Third-Generation Capsule Endoscopy Outperforms Second-Generation Based on the Detectability of Esophageal Varices

Background and Aim. The third-generation capsule endoscopy (SB3) was shown to have better image resolution than that of SB2. The aim of this study was to compare SB2 and SB3 regarding detectability of esophageal varices (EVs). Methods. Seventy-six consecutive liver cirrhosis patients (42 men; mean age: 67 years) received SB3, and 99 (58 men; mean age, 67 years old) received SB2. All patients underwent esophagogastroduodenoscopy within 1 month prior to capsule endoscopy as gold standard for diagnosis. The diagnosis using SB3 and SB2 for EVs was evaluated regarding form (F0–F3), location (Ls, Lm, and Li), and the red color (RC) sign of EVs. Results. SB2 and SB3 did not significantly differ on overall diagnostic rates for EV. Sensitivity, specificity, positive predictive value, and negative predictive value of SB2/SB3 for EV diagnosis were, respectively, 65%/81%, 100%/100%, 100%/100%, and 70%/62%. However, the diagnostic rates for EV form F1 were 81% using SB3 and 52% using SB2 (P=0.009). Further, the diagnostic rates for Ls/Lm varices were 79% using SB3 and 81% using SB2, and, for Li, varices were 84% using SB3 and 52% using SB2 (P=0.02). Conclusion. SB3 significantly improved the detectability of EVs compared with SB2

Cauda equina movement during the Valsalva maneuver in two patients with Lumbar spinal canal stenosis

Lumbar spinal canal stenosis (LSS) is a common spinal disorder among older people. Some LSS patients say that their pain worsens when they lift heavy objects. The Valsalva maneuver is the optimal breathing pattern for producing maximal force. Herein, we present two cases of LSS where the movement of the cauda equina was observed during the Valsalva maneuver. Case Summary: Case 1: A 74-year-old female with a history of LSS presented to our Department of Urology with frequent urination. The patient was diagnosed as having uterine and bladder prolapse. Pelvic cine MRI scan was conducted for detailed evaluation. While the Valsalva maneuver was performed to diagnose pelvic organ prolapses, we observed movement of the cauda equina. Spine MRI and CT, performed one year before presentation, showed severe LSS due to degenerative spondylolisthesis. Case 2: A 73-year-old male underwent radical prostatectomy for prostate cancer. A follow-up cine MRI to confirm urethrorrhea showed the cauda equina moving during the Valsalva maneuver. Moderate LSS due to degenerative spondylolisthesis was retrospectively found on abdominal CT performed before prostatectomy. Conclusion: The findings of our report suggest that movement of the cauda equina during the Valsalva maneuver may be implicated in LSS

Real time calculation of the head related transfer function based on the boundary element method

Presented at the 8th International Conference on Auditory Display (ICAD), Kyoto, Japan, July 2-5, 2002.In order to develop the 3D auditory display using a head phone which allow head movement, real time calculation of the head related transfer function (HRTF) is necessary. In the conventional studies, the calculations are performed approximately based on the mathematical model by regarding the head as the sphere shape. Although the boundary element method is also possible to calculate the transfer function by solving the wave equation from the accurate boundary condition of the head including the shape of the face and the ears measured by the 3D scanner, it is thought to be impossible to calculate it in real time because the amount of the calculation is too big. In this study, we discuss a new calculation method of the HRTF based on the reciprocity principle which enables significant speed-up of the calculation.The demonstrations are available at the website: http://acoust.archi.kyoto-u.ac.jp/HRTF