Surgically treated Zenker’s diverticulum： Diverticulectomy and cricopharyngeal myotomy

　Zenker's diverticulum is a very rare disease among gastorointestinal diverticulum. We report a case of Zenker's diverticulum successfully treated with diverticulectomy and cricophalyngial myotomy. A 71-year-old male complained of aspirating water for two years. He was diagnosed as Zenker's diverticulum. Due to his severe symptoms, the operation was performed in an open-neck approach. The left recurrent laryngeal nerve was identified and preserved. An incision was made in the diverticulum wall, and the internal diameter of normal cervical esophagus was measured. The diverticulum was then excised with an automatic suture device in the minor axis direction of the esophagus. A cricopharyngeal myotomy was conducted, because this muscle was fibrotic and stiffened. The patient's symptoms disappeared after the operation. Diverticulectomy and cricopharyngeal myotomy through an open-neck approach is a safe and reliable method that follows, direct access to the diverticulum and recurrent laryngeal nerve

Depth of interaction measured with LYSO (Ce) scintillator in a new method

　The importance of the information concerning the depth of interaction (DOI) in a PET device has been stressed by many authors. In this paper, the attenuation of the emitted light in a thin LYSO (Ce) scintillator crystal has been measured for the purpose of obtaining information about DOI from the ratio of the light output measured at both ends of the crystal. A pair of photomultipliers were attached to the two ends of the crystal for this purpose. An array of wave-length shifters(WLS) attached to the crystal from a side was used in order to find the hit point of the incident gamma rays along the crystal. The attenuation constant μ determined in this measurement is μ＝0.79 ± 0.0007/cm. This value is experimentally demonstrated to be appropriate for the DOI estimation using the ratio of the amounts of light. The obtainable DOI resolution, when the crystal is read out using WLS and a new kind of position-sensitive photomultipliers in our next prototype, is estimated