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1.
Sci Rep ; 13(1): 8647, 2023 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-37244951

RESUMO

Fuchs endothelial corneal dystrophy (FECD) is the most common inherited corneal disease. Fibrillar focal excrescences called guttae and corneal edema due to corneal endothelial cell death result in progressive vision loss. Multiple genetic variants have been reported, but the pathogenesis of FECD is not fully understood. In this study, we used RNA-Seq to analyze differential gene expression in the corneal endothelium obtained from patients with FECD. Differential expression analysis of transcriptomic profiles revealed that expression of 2366 genes (1092 upregulated and 1274 downregulated genes) was significantly altered in the corneal endothelium of patients with FECD compared to healthy subjects. Gene ontology analysis demonstrated an enrichment of genes involved in extracellular matrix (ECM) organization, response to oxidative stress, and apoptotic signaling. Several pathway analyses consistently indicated the dysregulation of ECM-associated pathways. Our differential gene expression findings support the previously proposed underlying mechanisms, including oxidative stress and apoptosis of endothelial cells, as well as the phenotypic clinical FECD hallmark of ECM deposits. Further investigation focusing on differentially expressed genes related to these pathways might be beneficial for elucidating mechanisms and developing novel therapies.


Assuntos
Distrofia Endotelial de Fuchs , Humanos , Distrofia Endotelial de Fuchs/metabolismo , Células Endoteliais/metabolismo , RNA-Seq , Endotélio Corneano/patologia , Córnea/patologia
2.
Kyobu Geka ; 76(3): 230-233, 2023 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-36861281

RESUMO

Criss-cross heart is an extreamly rare anomaly characterized by abnormal rotation of the heart on its long axis. Almost always there are associated cardiac anomalies such as pulmonary stenosis, ventricular septal defect (VSD) and ventriculoarterial connection discord, and most cases are candidates for Fontan procedure due to hypoplasia of right ventricle or straddling atrioventricular valve. We report a case of arterial switch operation for criss-cross heart with muscular ventricular septal defect. The patient was diagnosed with criss-cross heart, double outlet right ventricle, subpulmonary VSD, muscular VSD and patent ductus arteriosus (PDA). PDA ligation and pulmonary artery banding (PAB) was performed in the neonatal period, and an arterial switch operation (ASO) was planed at 6 months of age. Preoperative angiography showed nearly normal right ventricular volume and echocardiography showed normal subvalvular structures of atrioventricular valves. ASO, intraventricular rerouting and muscular VSD closure by sandwitch technique were successfully performed.


Assuntos
Transposição das Grandes Artérias , Coração Entrecruzado , Dupla Via de Saída do Ventrículo Direito , Permeabilidade do Canal Arterial , Comunicação Interventricular , Recém-Nascido , Humanos , Comunicação Interventricular/complicações , Comunicação Interventricular/diagnóstico por imagem , Comunicação Interventricular/cirurgia , Coração , Dupla Via de Saída do Ventrículo Direito/complicações , Dupla Via de Saída do Ventrículo Direito/diagnóstico por imagem , Dupla Via de Saída do Ventrículo Direito/cirurgia
3.
Kyobu Geka ; 76(2): 122-125, 2023 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-36731845

RESUMO

We successfully performed resection of a large asymptomatic left atrial appendage aneurysm( LAAA) under non-cardiac arrest. Although the patient was asymptomatic, chest X-ray showed projection of the third left aortic arch, and computed tomography angiography showed a huge left atrial appendage aneurysm. Therefore, we decided to perform LAAA resection via a partial median sternotomy. Aneurysmectomy was performed by placing the patient on pump beating heart. The size of the resected aneurysm was approximately 80 mm in diameter. Because the base of the LAAA was constricted and the tissue was not fragile, resection was performed using an automatic excision anastomosis device( Echelon Flex). The patient's postoperative course was uneventful. Left atrial appendage aneurysm is believed to be congenital;however, it is often detected in adulthood. Long-term follow-up is necessary to ensure maintenance of optimal cardiac function.


Assuntos
Apêndice Atrial , Procedimentos Cirúrgicos Cardíacos , Aneurisma Cardíaco , Humanos , Procedimentos Cirúrgicos Cardíacos/métodos , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Tomografia Computadorizada por Raios X , Aneurisma Cardíaco/diagnóstico por imagem , Aneurisma Cardíaco/cirurgia , Angiografia por Tomografia Computadorizada
4.
Kyobu Geka ; 75(8): 607-611, 2022 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-35892300

RESUMO

Congenitally corrected transposition of the great arteries( ccTGA) is a rare complex cardiac anomaly, where the heart twist and the ventricles are reversed during fetal development. Through a double switch operation (DSO), the morphologic left ventricle (LV) can be corrected back to pumping blood for systemic circulation. For successful DSO, the morphologic LV may need training with a pulmonary artery banding (PAB) before surgery. There have been reports of early LV failure in patients who underwent PAB training and a DSO, due to rapid pressure loading on the myocardium. We reported a case of DSO in a 16 years old male after prolonged LV training with a loose PAB. He was scheduled for a DSO, due to severe tricuspid regurgitation( TR). At eight years old, he underwent a loose PAB training with left ventricular pressure to right ventricular pressure ratio (LVp/RVp) of 0.5. After eight years, the LVp/RVp ratio increased to 0.77;he successfully underwent a DSO with good LV function.


Assuntos
Transposição das Grandes Artérias , Transposição dos Grandes Vasos , Adolescente , Criança , Transposição das Grandes Artérias Corrigida Congenitamente , Ventrículos do Coração/cirurgia , Humanos , Masculino , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Transposição dos Grandes Vasos/cirurgia , Resultado do Tratamento
5.
Cornea ; 41(2): 171-176, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34369393

RESUMO

PURPOSE: The purpose of this article was to study the clinical, optical, and morphological correlates of visual function in patients with Fuchs endothelial corneal dystrophy (FECD). METHODS: The case records were analyzed for patients diagnosed with FECD between September 2019 and March 2020. The best-corrected visual acuity (BCVA) was recorded as decimal visual acuity and converted to the logarithm of the minimum angle of resolution units. Contrast sensitivity was measured with the Pelli-Robson contrast sensitivity test. Corneal alterations, including central corneal thickness, depression of the posterior cornea, and corneal densitometry values, were evaluated using Scheimpflug images. Corneal epithelial thickness was measured by spectral-domain optical coherence tomography. RESULTS: A total of 107 eyes of 61 patients (18 male and 43 female) with FECD were retrospectively investigated. The Spearman rank correlation coefficient showed moderate correlation between BCVA and contrast sensitivity (ρ = -0.66, P < 0.001), with some patients maintaining relatively good BCVA but having reduced contrast sensitivity. Logistic regression analysis demonstrated that age, central corneal thickness, depression of the posterior cornea, and epithelial thickening were negatively associated with contrast sensitivity but not with BCVA. CONCLUSIONS: Contrast sensitivity is a useful tool for assessing visual dysfunction and should be incorporated into the assessment protocol of patients with FECD. Alterations in the cornea, including central corneal thickness, depression of the posterior cornea, and epithelial thickening, might be objective parameters that can help the clinician in grading the severity of the disease and tracking its progression.


Assuntos
Sensibilidades de Contraste/fisiologia , Córnea/diagnóstico por imagem , Paquimetria Corneana/métodos , Distrofia Endotelial de Fuchs/diagnóstico , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Distrofia Endotelial de Fuchs/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
6.
Cell Tissue Bank ; 22(4): 551-562, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33860873

RESUMO

In 2013, a clinical trial was initiated to investigate cell therapy for the treatment of corneal endothelial decompensation. Cultivating human corneal endothelial cells (CECs) while maintaining their functional phenotype is challenging; therefore, establishment of a confirmed protocol is pivotal for obtaining approval from regulatory authorities for use of cellular therapy products. In this study, we evaluated organ culture (OC) as a storage method for donor corneas used as a raw material for establishing CEC cultures. OC allows storage of corneal tissue for conventional corneal transplantation at 31-37 °C for up to 5 weeks, whereas storage at 4 °C is limited to 2 weeks. We investigated 20 pairs of corneas: one cornea of each pair was stored in OC and the other in cold storage for one week before CEC culture. In 15/20 cases, the CECs assumed a hexagonal sheet-like monolayer structure and expressed endothelial function-related markers. CECs were also obtained from OC corneas that had been stored for 1 (n = 19) and 2 (n = 7) months. As a further test, CECs were cultivated from 5 OC corneas that had been transported from France to Japan. In all cases, these corneas, even after international transport, generated CECs that formed hexagonal monolayers with clinically applicable and sufficiently high cell densities. In conclusion, the CEC cultures required for endothelial cell therapy can be obtained from OC corneas without changing the standard storage operating procedures of the eye banks.


Assuntos
Córnea , Células Endoteliais , Contagem de Células , Técnicas de Cultura de Células , Endotélio Corneano , Estudos de Viabilidade , Humanos , Técnicas de Cultura de Órgãos , Preservação de Órgãos
7.
Cornea ; 40(11): 1445-1452, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33859091

RESUMO

PURPOSE: The aim of this study was to investigate the immune cells on corneal endothelium of the graft in patients who underwent penetrating keratoplasty (PK), Descemet-stripping endothelial keratoplasty (DSEK), and Descemet membrane endothelial keratoplasty (DMEK). METHODS: A total of 43 eyes of 43 patients who underwent PK (17 eyes), DSEK (13 eyes), and DMEK (13 eyes) and who did not show any sign of graft rejection were recruited for the study. Patients who underwent cataract surgery (26 eyes) served as controls. Immune cells on the corneal endothelium were examined with laser in vivo confocal microscopy. The associations between the corneal endothelial cell density, type of keratoplasty, aqueous flare, repeated keratoplasty, and time after surgery versus the density of immune cells were investigated. RESULTS: In vivo confocal microscopy visualized similar numbers of immune cells on the corneal endothelium in the PK, DSEK, and DMEK groups, whereas no immune cells were observed in any of the control patients. The numbers of immune cells tended to be higher in regraft eyes in the PK group (P = 0.00221) and in the DSEK group (P = 0.168) than those in the primary graft eyes. No significant association was found between the density of immune cells and corneal endothelial cell density in the PK, DSEK, and DMEK groups. CONCLUSIONS: Immune cells were observed to a similar extent in the eyes of PK, DSEK, and DMEK subjects even in the absence of any clinical sign of immune rejection. A further prospective longitudinal study will evaluate the effect of immune cells on long-term graft survival and the risk for graft rejection.


Assuntos
Doenças da Córnea/cirurgia , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Endotélio Corneano/transplante , Imunidade Celular , Doadores de Tecidos , Acuidade Visual , Adolescente , Adulto , Idoso , Doenças da Córnea/diagnóstico , Doenças da Córnea/imunologia , Endotélio Corneano/diagnóstico por imagem , Endotélio Corneano/imunologia , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Adulto Jovem
8.
Sci Data ; 7(1): 407, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33219220

RESUMO

The corneal endothelium maintains corneal transparency; consequently, damage to this endothelium by a number of pathological conditions results in severe vision loss. Publicly available expression databases of human tissues are useful for investigating the pathogenesis of diseases and for developing new therapeutic modalities; however, databases for ocular tissues, and especially the corneal endothelium, are poor. Here, we have generated a transcriptome dataset from the ribosomal RNA-depleted total RNA from the corneal endothelium of eyes from seven Caucasians without ocular diseases. The results of principal component analysis and correlation coefficients (ranged from 0.87 to 0.96) suggested high homogeneity of our RNA-Seq dataset among the samples, as well as sufficient amount and quality. The expression profile of tissue-specific marker genes indicated only limited, if any, contamination by other layers of the cornea, while the Smirnov-Grubbs test confirmed the absence of outlier samples. The dataset presented here should be useful for investigating the function/dysfunction of the cornea, as well as for extended transcriptome analyses integrated with expression data for non-coding RNAs.


Assuntos
Endotélio Corneano/metabolismo , Transcriptoma , Humanos , RNA Ribossômico , RNA-Seq , População Branca
9.
Surg Case Rep ; 6(1): 237, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32990806

RESUMO

BACKGROUND: Discordant atrioventricular connection with concordant ventriculoarterial connection, otherwise known as isolated ventricular inversion (IVI), is an extremely rare congenital cardiac malformation. Reports on the corrective surgery for this anomaly in neonates are few, and the procedure is difficult and complicated. Herein, we report our use of atrial septostomy as a palliative procedure followed by corrective surgery for the repair of neonatal IVI with situs ambiguous(inversus) morphology. CASE PRESENTATION: A 2-day-old girl weighing 3.5 kg was admitted to our hospital with a low oxygen saturation (SpO2) of 70% She was diagnosed with IVI [situs ambiguous(inversus), D-loop, and D-Spiral], atrial septal defect, patent ductus arteriosus (PDA), interrupted inferior vena cava with azygos continuation to the left superior vena cava (SVC), and polysplenia by transthoracic echocardiography and cardiac computed tomography. We planned to perform corrective surgery and decided to first increase interatrial mixing by performing surgical atrial septostomy and PDA ligation 7 days after birth. However, despite the surgical septostomy, pulmonary venous blood flowed toward the right ventricle via the tricuspid valve rather than toward the left-sided atrium and hypoxemia persisted. We decided to perform the intra-atrial switch procedure at the age of 17 days via a re-median sternotomy. The cardiopulmonary bypass (CPB) circuit was established with ascending aorta and venous drainage through the SVC and hepatic veins. Utilizing a left-sided atrium(l-A) approach, a bovine pericardial patch was used for the intra-atrial baffle, which was trimmed into a trouser-shaped patch. Continuous suture using the patch was lying from the front of the right-sided upper pulmonary vein and rerouted SVC, hepatic vein, and coronary sinus to the tricuspid valve. Overall, CPB weaning proceeded smoothly; however, direct current cardioversion was performed for junctional ectopic tachycardia. The postoperative course was uneventful. Her postoperative SpO2 improved (approximately 99-100%); overall, the patient showed clinical improvement. Discharge echocardiography showed normal biventricular function and an intact atrial baffle with no venoatrial or atrioventricular obstruction. CONCLUSION: We successfully performed an intra-atrial switch procedure for isolated ventricular inversion in a neonate. Long-term follow-up will be necessary to ensure the maintenance of optimal cardiac function.

10.
Kyobu Geka ; 73(8): 614-617, 2020 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-32879292

RESUMO

We successfully performed the DKS+Rastelli procedure for Taussig-Bing anomaly (TBA) in an adult. A 22-year-old male was admitted to our hospital due to persistent lower leg edema and dyspnea. He had been diagnosed with TBA. On physical examination, his peripheral oxygen saturation (Spo2) was 73% in room air. Chest X-ray showed congestive heart failure. We decided to perform arterial switch operation (ASO) and VSD closure. Operation was performed via a re-median sternotomy. It seemed to be very difficult to dissect and mobilize great arteries and coronary arteries for ASO. Therefore, we decided to perform DKS, aortic valve closure, left ventricule to pulmonary artery rerouting, and right ventricular outflow reconstruction using expanded polytetrafluoroethylene (ePTFE) valved conduit. Postoperative course was uneventful, an oxygen saturation was improved. At 5 years after surgery, his oxygen saturation is about 97% in room air and he is now doing well without any symptoms. Long-term follow-up is necessary to ensure maintenance of optimal function.


Assuntos
Transposição das Grandes Artérias , Dupla Via de Saída do Ventrículo Direito , Transposição dos Grandes Vasos , Adulto , Valva Aórtica , Ventrículos do Coração , Humanos , Lactente , Masculino , Artéria Pulmonar , Adulto Jovem
11.
Kyobu Geka ; 73(8): 627-630, 2020 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-32879295

RESUMO

A 15-year-old boy with Noonan syndrome, who had been diagnosed with hypertrophic cardiomyopathy (HCM) at 4 and treated by drugs, was referred to our hospital because of progression of left ventricular outflow tract obstruction (LVOTO). Transthoracic echocardiogram (TTE) revealed left ventricular hypertrophy( LVH), LVOTO( systolic gradient:102 mmHg), and systolic anterior motion of the mitral valve( SAM) with mild mitral regurgitation(MR). We performed septal myectomy by transaortic and transapical approaches. Postoperative TTE revealed significant reduction in left ventricular outflow tract (LVOT) gradient (9 mmHg), resolution of SAM, and reduction in MR grade. The postoperative course was uneventful except for transient atrial tachyarrhythmia. Myectomy for HCM in a patient with Noonan syndrome is rare. This case suggests that myectomy is useful for the patients with Noonan syndrome.


Assuntos
Cardiomiopatia Hipertrófica , Insuficiência da Valva Mitral , Síndrome de Noonan , Obstrução do Fluxo Ventricular Externo , Adolescente , Ecocardiografia , Humanos , Masculino , Valva Mitral/diagnóstico por imagem
12.
Eye (Lond) ; 34(5): 880-885, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31554942

RESUMO

PURPOSE: To evaluate the association of single nucleotide polymorphisms (SNPs) and the intronic expansion of a trinucleotide repeat (TNR) in the TCF4 gene with Fuchs endothelial corneal dystrophy (FECD) in a Thai population. METHODS: In total, 54 Thai FECD patients and 54 controls were recruited for the study. Five SNPs (rs613872, rs2123392, rs17089887, rs1452787, and rs1348047), previously reported to be associated with FECD, were genotyped by direct sequencing. The repeat length was determined by direct sequencing of PCR-amplified DNA (a short tandem repeat; STR assay) and by triplet repeat primed PCR (TP-PCR). RESULTS: Only one of the 54 patients with FECD harboured rs613872 (1.9%). Four SNPs (rs2123392, rs17089887, rs1452787, and rs1348047), which are not rare polymorphisms in the Thai population, were found in approximately half of the patients. Of the 54 patients, 21 (1 homozygous and 20 heterozygous patients; 39%) harboured a TNR ≥ 40, while 33 patients (61%) harboured a TNR < 40. CONCLUSIONS: The association of TNR expansion in TCF4 with FECD is shown for the first time in the Thai population. The intronic TNR expansion identified in various ethnic groups underlines the importance of expansion as a potent pathophysiological cause of FECD.


Assuntos
Distrofia Endotelial de Fuchs , Distrofia Endotelial de Fuchs/genética , Predisposição Genética para Doença , Humanos , Tailândia , Fator de Transcrição 4/genética , Expansão das Repetições de Trinucleotídeos/genética
13.
Cornea ; 38(7): 799-805, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30973406

RESUMO

PURPOSE: To investigate single nucleotide polymorphisms (SNPs) and trinucleotide repeat (TNR) expansion in the transcription factor 4 (TCF4) gene in a large cohort of German patients with Fuchs endothelial corneal dystrophy (FECD). METHODS: Genomic DNA was obtained from 398 patients with FECD and from 58 non-FECD controls. Thirty-seven previously reported SNPs were evaluated by genotyping. The 398 FECD samples were analyzed for TNR expansions by short tandem repeat assays and Southern blotting. The possible associations between the TNR length and clinical parameters (age, sex, visual acuity, and central corneal thickness) were analyzed in 132 patients. RESULTS: The SNPs in COL8A2, TCF8, LOXHD1, and AGBL1 showed no heterogeneity in 36 cases, although SLCA411 showed 3 nonsense mutations. SNPs were detected for TCF4 (rs613872, rs2123392, rs17089887, rs1452787, and rs1348047), but only rs613872 showed a significant association with FECD (P = 9.93 × 10). Overall, 315/398 (79%) patients harbored TNR lengths >50, whereas no non-FECD controls harbored TNR lengths >50. The TCF4 SNP rs613872 genotype was TT: 39 (67%), TG: 18 (31%), and GG: 1 (2%) in non-FECD controls; TT: 39 (47%), TG: 38 (46%), and GG: 6 (7%) in FECD cases harboring TNR <50; and TT: 23 (8%), TG: 224 (79%), and GG: 38 (13%) in FECD cases harboring TNR >50 (P = 2.93 × 10). No significant association was detected between the TNR length and clinical parameters. CONCLUSIONS: Our large German cohort demonstrated a significant association between the risk allele G in rs613872 and FECD, irrespective of TNR expansion, although this risk allele was more frequent in FECD cases with TNR expansion than without.


Assuntos
Distrofia Endotelial de Fuchs/genética , Predisposição Genética para Doença , Fator de Transcrição 4/genética , Expansão das Repetições de Trinucleotídeos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Adulto Jovem
14.
Invest Ophthalmol Vis Sci ; 60(2): 779-786, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30811544

RESUMO

Purpose: CTG trinucleotide repeat (TNR) expansion is frequently found in transcription factor 4 (TCF4) in Fuchs' endothelial corneal dystrophy (FECD), though the effect of TNR expansion on FECD pathophysiology remains unclear. The purpose of this study was to evaluate the effect of TNR expansion on TCF4 expression in corneal endothelium of patients with FECD. Methods: Peripheral blood DNA and Descemet membrane with corneal endothelium were obtained from 203 German patients with FECD. The CTG TNR repeat length in TCF4 was determined by short tandem repeat (STR) assays and Southern blotting using genomic DNA. Genotyping of rs613872 in TCF4 was performed by PCR. TCF4 mRNA levels in corneal endothelium were evaluated by quantitative PCR using three different probes. Control corneal endothelial samples were obtained from 35 non-FECD subjects. Results: The STR assay and Southern blotting showed that 162 of the 203 patients with FECD (80%) harbored CTG trinucleotide repeat lengths larger than 50. Quantitative PCR using all three probes demonstrated that TCF4 mRNA is significantly upregulated in the corneal endothelium of patients with FECD, regardless of the presence of TNR expansion. However, the length of the TNR tended to show a positive correlation with TCF4 expression level. No correlation was shown between the genotype of TCF4 SNP, rs613872, and the level of TCF4 expression. Conclusions: Our findings showed that TCF4 mRNA is upregulated in the corneal endothelium of patients with FECD. Further studies on the effects of TCF4 upregulation on corneal endothelial cell function will aid in understanding the pathophysiology of FECD.


Assuntos
Distrofia Endotelial de Fuchs/genética , Regulação da Expressão Gênica/fisiologia , RNA Mensageiro/genética , Fator de Transcrição 4/genética , Expansão das Repetições de Trinucleotídeos , Adulto , Idoso , Idoso de 80 Anos ou mais , Southern Blotting , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
15.
Front Psychol ; 7: 1553, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27774080

RESUMO

Although viewing multiple stacks of medical images presented on a display is a relatively new but useful medical task, little is known about this task. Particularly, it is unclear how radiologists search for lesions in this type of image reading. When viewing cluttered and dynamic displays, continuous motion itself does not capture attention. Thus, it is effective for the target detection that observers' attention is captured by the onset signal of a suddenly appearing target among the continuously moving distractors (i.e., a passive viewing strategy). This can be applied to stack viewing tasks, because lesions often show up as transient signals in medical images which are sequentially presented simulating a dynamic and smoothly transforming image progression of organs. However, it is unclear whether observers can detect a target when the target appears at the beginning of a sequential presentation where the global apparent motion onset signal (i.e., signal of the initiation of the apparent motion by sequential presentation) occurs. We investigated the ability of radiologists to detect lesions during such tasks by comparing the performances of radiologists and novices. Results show that overall performance of radiologists is better than novices. Furthermore, the temporal locations of lesions in CT image sequences, i.e., when a lesion appears in an image sequence, does not affect the performance of radiologists, whereas it does affect the performance of novices. Results indicate that novices have greater difficulty in detecting a lesion appearing early than late in the image sequence. We suggest that radiologists have other mechanisms to detect lesions in medical images with little attention which novices do not have. This ability is critically important when viewing rapid sequential presentations of multiple CT images, such as stack viewing tasks.

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