In modern medicine, DSA is a powerful technique in visualizations of blood vessels of X-ray images. In DSA, the most important way for motion correction is image registration. In this paper, a new approach to the registration is used. It is based on means of template matching according to a combined invariants-based similarity measure and TPS image warping. Furthermore it has been improved through practice. and tests have proved to remove the motion artifacts effectively and rapidly.
Algorithms ; Angiography, Digital Subtraction ; methods

Angiography ; methods ; Coronary Angiography ; methods ; Coronary Vessels ; pathology ; Humans ; Magnetic Resonance Angiography ; methods ; Mucocutaneous Lymph Node Syndrome ; diagnosis ; diagnostic imaging

OBJECTIVES: In this paper, we present an automatic method to segment four chambers by extracting a whole heart, separating the left and right sides of the heart, and spliting the atrium and ventricle regions from each heart in cardiac computed tomography angiography (CTA) efficiently. METHODS: We smooth the images by applying filters to remove noise. Next, the volume of interest is detected by using k-means clustering. In this step, the whole heart is coarsely extracted, and it is used for seed volumes in the next step. Then, we detect seed volumes using a geometric analysis based on anatomical information and separate the left and right heart regions with the power watershed algorithm. Finally, we refine the left and right sides of the heart using the level-set method, and extract the atrium and ventricle from the left and right heart regions using the split energy function. RESULTS: We tested the proposed heart segmentation method using 20 clinical scan datasets which were acquired from various patients. To validate the proposed heart segmentation method, we evaluated its accuracy in segmenting four chambers based on four error evaluation metrics. The average values of differences between the manual and automatic segmentations were less than 3.3%, approximately. CONCLUSIONS: The proposed method extracts the four chambers of the heart accurately, demonstrating that this approach can assist the cardiologist.
Angiography ; Dataset ; Heart ; Humans ; Methods* ; Noise

This study was performed to examine the visualization and anatomical variants of the hepatic artery with dual-phase computed tomography (CT) angiography and three-dimensional volume rendering imaging analysis in clinically normal dogs. Seven healthy beagle dogs were enrolled and underwent dual CT angiography. Arterial phase images could be obtained with multi-detector CT angiography using the fixed-scan method in these dogs. Contrast enhancement of the hepatic parenchyma was quite minimal because of the unique blood supply system of the liver. In most dogs, the main hepatic arterial branches were the right lateral branch, left branch, and right medial branch. Although hepatic arterial variation appears to be common in dogs, only one dog in this study had the caudate lobar branch as the first branch of the hepatic artery. Further study on a larger number of dogs with CT images will be needed to identify and classify the pattern of hepatic arterial variations.
Angiography ; Animals ; Dogs ; Hepatic Artery ; Liver ; Methods

Renal artery embolization was induced experimentally in rabbits and microvascular changs were studiedangiographically, microangiographically and histopathologically. The results were as follows; 1. The mainmicroangiographic findings of renal artery embolization were arterial occlusion and collateral vessels arecharacterized by spiralling, dilatation, irregular lumen with abrupt caliber change, disoriented course andincreased number. 2. Collateral vessel formation was demonstrated in all cases of renal artery embolization bymicroangiography. 3. Recanalization of embolized vessels was better visualized by renal angiography thanmicorangiography. It was considered that microangiography is a valuable method for the observation ofmicrovascular changes in renal artery embolization and other renal diseases.
Angiography ; Dilatation ; Methods ; Rabbits ; Renal Artery

Computed tomography angiography (CTA) is a useful approach for diagnosing vascular diseases. In this paper, we proposed a reconstruction algorithm for dual-source spiral CT with variable pitch. The projection data are collected by the double-source double-multislice spiral CT (DSDMS-CT). However, the pitch of the DSDMS-CT is variable other than being constant. We have developed a new formula performing interpolation along Z-axis for dual-source spiral CT with variable pitch. The dual-source spiral CT with variable pitch can chase contrast bolus more flexibly and more effectively. The simulation results show the correctness and efficiency of the proposed algorithm.
Algorithms ; Coronary Angiography ; methods ; Humans ; Tomography, Spiral Computed ; instrumentation ; methods

OBJECTIVETo discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis.

DATE SOURCESWe retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis.

STUDY SELECTIONWe reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application.

RESULTSVWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy.

CONCLUSIONSThis review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management.

In this paper, signal-to-noise ratio (SNR) and signal different-to-noise ratio (SDNR) methods were used to compare image quality using two different radiofrequency coils. The two coil types included an eight-element phased-array coil and a quadrature birdcage head coil with endcap and the comparison studies performed on a uniform cylindrical phantom and volunteer respectively. The results showed phased-array coil have advantages and proved effectiveness of the method in the evaluation and selection of coils.
Adult ; Cerebral Angiography ; methods ; Humans ; Magnetic Resonance Angiography ; methods ; Male ; Signal-To-Noise Ratio

OBJECTIVE: To evaluate a modified subtraction coronary computed tomography angiography (CCTA) technique with a two-breathhold approach in terms of image quality and stenosis grading of calcified coronary segments and in the detection of significant coronary stenosis in segments with severe calcification. MATERIALS AND METHODS: The institutional board approved this study, and all subjects provided written consent. A total of 128 patients were recruited into this trial, of which 32 underwent subtraction CCTA scans and invasive coronary angiography (ICA). The average Agatston score was 356 ± 145. In severely calcified coronary segments, the presence of significant (> 50%) stenosis was assessed on both conventional CCTA and subtraction CCTA images, and the results were finally compared with ICA findings as the gold standard. RESULTS: For severely calcified segments, the image quality in conventional CCTA significantly improved from 2.51 ± 0.98 to 3.12 ± 0.94 in subtraction CCTA (p < 0.001). In target segments, specificity (70% vs. 87%; p = 0.005) and positive predictive value (61% vs. 79%, p < 0.01) were improved using subtraction CCTA in comparison with conventional CCTA, with no loss in the negative predictive value. The segment-based diagnostic accuracy for detecting significant stenosis was significantly better in subtraction CCTA than in conventional CCTA (area under the receiver operating characteristic curve, 0.94 vs. 0.85; p = 0.03). CONCLUSION: This modified subtraction CCTA method showed lower misregistration and better image quality in patients with limited breathhold capability. In comparison with conventional CCTA, modified subtraction CCTA would allow stenosis regrading and improve the diagnostic accuracy in coronary segments with severe calcification.
Angiography ; Constriction, Pathologic ; Coronary Angiography ; Coronary Stenosis ; Humans ; Methods ; ROC Curve ; Sensitivity and Specificity

Angiography has been playing important roles in diagnosis and treatment in the field of orthopaedic surgery. Conventional angiography is the most reliable and widely used method in diagnosis of peripheral arterial disease. But the clinical use of the conventional angiography has been limited by the risk of possible complications and time-consuming procedures. Radionuclide sngiography is rapidly performed, rapidly interpretable and time-saving procedure for the visualization of arterial tree prior to vascular intervention in the critically ill patient. We have analyzed and compared the 22 cases who had taken radionuclide angiography and conventional angiography simultaneously from November, 1986 to August, 1987 in Department of Orthopaedic Surgery, Hanysng University Hospital. The results were as follow 1. Radionuclide angiography is simple, non-invasive, accurste, reproducible method. It eliminstes the discomfort and morbidity of conventional angiography and can be done on an outpatient basis at a much lower cost. It is useful in the patients who may be allergic to the contrast medium. 2. In cases of arterial occlusion, radionuclide angiogrpahy is also useful in the evsluation of obstruction of major artery and can be substituted for conventionsl angiography. 3. For the purpose of evaluation of success in the cases of vascular reconstruction, radionuclide angiogrphy also demonstrate the vasculsr blood flow without any risk. 4. Although rsdionuclide angiography has limitstion in snatomic detsil, it could be psrtially substituted for conventionsl angiography in the diagnosis of vascular anomalies or tumors.
Angiography ; Arteries ; Critical Illness ; Diagnosis ; Humans ; Methods ; Outpatients ; Peripheral Arterial Disease ; Radionuclide Angiography ; Trees