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        find Keyword "Magnetic resonance imaging" 118 results
        • Relationship of Magnetic Resonance DiffusionWeighted Imaging to Histology in Chronic Viral Hepatitis

          【Abstract】ObjectiveTo investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. MethodsThirty-five patients of chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0T MRI device. Apparent diffusion coefficient (ADC) of the liver were measured respectively when b value were set as 100, 400, 600 and 800 s/mm2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). ResultsWhen b value was set as 800 s/mm2, statistical difference was showed between the fibrosis group and the nonfibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. ConclusionDWI is a valuable method for grading and staging of chronic viral hepatitis.

          Release date:2016-09-08 11:53 Export PDF Favorites Scan
        • Clinical characteristics of 10 cases of posterior scleritis

          Objectives To observe the clinical characteristics of patients with posterior scleritis. Methods Ten patients with 16 eyes diagnosed as posterior scleritis were enrolled in this study. Ten patients consisted of seven males and three females. Their age ranged from 18 to 75 years old, with a mean age of 42.0plusmn;14.7 years old. Except for two patients aged 18 and 75 years old, the other eight patients aged 33 to 55 years old. Routine eye examination was performed including visual acuity, slit lamp microscope, ophthalmoscope, B scan ultrasound, color fundus photography, fundus fluorescein angiography (FFA), orbit MRI and chest Xray. According to the B scan ultrasonic examination, these ten posterior scleritis cases were divided into diffused and nodular types. Among them, the diffused type had 8 cases (14 eyes), the nodular type had 2 cases (2 eyes). The visual acuities of ten patients were from light perception to 0.4. The blood laboratory tests were negative in all cases. The diffused posterior scleritis patients received systemic and (or) local glucocorticoid therapy. The nodular posterior scleritis patients could not be ruled out choroidal melanoma in the initial evaluation, and they underwent enucleation operation in other hospitals. Results In the 14 eyes of diffused posterior scleritis, conjunctival congestion and edema were observed in 8 eyes, eyelid edema in 2 eyes, normal eye surface in 4 eyes. In the two eyes of nodular posterior scleritis, there was no conjunctival congestion and edema or eyelids swelling. All 16 eyes performed FFA, 11 eyes had fundus posterior pole early dot-like hyperfluorescence followed by leakage of fluorescence in the late stage, two eyes had hyperfluorescence mixed with hypofluorescence in the nearby retina of the lesion, and the rest three eyes had no abnormality in FFA. In 14 eyes of diffused type posterior scleritis, B scan ultrasound showed diffused scleral thickening more than 2 mm in 10 eyes with a typical quot;Tquot; shape sign. The other 4 eyes did not show typical sign in ultrasound. In 2 eyes of nodular type, ultrasound showed nodular enhanced echo in choroid with medium internal reflection and abundant blood flow. Eleven eyes underwent orbit MRI scan, 9 eyes displayed diffused posterior sclera thickening, 2 eyes showed nodular lesions in choroid. All lesions showed low signal on T1WI, high signal on T2WI. After treatment, six diffused posterior scleritis patients recovered to normal scleral thickness. Two nodular posterior scleritis patients underwent enucleation showed granulomatous posterior scleritis and necrotic posterior scleritis in pathology. Overall, 16 eyes of 10 patients were misdiagnosed as chronic angleclosure glaucoma in 2 eyes, acute iridocyclitis in 1 eye, central serous chorioretinopathy in 2 eyes, retrobulbar neuritis in 2 eyes, and choroidal melanoma in 2 eyes. Conclusions Posterior scleritis occurs mostly in young patients. The diffused posterior scleritis patients usually has anterior segment signs including conjunctival congestion and edema or eyelids swelling, while the nodular posterior scleritis patients has normal anterior segment signs. B scan ultrasonic and MRI examination showed typical image features. Systemic and (or) local glucocorticoid therapy can effectively release the symptoms of these patients.

          Release date:2016-09-02 05:22 Export PDF Favorites Scan
        • A preliminary study on the analysis of myopic retinoschisis and posterior staphyloma in a cohort of patients with pathological myopia by optical coherence tomography and magnetic resonance imaging

          ObjectiveTo observe the correlation between posterior myopic retinoschisis(MRS) and posterior scleral staphyma (PS) in pathological myopia (PM), and to preliminarily explore the influencing factors of MRS.MethodsA retrospective case series study. From November 2016 to November 2019, 38 patients with PM with MRS diagnosed in Henan Eye Hospital & Henan Eye Institute from were included in the study. There were 10 males and 28 females; 13 patients were binocular and 25 patients were monocular. The average age was (49±13) years old. BCVA, retinoscopy optometry, frequency domain OCT, three-dimensional magnetic resonance imaging (3D-MRI) examination and axial length (AL) measurement were performed. According to the frequency domain OCT inspection results, MRS was divided into inner splitting, outer splitting and mixed splitting; based on the 3D-MRI scan results, PS was divided into broad macula, narrow macula,discoid, nasal, subdisc and other types. The correlation between MRS and PS was tested by χ2 test or Fisher exact test.ResultsAmong 60 eyes, 58 eyes (96.77%) of MRS combined with PS. Among them, the wide macula, narrow macula, discoid, nasal, subdisc, and other types were 30 (51.72%), 19 (32.75%), 1 (1.72%), 2 (3.48%), 2 (3.48%) and 4 (6.85%) eyes; inner split, outer split, and mixed split were 10 (17.24%), 24 (41.38%), 24 (41.38%) eyes. Of the 19 eyes with narrow macular PS, MRS involved the fovea in 16 eyes; of the 39 eyes with PS of other forms, MRS involved the fovea in 22 eyes. There was a statistically significant difference between the narrow macular type and other types involving foveal eyes (P=0.044). The correlation between MRS involving the fovea and narrow macular PS was moderate (Cramer's V=0.275). The ages of patients with inner split, outer split, and mixed split were 44±12, 56±10, and 44±13 years, respectively. Patients with inner splitting were younger than those with outer splitting, and those with outer splitting were older than those with inner splitting and mixed splitting. The differences were statistically significant (P=0.010, 0.010, 0.060).ConclusionPM with MRS mostly occur in PS-affected eyes, and mainly macular PS (wide macula, narrow macula).

          Release date:2020-11-19 09:16 Export PDF Favorites Scan
        • Magnetic Resonance Imaging in Female Pelvic Masses:A Meta-Analysis

          Objective To evaluate the sensitivity, specificity, and accuracy of magnetic resonance imaging (MRI) in characterizing adnexal masses. Methods The databases such as the Cochrane Library, PubMed, EMbase, CNKI, and WanFang Data were searched on computer from 1991 to 2011. The reviewers screened the trials according to inclusion and exclusion criteria strictly, extracted the data, and assessed the methodology quality. Meta-analysis were performed using the Metadisc 1.40 software. The acquired pooled sensitivity, specificity, and summary receiver operating characteristic curve (SROC) were used to describe the diagnostic value. The pooled likelihood ratios were calculated based on the pooled sensitivity and specificity. Results Ten case-control studies involving 649 women who were suspected to have pelvic masses were included and 729 masses were confirmed by the postoperative histopathology. The pooled statistical results of meta-analysis showed that:the sensitivity and specificity of MRI were 〔89%(84%-92%), P=0.046 6〕 and 〔87% (83%-90%), P=0.000 2〕 respectively, the positive and negative likelihood ratios of MRI were 6.25(P=0.008 5) and 0.14(P=0.029 1) respectively, and the area under the SROC curve (AUC) was 0.941. The sensitivity and specificity of ultrasound were 〔87%(82%-91%), P=0.000 0〕 and 〔73%(69%-77%), P=0.000 0〕 respectively, the positive and negative likelihood ratios of MRI were 3.07(P=0.000 0) and 0.18(P=0.000 1) respectively, and the AUC was 0.897. The speci?city and accuracy of MRI in characterizing female pelvic masses were higher than ultrasound obviously. Conclusion According these evidences, the MRI should be recommended to the women who are suspected to have pelvic masses as a preferred.

          Release date:2016-09-08 10:36 Export PDF Favorites Scan
        • Comparative Study of Dynamic Contrast-Enhanced Breast MRI, Ultrasound, and X-ray Mammography in Differential Diagnosis of Benign and Malignant Breast Lesions

          ObjectiveTo assess the values of MRI, ultrasound (US), and X-ray in the differential diagnosis of benign and malignant breast lesions. MethodsThe image data of 50 breast lesions confirmed with histopathology were analyzed retrospectively and the values of MRI, US and X-ray mammography in the differential diagnosis of benign and malignant breast lesions based on the breast imaging reporting and data system (BI-RADS) were assessed. The diagnostic efficiency of MRI, US, and X-ray in 50 benign and malignant breast lesions were compared using receiver operating characteristics (ROC) curves. The areas of ROC curves of MRI, US, and X-ray were calculated with Z test using SPSS 16.0. ResultsThere were 44 patients with 50 breast lesions, 26 malignant lesions, 24 benign lesions. Based on the BI-RADS, according to X-ray imaging features, 26 malignant breast lesions were classified as 5 lesions of category 5, 7 lesions of category 4, 6 lesions of category 3, 3 lesions of category 2, 1 lesion of category 1, 4 lesions of category zero. Twenty-four benign breast lesions were classified as 1 lesion of category 4, 3 lesions of category 3, 4 lesions of category 2, 13 lesions of category 1, 3 lesions of category zero. According to the characteristics of US findings, 26 malignant breast lesions were classified as 17 lesions of category 5, 4 lesions of category 4, 1 lesion of category 3, 1 lesion of category 2, 3 lesions of category 1. Twenty-four benign breast lesions were classified as 1 lesion of category 5, 2 lesions of category 4, 4 lesions of category 3, 14 lesions of category 2, 2 lesions of category 1, 1 lesion of category 0. According to MRI imaging findings, 26 malignant breast lesions were classified as 6 lesions of category 5, 18 lesions of category 4, 1 lesion of category 3, 1 lesion of category 1. Twenty-four benign breast lesions were classified as 20 lesions of category 1, 3 lesions of category 2, 1 lesion of category 3. The area under the ROC curve of the MRI, US, and X-ray was 0.977, 0.835, and 0.764, respectively. The differences of MRI with US (Z=2.05, P < 0.05) and MRI with X-ray mammography (Z=2.81, P < 0.05) were statistically significant. While the difference of US with X-ray mammography (Z=0.73, P > 0.05) was't statistically significant. ConclusionsDynamic contrast-enhanced MRI is an accurate examination in the differential diagnosis of benign and malignant breast lesions. The differential diagnostic efficiency of MRI is significantly better than those with US and X-ray.

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        • The value of 3.0 T MRI functional imaging in differential diagnosis of radiation brain injury and recurrence of glioblastoma multiforme

          ObjectiveTo explore the value of 3.0 T MRI functional imaging in differential diagnosis of radiation brain injury and recurrence of glioblastoma multiforme.MethodsFrom March 2017 to January 2018, 31 patients diagnosed with brain glioblastoma multiforme in Peking University International Hospital were collected continuously, including 14 cases of tumor recurrence and 17 cases of radiation-induced brain injury. All the patients routinely underwent conventional MRI head scan, three-dimension arterial spin labeling (3D-ASL), dynamic susceptibility contrastperfusion weighted imaging (DSC-PWI), and enhanced MRI scan sequence; related parameters were recorded and compared.ResultsCerebral blood flow (CBF) value of abnormal enhanced area in the recurrence group was significantly higher than that in the brain injury group with 3D-ASL scan (t=3.016, P=0.005), and no difference was found in edema area between the two groups (P>0.05). In the recurrence group, CBF value of abnormal enhanced area was significantly higher than that of the normal area (t=2.628, P=0.014); however, there was no significant difference in the CBF value between the abnormal enhancement foci and the normal areas in the radiation brain injury group (P>0.05). Relative cerebral blood volume (rCBV) ratio (t=2.894, P=0.007) and relative cerebral blood volume (rCBF) ratio (t=2.694, P=0.012) of abnormal enhanced area, as well as rCBV ratio (t=2.622, P=0.013) and rCBF ratio (t=2.775, P=0.010) of edema area in the recurrence group were significantly higher than those in the brain injury group with DSC-PWI scan. No differences were found in relative mean transit time (rMTT) ratio and relative time to peak (rTTP) ratio between the two groups (P>0.05). In the brain injury groupr, CBV ratio (t=2.921, P=0.008) and rCBF ratio (t=3.100, P=0.004) of abnormal enhanced area were significantly higher than those of the edema area, and no difference was found in rMTT ratio or rTTP ratio (P>0.05). In the recurrence group, no difference was found in all focal parameters between abnormal enhanced area and edema area (P>0.05). In diagnosis value analysis, the areas under the curve of CBF in 3D-ASL scan, and rCBF ratio, rCBV ratio in DSC-PWI scan were 0.752, 0.675, and 0.645, respectively; the cut-off values were 34.59, 1.48, and 1.67, respectively; the sensitivities were 79.2%, 61.5%, and 58.3%, respectively; and the specificities were 44.4%, 32.8%, and 22.4%, respectively.ConculsionThe diagnostic value of functional MRI imaging in distinguishing glioblastoma multiforme recurrence and radiation-induced brain injury is high recommendated; further research and clinical application should be needed.

          Release date:2018-06-26 08:57 Export PDF Favorites Scan
        • Clinical Value of Diffusion Weighted Imaging in the Diagnosis of Placenta Increta

          ObjectiveTo discuss the value of diffusion weighted imaging (DWI) in the diagnosis of placenta increta. MethodsThe clinical data of 42 patients with placenta increta admitted to Sichuan Provincial Hospital for Women and Children between May 2012 and January 2014 were retrospectively analyzed. All the patients were examined by prenatal magnetic resonance scans and DWI scans for subsequent comparison between ADC of the local convex placental region and ADC of the normal placental region and between the results of the two imaging methods. ResultsADC of the implantation area was significantly different from that of the normal placenta, so it could be used as a quantitative index. DWI had a higher sensitivity of diagnosis than conventional MRI. ConclusionCompared with conventional magnetic resonance imaging, DWI is more valuable in the clinical diagnosis of placenta increta, which provides a reliable basis for clinical treatment.

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        • Imaging Findings of Carcinoma of Body and Tail of Pancreas

          ObjectiveTo investigate the imaging findings of carcinoma of body and tail of the pancreas. MethodsTotally twentythree patients with carcinoma of body and tail of the pancreas were studied. The diagnosis was proven by surgery and pathological findings. The imaging features of twentythree cases were reviewed including the location, size, shape, texture, and enhancement patterns of the tumor masses. Five cases underwent enhanced MRI examination, 18 cases underwent enhanced spiral CT examination. ResultsThe tumors located in the pancreatic body in 5 cases, located in the tail in 7 cases, and located in the body and tail of pancreas in 11 cases. The tumor masses were irregular in shape and heterogeneously hypointense from CT scan. From MR, the masses were slightly hypointense on T1WI, and slightly or mixed hyperintense on T2WI. Nineteen cases showed heterogeneous slight enhancement and four cases had no enhancement. The tumors were well demarcated in five cases, while those were poorly defined in the other 18 cases. Metastatic lymphadenopathy was shown in 16 cases, vascular invasion in 8 cases, and metastatic lesions of other organs in 3 cases. ConclusionThe carcinoma of body and tail of the pancreas shows certain characteristic imaging. CT and MRI examination can reflect the morphologic features, the hemodynamic alterations, and the involvement of adjacent structures and organs.

          Release date:2016-09-08 10:45 Export PDF Favorites Scan
        • DWI Combined with 3D-VIBE in Evaluating Metastatic Lymph Nodes Secondary to Hilar Cholangiocarcinoma

          ObjectiveTo investigate the value of diffusion weighted imaging (DWI) combined with three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma. MethodsFrom July 2009 to March 2011, DWI examination was performed in 37 patients with hilar cholangiocarcinoma, which was compared with 3D-VIBE sequences. The morphological characteristics and distribution were analyzed for metastatic and nonmetastatic lymph nodes. Signal intensity (SI) was measured on DWI images and apparent diffusion coefficient (ADC) was calculated for each lymph node. The SI of lymph nodes (SILN) and liver (SIliver) were also measured and the ratio of SI was calculated. The ADC and the ratio of SI were compared between metastatic and nonmetastatic lymph nodes. ResultsThere were fifty-nine groups of lymph nodes in 37 patients with hilar cholangiocarcinoma, fifty-one groups were revealed in both DWI and 3D-VIBE sequences, and eight groups were only demonstrated in one sequence (P=0.070). The short diameters were (1.05±0.42) cm and (0.78±0.22) cm on 3D-VIBE images for metastatic and nonmetastatic lymph nodes, respectively (P=0.030). The ADC value in metastatic lymph nodes was (1.64±0.3)×10-3 mm2/s, which was significantly lower than that in nonmetastatic lymph nodes 〔(2.28±0.79)×10-3 mm2/s〕 on DWI images (P=0.033). There were no significant differences in SILN/SIliver between metastatic and nonmetastatic lymph nodes on images of portal venous phase and 3 min delayed contrast-enhanced phase. ConclusionsDifferences of ADC and short diameter can provide valuable information to differentiate metastatic lymph nodes with nonmetastatic lymph nodes. When combined with 3D-VIBE sequence, DWI is more effective in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma.

          Release date:2016-09-08 10:41 Export PDF Favorites Scan
        • Analysis of clinical and imaging characteristics of radiation-induced optic neuritis

          ObjectiveTo observe the clinical and imaging characteristics of radiation optic neuropathy (RION). MethodsA retrospective clinical study. A total of 43 patients (69 eyes) who were diagnosed with RION at the Chinese PLA General Hospital from 2010 to 2021 were included in this study. There were 23 males (36 eyes) and 20 females (33 eyes). The age of patients at the time of radiation therapy was 49.54±13.14 years. The main dose of radiotherapy for lesions was 59.83±14.12 Gy. Sixteen patients were treated with combined chemotherapeutic agents. The clinical details of best corrected visual acuity (BCVA) and color photography of the fundus were collected. Forty-six eyes underwent optical coherence tomography (OCT), visual field were examined in 30 eyes, magnetic resonance imaging (MRI) were performed in 40 eyes. The BCVA examination was performed using Snellen visual acuity chart, which was converted to minimum resolution angle logarithm (logMAR) visual acuity during recording. Hyperbaric oxygen therapy (HBOT) was performed in 10 patients (13 eyes), 9 patients (12 eyes) were treated with intravenous methylprednisolone (IVMP), 12 patients (23 eyes) were treated with HBOT combined with IVMP and control group of 12 patients (21 eyes) were only treated with basal treatment. And grouped accordingly. To observe the changes in onset, recovery, and final BCVA of the affected eye as well as thickness changes of the retinal nerve fiber layer (RNFL) of the optic disc and inner limiting membrane-retinal pigment epithelium (ILM-RPE) layer of the macular area, and final outcome of BCVA with different treatment modalities in affected eyes. The RNFL and ILM-RPE layer thicknesses were compared between patients with different disease duration as well as between treatment regimens using independent samples t-test. ResultsOf the 43 cases, vision loss was monocular in 17 patients (39.53%, 17/43) and binocular in 26 patients (60.47%, 26/43). The latency from radiotherapy to onset of visual loss was 36.33±30.48 months. The duration of RION ranged from 1 week to 10 years, in which the disease duration of 37 eyes ≤2 months. Subacute visual acuity loss was present in 41 eyes. logMAR BCVA<1.0, 1.0-0.3, >0.3 were 45, 15, and 9 eyes, respectively. Optic disc pallor and optic disc edema were found in 10 (27.03%, 10/37), 3 (8.11%, 3/37) eyes, respectively, within 2 months. The superior RNFL [95% confidence interval (CI) 2.08-66.56, P=0.038] and the outer circle of the inner limiting membrane to retinal pigment epithelium (ILM-RPE) (95%CI 4.37-45.39, P=0.021) layer thinned significantly during the first month. The center of the ILM-RPE layer thickened (95%CI -32.95--4.20, P=0.015) significantly during the first two months. The inner circle temporal quadrant of the ILM-RPE layer thickened (95%CI -42.22--3.83, P=0.022) significantly from the third to sixth month, and the RNFL except for the temporal quadrants and the average RNFL, inner circle superior quadrant and outer circle of the ILM-RPE layer thinned significantly after 6 months (P<0.05). Among the 40 eyes that underwent MRI examination, 33 eyes (82.50%, 33/40) were affected by T1 enhancement of optic nerve, including 23 eyes (69.70%, 23/33) in intracranial segment; 12 eyes with thickening and long T2 signal (36.36%, 12/33). After treatment, BCVA was restored in 17 eyes (24.6%, 17/69) and final BCVA improved in 9 eyes (13.0%, 9/69). There was no significant difference between HBOT, IVMP and HBOT combined with IVMP therapy in improving BCVA recovery or final BCVA compared with the control group, respectively (t=-1.04, 0.61, 1.31, -1.47, -0.42, 0.46; P>0.05). ConclusionsThe structural damage of the RNFL and ILM-RPE layer occurred during the first month, the RNFL showed progressive thinning during the follow-up period, while the ILM-RPE layer showed thinning-thickening-thinning. MRI shows T1 enhancement of the optic chiasma and segments of the optic nerve, and the enhanced segments are usually accompanied by thickening and long T2. HBOT and IVMP have no obvious effect on RION.

          Release date:2023-01-12 09:10 Export PDF Favorites Scan
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