Diffusion tensor imaging (DTI) is a rapid development technology in recent years of magnetic resonance imaging. The diffusion tensor interpolation is a very important procedure in DTI image processing. The traditional spectral quaternion interpolation method revises the direction of the interpolation tensor and can preserve tensors anisotropy, but the method does not revise the size of tensors. The present study puts forward an improved spectral quaternion interpolation method on the basis of traditional spectral quaternion interpolation. Firstly, we decomposed diffusion tensors with the direction of tensors being represented by quaternion. Then we revised the size and direction of the tensor respectively according to different situations. Finally, we acquired the tensor of interpolation point by calculating the weighted average. We compared the improved method with the spectral quaternion method and the Log-Euclidean method by the simulation data and the real data. The results showed that the improved method could not only keep the monotonicity of the fractional anisotropy (FA) and the determinant of tensors, but also preserve the tensor anisotropy at the same time. In conclusion, the improved method provides a kind of important interpolation method for diffusion tensor image processing.
Magnetic resonance imaging(MRI) can obtain multi-modal images with different contrast, which provides rich information for clinical diagnosis. However, some contrast images are not scanned or the quality of the acquired images cannot meet the diagnostic requirements due to the difficulty of patient's cooperation or the limitation of scanning conditions. Image synthesis techniques have become a method to compensate for such image deficiencies. In recent years, deep learning has been widely used in the field of MRI synthesis. In this paper, a synthesis network based on multi-modal fusion is proposed, which firstly uses a feature encoder to encode the features of multiple unimodal images separately, and then fuses the features of different modal images through a feature fusion module, and finally generates the target modal image. The similarity measure between the target image and the predicted image in the network is improved by introducing a dynamic weighted combined loss function based on the spatial domain and K-space domain. After experimental validation and quantitative comparison, the multi-modal fusion deep learning network proposed in this paper can effectively synthesize high-quality MRI fluid-attenuated inversion recovery (FLAIR) images. In summary, the method proposed in this paper can reduce MRI scanning time of the patient, as well as solve the clinical problem of missing FLAIR images or image quality that is difficult to meet diagnostic requirements.
ObjectiveTo summarize the research progress of near infra-red fluorescence imaging (NIRFI) in biliary tract surgery, and to provide protection for improvements of therapeutic effect and safety of biliary tract surgery.MethodThe relevant literatures about studies on NIRFI in the biliary tract surgery in recent years were reviewed.ResultsThe NIRFI had been preliminarily used in the surgical treatment of benign and malignant biliary diseases, and had shown its unique value in cholangiography. It provided a new method for effectively avoiding surgical complications, shortening operation time, reducing the rate of conversion to open surgery, evaluating blood supply of bile duct and improving the safety of operation.ConclusionsNIRFI has achieved notable successes in treatment of biliary tract diseases. With future application of fluorescence imaging in near infra-red Ⅱ window and new specific fluorescence targeting molecules, this technique will highlight its more important values in biliary surgery.
Tumor chemotherapy is a treatment method that employs chemotherapeutic drugs to eradicate cancer cells. These drugs are cytotoxic, meaning they can affect both tumor cells and normal cells. In recent years, there has been a gradual increase in chemotherapy-induced liver injury. Chemotherapy-induced parenchymal liver injury often manifests as diffuse lesions, although focal lesions can occasionally be observed. There is a diversity in the pathogenesis and pathological changes of chemotherapy-induced focal liver disease. Radiologically, there is often challenging in differentiating chemotherapy-induced focal liver disease from hepatic metastases. Therefore, early and accurate diagnosis of this condition poses a certain challenge in clinical practice. This article presents the radiological findings of a case of chemotherapy-induced focal liver disease induced by chemotherapy for gastric cancer, and summarizes the radiological features and differential diagnostic points of chemotherapy-induced focal liver disease, aiming to enhance the understanding of this type of lesion among radiologists and clinicians and reduce related missed diagnoses and misdiagnoses.
The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.
Amblyopia is a visual development deficit caused by abnormal visual experience in early life, mainly manifesting as defected visual acuity and binocular visual impairment, which is considered to reflect abnormal development of the brain rather than organic lesions of the eye. Previous studies have reported abnormal spontaneous brain activity in patients with amblyopia. However, the location of abnormal spontaneous activity in patients with amblyopia and the association between abnormal brain function activity and clinical deficits remain unclear. The purpose of this study is to analyze spontaneous brain functional activity abnormalities in patients with amblyopia and their associations with clinical defects using resting-state functional magnetic resonance imaging (fMRI) data. In this study, 31 patients with amblyopia and 31 healthy controls were enrolled for resting-state fMRI scanning. The results showed that spontaneous activity in the right angular gyrus, left posterior cerebellum, and left cingulate gyrus were significantly lower in patients with amblyopia than in controls, and spontaneous activity in the right middle temporal gyrus was significantly higher in patients with amblyopia. In addition, the spontaneous activity of the left cerebellum in patients with amblyopia was negatively associated with the best-corrected visual acuity of the amblyopic eye, and the spontaneous activity of the right middle temporal gyrus was positively associated with the stereoacuity. This study found that adult patients with amblyopia showed abnormal spontaneous activity in the angular gyrus, cerebellum, middle temporal gyrus, and cingulate gyrus. Furthermore, the functional abnormalities in the cerebellum and middle temporal gyrus may be associated with visual acuity defects and stereopsis deficiency in patients with amblyopia. These findings help explain the neural mechanism of amblyopia, thus promoting the improvement of the treatment strategy for amblyopia.
ObjectiveTo analyze the causes of unrelieved epilepsy thoroughly in children with isolated focal cortical dysplasia (FCD) based on MRI.MethodsRetrospective analysis of MRI and clinical data of 21 children with isolated FCD during July 2014 to January 2018, which confirmed by pathology and unrelieved thoroughly after operation performed, the pathological types and MRI signs were analyzed, as well as the frequency of different MRI signs in FCD of each pathological type. Analyzed the possible factors of surgical failure.ResultsAmong the 21 cases, there were 15 males and 6 females, with an average age of (5.7±0.3) years and an average course of disease of (3.4±0.5) years.MRI signs of this part of the children were mainly manifested by blurred focal gray matter boundaries, abnormal cortical structure changes (thickening and/or thinning), transmantle signs (abnormal cone signals extending from subcortical white matter to the ventricle) and abnormal gray matter signals, which were similar to MRI signs of FCD with satisfactory postoperative epilepsy control. 17 cases (80.9%) appeared epileptic discharge after operation in the EEG monitoring area 2 weeks to 6 months, FCD type I and type Ⅱ accounted for 35.3%, 64.7% respectively. During intraoperative EEG monitoring, no epileptiform discharge was observed in the transmantle sign region in 6 cases, and the region was retained, and only the surrounding abnormal discharge cortex was removed, complete removal of the tansmantle sign and surrounding abnormal discharge area was performed in 2 cases, and different degrees of epileptic epilepsy were observed in both methods.ConclusionMRI signs of isolated FCD with unrelieved epilepsy after operation were nonspecific, there were still epilepsy of varying degrees after all epileptogenic lesions have been removed, the cause may be related to potential epileptic factors.
Primary breast angiosarcoma (PBA) is a rare malignant tumor, and few clinical cases have been reported. In this case, the mammographic and contrast-enhanced magnetic resonance imaging of PBA were reported, and the relevant pathologic basis was also briefly introduced in order to enhance the clinicians’ understanding of the imaging manifestations of this rare disease.
ObjectiveTo preliminarily evaluate the feasibility of ultra-wide-angle fundus imaging (UWFI) to observe the Weiss ring (vitreous floats) and the effectiveness and safety of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser ablation in the treatment of symptomatic Weiss ring. MethodsA retrospective clinical study. From March 2016 to December 2019, 80 eyes of 68 patients with symptomatic Weiss ring who were diagnosed and treated at Guangzhou Aier Eye Hospital were included in the study. Among them, there were 39 eyes in 32 males and 41 eyes in 36 females; the average age was 53.7±10.8 years old. All the affected eyes were examined by slit lamp microscope combined with 90 D front lens and UWFI. The position and shape of the vitreous floating objects by drawing pictures were recorded. All the affected eyes underwent Nd: YAG laser ablation treatment. Three months after treatment, a questionnaire survey was conducted on the patients to assess the improvement of subjective symptoms. Those with a total score of 10, 7-9, 3-6, and ≤2 points were defined as cured, significant improvement, partial improvement, and no improvement, respectively. The measurement software Gauge 1.0 was used to manually measure the long diameter, circumference and area of the vitreous float on the UWFI image. The diameter of the optic disc to 1 Unit (U) was set as a standardized reference value. Those who did not show UWFI and no floating objects were found on the front mirror were recorded as 0. The changes of vitreous floats before and after treatment were compared by Wilcoxon rank sum test; the changes in their size before and after treatment and the patients' subjective symptom improvement scores after treatment were analyzed by Spearman rank correlation. ResultsAfter treatment, in 80 eyes, there were no vitreous floats in 59 eyes (73.8%, 59/80) on UWFI. Before treatment, the circumference of the vitreous float was 1.84 (1.07, 2.64) U, the long diameter was 1.17 (0.84, 1.66) U, and the area was 0.18 (0.08, 0.30) U2; after treatment, the circumference was 0.00 (0.00, 0.23) U, The long diameter is 0.00 (0.00, 0.23) U, and the area was 0.00 (0.00, 0.01) U2. There were statistically significant differences in the perimeter, diameter, and area of floating objects before and after treatment (Z=−7.722, −7.560, −7.655; P＜0.001). The results of the questionnaire survey showed that the patient's subjective symptoms were cured, significantly improved, and partially improved in 49 (61.3%, 49/80), 25 (31.2%, 25/80), and 6 (7.5%, 6/80) eyes, respectively. The results of correlation analysis showed that the degree of improvement of the patient's subjective symptoms was related to the circumference (r=0.812), long diameter (r=0.796), and area (r=0.791) of the vitreous float on UWFI before and after treatment (P＜0.01). During the follow-up period, no complications such as increased intraocular pressure or decreased vision occurred. ConclusionsUWFI can objectively image the Weiss ring, and its size can be quantified relatively to the measurement software. Nd: YAG laser ablation treatment of symptomatic Weiss ring is safe and effective.
ObjectiveTo observe the imaging features of cystoid macular edema (CME) in multicolor imaging (MC), and to evaluate the value of MC in the diagnosis of CME.MethodsDescriptive case series study. From August 2017 to June 2018, 42 eyes of 37 patients with CME diagnosed in the people's Hospital of Wuhan University were included in the study. Among them, there were 24 males and 13 females, with an average age of 48.51±10.29 years. There were 14 eyes with diabetic retinopathy, 14 eyes with central retinal vein occlusion, 8 eyes with branch retinal vein occlusion, 4 eyes with uveitis, and 2 eyes with Eales disease. The macular color fundus photography (CFP) was performed with Visucam 200 non-mydriatic fundus camera of Zeiss company in Germany. MC, frequnce domainoptical OCT (SD-OCT) and FFA were examined by Spectralis HRA2 + OCT of Heidelberg company in Germany. According to the MC standard method, five images, including 488 nm blue reflection (BR), 515 nm green reflection (GR), 820 nm infrared reflection (IR) imaging and standard MC and blue-green enhancement (BG), were obtained at the same time. Compared with SD-OCT, CFP and MC images were scored. Friedman M test and Wilcoxon signed rank test were used for statistical analysis.ResultsThe standard MC and BG images showed blue-green uplift area or petal-shaped appearance, surrounded by green reflection areas with clear boundaries. BR image can be seen in the low reflexes area. On the GR image, there were patches or cystic low reflection areas, surrounded by a slightly high reflection. On the IR image, patches or cystoid high reflexes can be seen, surrounded by low reflection dark areas with clear boundaries. The average scores of CFP, standard MC, GB, IR, GR and BR were 1.20±0.94, 3.05±0.99, 2.90±1.04, 2.55±1.27, 2.00±0.94, 0.51±0.85 respectively, and the differences were statistically significant (χ2= 151.61, P=0.000). The score of CFP were significantly lower than that of standard MC (Z=－5.421), BG (Z=－5.354), IR (Z=－4.714), GR (Z=－4.438) and higher than that of BR (Z=－3.435). The differences were statistically significant (P=0.000, 0.000, 0.000, 0.000, 0.001).ConclusionsThe quality of MC imaging is better than that of CFP. Combined with SD-OCT, it can be used as an assistant method to diagnose CME.