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find Keyword "magnetic resonance" 151 results
  • Relationship between signal heterogeneity on hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI and prognosis of hepatocelluar carcinoma

    Objective To clarify relationship between signal heterogeneity on hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI and prognosis of hepatocellular carcinoma (HCC). Methods From January 2014 to January 2017 in the First Affiliated Hospital of Chongqing Medical University, a total of 77 patients with the pathologically proved HCC underwent Gd-EOB-DTPA-enhanced MRI prior to surgery were included in this study. On the basis of the signal heterogeneity in the hepatobiliary phase, the included patients were designed to homogeneous hypointensity group and heterogeneous hyperintensity group. The disease-free survival time were compared between the 2 groups and it’s influencing factors were analyzed. Results Seventy-seven patients with HCC were included, including 45 cases of homogeneous hypointensity and 32 cases of heterogeneous hyperintensity. There were no significant differences in the age, gender, etiology, liver function, alpha-fetoprotein, differentiated degree, Child-Pugh grade, lesion diameter, lesion border, and number of lesions between the 2 groups (P>0.05). However, the HCC patients with heterogeneous hyperintensity had a later BCLC staging (P=0.001). The disease-free survival time of the patients with homogeneous hypointensity and heterogeneous hyperintensity was (17.0±9.8) months and (12.4±10.4)months, respectively. The Kaplan-Meier survival curve showed that the disease-free survival time in the patients with homogeneous hypointensity was significantly better than that in the patients with heterogeneous hyperintensity (P=0.020). The results of univariate analysis showed that the other confounding factors had no effect on the disease-free survival time of patients with hepatocellular carcinoma (P>0.05) except for the signal of hepatobiliary phase (P<0.05). Furthermore, the hepatobiliary phase signal, BCLC stage, and degree of differentiation, which might be clinically considered as potentially influencing for the prognosis of patients with HCC, were included in the Cox multivariate proportional hazard regression model and found that the heterogeneous hyperintensity was still the risk factor of the disease-free survival rate in patients with HCC (P=0.047). Conclusion Signal heterogeneity on hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is related to prognosis of patients with HCC, heterogeneous hyperintensity may indicate a lower disease-free survival rate.

    Release date:2018-06-15 10:49 Export PDF Favorites Scan
  • Application of magnetic resonance angiography navigation technology in target bypass of moyamoya disease surgery

    Objective To explore the application value of time of flight magnetic resonance angiography (TOF-MRA) in target bypass surgery for moyamoya disease. Methods The data of patients with moyamoya disease in Affiliated Drum Tower Hospital, Medical College, Nanjing University between May 1 and August 30, 2020 were retrospectively analyzed. Patients were divided into navigation group and control group according to whether navigation technology was used during operation. All patients completed TOF-MRA evaluation before operation, and all patients completed surgical treatment. One week after operation, TOF-MRA was reviewed to evaluate the patency of anastomotic stoma. The intraoperative and postoperative conditions of the two groups were compared. Results Finally, 48 patients with moyamoya disease were included. 22 patients who used intraoperative navigation were included in the navigation group, and 26 patients with moyamoya disease who did not use intraoperative navigation in the same period were included in the control group. There was no significant difference between the two groups in gender, age, Suzuki stage before operation, proportion of posterior circulation involvement, proportion of bleeding type, proportion of hypertension and proportion of diabetes (P>0.05). The operation duration [(3.3±0.4) vs. (3.6±0.6) h] and postoperative hospital stay [(7.3±1.9) vs. (8.8±2.7) d] in the navigation group were shorter than those in the control group (P<0.05). There was no significant difference between the two groups in the proportion of patients who completed bypass surgery, the proportion of middle meningeal artery retained, the postoperative patency rate, the proportion of temporary dysfunction, and the proportion of serious complications (P>0.05). Conclusion TOF-MRA sequence combined with navigation technology can effectively guide the surgical scheme design and postoperative evaluation of moyamoya disease.

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  • Advances in migraine without aura based on resting-state functional MRI

    Migraine is the most common primary headache clinically, with high disability rate and heavy burden. Functional MRI (fMRI) plays a significant role in the study of migraine. This article reviews the main advances of migraine without aura (MwoA) based on resting-state fMRI in recent years, including the exploration of the mechanism of fMRI in the occurrence and development of MwoA in terms of regional functional activities and functional network connections, as well as the research progress of the potential clinical application of fMRI in aiding diagnosis and assessing treatment effect for MwoA. At last, this article summarizes the current distresses and prospects of fMRI research on MwoA.

    Release date:2024-06-24 02:56 Export PDF Favorites Scan
  • Imaging findings of pancreatic hematologic malignancies

    Objective To summarize the CT, MRI, and positron emission computed tomography (PET) imaging findings of hematologic malignancies of the pancreas, so as to improve the capacity of its diagnosis. Methods After searching articles concerning radiological research about hematologic malignancies of the pancreas, summarizing its imaging characteristics. Results Hematologic malignancies of the pancreas include pancreatic lymphoma, pancreatic multiple myeloma, myeloid sarcoma, posttransplantation lymphoproliferative disorder, and giant lymph node hyperplasia. ① Pancreatic lymphoma: imaging features of pancreatic lymphoma are segmental or diffuse homogeneous enlargement of the pancreas, diameter of mass >5 cm, adenopathy below the level of renal veins, and lack of pancreatic duct dilation. Blurred margins of pancreas by lymphadenopathy is highly suggestive of lymphoma. ② Pancreatic multiple myeloma: pancreatic multiple myeloma are hyperintense on both T1- and T2-weighted images. ③ Pancreatic granulocytic sarcoma: pancreatic granulocytic sarcoma present as homogeneous hypoenhancing mass on CT, usually without pancreatic duct dilation. On MRI, the lesions are isointense and mildly hyperintense on T1- and T2-weighted images respectively. ④ Posttransplantation lymphoproliferative disorder: diameter of leison of posttransplantation lymphoproliferative disorder usually is >5 cm with poor enhancement. Lesions are mildly hyperintense on T2-weighted images and extremely hypermetabolic on PET images. ⑤ Giant lymph node hyperplasia: it mainly appear as solitary noninvasive masses. Punctate calcification and surrounding supply vessels are observed in hyaline vascular type. Plasma cell type demonstrate unapparent enhancement and less calcification. Conclusions Hematologic malignancies of the pancreas manifest different imaging features on CT, MRI, and PET. Familiarity with such characteristics helps to early recognize diseases and determine next-step measures.

    Release date:2017-11-22 03:58 Export PDF Favorites Scan
  • Development of a risk stratification model for subscapularis tendon tear based on patient-specific data from 528 shoulder arthroscopy

    Objective To identify and screen sensitive predictors associated with subscapularis (SSC) tendon tear and develop a web-based dynamic nomogram to assist clinicians in early identification and intervention of SSC tendon tear. Methods Between July 2016 and December 2021, 528 consecutive cases of patients who underwent shoulder arthroscopic surgery with completely MRI and clinical data were retrospectively analyzed. Patients admitted between July 2016 and July 2019 were included in the training cohort, and patients admitted between August 2019 and December 2021 were included in the validation cohort. According to the diagnosis of arthroscopy, the patients were divided into SSC tear group and non-SSC tear group. Univariate analysis, least absolute shrinkage and selection operator (LASSO) method, and 10-fold cross-validation method were used to screen for reliable predictors highly associated with SSC tendon tear in a training set cohort, and R language was used to build a nomogram model for internal and external validation. The prediction performance of the nomogram was evaluated by concordance index (C-index) and calibration curve with 1 000 Bootstrap. Receiver operating curves were drawn to evaluate the diagnostic performance (sensitivity, specificity, predictive value, likelihood ratio) of the predictive model and MRI (based on direct signs), respectively. Decision curve analysis (DCA) was used to evaluate the clinical implications of predictive models and MRI. Results The nomogram model showed good discrimination in predicting the risk of SSC tendon tear in patients [C-index=0.878; 95%CI (0.839, 0.918)], and the calibration curve showed that the predicted results were basically consistent with the actual results. The research identified 6 predictors highly associated with SSC tendon tears, including coracohumeral distance (oblique sagittal) reduction, effusion sign (Y-plane), subcoracoid effusion sign, biceps long head tendon displacement (dislocation/subluxation), multiple posterosuperior rotator cuff tears (≥2, supra/infraspinatus), and MRI suspected SSC tear (based on direct sign). Compared with MRI diagnosis based on direct signs of SSC tendon tear, the predictive model had superior sensitivity (80.2% vs. 57.0%), positive predictive value (53.9% vs. 53.3%), negative predictive value (92.7% vs. 86.3%), positive likelihood ratio (3.75 vs. 3.66), and negative likelihood ratio (0.25 vs. 0.51). DCA suggested that the predictive model could produce higher clinical benefit when the risk threshold probability was between 3% and 93%. ConclusionThe nomogram model can reliably predict the risk of SSC tendon tear and can be used as an important tool for auxiliary diagnosis.

    Release date:2022-06-29 09:19 Export PDF Favorites Scan
  • Magnetic resonance diffusion tensor imaging for optic nerves and optic radiation in blind patients

      Objective To observe the characteristics of magnetic resonance diffusion tensor imaging(MR-DTI)for optic nerves and optic radiation in blind patients.Methods The optic nerves and optic radiation of 20 blind patients(blind group)and 20 controls(control group) were scanned by MR-DTI. Fractional anisotropy (FA) and directional encoded color (DEC) maps were acquired through postprocessing with the aid of volumeone 1.72 software. The signal intensity of optic nerves and optic radiation were then observed. The FA, mean diffusivity (MD), lambda;∥ and lambda;perp; value of bilateral optic nerves and optic radiation in two groups were measured in the DEC maps.Results While the high signal intensity was found in bilateral optic nerves in FA and DEC maps in control group,the signal decreased markedly in the blind group. The FA and lambda;∥ value of optic nerves in the blind group were declined obviously compared to that in the control group. The difference was statistically significant (t=16.294, 14.660;P=0.000). The MD and lambda;perp; value of optic nerves in the blind group were increased obviously compared to that in the control group, the difference was also statistically significant (t=8.096, 8.538; P=0.000). The high signal intensity was found in bilateral optic radiation in FA and DEC maps in both the blind and control groups. There were no statistic differences in FA and MD value in bilateral optic radiation between the blind and control groups (Left:t=1.456,1.811;P=0.152,0.076. Right:t=0.779,0.073;P=0.440,0.942). Conclusion A low signal intensity of bilateral optic nerves and a high signal intensity of bilateral optic radiation were found in blind patients.

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • Application of MRI imaging features and tumor distance measurement in preoperative evaluation of rectal cancer

    Objective To investigate the application of magnetic resonance imaging (MRI) in preoperative assessment of rectal cancer. Methods Combined with the literatures, the MRI features and measurements of rectal tumor staging, extramural vascular invasion, circumferential margin involvement, and the distance between distal margin of the tumor from the anorectal ring and the anal margin were described. Results On T2-weighted images (T2WI), T1 staging-tumors were those in which the normal submucosa was replaced by the iso-intensity of tumor tissue without invasion of muscularis propria; T2 staging-tumors were those with extension into the muscularis propria, but not invaded the high-intensity of mesorectal fat; T3 staging-tumors manifested as the rectal tumor penetrated into the muscularis propria and invaded the high-intensity of mesorectal fat; T4 staging-tumors manifested as the tumor invaded adjacent structures or organs. The metastatic lymph nodes were showed with irregular boundaries and mixed signals on T2WI. The tumor signals could be found in the extramural vascular on T1-weighted images (T1WI), accompanied by irregular distortion and expansion of the blood vessels. On T2WI, metastatic lymph nodes, extramural vascular invasion, and the distance between the residual tumor and the low-signal of mesorectal fascia was within 1 mm, indicated the positive circumferential margin. On T2WI, the distal margin of the tumor was located at the junction of hyperintense submucosa and iso-signal of tumor, the tip of the iso-signal puborectal muscle was the apex of the anorectal ring, and the lowest point of the iso-signal external sphincter was the anal margin. Conclusion MRI can provide reliable imaging information for preoperative staging, height measurement, and prognosis of rectal cancer, and it is helpful for early diagnosis and treatment of rectal cancer.

    Release date:2018-11-16 01:55 Export PDF Favorites Scan
  • CT and MRI diagnosis of rare pancreatic tumors

    Objective To investigate the CT and MR imaging manifestation of rare pancreatic tumors in order to deepen the understanding of their imaging characteristics and improve the diagnostic accuracy. Methods Clinical and image date of 34 cases with rare pancreatic tumors proved by surgery and histopathologically were analyzed retrospectively. Including neuroendocrine tumors of the pancreas (NETP,n=13), solid-pseudopapillary tumors of pancreas (SPTP,n=10), intraductal papillary mucinous neoplasms (IPMN,n=2), serous cystadenoma (SCA,n=7), and mucinous cystadenoma (MCA,n=2). Examined by CT in 19 cases, by MRI in 11 cases, examined by CT and MRI at the same time in 4 cases. The characterized imaging features of each kind of tumors were analyzed emphatically. Results Of the 13 cases of NETP, solid lesions in 6 cases, predominantly soild in 4 cases, predominantly cystic in 3 cases. Homogenous enhancement in 6 cases, heterogeneous enhancement in 7cases, the soild constituent of all cases were showed moderate to marked enhancement. Of the 10 cases of SPTP, predominantly soild in 2 cases, soild and cystic in 5 cases, predominantly cystic in 3 cases. The solid part of 10 cases presented as gradually enhancement, 2 cases appeared hemorrhage, 1 case appeared stippled calcification. Of the 2 cases of IPMN, both of them were combined type, showed multilocular cystic tumors due to the dilated of the pancreatic duct. Of the 7 cases of SCA, microcystic partten in 3 cases and single cyst partten in 4 cases, showed unilocular or multilocular cystic with clear boundary. The 2 cases of MCA, showed unilocular cystic with clear boundary. Conclusion Different histological types of pancreatic rare tumor appeared different kinds of imaging characteristic, we may improve the diagnostic accuracy by analyzing their features.

    Release date:2017-01-18 08:04 Export PDF Favorites Scan
  • Research progress on the application value of cardiac magnetic resonance in cryptogenic stroke

    Cryptogenic stroke (CS) accounts for 25% of ischemic stroke. The etiology of undetermined stroke is unclear leading to untargeted secondary prevention, high recurrence rate, so the clinical burden of cryptogenic stroke is substantial. Cardiac magnetic resonance (CMR) imaging can identify more occult cardiac embolism that cannot be identified by standard cardiac assessment based on its excellent spatial resolution and contrast, three-dimensional imaging capacity and ability to depict soft tissues, to accelerate the initiation of optimal secondary prevention and improve the prognosis of patients. This review summarizes the application of CMR in the field of CS in recent years. Based on the latest evidence of diagnosis and management strategies, this paper proposes a cardiac diagnostic examination plan for CS patients, thereby improving the secondary prevention strategy of CS patients and improving their quality of life.

    Release date:2021-07-22 06:28 Export PDF Favorites Scan
  • Multimodal imaging study on localization and qualitative diagnosis of biliary obstruction

    ObjectiveTo evaluate the diagnostic value of CT, MRI, and magnetic resonance cholangiopancreatography (MRCP) in the localization and qualitative diagnosis of biliary obstruction.MethodsA total of 80 patients with biliary obstruction in our hospital from January 2018 to June 2020 were retrospectively collected. The patients were all examined by CT, MRI, and MRCP. The imaging images of all patients were interpreted by two radiologists with more than 5 years of working experience. Taking the results of operation and histopathology as the gold standard, the diagnostic value of CT, MRI+MRCP, CT+MRI+MRCP in the localization and qualitative diagnosis of biliary obstruction lesions were evaluated.ResultsCompared with the location results of surgery and histopathology, the coincidence rates of CT+MRI+MRCP and MRI+MRCP were higher than that of CT (P<0.05), but there was no significant difference between CT+MRI+MRCP and MRI+MRCP (P>0.05); compared with the benign and malignant results of surgery and histopathology, the coincidence rates of CT, CT+MRI+MRCP and MRI+MRCP were close, and there was no statistical significance among them (P>0.05).ConclusionsMRI+MRCP and CT+MRI+MRCP have the same value in the localization and qualitative diagnosis of biliary obstruction. However, MRI+MRCP have the advantages ofnon-radiation or contrast media, it is more suitable for patients who are worried about the impact of radiation, have contrast media allergy or renal insufficiency.

    Release date:2021-05-14 09:39 Export PDF Favorites Scan
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