Objective To evaluate the clinical value of cardiac MRI for the diagnosis of viral myocarditis (VMC). Methods Such databases as PubMed (1950 to 2009), EMbase (1974 to 2009), and The Cochrane Library (December 2009) were searched to include clinical research reports of diagnosing viral myocarditis with MRI. QUADAS items were used to evaluate the quality of the included studies. The Meta-disc software was used to conduct merger analyses on sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. The Heterogeneity test was performed and summary receiver operating characteristic curve (SROC) was completed. Results Five trials were included. The value of merger sensitivity, specificity, and diagnostic odds ratio (DOR) were 0.94, 0.69, 2.76, and 28.11, respectively. The area under of SROC curve (AUC) was 0.871 9. Conclusion The current evidence shows that cardiac MRI has high sensitivity (94%) and moderate specificity (69%) in the diagnosis of viral myocarditis. The positive rate in the viral myocarditis group is 28.11 times as high as that in the non-viral myocarditis group, so Cardiac MRI has good diagnostic values for viral myocarditis.
ObjectiveTo investigate the clinical value of magnetic resonance imaging (MRI) combined with ultrasound (US) contrasting with MRI in evaluating the pathological complete response (pCR) of breast cancer after neoadjuvant chemotherapy (NAC).MethodsThe imaging data of patients with primary invasive breast cancer who completed the surgical resection after NAC and met the inclusion criteria in the Breast Disease Diagnosis and Treatment Center of Affiliated Hospital of Qingdao University from December 2016 to December 2019 were collected retrospectively. These patients were evaluated by MRI and MRI combined with US examination respectively. The results of MRI alone and MRI combined with US were designed into imaging of complete remission (rCR) and imaging of non-complete remission (non-rCR). With results of postoperative pathology as the gold standard, the sensitivity, specificity, and positive predictive value (PPV) of MRI alone and MRI combined with US in predicting pCR of patients with rCR or non-rCR were calculated and which were further analyzed in the 4 subtypes of breast cancer (HR+/HER2+, HR+/HER2–, HR–/HER2+, and HR–/HER2– subtype).Results① According to the inclusion and exclusion criteria, a total of 146 patients with primary invasive breast cancer were included, including 34 cases of HR+/HER2+subtype, 63 cases of HR+/HER2– subtype, 23 cases of HR–/HER2+ subtype, and 26 cases of HR–/HER2– subtype. ② After NAC, 36 cases had a pCR, among which 9 cases (26.5%) were in HR+/HER2+ subtype, 10 cases (15.9%) were in HR+/HER2– subtype, 8 cases (34.8%) were in HR–/HER2+ subtype, and 9 cases (34.6%) were in HR–/HER2– subtype. ③ After NAC, 22 (78.6%) of the 28 patients evaluated by MRI alone achieved pCR, 17 (81.0%) of the 21 patients evaluated by MRI combined with US achieved pCR, and the PPV value of pCR evaluated by MRI alone and MRI combined with US was 78.6% and 81.0%, respectively. ④ Both MRI alone and MRI combined with US predicted NAC showed the highest PPV values in patients with HR–/HER2– subtype breast cancer (85.7% and 100%, respectively), and the lowest values in HR+/ HER2– subtype breast cancer (71.4% and 60.0%, respectively).ConclusionFor the overall patients with primary invasive breast cancer, MRI combined with US is superior to MRI alone in the evaluation of efficacy after NAC, and among the patients with different subtypes of breast cancer, except HR+/HER2– subtype, MRI combined with US is still more effective in predicting efficacy after NAC than MRI alone.
Acute aortic dissection is featured as sudden onset and high mortality. Regardless early optimal surgical intervention and strict medical therapy, incidence of late complications is still high. Thus, specific imaging techniques and precise measurement of biomarkers to predict complications are needed. In the present study, we reviewed related papers to compare traditional imaging techniques (computed tomography, echocardiography) and magnetic resonance imaging (MRI) in the diagnosis of chronic aortic dissection. In addition, we discussed how to further evaluate aortic dissection by MRI.
Urokinase plasminogen activator receptor (uPAR) is a membrane protein which is attached to the cellular external membrane. The uPAR expression can be observed both in tumor cells and in tumor-associated stromal cells. Thus, in the present study, the human amino-terminal fragment (hATF), as a targeting element to uPAR, is used to conjugate to the surface of superparamagnetic iron nanoparticle (SPIO). Flowcytometry was used to examine the uPAR expression in different tumor cell lines. The specificity of hATF-SPIO was verified by Prussian blue stain and cell phantom test. The imaging properties of hATF-SPIO were confirmed in vivo magnetic resonance imaging (MRI) of uPAR-elevated colon tumor. Finally, the distribution of hATF-SPIO in tumor tissue was confirmed by pathological staining. Results showed that the three cells in which we screened, presented different expression characteristics, i.e., Hela cells strongly expressed uPAR, HT29 cells moderately expressed uPAR, but Lovo cells didn't express uPAR. In vitro, after incubating with Hela cells, hATF-SPIO could specifically combined to and be subsequently internalized by uPAR positive cells, which could be observed via Prussian blue staining. Meanwhile T2WI signal intensity of Hela cells, after incubation with targeted probe, significantly decreased, and otherwise no obvious changes in Lovo cells both by Prussian blue staining and MRI scans. In vivo, hATF-SPIO could be systematically delivered to HT29 xenograft and accumulated in the tumor tissue which was confirmed by Prussian Blue stain compared to Lovo xenografts. Twenty-four hours after injection of targeting probe, the signal intensity of HT29 xenografts was lower than Lovo ones which was statistically significant. This targeting nanoparticles enabled not only in vitro specifically combining to uPAR positive cells but also in vivo imaging of uPAR moderately elevated colon cancer lesions.
To address the issues of difficulty in preserving anatomical structures, low realism of generated images, and loss of high-frequency image information in medical image cross-modal translation, this paper proposes a medical image cross-modal translation method based on diffusion generative adversarial networks. First, an unsupervised translation module is used to convert magnetic resonance imaging (MRI) into pseudo-computed tomography (CT) images. Subsequently, a nonlinear frequency decomposition module is used to extract high-frequency CT images. Finally, the pseudo-CT image is input into the forward process, while the high-frequency CT image as a conditional input is used to guide the reverse process to generate the final CT image. The proposed model is evaluated on the SynthRAD2023 dataset, which is used for CT image generation for radiotherapy planning. The generated brain CT images achieve a Fréchet Inception Distance (FID) score of 33.159 7, a structure similarity index measure (SSIM) of 89.84%, a peak signal-to-noise ratio (PSNR) of 35.596 5 dB, and a mean squared error (MSE) of 17.873 9. The generated pelvic CT images yield an FID score of 33.951 6, a structural similarity index of 91.30%, a PSNR of 34.870 7 dB, and an MSE of 17.465 8. Experimental results show that the proposed model generates highly realistic CT images while preserving anatomical accuracy as much as possible. The transformed CT images can be effectively used in radiotherapy planning, further enhancing diagnostic efficiency.
ObjectiveTo investigate clinical value of MRI examination in diagnosis of xanthogranulomatous cholecystitis (XGC), and to analyze pathologic correlation of various imaging findings.
MethodsMRI imaging data of 7 patients with XGC proved by surgery and pathology who underwent entire MRI sequences examination in Sichuan Provincial People's Hospital from Jan. 2013 to Dec. 2015, were analyzed retrospectively. The thickness and contrast enhancement of gallbladder wall, gallbladder wall nodules, completeness of gallbladder mucosa lines, gallbladder stones, and the changes around the gallbladder were focused in every patient.
ResultsIn 7 patients with XGC: gallbladder wall thickening occurred in all patients, in which 2 patients were local thickening, 5 patients were diffuse thickening; ‘hypodense band sign' was found by enhance scan in 4 patients; the multiple intramural nodules were presented in 5 patients, which were low signal intensity on T1WI image and high signal intensity on T2WI image; the mucosal lines were continuous in 6 patients and discontinuous in 1 patient; 6 patients combined with cholecystolithiasis. The fat layer around the gallbladder was found fuzz in 7 patients, liver and gallbladder boundaries were not clear in 7 patients; temporal enhancement of arterial phase in liver parenchyma was observed in all patients, and 1 patient combined with liver abscess. Hilar bile duct narrowed and intra-hepatic bile duct dilated in 2 patients, intra-hepatic and extra-hepatic bile duct slightly dilated in 2 patients (lower part of the choledochus stone was found in 1 patient), liver cyst was observed in 3 patients, single or double kidney cyst was observed in 4 patients; all patients were not found intraperitoneal or retroperitoneal swelling lymph nodes.
ConclusionMRI examination can accurately describe various imaging features of XGC, so MRI has important value in diagnosis of XGC.
ObjectiveTo investigate the CT and MR imaging manifestation of solid-pseudopapillary neoplasm of pancreas (SPNP), deepen the understanding of imaging and clinical pathological characteristics of SPNP and improve the level of diagnosis.
MethodsBetween Jan 2010 and Dec 2015, the CT and MR imaging data of seven patients with SPTP proved by surgery and histopathologically were analyzed retrospectively. The following imaging features were reviewed: tumor size, location, shape, margin, encapsulation, calcification, hemorrhage, solid-cystic ratio, pancreatic and bile duct dilatation, the manifestation of plain scan and dynamic pattern of enhancement.
ResultsThe population comprised 7 women, the average age was 28.3 years oldwith a median tumor size of 5.7 cm. Tumors were located at body tail of pancreas in 5 cases, at the head in 1 case, and at the tail in 1 case. The tumor were exogenous in 5 cases, endogenous in 2 cases. Five tumors showed the regular margin, inregular in 2 cases. Four cases of plain and enhanced CT scan showed cystic-solid tumors, the solid and encapsulation part ofSPNP presented as hipo-, iso-density, and gradually enhancement after injecting contrast medium. Three cases were examined by MRI, 2 cases appeared hemorrhage, tumor located in the head of pancreas leaded to the secondary ducts dilatations in 1 case. Conciusions There are some characteristics in CT and MRI manifestation of SPNP. Accurate diagnosis meybe created by the imaging study combined with the clinical feature.
