Entrance surface dose measurements using a small OSL dosimeter with a computed tomography scanner having 320 rows of detectors.

Entrance surface dose (ESD) measurements are important in X-ray computed tomography (CT) for examination, but in clinical settings it is difficult to measure ESDs because of a lack of suitable dosimeters. We focus on the capability of a small optically stimulated luminescence (OSL) dosimeter. The aim of this study is to propose a practical method for using an OSL dosimeter to measure the ESD when performing a CT examination. The small OSL dosimeter has an outer width of 10 mm; it is assumed that a partial dose may be measured because the slice thickness and helical pitch can be set to various values. To verify our method, we used a CT scanner having 320 rows of detectors and checked the consistencies of the ESDs measured using OSL dosimeters by comparing them with those measured using Gafchromic™ films. The films were calibrated using an ionization chamber on the basis of half-value layer estimation. On the other hand, the OSL dosimeter was appropriately calibrated using a practical calibration curve previously proposed by our group. The ESDs measured using the OSL dosimeters were in good agreement with the reference ESDs from the Gafchromic™ films. Using these data, we also estimated the uncertainty of ESDs measured with small OSL dosimeters. We concluded that a small OSL dosimeter can be considered suitable for measuring the ESD with an uncertainty of 30 % during CT examinations in which pitch factors below 1.000 are applied.

The state of the art in arthroscopic hip surgery.

Hip arthroscopy is among the most rapidly evolving arthroscopic techniques in the last decade and offers the benefits of being both a minimally invasive procedure and an excellent diagnostic tool. Improvements in instrumentation and surgical skills have advanced our ability to accurately diagnose and treat various conditions of the hip joint, and hip arthroscopy has elucidated several pathologies that cause disabling symptoms. Many of these conditions were previously unrecognized and left untreated. The indications for hip arthroscopy include the management of early osteoarthritis, synovial disorders (e. g., synovial osteochondromatosis), labral tears, chondral lesions, and femoroacetabular impingement (FAI), which is increasingly recognized as a disorder that can lead to the development of early cartilage and labral injury. A better understanding of hip arthroscopy, including the anatomy, improved surgical techniques, indications, and complications of the procedure, is essential for its success. This review article discusses the state of the art of arthroscopic hip surgery.

Idiopathic spinal cord herniation with duplicated dura mater and dorsal subarachnoid septum. Report of a case and review of the literature.

BACKGROUND: Idiopathic spinal cord herniation (ISCH) is a rare condition and its pathogenesis remains unclear. The purpose of this case report is to present an ISCH case with dorsal subarachnoid septum suggesting the pathogenesis of ISCH being adhesions from preexisting inflammation. METHODS: Single case report. RESULTS: A 60-year-old woman presented with Brown-Séquard syndrome below the level of T6. Magnetic resonance imaging revealed the thoracic spinal cord was displaced ventrally, and the dorsal subarachnoid space was enlarged and had a septum between the spinal cord and dura mater. Intraoperatively, the dorsal dura mater was seen to be adherent and the subarachnoid septum was identified after durotomy. The inner layer defect of the duplicated dura mater was found in the ventral dura mater, through which the spinal cord had herniated. After releasing the septum, the adhesions around the dura mater, and the hiatus, the spinal cord was reduced. CONCLUSIONS: The present case indicates that adhesions around the dura mater can be the pathogenesis of ISCH.