Autorrelato de dificuldades auditivas e desempenho em teste de fala com ruído - o que podemos encontrar por trás de um audiograma "normal"? / Self-reported hearing difficulties and speech-in-noise test performance - what can we find behind a "normal" audiogram?

RESUMO Objetivo Investigar a queixa de dificuldade de inteligibilidade na presença de ruído, em sujeitos sem perda auditiva e compará-la com o desempenho em um teste de fala no ruído. Método A casuística foi constituída por 39 sujeitos de 18 a 59 anos e 11 meses foram divididos em quatro grupos em função da década de vida. Estes foram submetidos à audiometria, timpanometria, testes de processamento auditivo, mini exame do estado mental, autorrelato da percepção auditiva com o Pt-AIADH e a um teste de sentenças no silêncio e no ruído. Resultados Todos os grupos pontuaram para os domínios do Pt-AIADH, com maior pontuação média para o domínio de inteligibilidade no ruído. Houve diferenças entre o G18 vs G40, G18 vs G50, e G30 vs G50 para a autopercepção auditiva na inteligibilidade no ruído; e diferenças entre o G18 e os demais grupos no teste de fala com ruído, com menor relação sinal-ruído para os adultos mais velhos. Houve correlação moderada e significativa para a inteligibilidade no ruído e o teste de fala no ruído. Conclusão Normo-ouvintes de todas as faixas etárias estudadas apresentaram queixa de inteligibilidade no ruído. Quanto maior a dificuldade auditiva neste domínio pior o desempenho no teste de fala com ruído, sendo mais significativo em adultos de meia idade.

ABSTRACT Purpose To investigate complaints of difficulty understanding speech in the presence of noise in subjects without hearing loss and their performance on a speech-in-noise test. Methods Thirty-nine subjects aged 18 to 59 years and 11 months were divided into four groups according to their decade of life. They underwent audiometry, tympanometry, auditory processing tests, the Mini-Mental State Examination, a self-report on auditory perception combined with the Amsterdam Inventory for Auditory Disability and Handicap (Pt-AIADH), and a sentence test in silence and in noise. Results All groups scored high on the Pt-AIADH domains, with the highest average score obtained for the noise intelligibility domain. There were differences between G18 vs. G40, G18 vs. G50, and G30 vs. G50 for auditory self-perception in noise intelligibility, and differences between the youngest and all other groups on the speech-in-noise test in particular, with a lower signal-to-noise ratio for older adults. We also identified a moderate and significant correlation between intelligibility in noise and the speech-in-noise test. Conclusion Normal hearers of all age groups complained of intelligibility in noise. We found that the higher an individual's auditory difficulty in this domain, the worse their performance on the speech-in-noise test; this is especially true for middle-aged adults.

Planning principles analysis of 7T MRI room / 医疗卫生装备

Objective To draw up a plan for 7T MRI room based on analyzing its features.Methods 3T and 7T MRI machines were compared from the aspects of weight,installation,transport space requirement,dynamic interference and magnetic field distribution.The data related to 7T MRI were studied to plan the room rationally.Results When compared with 3T MRI,7T MRI had the weight increased by 4 to 6 times,the volume raised by 30％,more dynamic interference and irregular magnetic field distribution.The ground bearing of 7T room was higher than 40 t,the minimum installation space was larger than 54 m2,and shielding was executed by ferro-magnetic structure internally and by radio externally.Conclusion 7T MRI poses high requirements on the room,and plans have to be made at advance.

The detection of quality control for image quality of 3.0T MRI / 中国医学装备

Objective: To investigate the situation of quality control of 3.0T magnetic resonance imaging (MRI) system. Methods: A series of indicators, including signal noise ratio(SNR), image uniformity, resolution of long-scale contrast, resolution of space, linearity and quality control of slice thickness, of 3.0T MRI system were measured by using Magphan SMR170 phantom (made by the phantom laboratory in American) on the Discovery MR 750 w system which made by GE company of American. And a series of formula, including SNR=(Sinside-Soutside)÷SDinside, U∑=(1-Smax-Smin/Smax+Smin ×100%, linearity=LR-LM/LR×100%、thickness=half of height and width ×0.25, were used to calculate SNR, image uniformity, linearity and quality control of slice thickness, and all of these results were used to evaluate the situation of quality control of 3.0T MRI system. Results:The results revealed that SNR of 3.0T MRI was 105, the imaging uniformity achieved to 99.13%, the resolution of long-scale contrast was 5mm/0.5mm, the resolution of space was 6 LP/cm, linearity achieved to 0.89% and the deviation of slice thickness was 0.6mm. All of these indicators has achieved the standards of detection. Conclusion: Through detecting the SNR, imaging uniformity, resolution, linearity and the deviation of slice thickness of 3.0T MRI system, the performance of the MRI can be accurately obtained, and these contribute to ensure the equipment operating in ideal situation.

Planning principles analysis of 7T MRI room / 医疗卫生装备

Objective To draw up a plan for 7T MRI room based on analyzing its features.Methods 3T and 7T MRI machines were compared from the aspects of weight,installation,transport space requirement,dynamic interference and magnetic field distribution.The data related to 7T MRI were studied to plan the room rationally.Results When compared with 3T MRI,7T MRI had the weight increased by 4 to 6 times,the volume raised by 30％,more dynamic interference and irregular magnetic field distribution.The ground bearing of 7T room was higher than 40 t,the minimum installation space was larger than 54 m2,and shielding was executed by ferro-magnetic structure internally and by radio externally.Conclusion 7T MRI poses high requirements on the room,and plans have to be made at advance.

Preliminary research of reducing radiation dose In aortic CT angiography with 80 kV tube kilovoltage / 中华放射医学与防护杂志

Objective To evaluate the feasibility of 80 kV tube kilovoltage in aortic artery CT angiography with 256-slice CT. Methods A total of 62 patients undergoing aortic artery CTA were enrolled into this study and divided into conventional tube kilovoltage (120 kV, n = 31 ) and low tube kilovoltage (80 kV, n = 31 ). The signal-to-noise ratio (SNR) , contrast-to-noise ratio (CNR), volume CT dose index (CTDIvol) and effective dose (E) were evaluated, respectively. Results The mean image SNR was ( 35.92 ± 5.04) and ( 33.95 ± 8. 30) for conventional tube kilovoltage and low tube kilovoltage,respectively, with no significant difference (t = 1. 131, P =0. 263). The mean image CNR was (30. 32 ±4.78) and (28.71 ± 7.96 ) for conventional tube kilovoltage and low tube kilovoltage, respectively, with no significant difference ( t = 0. 964, P = 0. 339 ). The average effective dose ( E ) was ( 14. 28 ± 0.96 )mSv and (9. 72± 0. 81 )mSv for conventional tube kilovoltage and low tube kilovoltage, respectively, with significant difference ( t = 20. 12, P ＜ 0. 001 ). Conclusions 80 kV tube kilovoltage aortic artery CTA can reduce radiation dose by 31.9% , and contrast dose 50% ,and maintain image quality compared with 120 kV tube kilovoltage.

Impact of the number of diffusion gradient directions on measuring values in diffusion tensor imaging / 中国医学影像技术

Objective To assess the impact of different number of diffusion gradient directions (NDGD) of diffusion tensor imaging (DTI) on dispersion degree of fractional anisotropy (FA) values and signal-to-noise ratio (SNR) for adult brain tissues. Methods Eight healthy volunteers underwent DTI with 7 NDGD respectively, and the associated FA maps were obtained. Four region of interest (ROI) (genu and splenial of corpus callosum, genu and posterior limb of internal capsule) were chosen in white matter of FA maps, FA values and the corresponding SNRs of the ROIs were computed and analyzed with NDGD increasing. Results FA values within all ROIs did not change remarkably with NDGD increasing. Variance of FA value within two ROIs with high gray value (genu and splenial of corpus callosum) fluctuated randomly and SNR increased slightly, while variance of FA value within the ROIs with low gray value (genu and posterior limb of internal capsule) diminished significantly with NDGD increasing. Conclusion In clinical applications of DTI, an optimum NDGD for DTI data acquisition should be selected according to the ROIs in human brain to be inspected.

The Advantages of MR LAVA Sequence in Abdominal Examination at 3.0T Magneton / 实用放射学杂志

Objective To evaluate the advantages of MR LAVA multi-phase dynamic contrast enhancement in abdominal MRI.Methods 42 cases which clinically suspected liver lesions and 15 normal volunteers underwent MRI examination,including routine T_1WI and T_2WI scan,T_1W 2D and 3D FSPGR,LAV A multi-phase contrast enhancement.The detecting rates of 2D,3D and LAVA images were analysed and the signal noise ratio(SNR)of the liver and spleen was observed.Results 68 lesions were detected by LAVA sequence,the detecting rate was 100%,the accurate rate of diagnosis was 95.6%(65/68),while the detecting rates of the lesions were 91.2%(62/68)and 89.7%(61/68)with 3D T1W FSPGR and 2D T1W FSPGR,respectively,the accurate rates in diagnosing the lesions were 76.5%(52/68)and 70.6%(48/68)with 3D and 2D sequences,respectively.The SNR of liver,spleen of 15 normal volunteers were:29.68±2.31 in liver,36.21 ±3.67 in spleen at LAVA plain scan,46.21 ±5.32 in liver,58.75±4.68 in spleen at 2D T_1W FSPGR,19.79±2.23 in liver,23.63±2.14 in spleen at 3D T_1W FSPGR,41.75±5.13 in liver,57.96±6.13 in spleen at LAVA contrast enhancement,56.33±5.63 in liver,63.21±5.32 in spleen at 2D contrast enhancement,29.05±4.68 in liver,46.37±5.17 in spleen at 3D contrast enhancement sequence.Conclusion LAVA multi-phase dynamic contrast enhancement is more predominant than T1W 2D and 3D and 3D FSPGR in displaying the lesions and blood vessels of liver.

Feasibility of low radiation dose in craniocervical artery CT angiography with automatic tube current modulation / 中国普通外科杂志

Objective To evaluate the feasibility of automatic tube current modulation(ATCM) in craniocervical artery CT angiography with 256-slice CT,while maintaining the image quality.Methods Sixty patients undergoing craniocervical artery CTA were enrolled into this study,and were divided into conventional tube current group(250 mAs,group A,n=30) and low tube current group(ATCM,group B,n=30).The signal-to-noise ratio(SNR),contrast-to noise ratio(CNR),volume CT dose index(CTDIvol) and effective dose(ED) were evaluated respectively.Results The mean image SNR was(37.47?9.39) and(36.85?7.96) for group A and group B respectively,and was not significantly different(P=0.79).The mean image CNR was(32.13?9.06) and(31.86?7.66) for group A and group B respectively,and was not significantly different(P=0.90).The CT volume dose index(CTDI) was 16.5 mGy and 410.55?0.94mGy for group A and group B respectively,and was significantly different(P