Objective To investigate the relationship between Oxfordshire community stroke project (OCSP) classification and MRI classification in acute cerebral infarction. Methods A total of 282 patients with acute cerebral infarction were retrospectively evaluated with OCSP classification and imaging characteristics. Results According to OCSP classification, of all 282 patients with acute cerebral infarction, 32 (11.3%) experienced total anterior circulation infarction (TACI), 86 (30.5%) partial anterior circulation infarction (PACI), 111 (39.4%) lacunar infarction (LACI), and 53 (18.8%) posterior circulation infarction (POCI). The consistency was found in 201 cases (71.3%) between the OCSP classification and imaging classification, with the accuracy of 77% (27/35) for TACI, 79% (42/53) for PACI, 69% (95/137) for LACI and 65% (37/57) for POCI. Conclusion OCSP classification can predict the location and size of cerebral infarction with a high accuracy, and is well consistent with the MRI findings.
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 investigate multi-slice spiral CT (MSCT) and MRI features of stasis cirrhosis and the diagnostic value of MSCT and MRI. Methods MSCT and MRI findings of 35 patients with stasis cirrhosis were studied. The size of liver and spleen, the diameter of hepatic vein (HV), enhancement pattern of liver parenchyma, contrast medium reflux in inferior vena cava (IVC) and (or) HV, ascites, number of varices and correlated abnormalities were reviewed. Results The volume index of liver and spleen of 35 patients was 4434.95 cm3 and 621.92 cm3 respectively. The mean diameter of HV of 27 patients (77.1%) was 3.61 cm and HV of other 8 patients (22.9%) were too small to show. Number of patients showed waves of borderline, inhomogeneous pattern of parenchymal contrast enhancement, contrast medium reflux in IVC and (or) HV, varices and ascites was 5 (14.3%), 29 (82.9%), 20 (57.1%), 16 (45.7%), and 6 (17.1%), respectively. Correlated abnormalities included cardiac enlargement 〔4 cases (11.4%)〕, pericardium thickening 〔11 cases (31.4%)〕, and pericardial effusion 〔2 cases (5.7%)〕. Conclusions Stasis cirrhosis mainly demonstrate liver enlargement, inhomogeneous pattern of parenchymal contrast enhancement, contrast medium reflux in IVC and (or) HV, and slight portal hypertension. MSCT and MRI play invaluable roles in diagnosis, differential diagnosis and etiological diagnosis of stasis cirrhosis.
ObjectiveTo systematically review the diagnostic accuracy of MRI in preschool children with autism spectrum disorder. MethodsDatabases including Web of Science, PubMed, The Cochrane Library, EMbase, CBM, CNKI, WanFang Data, and VIP were electronically searched for studies on MRI in diagnosis of preschool children with autism spectrum disorder from inception to January 2022. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias the included studies. Then, meta-analysis was performed using Meta-Disc, RevMan 5.4 and Stata 16.0 software. ResultsA total of 17 studies were finally included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnosis odds ratio and area under the curve of SROC were 0.78 (95%CI 0.76 to 0.81), 0.77 (95%CI 0.75 to 0.79), 3.92 (95%CI 2.83 to 5.41), 0.28 (95%CI 0.23 to 0.35), 14.8 (95%CI 9.31 to 23.52) and 0.86, respectively. Subgroup analysis revealed that the source of patients, age, prediction methods and analysis features were potential sources of heterogeneity. Heterogeneity in the subgroup of 1-3 years old was small, and the pooled sensitivity, specificity and area under the curve of SROC were 0.81 (95%CI 0.76 to 0.85), 0.82 (95%CI 0.78 to 0.86) and 0.87, respectively. The pooled sensitivity, specificity and area under the curve of SROC for non-site studies were 0.80 (95%CI 0.75 to 0.84), 0.80 (95%CI 0.76 to 0.85) and 0.86, respectively. ConclusionMRI has a high accuracy in the diagnosis of preschool children with autism spectrum disorder; however, the possibility of misdiagnosis and missed diagnosis should be considered. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.
Objective To evaluate the values of magnetic resonance imaging (MRI) in the diagnosis of acetabular labral tears (ALT) by meta-analysis. Methods The studies concerning the diagnosis of ALT tears by using MRI from January 1990 to October 2016 were searched in the databases such as CBM, VIP, WanFang Data, CNKI, PubMed, EMbase, The Cochrane Library and Web of Science. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies by using the QUADAS-2 tool. Then, meta-analysis was performed by using Stata 12.0 software. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (–LR) and the diagnostic odds ratio (DOR) were calculated, and the summary receiver operating characteristic curve (SROC) was drawn and the area under the carve was calculated. Results A total of 25 studies from 21 articles were included, involving 1 123 hips from 1 099 patients. The results of meta-analysis showed that, the pooled Sen, Spe, +LR, –LR, DOR and area under SROC curve of MRI for diagnosing ALT were 0.66 (95% CI 0.38 to 0.86), 0.72 (95% CI 0.47 to 0.89), 2.37 (95% CI 1.18 to 4.67), 0.48 (95% CI 0.25 to 0.92), 4.97 (95% CI 1.60 to 15.47), 0.75 (95% CI 0.71 to 0.79). The pooled Sen, Spe, +LR, –LR, DOR and area under SROC curve of MRA for diagnosing ALT were 0.86 (95% CI 0.80 to 0.90), 0.71 (95% CI 0.55 to 0.83), 2.91 (95% CI 1.77 to 4.80), 0.20 (95% CI 0.13 to 0.32), 14.44 (95% CI 5.80 to 35.95), 0.87 (95% CI 0.84 to 0.90), respectively. Conclusion MRI is efficiency diagnostic method for acetabular labral tears.
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 Xray. 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 angleclosure 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.
ObjectiveTo investigate the clinical features of Hirayama disease (HD). MethodsWe analyzed the clinical manifestations and assistant examination results of one patient with HD diagnosed in November, 2010. In addition, we reviewed the related literatures. ResultsThe patient was a young man, and the main symptoms were bilateral hand weakness with muscular atrophy. The muscle bundles trembled when he stretched his fingers. The electromyography showed neurogenic damage of both the thenar muscles and the first interosseous muscles. Brain magnetic resonance imaging (MRI) showed normal; cervical spine flexion MRI showed thinning cervical spinal cord with spinal canal narrowing at C5-C7 plane. In addition, epidural fat gap widened at C4-T1 plane, and enhanced scan showed cord-like changes, patchy strengthening and blood flow void shadow. ConclusionWhen asymmetric distal upper limb muscle weakness with muscle atrophy appears in adolescents, HD should be considered. The combination of neuroelectrophysiological examination and cervical spine flexion MRI scan is helpful for diagnosis. Wearing cervical collar may slow disease progression.
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.
The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.
Objective To determine the safety of the fetal olfactory ensheathing cell(OEC) transplantation in patients with chronic spinal cord injury (SCI) by examination of the magnetic resonance imaging (MRI). Methods A prospective clinical study involving 16 patients with chronic SCI was designed to investigate the feasibility and biological safety of the fetal OEC transplantation in treatment of SCI. The olfactory bulbs from the 3-4-month-old aborted human fetuses following the strict ethical guidelines were harvested and trypsinized down to single fetal OEC. These cells were then cultured for 12-17 days and were prepared for a clinical use. From November 2001 to December 2002, 16 patients with chronic SCI were randomly enrolled. The patients suffered from SCI for1.5-8 years (average 4-3 years) after the injury. The suspension (50 μl) containing about 1×106 fetal OECs was transplanted by an injection into the patients’ spinal cords above and below the injury site. All the patients were assessed before thetransplantation and were followed up with MRI for 29-42 months (average 38 mon)after the transplantation. Results No cell-related adverse effects were observed in any patient during the followup period. The follow-up with MRI did not reveal any development of optic glial tumor, tumor-like mass, new hemorrhage,edema, expanding cyst, new cyst formation, infection or disruption of the neuralstructure in the transplant site of all the patients. Conclusion This is the first clinical study demonstrating the long-term safety of theOEC therapy for SCI. The results indicate that our protocol is feasible and safe in treatment of patients with chronic SCI within 38 months after the injury. Although the size of the samples for our study was not big enough, the positive results of the study have encouraged us to make a further research in this field.