hepatocellular carcinoma.


Assuntos
Biomarcadores Tumorais/sangue , Biomarcadores/sangue , Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Precursores de Proteínas/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Protrombina , Curva ROC , alfa-Fetoproteínas/análise
20.
Korean J Intern Med ; 21(2): 116-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16913441

RESUMO

A 40-year-old Korean man presented with painful swelling and tenderness of both ankle joints as well as the plantar surfaces of both feet, along with inflammatory back pain, and a purulent discharge from the urethral orifice. The patient also complained of sicca-like symptoms including dry eyes and dry mouth. An immunological analysis revealed a high titer of rheumatoid factor, positive results for antinuclear antibody and anti-Ro antibody, and a positive result for HLA-B27. An antibody titer for Chlamydia was also significantly increased. Positive results of the Schirmer's test and for keratoconjunctivitis sicca were confirmed by an ophthalmologist. These clinical manifestations were compatible with Chlamydia-induced reactive arthritis (ReA) accompanied by Sjögren's syndrome (SS). This is the first report of the combination of these two distinct disease entities in the Korean population.


Assuntos
Artrite Reativa/complicações , Infecções por Chlamydia/complicações , Chlamydia trachomatis , Síndrome de Sjogren/complicações , Adulto , Anticorpos Antinucleares/sangue , Humanos , Masculino , Proibitinas
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