Research on Search Laws of Image Guided Missile

When image guided missile adopts guided search and common search law to search ground targets, under some conditions the movement of image on the monitor screen will be dissymmetrical, which is harmful for shooter to acquire and capture targets. To remove the dissymmetry of the image movement, such common search laws as parallel search law, ＂X＂ style search law, search law of one-dimension visual effect and cone search law are improved and designed again. Simulation results show that the dissymmetry can be removed by adopting all the above four improved search laws, but the search track of improved cone search law has serious transmutation compared with the original search track. The other three improved search laws have little transmutation of the search track, and they all can keep the main characters of the original search law. Study resuits are helpful for image guided missile in adopting guided search to choose appropriate search law.

A new projection model based robust 2D-3D registration method on Fourier-Mellin space for image guided intervention

An automatic method is proposed to solve the registration problem,which aligns a single 2D fluoroscopic image to a 3D image volume without demanding any additional media like calibration plate or user interactions.First,a mathematic projection model is designed which can reduce the influence of projection distortion on parameter optimization and improve the registration accuracy.Then,a two stage optimization method is proposed,which enables a robust registration in a wide parameter space.Furthermore,an automatic registration framework is proposed based on the FourierMellin robust image comparison descriptor.Experimental results show that the registration method has a high accuracy with average rotation error of 0.6 degree and average translation error of 1.4mm.

Imaged guided surgery during arteriovenous malformation of gastrointestinal stromal tumor using hyperspectral and indocyanine green visualization techniques:A case report

BACKGROUND This case report demonstrates the simultaneous development of a gastrointestinal stromal tumour(GIST)with arteriovenous malformations(AVMs)within the jejunal mesentery.A 74-year-old male presented to the department of surgery at our institution with a one-month history of abdominal pain.Contrast-enhanced computed tomography revealed an AVM.During exploratory laparotomy,hyperspectral imaging(HSI)and indocyanine green(ICG)fluorescence were used to evaluate the extent of the tumour and determine the resection margins.Intraoperative imaging confirmed AVM,while histopathological evaluation showed an epithelioid,partially spindle cell GIST.CASE SUMMARY This is the first case reporting the use of HSI and ICG to image GIST intermingled with an AVM.The resection margins were planned using intraoperative analysis of additional optical data.Image-guided surgery enhances the clinician’s knowledge of tissue composition and facilitates tissue differentiation.CONCLUSION Since image-guided surgery is safe,this procedure should increase in popularity among the next generation of surgeons as it is associated with better postoperative outcomes.

Accuracy of combined PET/CT in image-guided interventions of liver lesions: An ex-vivo study

AIM： Positioning of interventional devices in liver lesions is a challenging task if only CT is available. We investigated the potential benefit of combined PET/CT images for localization of interventional devices in interventional liver studies. METHODS： Thirty lesions each of hyperdense, isodense and hypodense attenuation compared to normal liver parenchyma were injected into 15 ex-vivo pig livers. All lesions were composed of the same amounts of gelatine containing 0.5 MBq of ^18F-FDG. Following lesion insertion, an interventional needle was placed in each lesion under CT-guidance solely. After that, a PET/CT study was performed. The localization of the needle within the lesion was assessed for CT alone and PET/CT and the root mean square （RMS） was calculated. Results were compared with macroscopic measurements after lesion dissection serving as the standard of reference. RESULTS： In hypo- and isodense lesions PET/CT proved more accurate in defining the position of the interventional device when compared with CT alone. The mean RMS for CT and PET/CT differed significantly in isodense and hypodense lesions. No significant difference was found for hyperdense lesions. CONCLUSION： Combined FDG-PET/CT imaging provides more accurate information than CT alone concerning the needle position in FDG-PET positive liver lesions. Therefore combined PET/CT might be potentially beneficial not only for localization of an interventional device, but may also be beneficial for guidance in interventional liver procedures.

Static-shift suppression and anti-interference signal processing for CSAMT based on Guided Image Filtering

Shallow conductive heterogeneity can lead to static shifts ain the apparent resistivity sounding curve of controlled-source audio-frequency magnetotellurics(CSAMT).The static effect will shift the apparent resistivity curves along with axial log-log coordinates.Such an effect,if not properly processed,can distort the resistivity of rock formation and the depth of interfaces,and even make the geological structures unrecognizable.In this paper,we discuss the reasons and characteristics of the static shift and summarize the previous studies regarding static shift correction.Then,we propose the Guided Image Filtering algorithm to suppress static shifts in CSAMT.In detail,we use the multi-window superposition method to superimpose 1D signals into a 2D matrix image,which is subsequently processed with Guided Image Filtering.In the synthetic model study and field examples,the Guided Image Filtering algorithm has effectively corrected and suppressed static shifts,and finally improved the precision of data interpretation.

Clinical application of improved 2D computer-assisted fluoroscopic navigation through simulating a 3D vertebrae image to guide pedicle screw internal fixation

Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixation,distraction

Pyogenic liver abscess:An audit of 10 years’experience

AIM:To describe our own experience with pyogenic liver abscesses over the past 10 years and investigate the risk factors associated with failure of initial percutaneous therapy.METHODS:A retrospective study of records of 63 PLA patients presenting between 1998 and 2008 to Australian tertiary referral centre,were reviewed.Amoebic and hydatid abscesses were excluded.Demographic,clinical,radiological,and microbiological characteristics,as well as surgical/radiological interventions,were recorded.RESULTS:Sixty-three patients(42 males,21 females) aged 65(±14) years[mean±(SD) ]had prodromal symptoms for a median(interquartile range;IQR) of 7(5-14) d.Only 59%of patients were febrile at presentation;however,the serum C-reactive protein was elevated in all 47 in whom it was measured.Liver function tests were non-specifically abnormal.67%of patients had a solitary abscess,while 32%had>3 abscesses with a median(IQR) diameter of 6.3(4-9) cm.Causative organisms were:Streptococcus milleri 25%,Klebsiella pneumoniae 21%,and Escherichia coli 16%.A presumptive cryptogenic cause was most common (34%).Four patients died in this series:one from sepsis,two from advanced cancer,and one from acute myocardial infarction.The initial procedure was radiological aspiration±drainage in 54 and surgery in two patients.17%underwent surgical management during their hospitalization.Serum hypoalbuminaemia[mean (95%CI) :32(29-35) g/L vs 28(25-31) g/L,P=0.045] on presentation was found to be the only factor related to failure of initial percutaneous therapy on univariate analysis.CONCLUSION:PLA is a diagnostic challenge,because the presentation of this condition is non-specific.Intravenous antibiotics and radiological drainage in the first instance allows resolution of most PLAs;However,a small proportion of patients still require surgical drainage.

Navigated liver surgery:State of the art and future perspectives

Background:In recent years,the development of digital imaging technology has had a significant influence in liver surgery.The ability to obtain a 3-dimensional(3D)visualization of the liver anatomy has provided surgery with virtual reality of simulation 3D computer models,3D printing models and more recently holograms and augmented reality(when virtual reality knowledge is superimposed onto reality).In addition,the utilization of real-time fluorescent imaging techniques based on indocyanine green(ICG)uptake allows clinicians to precisely delineate the liver anatomy and/or tumors within the parenchyma,applying the knowledge obtained preoperatively through digital imaging.The combination of both has transformed the abstract thinking until now based on 2D imaging into a 3D preoperative conception(virtual reality),enhanced with real-time visualization of the fluorescent liver structures,effectively facilitating intraoperative navigated liver surgery(augmented reality).Data sources:A literature search was performed from inception until January 2021 in MEDLINE(Pub Med),Embase,Cochrane library and database for systematic reviews(CDSR),Google Scholar,and National Institute for Health and Clinical Excellence(NICE)databases.Results:Fifty-one pertinent articles were retrieved and included.The different types of digital imaging technologies and the real-time navigated liver surgery were estimated and compared.Conclusions:ICG fluorescent imaging techniques can contribute essentially to the real-time definition of liver segments;as a result,precise hepatic resection can be guided by the presence of fluorescence.Furthermore,3D models can help essentially to further advancing of precision in hepatic surgery by permitting estimation of liver volume and functional liver remnant,delineation of resection lines along the liver segments and evaluation of tumor margins.In liver transplantation and especially in living donor liver transplantation(LDLT),3D printed models of the donor’s liver and models of the recipient’s hilar anatomy can contribute further to improving the results.In particular,pediatric LDLT abdominal cavity models can help to manage the largest challenge of this procedure,namely large-for-size syndrome.

Extrahepatic metastasis of hepatocellular carcinoma to the paravertebral muscle:A case report

Identification of extrahepatic metastases(EHM) of hepatocellular carcinoma(HCC) has been paradoxically increasing due to an increase in the survival of HCC patients. However, metastasis of HCC to the skeletal muscle tissue is extremely rare. We describe a unique case of HCC metastasizing to the paravertebral muscle. A 55-year-old man with a history of hepatitis B cirrhosis underwent partial liver resection with complete removal of HCC. Three months later, a computed tomography(CT) scan showed intrahepatic recurrence. The tumors were treated with yttrium-90 microspheres, transcatheter arterial chemoembolization, and sorafenib. Six months later, a CT scan showed an enhancing lesion of the left paravertebral muscle that on biopsy were consistent with metastatic HCC. The tumor was treated with stereotactic hypo-fractionated imageguided radiation therapy(SHFRT). A follow-up scan 3 mo post-radiotherapy revealed a stable appearance of the paravertebral muscle metastasis. Because of the progression in the intrahepatic tumors, the patient was treated with capecitabine, which was changed to dasatinib 6 mo later. The patient passed away three years after the primary surgical resection. Management of EHM poses an extreme challenge. This is the first case of HCC with EHM to the paravertebral muscle in which stability of disease was achieved using SHFRT. This case highlights the importance of early detection of hepatitis B viral infection and initiation of anti-viral therapy to decrease recurrence of HCC and prevent EHM.

Treatment of Massive Low-Grade Chondrosarcoma of Nasal Septum with Helical Tomotherapy: A Case Report

Chondrosarcomas are malignant bone tumors which develop as a cartilaginous differentiation of primary mesenchymal cells and the second most frequently seen malignant tumor of the bone after osteosarcoma. These malignancies are slowly growing non-epithelial tumors with unknown etiology and most frequently seen during the 4 decades of life. They are frequently localized on pelvis, ribs and long bones. Nasal septum CSs are very rarely seen malignancies. They originate from septal mucosa or cartilage and it is difficult to make a diagnosis unless they reach a certain size. A few cases of CSs with nasal septum have been reported in the literature. In cases of CSs, surgery is the gold standard treatment modality;however in surgically unresectable cases or close to margins, radiotherapy plays a significant role in primary and adjuvant treatment. Based on the position of the tumor in head and neck and extremely closeness of the tumor to vital organs as optic nerve, chiasm and brain, image guided-intensity modulated radiation therapy (IG-IMRT) becomes very effective and reliable modalities and may be a favorable treatment alternative.

Clinical use of augmented reality,mixed reality,three-dimensionalnavigation and artificial intelligence in liver surgery

A precise knowledge of intra-parenchymal vascular and biliary architecture and the location of lesions in relation to the complex anatomy is indispensable to perform liver surgery.Therefore,virtual three-dimensional(3D)-reconstruction models from computed tomography/magnetic resonance imaging scans of the liver might be helpful for visualization.Augmented reality,mixed reality and 3Dnavigation could transfer such 3D-image data directly into the operation theater to support the surgeon.This review examines the literature about the clinical and intraoperative use of these image guidance techniques in liver surgery and provides the reader with the opportunity to learn about these techniques.Augmented reality and mixed reality have been shown to be feasible for the use in open and minimally invasive liver surgery.3D-navigation facilitated targeting of intraparenchymal lesions.The existing data is limited to small cohorts and description about technical details e.g.,accordance between the virtual 3D-model and the real liver anatomy.Randomized controlled trials regarding clinical data or oncological outcome are not available.Up to now there is no intraoperative application of artificial intelligence in liver surgery.The usability of all these sophisticated image guidance tools has still not reached the grade of immersion which would be necessary for a widespread use in the daily surgical routine.Although there are many challenges,augmented reality,mixed reality,3Dnavigation and artificial intelligence are emerging fields in hepato-biliary surgery.

Optical flow based guidance system design for semi-strapdown image homing guided missiles

This paper focuses mainly on semi-strapdown image homing guided （SSIHG） system design based on optical flow for a six-degree-of-freedom （6-DOF） axial-symmetric skid-to-turn missile. Three optical flow algorithms suitable for large displacements are introduced and compared. The influence of different displacements on computational accuracy of the three algorithms is analyzed statistically. The total optical flow of the SSIHG missile is obtained using the Scale Invariant Feature Transform （SIFT） algorithm, which is the best among the three for large displacements. After removing the rotational optical flow caused by rotation of the gimbal and missile body from the total optical flow, the remaining translational optical flow is smoothed via Kalman filtering. The circular navigation guidance （CNG） law with impact angle constraint is then obtained utilizing the smoothed translational optical flow and position of the target image. Simulations are carried out under both disturbed and undisturbed conditions, and results indicate the proposed guidance strategy for SSIHG missiles can result in a precise target hit with a desired impact angle without the need for the time-to-go parameter.

Low and non-uniform illumination color image enhancement using weighted guided image filtering

In the state of the art,grayscale image enhancement algorithms are typically adopted for enhancement of RGB color images captured with low or non-uniform illumination.As these methods are applied to each RGB channel independently,imbalanced inter-channel enhancements(color distortion)can often be observed in the resulting images.On the other hand,images with non-uniform illumination enhanced by the retinex algorithm are prone to artifacts such as local blurring,halos,and over-enhancement.To address these problems,an improved RGB color image enhancement method is proposed for images captured under nonuniform illumination or in poor visibility,based on weighted guided image filtering(WGIF).Unlike the conventional retinex algorithm and its variants,WGIF uses a surround function instead of a Gaussian filter to estimate the illumination component;it avoids local blurring and halo artifacts due to its anisotropy and adaptive local regularization.To limit color distortion,RGB images are first converted to HSI(hue,saturation,intensity)color space,where only the intensity channel is enhanced,before being converted back to RGB space by a linear color restoration algorithm.Experimental results show that the proposed method is effective for both RGB color and grayscale images captured under low exposure and non-uniform illumination,with better visual quality and objective evaluation scores than from comparator algorithms.It is also efficient due to use of a linear color restoration algorithm.

Retinex based low-light image enhancement using guided filtering and variational framework

A new image enhancement algorithm based on Retinex theory is proposed to solve the problem of bad visual effect of an image in low-light conditions. First, an image is converted from the RGB color space to the HSV color space to get the V channel. Next, the illuminations are respectively estimated by the guided filtering and the variational framework on the V channel and combined into a new illumination by average gradient. The new reflectance is calculated using V channel and the new illumination. Then a new V channel obtained by multiplying the new illumination and reflectance is processed with contrast limited adaptive histogram equalization(CLAHE). Finally, the new image in HSV space is converted back to RGB space to obtain the enhanced image. Experimental results show that the proposed method has better subjective quality and objective quality than existing methods.

Low-light color image enhancement based on NSST

In order to improve the visibility and contrast of low-light images and better preserve the edge and details of images,a new low-light color image enhancement algorithm is proposed in this paper.The steps of the proposed algorithm are described as follows.First,the image is converted from the red,green and blue(RGB)color space to the hue,saturation and value(HSV)color space,and the histogram equalization(HE)is performed on the value component.Next,non-subsampled shearlet transform(NSST)is used on the value component to decompose the image into a low frequency sub-band and several high frequency sub-bands.Then,the low frequency sub-band and high frequency sub-bands are enhanced respectively by Gamma correction and improved guided image filtering(IGIF),and the enhanced value component is formed by inverse NSST transform.Finally,the image is converted back to the RGB color space to obtain the enhanced image.Experimental results show that the proposed method not only significantly improves the visibility and contrast,but also better preserves the edge and details of images.

Improved single image dehazing using dark channel prior

An improved single image dehazing method based on dark channel prior and wavelet transform is proposed. This proposed method employs wavelet transform and guided filter instead of the soft matting procedure to estimate and refine the depth map of haze images. Moreover, a contrast enhancement method based on just noticeable difference(JND) and quadratic function is adopted to enhance the contrast for the dehazed image, since the scene radiance is usually not as bright as the atmospheric light,and the dehazed image looks dim. The experimental results show that the proposed approach can effectively enhance the haze image and is well suitable for implementing on the surveillance and obstacle detection systems.

影像导航鼻内镜系统在鼻内翻性乳头状瘤、鼻窦骨瘤中的应用

目的通过影像导航行鼻腔内翻性乳头状瘤、鼻窦骨瘤鼻内镜手术,与传统鼻内镜手术在手术时间、麻醉时间及出血量和复发率、并发症等方面进行比较分析。方法 73例鼻腔内翻性乳头状瘤、鼻窦骨瘤患者被分成导航组与非导航组,导航组采用影像导航下鼻内镜手术,非导航组采用传统鼻内镜手术。分析两组在手术时间、麻醉时间、出血量、并发症及术后疗效等情况。结果导航组与非导航组患者在麻醉时间比较差异无统计学意义(P=0.287),在手术时间、出血量比较差异有统计学意义(P<0.05)。鼻腔内翻性乳头状瘤导航组与非导航组I+II级复发率比较差异无统计学意义,而在III+IV级中复发率比较差异有统计学意义(P=0.043)。鼻窦骨瘤中非导航组有1例复发,导航组未见复发病例。鼻腔内翻性乳头状瘤中,导航组与非导航组鼻内并发症比较差异有统计学意义(P<0.05),I+II级鼻内并发症导航组与非导航组的发生率比较无显著差异(P>0.05),而在III+IV级中鼻内并发症的发生率比较有显著差异(P<0.05)。在鼻窦骨瘤中导航组与非导航组鼻内并发症比较差异有统计学意义(P<0.05)。结论对于鼻窦骨瘤及III+IV级鼻腔内翻性乳头状瘤,影像导航引导下鼻内镜术优于常规鼻内镜手术,尤其是在术前评价和确保术中的安全性有重要辅助作用,且肿瘤切除更彻底,复发概率更低。

Stereotactic ablative radiotherapy for hepatocellular carcinoma

Patients with hepatocellular carcinoma(HCC)often present with underlying liver disease and significant comorbidities,limiting treatment tolerance.With the development of improved toxicity models and highly conformal radiation delivery systems,external beam radiotherapy has become a valuable treatment option for liver cancer.Using cutting edge technology,stereotactic ablative radiotherapy(SABR)allows for the delivery of ablative doses in few fractions while sparing uninvolved liver tissue.This approach permits dose escalation and precise tumor targeting with minimal risk of radiation induced liver disease.This review clarifies SABR's role alongside liver-directed treatments such as radiofrequency ablation,transarterial radioembolization,and transarterial chemoembolization in the management of HCC.It also examines the promising potential of SABR combined with immunotherapy to treat advanced HCC.

^(64)Cu radiolabeled nanomaterials for positron emission tomography(PET)imaging

The prevalence of positron emission tomography(PET)imaging has advanced biomedical applications for its ultrahigh sensitivity,deep tissue penetration and quantitative visualization of diseases in vivo.^(64)Cu with ideal half-life and decay characteristics has been designed as radioactive probes for disease diagnosis.The currently reported ^(64)Cu-labeled nanomaterials have the advantages of long circulation time in serum,good biocompatibility and mature preparation methods,and have been used in vivo PET imaging,biodistribution and pharmacokinetic monitoring,and imaging guided therapy.At the same time,suitable carrier characteristics and radiolabeling strategies are particularly important in the ^(64)Cu PET imaging process.In this review,we summarize different imaging probe designs and ^(64)Cu radiolabeling strategies,as well as their eventual applications in biomedicine.The potential challenges and prospects of ^(64)Cu labeled nanomaterials are also described,which provides broad prospects for radiolabeling strategies and further applications.