摘要:目的: 分析肝臟局灶性結節增生(FNH)的MRI表現和病理特點,探討兩者的相關性,提高FNH診斷的準確率。 方法 :回顧性分析23例(共28個病灶)經手術切除病理證實為FNH的MRI平掃及增強表現,與其病理特點進行對照。 結果 :25個病灶在平掃T1WI上呈等或稍低信號,T2WI上呈等或稍高信號,3個病灶在平掃T1WI及T2WI上均呈稍高信號,增強后所有28病灶動脈期可見明顯強化,門脈期及延遲期呈稍高、等或稍低信號,其中12個病灶可見中心纖維瘢痕延遲強化。FNH組織病理上表現為富血供的實質性腫塊,腫物內部組織較均勻,沒有異型細胞,中心可見纖維瘢痕。 結論 :肝臟MRI平掃及增強檢查能很好的反映FNH的組織病理及血供特點,能為FNH的診斷及鑒別診斷提供可靠證據。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．
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.
Focus on the inconsistency of the shape, location and size of brain glioma, a dual-channel 3-dimensional (3D) densely connected network is proposed to automatically segment brain glioma tumor on magnetic resonance images. Our method is based on a 3D convolutional neural network frame, and two convolution kernel sizes are adopted in each channel to extract multi-scale features in different scales of receptive fields. Then we construct two densely connected blocks in each pathway for feature learning and transmission. Finally, the concatenation of two pathway features was sent to classification layer to classify central region voxels to segment brain tumor automatically. We train and test our model on open brain tumor segmentation challenge dataset, and we also compared our results with other models. Experimental results show that our algorithm can segment different tumor lesions more accurately. It has important application value in the clinical diagnosis and treatment of brain tumor diseases.
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.
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.
Objective
To analyze and summarize advantages, disadvantages, and limitations of present imaging techniques in assessing efficacy of immunotherapy for patient with hepatocellular carcinoma in order to provide strong evidence for drug therapy evaluation and clinical decision-making for it.
Method
The relevant literatures about imaging evaluation of immunotherapy for hepatocellular carcinoma were collected to make a review, then analyze and summarize the value of different imaging techniques.
Results
The immunotherapy, characterized by the noninvasive, high specificity and good curative effect, had been playing an important role in the treatment of hepatocellular carcinoma in recent years. The imaging techniques currently used to assess the immunotherapy results of hepatocellular carinoma mainly included the CT, MRI, ultrasound, and nuclear medicine, which could be used to better evaluate the effectiveness of immunotherapy. It was very important for screening of the patients’ treatment options and judging of the survival and prognosis. The most of the evaluation indicators were based on the anatomic evaluation criteria and it had some certain limitations in evaluating the immunotherapy efficacy of patient with hepatocellular carcinoma.
Conclusions
As an emerging biological therapy, immunotherapy has gradually become a hotspot in diagnosis and treatment of hepatocellular carcinoma in future. Present imaging techniques and evaluation criteria have certain limitations. More multifunctional imaging indicators need to be improved and developed so as to provide strong evidence for drug therapy evaluation and clinical decision of patient with hepatocellular carcinoma.
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.
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.
