This paper presents a three-dimensional electronic laparoscopy system, including three-dimensional laparoscope pipe and medical video system. The three-dimensional laparoscope pipe adopts a dual-optical structure, which can collect three-dimensional information of the surgical region. By selecting a reasonable initial structure, the MTF curve of the objective lens is close to the diffraction limit, and the distortion is less than 25%. The medical video system also achieved high-definition image with 1 080 P, 30 Hz by GPU. At the mean time, the three-dimensional electronic laparoscope has achieved quantitative production and has been tested in a number of animals, which has broad application prospects and significant clinical application value.
Electronics, Medical ; Imaging, Three-Dimensional ; Laparoscopes ; Laparoscopy

Medical students and doctors should study the appearance of normal anatomical structures in the magnetic resonance images (MRIs). For this purpose, horizontal, coronal, sagittal MRIs of a healthy entire body and corresponding segmented images were prepared. However, it is inconvenient to select interesting MRIs and segmented images; and it is difficult to understand how stereoscopic anatomical structures appear in the MRIs. Therefore, in this research, a software, on which interesting MRIs can be conveniently displayed among the horizontal, coronal, sagittal MRIs and corresponding segmented images can be displayed together, was composed. And after stacking the segmented images, three-dimensional (3D) image of each anatomical structure was manually reconstructed by surface rendering. Then another software, on which interesting 3D images of anatomical structures can be displayed and rotated, was composed too. These softwares are expected to help medical students and doctors understand normal anatomical structures in the MRIs and read pathological findings in the MRIs of patients.
Humans ; Imaging, Three-Dimensional* ; Magnetic Resonance Imaging* ; Students, Medical

PURPOSE: Diffusion-weighted magnetic resonance imaging (DWI) has been known to visualize hyperacute ischemic stroke. And it takes only a few minutes to do. Moreover only a small amount of time and little cost is required to add T2-weighted imaging (T2WI) to DWI. The purpose of this study is to determine the usefulness of T2WI in addition to DWI as a primary imaging modality for patients with suspected ischemic stroke. METHODS: DWI plus T2WI was performed from January to May 2001 on the patients with suspected ischemic stroke. Two emergency physicians reviewed the films and medical records. The sensitivity and the specificity of DWI and T2WI for acute ischemic stroke were calculated. The agreement between DWI and T2WI was calculated using kappa statistics. RESULTS: A total of 241 patients were enrolled. Acute ischemic stroke was confirmed in 86 (35.7%) patients. The sensitivity and the specificity of DWI for acute ischemic stroke were 94.2% and 98.7%, and those for T2WI were 60.5% and 94.2%, respectively. The kappa value was 0.721 (p<0.01). Among the 86 acute ischemic stroke patients, the number of cases who presented less than 6 hours after symptom onset was significantly lower in the T2WI positive group (31% vs. 68.7%, p<0.05). CONCLUSION: This study suggests that the addition of T2WI to DWI as a primary imaging modality for acute ischemic stroke has little benefit compared to DWI alone, especially, when the symptom duration has been less than 6 hours.
Emergencies ; Humans ; Magnetic Resonance Imaging* ; Medical Records ; Sensitivity and Specificity ; Stroke*

No abstract available.
*Diagnostic Imaging ; Human ; Radiology/*trends ; Radiology, Interventional ; Specialties, Medical

This study presents an electronic portal imaging devices (EPIDs) based on daily check tool for Linac that is usable for different cancer centers.Several images of open rectangle fields were acquired with EPID and the key items of daily Linac check were derived from the obtained images using an in-house developed automatic analysis software.The experiment results showed that each parameter calculated by this tool is as reliable as the corresponding result measured by the commercial quality assurance devices and its measuring efficiency is much higher.
Electronics, Medical ; Electrons ; Particle Accelerators ; Phantoms, Imaging ; Radiometry ; Software

This paper mainly introduces the material composition and structure of two kinds of compound tabletop which currently used in large medical imaging equipment, also introduces the proper material choosing and production processing, together with the advantage and shortage of this two kinds of tabletop and different application occasion.
Construction Materials ; Diagnostic Imaging ; instrumentation ; Durable Medical Equipment

Image registration methods based on mutual information, including mutual information and normalized mutual information, have been accepted as the most accurate and efficient methods. But there are many fluctuations in the registration functions that hinder the optimization procedure and lead to registration failure in intra-modal registration. We found that besides the interpolation artifacts, the uncertainty of the changing of entropy with the changing of overlap also contributes to the fluctuations. The effect of interpolation artifacts can be eliminated, but it is difficult to eliminate the effect of uncertainty of entropy. Luckily, this effect is not significant in normalized mutual information. Normalized mutual information is more stable and robust than standard mutual information and its better performance and wider application can be expected.
Algorithms ; Diagnostic Imaging ; Humans ; Image Processing, Computer-Assisted ; methods ; Magnetic Resonance Imaging ; methods ; Medical Informatics ; methods ; Registries

PURPOSE: Pylorus-preserving pancreatoduodenectomy (PPPD) is an alternative surgical procedure for periampullary lesions. Early delayed gastric emptying is the most common and frustrating complication in the immediate postoperative period after PPPD and late delayed gastric emptying has been reported in some long-term follow-up studies. We evaluated the incidence of early delayed gastric emptying and analyzed temporal changes in gastrointestinal function after PPPD. METHODS: The incidence of early delayed gastric emptying was retrospectively evaluated from the medical records of 15 patients who underwent PPPD. Gastric emptying tests (GETs) using 99mTc-DTPA scan were performed on 11 of the patients every three months until 1 year, where possible. RESULTS: The incidence of early delayed gastric emptying was 6.7%. Five of the eight patients (62.5%) and six of the eight (75%) who underwent scintigraphy at 3 months and 6 months respectively, showed delayed gastric emptying. But at 12 months, all of the four patients who underwent GETs showed normal gastric emptyings. CONCLUSION: The incidence of early delayed gastric emptying after PPPD was 6.7%. Though there were few symptoms in long-term follow-up study using 99mTc-DTPA scan, delayed gastric emptying was frequently observed 3 to 9 months after PPPD. However, gastric emptying might be normalized in almost all patients around 1 year after PPPD.
Follow-Up Studies ; Gastric Emptying* ; Humans ; Incidence ; Medical Records ; Pancreaticoduodenectomy* ; Postoperative Period ; Radionuclide Imaging ; Retrospective Studies

OBJECTIVE: It is rare that the medial loop in the V2 segment of the vertebral artery (VA) causes compression of the proximal cervical root of the spinal cord without leading to bony erosion and an enlarged foramen. We evaluated the clinical significance and incidence of the medial loop in the V2 segment of the VA. METHODS: We reviewed the records from 1000 consecutive patients who had undergone magnetic resonance imaging evaluation of the cervical spine between January 2005 and January 2008. The inclusion criteria were that over a third of the axial aspect of the VA located in the intervertebral foramen was inside the line between the most ventral points of the bilateral lateral mass, and that the ipsilateral proximal root deviated dorsally because of the medial loop of the VA. We excluded cases of bone erosion, a widened foramen at the medial loop of the VA, any bony abnormalities, tumors displacing VA, or vertebral fractures. The medical records were reviewed retrospectively to search for factors of clinical significance. RESULTS: In six patients (0.6%), the VA formed a medial loop that caused compression of the proximal cervical root. One of these patients had the cervical radiculopathy that developed after minor trauma but the others did not present with cervical radiculopathy related to the medial loop of the VA. CONCLUSION: The medial loop of the VA might have a direct effect on cervical radiculopathy. Therefore, this feature should be of critical consideration in preoperative planning and during surgery.
Humans ; Incidence ; Magnetic Resonance Imaging ; Medical Records ; Radiculopathy ; Retrospective Studies ; Spinal Cord ; Spine ; Vertebral Artery

OBJECTIVE: The inter-rater reliability of the modified Knosp's classification was measured before the analysis. The clinical validity of the parasellar extension grading system was evaluated by investigating the extents of resection and complication rates among the grades in the endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenomas. METHODS: From November 2008 to August 2015, of the 286 patients who underwent EETS by the senior author, 208 were pituitary adenoma cases (146 non-functioning pituitary adenomas, 10 adrenocorticotropic hormone-secreting adenomas, 31 growth hormone-secreting adenomas, 17 prolactin-secreting adenomas, and 4 thyroid-stimulating hormone-secreting adenomas; 23 microadenomas, 174 macroadenomas, and 11 giant adenomas). Two neurosurgeons and a neuroradiologist independently measured the degree of parasellar extension on the preoperative sellar MRI according to the modified Knosp's classification. Inter-rater reliability was statistically assessed by measuring the intraclass correlation coefficient. The extents of resection were evaluated by comparison of the pre- and post-operative MR images; the neurovascular complications were assessed by reviewing the patients' medical records. The extent of resection was measured in each parasellar extension grade; thereafter, their statistical differences were calculated. RESULTS: The intraclass correlation coefficient value of reliability across the three raters amounted to 0.862. The gross total removal (GTR) rates achieved in each grade were 70.0, 69.8, 62.9, 21.4, 37.5, and 4.3% in Grades 0, 1, 2, 3A, 3B, and 4, respectively. A significant difference in the extent of resection was observed only between Grades 2 and 3A. In addition, significantly higher complication rates were observed in the groups above Grade 3A. CONCLUSION: Although the modified Knosp's classification system appears to be complex, its inter-rater reliability proves to be excellent. Regarding the clinical validity of the parasellar extension grading system, Grades 3A, 3B, and 4 have a negative predictive value for the GTR rate, with higher complication rates.
Adenoma ; Cavernous Sinus ; Classification ; Endoscopy ; Humans ; Magnetic Resonance Imaging ; Medical Records ; Neurosurgeons ; Pituitary Neoplasms*