Kazuo Awai - Academia.edu (original) (raw)
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ISCTE - University Institute of Lisbon (ISCTE-IUL)
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Papers by Kazuo Awai
American Journal of Roentgenology, 2010
C a r d io p u lm o n a r y I m ag i ng • O r ig i n a l R e s e a rc h
Radiology, 2006
To evaluate the effect of a computer-aided diagnosis (CAD) system on the diagnostic performance o... more To evaluate the effect of a computer-aided diagnosis (CAD) system on the diagnostic performance of radiologists for the estimation of the malignancy of pulmonary nodules on thin-section helical computed tomographic (CT) scans. Materials and Methods: The institutional review board approved use of the CT database; informed specific study-related consent was waived. The institutional review board approved participation of radiologists; informed consent was obtained from all observers. Thirty-three (18 malignant, 15 benign) pulmonary nodules of less than 3.0 cm in maximal diameter were evaluated. Receiver operating characteristic (ROC) analysis with a continuous rating scale was used to compare observer performance for the estimation of the likelihood of malignancy first without and then with the CAD system. The participants were 10 board-certified radiologists and nine radiology residents. Results: For all 19 participants, the mean area under the best-fit ROC curve (A z) values achieved without and with the CAD system were 0.843 Ϯ 0.097 (standard deviation) and 0.924 Ϯ 0.043, respectively. The difference was significant (P ϭ .021). The mean A z values achieved without and with the CAD system were 0.910 Ϯ 0.052 and 0.944 Ϯ 0.040, respectively, for the 10 board-certified radiologists (P ϭ .190) and 0.768 Ϯ 0.078 and 0.901 Ϯ 0.036, respectively, for the nine radiology residents (P ϭ .009). Conclusion: Use of the CAD system significantly (P ϭ .009) improved the diagnostic performance of radiology residents for assessment of the malignancy of pulmonary nodules; however, it did not improve that of board-certified radiologists.
Neuroradiology, 2011
Introduction The purpose of this study was to assess the clinical feasibility of diffusion tensor... more Introduction The purpose of this study was to assess the clinical feasibility of diffusion tensor imaging (DTI) for the evaluation of peripheral nerves in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Methods Using a 3-T magnetic resonance imaging scanner, we obtained DTI scans of the tibial nerves of 10 CIDP patients and 10 sex-and age-matched healthy volunteers. We prepared fractional anisotropy (FA) maps, measured the FA values of tibial nerves, and compared these values in the two study groups. In nine patients, we also performed tibial nerve conduction studies and analyzed the correlation between the FA values and parameters of the nerve conduction study.
American Journal of Roentgenology, 2010
C a r d io p u lm o n a r y I m ag i ng • O r ig i n a l R e s e a rc h
Radiology, 2006
To evaluate the effect of a computer-aided diagnosis (CAD) system on the diagnostic performance o... more To evaluate the effect of a computer-aided diagnosis (CAD) system on the diagnostic performance of radiologists for the estimation of the malignancy of pulmonary nodules on thin-section helical computed tomographic (CT) scans. Materials and Methods: The institutional review board approved use of the CT database; informed specific study-related consent was waived. The institutional review board approved participation of radiologists; informed consent was obtained from all observers. Thirty-three (18 malignant, 15 benign) pulmonary nodules of less than 3.0 cm in maximal diameter were evaluated. Receiver operating characteristic (ROC) analysis with a continuous rating scale was used to compare observer performance for the estimation of the likelihood of malignancy first without and then with the CAD system. The participants were 10 board-certified radiologists and nine radiology residents. Results: For all 19 participants, the mean area under the best-fit ROC curve (A z) values achieved without and with the CAD system were 0.843 Ϯ 0.097 (standard deviation) and 0.924 Ϯ 0.043, respectively. The difference was significant (P ϭ .021). The mean A z values achieved without and with the CAD system were 0.910 Ϯ 0.052 and 0.944 Ϯ 0.040, respectively, for the 10 board-certified radiologists (P ϭ .190) and 0.768 Ϯ 0.078 and 0.901 Ϯ 0.036, respectively, for the nine radiology residents (P ϭ .009). Conclusion: Use of the CAD system significantly (P ϭ .009) improved the diagnostic performance of radiology residents for assessment of the malignancy of pulmonary nodules; however, it did not improve that of board-certified radiologists.
Neuroradiology, 2011
Introduction The purpose of this study was to assess the clinical feasibility of diffusion tensor... more Introduction The purpose of this study was to assess the clinical feasibility of diffusion tensor imaging (DTI) for the evaluation of peripheral nerves in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Methods Using a 3-T magnetic resonance imaging scanner, we obtained DTI scans of the tibial nerves of 10 CIDP patients and 10 sex-and age-matched healthy volunteers. We prepared fractional anisotropy (FA) maps, measured the FA values of tibial nerves, and compared these values in the two study groups. In nine patients, we also performed tibial nerve conduction studies and analyzed the correlation between the FA values and parameters of the nerve conduction study.