Coronary microcirculation dysfunction (CMVD) is an important risk factor for the prognosis of re-perfused ischemic heart. Recent studies showed that the evaluation of CMVD has significant impact on both the early diagnosis of heart diseases relevant to blood supply and prognosis after myocardial reperfusion. In this review, the definition of CMVD from the perspective of pathophysiology was clarified, the principles and features of the state-of-the-art imaging technologies for CMVD assessment were reviewed from the perspective of engineering and the further research direction was promoted.
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.
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.
摘要:目的: 分析肝脏局灶性结节增生(FNH)的MRI表现和病理特点,探讨两者的相关性,提高FNH诊断的准确率。 方法 :回顾性分析23例(共28个病灶)经手术切除病理证实为FNH的MRI平扫及增强表现,与其病理特点进行对照。 结果 :25个病灶在平扫T1WI上呈等或稍低信号,T2WI上呈等或稍高信号,3个病灶在平扫T1WI及T2WI上均呈稍高信号,增强后所有28病灶动脉期可见明显强化,门脉期及延迟期呈稍高、等或稍低信号,其中12个病灶可见中心纤维瘢痕延迟强化。FNH组织病理上表现为富血供的实质性肿块,肿物内部组织较均匀,没有异型细胞,中心可见纤维瘢痕。 结论 :肝脏MRI平扫及增强检查能很好的反映FNH的组织病理及血供特点,能为FNH的诊断及鉴别诊断提供可靠证据。Abstract: Objective: To analyze the MRI manifestations and pathology characteristic of hepatic focal nodular hyperplasia(FNH),and to investigate their correlation. Methods : A retrospective analysis was made on the unenhanced and dynamic enhanced MR images of 23 patients (totally 28 lesions) with surgical and pathological proved FNH. Results :25 FNH lesions demonstrated isointensity or slightly hypointense on unenhanced T1WI,and isointensity or slightly hyperintense on unenhanced T2WI,3 FNH demonstrated hyperintense on both unenhanced T1WI and T2WI. 28 FNHs were markediyhyperintense in the arterial phase of dynamic contrast enhanced MRI, and isointense or slightly hyperintense in the portal and delayed phase．The seals were shown in 12 lesions, and enhanced in delayed phase．FNH is solid mass with vast blood supply,its inside structure is homogemeous. Typical seal can be found by microscopic examination．〖WTHZ〗Conclusion : MRI could disclose the pathologic features of FNH and its blood supply and improve the accuracy 0f its diagnosis．
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.
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 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.