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1.
Retina ; 44(1): 47-55, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37657069

RESUMEN

PURPOSE: To investigate the characteristics and natural history of treatment-naive nonexudative polypoidal choroidal vasculopathy (PCV) and to determine biomarkers predicting exudative conversion. METHODS: Patients diagnosed with nonexudative PCV based on indocyanine green angiography and optical coherence tomography were included. Incidence of exudative conversion in nonexudative PCV patients and cumulative estimates for overall risk were assessed. Indocyanine green angiography and optical coherence tomography imaging-based features were analyzed to identify risk factors for exudative conversion. RESULTS: The study included 42 eyes of 40 patients with nonexudative PCV. The mean follow-up duration was 54.3 ± 35.5 months. Of the 42 eyes with nonexudative PCV, exudative conversion developed in 23 eyes (54.8%) after 42.2 ± 28.3 months (range, 8-103 months). Kaplan-Meier analysis showed that the exudation-free survival at 5 years after baseline was estimated to be 53.6%. Multivariate regression analysis showed that sequentially increased protrusion of retinal pigment epithelium in the polyp area was a significant risk factor for exudation in nonexudative PCV (odds ratio = 10.16; 95% CI 1.78-57.81; P = 0.01). CONCLUSION: Exudative conversion has been noted in nearly half of the nonexudative PCV cases in 5 years. The progressive protrusion of polypoidal lesions on optical coherence tomography examination may be a significant biomarker for predicting the near-term onset of exudation.


Asunto(s)
Enfermedades de la Coroides , Neovascularización Coroidal , Pólipos , Humanos , Verde de Indocianina , Coroides , Vasculopatía Coroidea Polipoidea , Angiografía con Fluoresceína/métodos , Tomografía de Coherencia Óptica/métodos , Pólipos/diagnóstico , Pólipos/epidemiología , Neovascularización Coroidal/diagnóstico , Estudios Retrospectivos , Enfermedades de la Coroides/diagnóstico , Enfermedades de la Coroides/epidemiología
2.
Proc Natl Acad Sci U S A ; 114(28): 7307-7312, 2017 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-28652342

RESUMEN

Until at least 6 mo of age, infants show good discrimination for familiar phonetic contrasts (i.e., those heard in the environmental language) and contrasts that are unfamiliar. Adult-like discrimination (significantly worse for nonnative than for native contrasts) appears only later, by 9-10 mo. This has been interpreted as indicating that infants have no knowledge of phonology until vocabulary development begins, after 6 mo of age. Recently, however, word recognition has been observed before age 6 mo, apparently decoupling the vocabulary and phonology acquisition processes. Here we show that phonological acquisition is also in progress before 6 mo of age. The evidence comes from retention of birth-language knowledge in international adoptees. In the largest ever such study, we recruited 29 adult Dutch speakers who had been adopted from Korea when young and had no conscious knowledge of Korean language at all. Half were adopted at age 3-5 mo (before native-specific discrimination develops) and half at 17 mo or older (after word learning has begun). In a short intensive training program, we observe that adoptees (compared with 29 matched controls) more rapidly learn tripartite Korean consonant distinctions without counterparts in their later-acquired Dutch, suggesting that the adoptees retained phonological knowledge about the Korean distinction. The advantage is equivalent for the younger-adopted and the older-adopted groups, and both groups not only acquire the tripartite distinction for the trained consonants but also generalize it to untrained consonants. Although infants younger than 6 mo can still discriminate unfamiliar phonetic distinctions, this finding indicates that native-language phonological knowledge is nonetheless being acquired at that age.


Asunto(s)
Adopción , Lenguaje , Fonética , Aprendizaje Verbal , Adulto , Femenino , Humanos , Lactante , Recién Nacido , Desarrollo del Lenguaje , Pruebas del Lenguaje , Aprendizaje , Masculino , Memoria , Países Bajos , República de Corea , Vocabulario
3.
J Clin Ultrasound ; 47(1): 44-46, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30393879

RESUMEN

Metastasis to the thyroid is very rare in hepatocellular carcinoma (HCC) and only a few cases have been reported. Herein, we report a rare case of metastatic HCC to the thyroid in a 63-year-old man and discuss the various radiologic findings. Computed tomography (CT) revealed a heterogeneous enhancing mass that had invaded the thyroid cartilage in the left upper thyroid, compressing the airway. Ultrasonography (US) showed a heterogeneous hypoechoic mass with increased vascularity in the peripheral portion. The mass showed focal intense uptake on positron emission tomography-computed tomography (PET-CT). The patient underwent US-guided core needle biopsy and the final diagnosis was metastatic HCC.


Asunto(s)
Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/secundario , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad , Glándula Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/radioterapia , Ultrasonografía/métodos
4.
J Acoust Soc Am ; 139(3): EL76-82, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27036291

RESUMEN

This study investigated how the L1 phonetics-prosody interface transfers to L2 by examining prosodic strengthening effects (due to prosodic position and focus) on English voicing contrast (bad-pad) as produced by Korean vs English speakers. Under prosodic strengthening, Korean speakers showed a greater F0 difference due to voicing than English speakers, suggesting that their experience with the macroprosodic use of F0 in Korean transfers into L2. Furthermore, Korean speakers produced voiced stops with low F0 and short voice onset time as English speakers did, although such a cue pairing is absent in Korean, showing dissociation of cues from L1 segments for L2 production.


Asunto(s)
Multilingüismo , Fonética , Acústica del Lenguaje , Calidad de la Voz , Acústica , Adulto , Señales (Psicología) , Femenino , Humanos , Masculino , Espectrografía del Sonido , Medición de la Producción del Habla , Factores de Tiempo , Adulto Joven
5.
Am J Infect Control ; 52(2): 214-219, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37406965

RESUMEN

BACKGROUND: This study analyzed the validity of healthcare-associated infection (HAI) data of the Korean National healthcare-associated Infections Surveillance System. METHODS: The validation process consisted of external (EV) and internal (IV) validation phases. Of the 193 hospitals that participated from July 2016 through June 2017, EV was performed for 10 hospitals that were selected based on the HAI rate percentile. The EV team reviewed 295 medical records for 60 HAIs and 235 non-HAI control patients. IV was performed for both the 10 EV hospitals and 11 other participating hospitals that did not report any HAIs. RESULTS: In the EV, the diagnosis of urinary tract infections had a sensitivity of 72.0% and a specificity of 99.3%. The respective sensitivities of bloodstream infection and pneumonia were 63.2% and 70.6%; the respective specificities were 98.8% and 99.6%. The agreement (ĸ) between the EV and IV for 10 hospitals was 0.754 for urinary tract infections and 0.674 for bloodstream infections (P < .001, respectively). Additionally, IV found additional cases among 11 zero-report hospitals. DISCUSSION: This study demonstrates the need for ongoing validation and continuous training to maintain the accuracy of nationwide surveillance data. CONCLUSIONS: IV should be considered a validation method to supplement EV.


Asunto(s)
Infecciones Relacionadas con Catéteres , Enfermedades Transmisibles , Infección Hospitalaria , Sepsis , Infecciones Urinarias , Humanos , Infección Hospitalaria/epidemiología , Infecciones Urinarias/epidemiología , Sepsis/epidemiología , República de Corea/epidemiología , Atención a la Salud , Infecciones Relacionadas con Catéteres/epidemiología
6.
Data Brief ; 46: 108816, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36593767

RESUMEN

This data article provides acoustic data for individual speakers' production of coda voicing contrast between stops in English, which are based on laboratory speech recorded by twelve native speakers of American English and twenty-four Korean learners of English. There were four pairs of English monosyllabic target words with voicing contrast in the coda position (bet-bed, pet-ped, bat-bad, pat-pad). The words were produced in carrier sentences in which they were placed in two different prosodic boundary conditions (Intonational Phrase initial and Intonation Phrase medial), two pitch accent conditions (nuclear-pitch accented and unaccented), and three focus conditions (lexical focus, phonological focus and no focus). The raw acoustic measurement values that are included in a CSV-formated file are F0, F1, F2 and duration of each vowel preceding a coda consonant; and Voice Onset Time of word-initial stops. This article also provides figures that exemplify individual speaker variation of vowel duration, F0, F1 and F2 as a function of focus conditions. The data can thus be potentially reused to observe individual variations in phonetic encoding of coda voicing contrast as a function of the aforementioned prosodically-conditioned factors (i.e., prosodic boundary, pitch accent, focus) in native vs. non-native English. Some theoretical aspects of the data are discussed in the full-length article entitled "Phonetic encoding of coda voicing contrast under different focus conditions in L1 vs. L2 English" [1].

7.
Sci Rep ; 12(1): 21885, 2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-36536024

RESUMEN

Externally oblique border tissue (EOBT) configuration is topographically associated with glaucomatous damage in the optic nerve head. We investigated the relationship between the EOBT characteristics and macular retinal ganglion cell (RGC) thickness in patients with open-angle glaucoma (OAG). A total of 149 eyes with OAG that had an EOBT observed on optical coherence tomography exams were included. After determining the maximum EOBT length and angular location of the maximal EOBT length, we analyzed their correlation with macular ganglion cell inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thickness. The macular GCIPL and pRNFL thickness were compared based on the angular location of the longest EOBT, and their association was assessed using multivariable regression analysis. Maximum EOBT length was significantly correlated with macular GCIPL thickness, but not with pRNFL thickness. Macular GCIPL was thinnest in eyes with EOBT located in a temporal direction to the optic disc. Longer maximum EOBT and temporally elongated EOBT were independently associated with a thinner macular GCIPL in the multivariable regression analysis. These suggest that temporal elongation of the EOBT may increase the stress and strain on the RGCs derived from the macula and make RGCs more susceptible to glaucoma-inducing damage.


Asunto(s)
Glaucoma de Ángulo Abierto , Glaucoma , Disco Óptico , Humanos , Glaucoma de Ángulo Abierto/complicaciones , Fibras Nerviosas , Glaucoma/complicaciones , Células Ganglionares de la Retina , Tomografía de Coherencia Óptica/métodos , Presión Intraocular
8.
Lang Speech ; 64(2): 413-436, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31631754

RESUMEN

Prominence, the expression of informational weight within utterances, can be signaled by prosodic highlighting (head-prominence, as in English) or by position (as in Korean edge-prominence). Prominence confers processing advantages, even if conveyed only by discourse manipulations. Here we compared processing of prominence in English and Korean, using a task that indexes processing success, namely recognition memory. In each language, participants' memory was tested for target words heard in sentences in which they were prominent due to prosody, position, both or neither. Prominence produced recall advantage, but the relative effects differed across language. For Korean listeners the positional advantage was greater, but for English listeners prosodic and syntactic prominence had equivalent and additive effects. In a further experiment semantic and phonological foils tested depth of processing of the recall targets. Both foil types were correctly rejected, suggesting that semantic processing had not reached the level at which word form was no longer available. Together the results suggest that prominence processing is primarily driven by universal effects of information structure; but language-specific differences in frequency of experience prompt different relative advantages of prominence signal types. Processing efficiency increases in each case, however, creating more accurate and more rapidly contactable memory representations.


Asunto(s)
Percepción del Habla , Humanos , Lenguaje , Semántica
9.
Water Sci Technol ; 61(7): 1819-27, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20371941

RESUMEN

Oxygen has been so far addressed as the most preferable terminal electron acceptor in the cathodes of microbial fuel cells (MFCs). However, to reduce the oxygen reduction overpotential at the cathode surface, eco-unfriendly and costly catalysts have been commonly employed. Here, we pursued the possibility of using a high surface area electrode to reduce the cathodic reaction overpotential rather than the utilization of catalyzed materials. A dual chambered MFC reactor was designed with the use of graphite-granule electrodes and a permeable membrane. The performance of the reactor in terms of electricity generation and organic removal rate was examined under a continuous-feed manner. Results showed that the maximum volumetric power of 4.4+/-0.2 W/m(3) net anodic compartment (NAC) was obtained at a current density of 11+/-0.5 A/m(3) NAC. The power output was improved by increasing the electrolyte ionic strength. An acceptable effluent quality was attained when the organic loading rate (OLR) of 2 kgCOD/m(3) NAC d was applied. The organic removal rate seemed to be less affected by shock loading. Our system can be suggested as a promising approach to make MFC-based technology economically viable for wastewater treatment applications. This study shows that current generation can be remarkably improved in comparison with several other studies using a low-surface-area plain graphite electrode.


Asunto(s)
Fuentes de Energía Bioeléctrica , Conservación de los Recursos Naturales , Grafito/química , Eliminación de Residuos Líquidos , Reactores Biológicos , Electrodos , Membranas Artificiales
10.
PLoS One ; 15(10): e0240682, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33091043

RESUMEN

In present-day Seoul Korean, the primary phonetic feature for the lenis-aspirated stop distinction is shifting from VOT to F0. Some previous studies have considered this sound change to be a tonogenesis, whereby the low-level F0 perturbation has developed into tonal features (L for the lenis and H for the aspirated) in the segmental phonology. They, however, have examined the stop distinction only at a phrase- or utterance-initial position. We newly explore the sound change in relation to various prosodic structural factors (position and prominence). Apparent-time production data were recorded from four speaker groups: young female, young male, old female, old male. The way the speakers use VOT versus F0 indeed varies as a function of position and prominence. Crucially, in all groups, VOT is still used for the lenis-aspirated distinction phrase-medially due to the lenis stop voicing. This role of VOT, however, is found only in the non-prominent (unfocused) condition, in which the F0 difference is reduced to a low-level perturbation effect. In the prominent (focused) context in which tones come into play, the role of VOT diminishes, led by young female speakers. These can be interpreted as a prosodically-conditioned, complementary use of the features to maintain sufficient contrast. Importantly, however, the tonal difference under focus is not bidirectionally polarized, so that F0 is not lowered for the lenis stop. A lack of direct enhancement of the distinctive L tone weakens a possibility that F0 is transphonologized to the phonemic feature system of the language. As an alternative to the view that tonal features are newly introduced in the segmental phonology, we propose a prosodic account: the sound change is best characterized as a prosodically-conditioned change in the use of the segmental voicing feature (implemented by VOT) versus already available post-lexical tones in the intonational phonology of Korean.


Asunto(s)
Fonética , Acústica del Lenguaje , Percepción del Habla , Voz , Adulto , Pueblo Asiatico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Seúl , Adulto Joven
11.
Dev Psychol ; 55(4): 809-822, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30676042

RESUMEN

Language and accent strongly influence the formation of social groups. By five years of age, children already show strong social preferences for peers who speak their native language with a familiar accent (Kinzler, Shutts, DeJesus, & Spelke, 2009). However, little is known about the factors that modulate the strength and direction of children's accent-based group preferences. In three experiments, we examine the development of accent-based friendship preferences in children growing up in Toronto, one of the world's most linguistically and culturally diverse cities. We hypothesized that the speaker's type of accent and the amount of accent exposure children experienced in their everyday lives would modulate their preferences in a friend selection task. Despite literature suggesting that exposure leads to greater acceptance (Allport, 1954), we find no evidence that routine exposure to different accents leads to greater acceptance of unfamiliarly accented speakers. Children still showed strong preferences for peers who spoke with the locally dominant accent, despite growing up in a linguistically diverse community. However, children's preference for Canadian-accented in-group members was stronger when they were paired with non native (Korean-accented) speakers compared to when they were paired with regional (British-accented) speakers. We propose that children's ability to perceptually distinguish between accents may have contributed to this difference. Children showed stronger preferences for in-group members when the difference between accents was easier to perceive. Overall, our findings suggest that although the strength of accent-based social preferences can be modulated by the type of accent, these preferences still persist in the face of significant diversity in children's accent exposure. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Asunto(s)
Lenguaje , Multilingüismo , Conducta Social , Percepción del Habla , Niño , Preescolar , Femenino , Humanos , Masculino , Ontario
12.
R Soc Open Sci ; 4(1): 160660, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28280567

RESUMEN

Children adopted early in life into another linguistic community typically forget their birth language but retain, unaware, relevant linguistic knowledge that may facilitate (re)learning of birth-language patterns. Understanding the nature of this knowledge can shed light on how language is acquired. Here, international adoptees from Korea with Dutch as their current language, and matched Dutch-native controls, provided speech production data on a Korean consonantal distinction unlike any Dutch distinctions, at the outset and end of an intensive perceptual training. The productions, elicited in a repetition task, were identified and rated by Korean listeners. Adoptees' production scores improved significantly more across the training period than control participants' scores, and, for adoptees only, relative production success correlated significantly with the rate of learning in perception (which had, as predicted, also surpassed that of the controls). Of the adoptee group, half had been adopted at 17 months or older (when talking would have begun), while half had been prelinguistic (under six months). The former group, with production experience, showed no advantage over the group without. Thus the adoptees' retained knowledge of Korean transferred from perception to production and appears to be abstract in nature rather than dependent on the amount of experience.

13.
Front Psychol ; 7: 624, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27242571

RESUMEN

This study investigated how coda voicing contrast in English would be phonetically encoded in the temporal vs. spectral dimension of the preceding vowel (in vowel duration vs. F1/F2) by Korean L2 speakers of English, and how their L2 phonetic encoding pattern would be compared to that of native English speakers. Crucially, these questions were explored by taking into account the phonetics-prosody interface, testing effects of prominence by comparing target segments in three focus conditions (phonological focus, lexical focus, and no focus). Results showed that Korean speakers utilized the temporal dimension (vowel duration) to encode coda voicing contrast, but failed to use the spectral dimension (F1/F2), reflecting their native language experience-i.e., with a more sparsely populated vowel space in Korean, they are less sensitive to small changes in the spectral dimension, and hence fine-grained spectral cues in English are not readily accessible. Results also showed that along the temporal dimension, both the L1 and L2 speakers hyperarticulated coda voicing contrast under prominence (when phonologically or lexically focused), but hypoarticulated it in the non-prominent condition. This indicates that low-level phonetic realization and high-order information structure interact in a communicatively efficient way, regardless of the speakers' native language background. The Korean speakers, however, used the temporal phonetic space differently from the way the native speakers did, especially showing less reduction in the no focus condition. This was also attributable to their native language experience-i.e., the Korean speakers' use of temporal dimension is constrained in a way that is not detrimental to the preservation of coda voicing contrast, given that they failed to add additional cues along the spectral dimension. The results imply that the L2 phonetic system can be more fully illuminated through an investigation of the phonetics-prosody interface in connection with the L2 speakers' native language experience.

14.
Front Psychol ; 7: 985, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27445943

RESUMEN

This study investigates whether the learning of prosodic cues to word boundaries in speech segmentation is more difficult if the native and second/foreign languages (L1 and L2) have similar (though non-identical) prosodies than if they have markedly different prosodies (Prosodic-Learning Interference Hypothesis). It does so by comparing French, Korean, and English listeners' use of fundamental-frequency (F0) rise as a cue to word-final boundaries in French. F0 rise signals phrase-final boundaries in French and Korean but word-initial boundaries in English. Korean-speaking and English-speaking L2 learners of French, who were matched in their French proficiency and French experience, and native French listeners completed a visual-world eye-tracking experiment in which they recognized words whose final boundary was or was not cued by an increase in F0. The results showed that Korean listeners had greater difficulty using F0 rise as a cue to word-final boundaries in French than French and English listeners. This suggests that L1-L2 prosodic similarity can make the learning of an L2 segmentation cue difficult, in line with the proposed Prosodic-Learning Interference Hypothesis. We consider mechanisms that may underlie this difficulty and discuss the implications of our findings for understanding listeners' phonological encoding of L2 words.

15.
Nucl Med Mol Imaging ; 50(1): 76-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26941863

RESUMEN

Splenosis is defined as the acquired heterotopic autotransplantation of splenic tissue in other sites of the body after splenic rupture, usually due to either traumatic or iatrogenic causes. It is often found incidentally and is usually asymptomatic. These implants are not limited to the left upper quadrant of the abdomen, however, and splenosis in other locations can mimic various pathologic entities. There are several reports on abdominal splenosis, but intrathoracic and subcutaneous splenosis are rare. We report two cases of intrathoracic and subcutaneous splenosis that were diagnosed using spleen scintigraphy, avoiding the need for an invasive procedure.

16.
Ann Nucl Med ; 29(2): 190-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25413273

RESUMEN

OBJECTIVE: The purpose of this study was to investigate the clinical significance of diffuse hepatic uptake on post-therapeutic early and delayed (131)I scan in patients with differentiated thyroid cancer (DTC). METHODS: We retrospectively analyzed 219 DTC patients who underwent high-dose (131)I treatment and subsequent post-therapeutic dual (131)I scan. Both early (third day after (131)I treatment) and delayed (5-6th day after (131)I treatment) (131)I scan images were visually assessed and diffuse hepatic uptake was scored using a 4-point grading system depending on intensity. RESULTS: On early (131)I scan, 73 patients (33.4 %) showed diffuse hepatic uptake, while 191 patients (87.2 %) patients showed diffuse hepatic uptake on delayed scan (p < 0.0001). The serum levels of ALT in patients with diffuse hepatic uptake on early scan were higher than those without diffuse hepatic uptake on early scan (p = 0.03 for ALT and p = 0.08 for AST). The serum levels of ALT and AST trended with the grade of hepatic uptake on delayed scan (p = 0.03 for ALT and p = 0.05 for AST). Diffuse hepatic uptake on early or delayed scan showed no significant relationship in the presence of thyroid remnants, metastatic DTC lesions, tumor recurrence during follow-up, and the serum thyroglobulin level (p > 0.05). On logistic regression analysis, both serum ALT (p = 0.01) and AST (p = 0.04) levels were significant predictive factors for diffuse hepatic uptake on early scan, while only serum ALT (p = 0.01) level was significant predictive factor for diffuse hepatic uptake on delayed scan. CONCLUSIONS: The frequency of diffuse hepatic uptake on the delayed scan was significantly higher than the early scan. Diffuse hepatic uptake on early post-therapeutic scan and the intensity of diffuse hepatic uptake on delayed scan showed significant correlation with the serum levels of hepatic enzymes, but no significant association in the presence of thyroid remnants, metastatic DTC lesions, and tumor recurrence during follow-up. The timing and intensity of diffuse hepatic uptake on post-therapeutic scan may be related with factors such as hepatic function other than the thyroid tissue or DTC.


Asunto(s)
Hígado/metabolismo , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/radioterapia , Adolescente , Adulto , Anciano , Transporte Biológico , Femenino , Humanos , Radioisótopos de Yodo/metabolismo , Radioisótopos de Yodo/uso terapéutico , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Cintigrafía , Estudios Retrospectivos , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/patología , Factores de Tiempo , Adulto Joven
17.
Nucl Med Commun ; 36(1): 38-44, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25299469

RESUMEN

OBJECTIVE: The aim of this study was to predict the success of 131I ablation using preablative 99mTc pertechnetate salivary scintigraphy and a postablative dual 131I scan in differentiated thyroid cancer (DTC). PATIENTS AND METHODS: A total of 168 DTC patients who underwent 131I ablation with preablative salivary scintigraphy and a postablative dual (early and delayed) 131I scan were enrolled. For salivary scintigraphy, the thyroid remnant uptake was visually assessed. For the dual 131I scan, the thyroid remnant to background uptake ratios (TBRs) on early and delayed scans were measured and the percentage change in TBR (TBRΔ) was calculated. RESULTS: Thyroid remnant uptake was seen in 69 (41%) patients on salivary scintigraphy and in 162 (96%) patients on the dual 131I scan. The success rate of ablation was higher in patients with negative remnant uptake on salivary scintigraphy (86%) than in patients with positive remnant uptake (58%, P=0.0001). The success rate of ablation was 100% in patients with no remnant uptake on both salivary scintigraphy and the dual 131I scan. The success rate of ablation was higher in patients with TBRΔ 0 or more than in patients with TBRΔ less than 0, irrespective of remnant uptake on salivary scintigraphy (91 vs. 70%, P=0.03, for patients without remnant uptake on salivary scintigraphy; 74 vs. 48%, P=0.05, for patients with remnant uptake on salivary scintigraphy). CONCLUSION: The success of thyroid remnant ablation in DTC can be predicted by the presence of remnant uptake on preablative 99mTc pertechnetate scintigraphy and change in remnant uptake on the postablative dual 131I scan.


Asunto(s)
Técnicas de Ablación , Glándulas Salivales/diagnóstico por imagen , Pertecnetato de Sodio Tc 99m , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/cirugía , Adolescente , Adulto , Anciano , Femenino , Humanos , Radioisótopos de Yodo , Modelos Logísticos , Masculino , Persona de Mediana Edad , Cintigrafía , Estudios Retrospectivos , Tiroidectomía , Resultado del Tratamiento , Adulto Joven
18.
Nucl Med Mol Imaging ; 49(1): 69-72, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25767626

RESUMEN

A follow-up (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT scan of a 57-year-old asymptomatic male who had undergone total thyroidectomy for thyroid cancer revealed a 5.0 × 4.0-cm, well-defined, ovoid-shaped mass around the left adrenal gland without definite FDG uptake. On the adrenal CT scan, the left paraadrenal tumor showed high attenuation on the precontrast scan without enhancement. The average Hounsfield unit (HU) was 58.1 on the precontrast scan and 58.4 on the postcontrast scan. The patient underwent laparoscopic adrenalectomy for resection of the left paraadrenal tumor. The final histopathologic examination revealed a bronchogenic cyst. Although retroperitoneal bronchogenic cysts are rare, they should be considered in the differential diagnosis of retroperitoneal cystic tumors. The preoperative diagnosis is difficult, but a contrast-enhanced CT scan or (18)F-FDG PET/CT scan may be useful for differentiating hyperattenuated cysts from other soft tissue masses.

19.
Clin Nucl Med ; 39(3): e193-6, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23989446

RESUMEN

INTRODUCTION: Increased F-FDG uptake is often seen in soft-tissue components or in neuronal components of teratomas, which makes differentiation of mature and immature teratoma difficult using only F-FDG uptake. The distribution pattern of fat and calcification in teratomas is characteristic on CT, which can also be well seen on attenuation correction CT (AC-CT). We hypothesize that the fat and calcification distribution patterns on AC-CT taken during PET/CT will provide additional diagnostic information in differentiating between mature and immature teratomas. PATIENTS AND METHODS: This retrospective study included 34 patients (44 masses; mean age 32 ± 16.3 years, range 0.2-70 years) who underwent F-FDG PET/CT before surgical resection for teratomas. F-FDG equal to or higher than the liver was visually considered positive. AC-CT images acquired during PET/CT were reviewed for calcification and fat distribution patterns. AC-CT findings for immature teratomas were scattered fat and/or disperse coarse calcification. Pathologic results were categorized into mature and immature teratomas. SUVmax and AC-CT findings were correlated with pathologic results. RESULTS: Out of the 44 lesions, 11 teratomas were immature, with higher F-FDG uptake in these tumors (7.8 ± 4.10 vs. 2.1 ± 2.28, P < 0.001). SUVmax higher than 2.8 were 91% accurate, but fat and/or calcification patterns on AC-CT were extremely helpful in reducing false-positive findings based on F-FDG uptake alone. CONCLUSION: Characteristic fat and calcification patterns on AC-CT of PET/CT were extremely helpful in differentiating mature from immature teratomas, especially in mature teratomas with increased F-FDG uptake. This can potentially reduce unnecessary radiation exposure from additional contrast-enhanced CT.


Asunto(s)
Fluorodesoxiglucosa F18 , Imagen Multimodal , Tomografía de Emisión de Positrones , Teratoma/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Niño , Preescolar , Demografía , Diagnóstico Diferencial , Humanos , Lactante , Persona de Mediana Edad , Adulto Joven
20.
Nucl Med Mol Imaging ; 48(2): 130-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24900153

RESUMEN

PURPOSE: To determine whether persisting cervical fluorodeoxyglucose (FDG) uptake after concurrent chemoradiotherapy (CCRT) for cervical cancer can reflect residual malignancy. METHODS: F-FDG PET/CT was performed before and after CCRT in 136 patients with cervical cancer. The maximum and mean standardized uptake values (SUVmax and SUVmean) were recorded from PET/CT scans performed pre- and post-treatment. SUVs were correlated with treatment response after CCRT. Final treatment response was determined by MRI and further follow-up PET/CT. One hundred four of 136 patients underwent pelvic MRI, and 32 of 136 patients underwent further follow-up PET/CT. Patients were classified into two categories: patients with residual tumor or patients without residual tumor (complete responder). Pre- and post-treatment serum squamous cell carcinoma antigen (SCC) levels were also recorded for comparison. The optimal cutoff value of SUVmax for predicting residual cervical tumor was determined using receiver-operating characteristic (ROC) analysis. RESULTS: Of 136 patients, 124 showed complete response on further follow-up studies and 12 were confirmed to have residual tumor. The post-treatment SUVmax and pre-/post-treatment SUVmean of complete responders were significantly lower than those of patients with residual tumor: 2.5 ± 0.8 and 7.2 ± 4.2/1.9 ± 0.7 for complete responders and 5.7 ± 2.6 and 12.8 ± 6.9/3.7 ± 0.7 for patients with residual tumor (p < 0.05). The pre-treatment SUVmax and pre-/post-treatment serum SCC levels of the complete responders tended to be lower than those of patients with residual tumor, but this did not have statistical significance. Using ROC analysis, an optimal cutoff SUVmax of 4.0 on the post-treatment PET/CT yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 92 %, 94 %, 61 %, and 99 %, respectively (p < 0.001). CONCLUSIONS: Persistent cervical FDG uptake in(18)F-FDG PET/CT after CCRT for cervical cancer may be caused by residual tumor or post-therapy inflammation. A higher cutoff SUVmax than conventional criteria for cervical cancer in post-CCRT PET/CT might help to detect residual tumor.

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