Background: Lower Gastrointestinal bleeding (LGIB) is a serious and urgent condition which can be assessed using several different modalities. Tc-99m tagged RBC scintigraphy has been established as a diagnostic tool in Nuclear Medicine but several other modalities, including CT-based imaging (i.e. angiography) currently exist. Objective: The objective of this study is to compare Tc-99m tagged RBC scintigraphy with CT-based imaging studies in terms of clinical utility and diagnostic outcomes. Methods: A systematic review of available literature was done, with the goal of creating a meta-analysis focusing on the reported diagnostic outcomes - mainly sensitivity and specificity on the presence of a LGIB. Aside from this, a systematic review of the clinical utility and the differences of each test were discussed, including non-quantifiable advantages. The literature search was conducted following the guidelines of PRISMA, with searches from PubMed, Medline, and other pertinent databases. Quality assurance was done using the QUADAS tool. Statistical analyses of sensitivity, specificity, and a summary receiver operating characteristics plot were computed for the meta-analysis. Results: Pooled sensitivity and specificity for RBC scintigraphy were 0.886 and 0.119, respectively. Pooled sensitivity and specificity for CT-based imaging were 0.729 and 0.660, respectively. CT based imaging also showed higher localization and faster completion times. RBC scintigraphy had a longer acquisition window. Conclusion Both Tc99m-tagged RBC scintigraphy and CT-based imaging have important clinical utility, with each modality having different advantages that the other test cannot provide.
Computed Tomography Angiography

In order to solve the problems of slow operation speed and low registration accuracy of thin plate spline (TPS) interpolation method for motion vector field in coronary computed tomography angiography (CTA), a multi-level B-spline interpolation method (MBS) with uniform grid is proposed. On the one hand, the interpolation method used local B-spline to refine the sparse mesh layer by layer in a multiscale way to improve the accuracy of registration. On the other hand, it used the splitting matrix method to interpolate the motion vector field, greatly reducing the operation time of interpolation. The experimental results show that the proposed method can be used for CTA image registration efficiently.
Algorithms ; Computed Tomography Angiography ; Heart ; Motion ; Tomography, X-Ray Computed

No abstract available.
Angiography* ; Glomus Tumor* ; Multidetector Computed Tomography*

Virtual autopsy is a new technique for investigating the morphological changes of cadaveric tissues and organs by medical imaging technology. It has been widely used in the identification of causes of death. Multislice spiral computed tomography （MSCT） has become a routine inspection method in some identification institutions, although it cannot completely replace traditional autopsy, it plays a key auxiliary or substitute role in the identification of certain abnormal causes of death. Plain MSCT scan cannot visualize cadaveric vessels, but can perform cadaveric angiography to determine vascular injury or disease. This technology has entered a rapid development period in recent years, and has made a considerable progress in contrast agent, perfusion methods and imaging methods. This article summarizes several common cadaveric MSCT angiography methods, such as systemic angiography, angiography through cardiopulmonary resuscitation, targeted angiography, and angiography by cardiac puncture, and analyzes and compares the application prospects.
Angiography ; Autopsy ; Coronary Angiography ; Heart ; Humans ; Tomography, Spiral Computed

Aneurysm ; Angiography ; Computed Tomography Angiography ; Coronary Angiography ; Coronary Artery Bypass ; Humans ; Saphenous Vein/diagnostic imaging*

Helical CT has improved with faster gantry rotation, more powerful X-ray tubes, and improved interpolation algorithms; however, the greatest advance has been made by the recent introduction of multi detector-row computed tomography (MDCT) scanners. Fundamental advantages of MDCT include substantially shorter acquisition times, retrospective creation of thinner or thicker sections from the same raw data, and improved threedimensional (3-D) rendering with diminished helical artifacts. While these features will likely be important to many applications of CT scanning, the greatest impact has been on CT angiography. The advantages of MDCT over single detector-row CT scanners when imaging the vascular system can be broken down into three fundamental improvements, that is, speed (faster scan time), distance (longer coverage), and section thickness (better resolution). This article will focus on how the MDCT technology has substantially improved imaging of the vascular system, including pulmonary artery, aorta and extremity vessels.
Angiography ; Aorta ; Artifacts ; Extremities ; Pulmonary Artery ; Retrospective Studies ; Tomography, Spiral Computed ; Tomography, X-Ray Computed

PURPOSE: To correlate the enhancement pattern of hepatocellular carcinoma during the arterial phase of spiral CT with vascularity on angiography. MATERIALS AND METHODS: Forty-Two patients with hepatocellular carcinoma underwent spiral CT and angioigraphy. spiral CT was performed with a section thickness of 10mm and a table speedof 10 or 13 mm/sec. 120mL of contrast medium was injected at 3 mL/sec. Spiral CT scans during the arterial phase were obtained 35 seconds after the injection of contrast medium. CT findings of 78 lesions less than 4cm indiameter were correlated with angiographic findings. RESULTS: The attenuation of lesions was high(n=69),iso(n=5), and low(n=4) compared with liver parenchyma during the arterial phase of spiral CT. in lesions with high-, iso-, and low-attenuation during the arterial phase of spiral CT, hypervascularity on angiograms was foundin 63 of 69(91.3%), three of five(60%), and three of four lesions(75%), respectively. Six lesions with high-attenuation on the arterial phase of spiral CT were not seen on angiography. Two iso-attenuated and onelow-attenuated lesion were hypovascular on angiograms. CONCLUSION: The results of this study suggest that with some exceptions there was good correlation between the arterial phase of spiral CT and angiography.
Angiography* ; Carcinoma, Hepatocellular* ; Humans ; Liver ; Tomography, Spiral Computed* ; Tomography, X-Ray Computed*

INTRODUCTIONC-arm Cone Beam CT (CBCT) is a technology that is being integrated into many of the newer angiography systems in the interventional suite. Due to its ability to provide cross sectional imaging, it has opened a myriad of opportunities for creating new clinical applications. We review the technical aspects, current reported clinical applications and potential benefits of this technology.

MATERIALS AND METHODSSearches were made via PubMed using the string "CBCT", "Cone Beam CT", "Cone Beam Computed Tomography" and "C-arm Cone Beam Computed Tomography". All relevant articles in the results were reviewed.

RESULTSCBCT clinical applications have been reported in both vascular and non-vascular interventions. They encompass many aspects of a procedure including preprocedural planning, intraprocedural guidance and postprocedural assessment. As a result, they have allowed the interventionalist to be safer and more accurate in performing image guided procedures. There are however several technical limitations. The quality of images produced is not comparable to conventional computed tomography (CT). Radiation doses are also difficult to quantify when compared to CT and fluoroscopy.

CONCLUSIONCBCT technology in the interventional suite has contributed significant benefits to the patient despite its current limitations. It is a tool that will evolve and potentially become an integral part of imaging guidance for intervention.

The computed tomography (CT) technology has recently leaped with the advent of the multidetector row technique since the introduction of spiral CT. The most important advantages of multidetector spiral CT (MDCT) are its rapid scan speed and the increased zaxis spatial resolution. MDCT permits selection of high resolution for isometric imaging in any imaging planes, long coverage of study volume, or decreased scan time for clinical purposes and needs. The most widely applied clinical indication of MDCT is CT angiography. MDCT makes a dynamic study or multiphase study easier and more reliable. Combination of isometric imaging in any anatomic planes, CT angiography, multiphase dynamic study, 2or 3dimensional image reconstruction has made radiologic diagnoses more accurate and has provided more useful information for preoperative surgical design and educational purposes. The combined increase of temporal resolution (200 msec) opens the era of cardiac imaging. With its inherent contrast resolution, coronary CT angiogram can reveal atherosclerotic changes of the arterial wall as well as the degree of luminal narrowing. MDCT has provided new opportunities for medical imaging and will expand rapidly with further clinical applications.
Angiography ; Diagnosis ; Diagnostic Imaging ; Image Processing, Computer-Assisted ; Multidetector Computed Tomography* ; Phenobarbital ; Tomography, Spiral Computed

Conventional angiography has been used to identify detailed vascular anatomy for surgery in which parenchymal salvage should be necessary. Recently, we experienced a case in which 3-dimensional CT was very helpful in salvaging the part of the kidney. A 2 year-old girl was diagnosed as bilateral Wilms` tumor. Conventional CT scan showed right huge mass and left upper pole mass of the kidney. The patient was planned to have neoadjuvant chemotherapy. Spiral CT scan with three-dimensional reconstruction was performed after 3-month chemotherapy and detailed anatomical information regarding vessels, tumor mass and normal parenchyma was obtained. Based on these anatomical information, right radical nephrectomy and left partial nephrectomy was successfully performed. Surgical findings was quite similar to that obtained by preoperative 3-dimensional CT images. Three-dimensional reconstruction of spiral CT imaging is considered to be useful in the evaluation of surgical anatomy in kidney-saving surgery preoperatively.
Angiography ; Child, Preschool ; Drug Therapy ; Female ; Humans ; Kidney ; Nephrectomy ; Tomography, Spiral Computed* ; Tomography, X-Ray Computed