ObjectiveTo observe the pathological changes of central retinal artery occlusion (CRAO) by optical coherence tomography (OCT).MethodsFifty-three eyes of 53 patients who were diagnosed as CRAO in our center between January 2001 to January 2004 underwent the examination by OCT. The intervals between the disease onset and OCT examination were less than 2 weeks. The scan modes of OCT were horizontal or vertical line scan. The locations of scanning were macular, posterior pole of retina, optical papilla and the focus of bleeding or exudation.ResultsThe OCT pathological changes of CRAO in vivo includes increase of retinal thickness and reflex of retina, width of dark layer of photoreceptor (edema), edema or cystoid edema of fovea, retinal bleeding, cotton-wool spot and papilla edema. Four patients who had ciliary retinal artery showed normal retinal structure in the supply region of ciliary retinal artery.ConclusionOCT can display the pathological changes of retinal tissues in CRAO in vivo, especially on the old patients or the patients with systemic disease who were contraindicated by FFA. The unique OCT image of pathological changes of CRAO supply the objective signs for the instant clinical diagnosis.(Chin J Ocul Fundus Dis, 2005,21:74-78)
Objective To investigate the situation and prospect of local recurrence of rectal cancer by using CT and MRI. Method Relevant references about the imaging diagnosis of local recurrence of rectal cancer， which were published domestic and abroad in recent years， were collected and reviewed. Results In the diagnosis of local recurrence of rectal cancer， the sensitivity of CT was higher than that of MRI， while the specificity and accuracy were not. Perfusion CT， dynamic contrast-enhanced MRI， and diffusion weighted imaging were valuable in diagnosing local recurrence of rectal cancer， as new diagnostic techniques. Conclusion Both CT and MRI are important and valuable methods in diagnosing for local recurrence of rectal cancer.
Objective To verifying the characteristics of optical coherence tomography(OCT) in exudative age-related macular degeneration (AMD). Methods The patients being investigated in this series included 16 cases (19 eyes) of exudative age-related macular degeneration diagnosed by FFA and OCT examinations, among them 4 cases (6 eyes) were examined with ICGA. The color photographs of ocular fundi, FFA, ICGA and OCT were investigated by contrasting each other. Results As compared with the FFA and ICGA examinations, the characteristic findings found in OCT in patients with exudative AMD in this series were as the following:①serous detachment of neurosensory epithelium in 11 eyes,②retinal hemorrhage in 2 eyes,③serous detachment of retinal pigment epithelium in 5 eyes,④hemorrhagic detachment of retinal pigment epithelium in 10 eyes,⑤disciform scar in 4 eyes,⑥fibrovascular pigment epithelial detachment and occult CNV in 12 eyes. Conclusion OCT can supply a comprehensive survey of exudative AMD, in making the diagnosis as an important complementary examination of FFA and ICGA. (Chin J Ocul Fundus Dis,2000,16:220-223)
Objective To evaluate the value of 16slice spiral computed tomography (SCT) and its threedimensional reconstruction in diagnosis of aortic dissection (AD). Methods Fortyfive cases with AD underwent 16slice SCT, performed with unenhanced, contrastenhanced scanning and threedimensional reconstructions. Emphasis was placed on the true and false lumen, intimal flap, the entry and reentry tear and the involvement of branches of AD. Eleven cases were confimed by operation. Results True and false lumen and intimal flap of AD could be shown in all 45 cases (100%), the entry and reentry tears were revealed in 44 cases (97.8%) and 33 cases (73.3%), respectively. The right common iliac arteries were most easily involved by AD, 21 cases (46.7%). The thrombi in false lumen were shown in 29 cases (64.4%). Compared with surgery, the location and size of initial entry sites of 11 cases were consistent with the former. Conclusion 16slice SCT can exactly and completely diagnose AD, and provide detailed imaging information for clinical therapy. It’s very important for the selection of treatment methods and the observation of curative effect of patients.
Descending necrotizing mediastinitis （DNM）is a severe infection spreading from the cervical or odontoiatric region to the mediastinum through the anatomic cervical spaces. DNM is very rare but fatal. The course of the illness proceeds rapidly and the mortality rate is high. The pathogenic process is closely related to anatomical and physiological characteristic of cervix and mediastinum. The most valuable way for decreasing its high mortality rate is to give early diagnosis and treatments. Computed tomography(CT) scan is especially important method in early diagnosis.The early and enough use of broad spectrum antibiotics, individual surgical management based on neck and chest CT, such as clearing necrotic tissues,drainage and flushing are all effective methods to decrease mortality rate. Related management , such as department of stomatology, head and neck surgery, thoracic surgery,intensive care unit, and infectious department,should give cooperative therapy when necessary. At the same time, more attention should be paid to the patients who have some systemic disease such as diabetes mellitus and whose physical constitutions are very poor, which could lead to DNM and worsening. It can help to decrease the incidence rate of fatal complications and to increase cure rate.
ObjectiveTo summarize the research progress of CT related to esophageal varices of cirrhotic patients complicated with portal hypertension.MethodsRelevant CT literatures of esophageal varices of cirrhotic patients complicated with portal hypertension were collected to make an review,then summarized the research status and progress of CT in the diagnosis and evaluation of lower esophageal varices.ResultCT had a good correlation with endoscopic diagnosis of esophageal varices, and CT was of great value in evaluating the presence, degree, and risk of esophageal varicose veins, especially in predicting the risk of esophageal varicose veins, which could be used as an effective modality to assist endoscopic examination to a certain extent.ConclusionsCT is an important examination method for esophageal varices, which has important value in diagnosis and evaluation. In the future, more further researches can be carried out to provide more strong and accurate support for the diagnosis and treatment of esophageal varices.
Electrical impedance tomography (EIT) is a new non-invasive functional imaging technology, which has the advantages of non-invasion, non-radiation, low cost, fast response, portability and visualization. In recent years, more and more studies have shown that EIT has great potential in the detection of lung diseases and has been applied to early diagnosis and treatment of some diseases. This paper introduced the basic principle of EIT, discussed the research and clinical application of EIT in the detection of acute respiratory distress syndrome, chronic obstructive pulmonary disease, pneumothorax and pulmonary embolism, and focused on the summary and introduction of indicators and functional images of EIT related to the detection of lung diseases. This review will help medical workers understand and use EIT, and promote the further development of EIT in lung diseases as well as other fields.
Ultrasound diffraction tomography (UDT) possesses the characteristics of high resolution, sensitive to dense tissue, and has high application value in clinics. To suppress the artifact and improve the quality of reconstructed image, classical interpolation method needs to be improved by increasing the number of projections and channels, which will increase the scanning time and the complexity of the imaging system. In this study, we tried to accurately reconstruct the object from limited projection based on compressed sensing. Firstly, we illuminated the object from random angles with limited number of projections. Then we obtained spatial frequency samples through Fourier diffraction theory. Secondly, we formulated the inverse problem of UDT by exploring the sparsity of the object. Thirdly, we solved the inverse problem by conjugate gradient method to reconstruct the object. We accurately reconstructed the object using the proposed method. Not only can the proposed method save scanning time to reduce the distortion by respiratory movement, but also can reduce cost and complexity of the system. Compared to the interpolation method, our method can reduce the reconstruction error and improve the structural similarity.
Objective To introduce the current study on 18F-fluorodexyglucose positron emission tomography (18F-FDG PET) scanning in diagnosis and treatment of carcinoma of large intestine. Methods The literatures about 18F-FDG PET scanning in diagnosis and treatment of carcinoma of large intestine in recent years were reviewed. Results 18F-FDG PET scanning is superior to CT and MRI in identificating carcinoma of large intestine recurrence, metastasis in the early stage after operation and staging carcinoma of large intestine. Conclusion 18F-FDG PET scanning may be one of the accessory examinations in carcinoma of large intestine and may be helpful for the choice of treatment.
Epilepsy is a clinical syndrome characterized by recurrent epileptic seizures caused by various etiologies. Etiological diagnosis and localization of the epileptogenic focus are of great importance in the treatment of epilepsy. Positron emission tomography-computed tomography (PET-CT) technology plays a significant role in the etiological diagnosis and localization of the epileptogenic focus in epilepsy. It also guides the treatment of epilepsy, predicts the prognosis, and helps physicians intervene earlier and improve the quality of life of patients. With the continuous development of PET-CT technology, more hope and better treatment options will be provided for epilepsy patients. This article will review the guiding role of PET-CT technology in the diagnosis and treatment of epilepsy, providing insights into its application in etiological diagnosis, preoperative assessment of the condition, selection of treatment plans, and prognosis of epilepsy.