Imaging Techniques: Echocardiography, Magnetic Resonance Imaging, and Computerized Tomography

2006 ◽  
pp. 183-211
Author(s):  
TAL GEVA ◽  
MARY E. VAN DER VELDE
1986 ◽  
Vol 31 (7) ◽  
pp. 675-680 ◽  
Author(s):  
Trevor Young ◽  
Peter Williamson

The application of brain imaging techniques to psychiatry is reviewed with respect to computerized tomography (CT), EEG topography, positron emission tomography (PET), and magnetic resonance imaging (MRI). While early computerized tomography studies have suggested structural abnormalities in schizophrenia, more recent studies have shown that most schizophrenics and patients with other disorders have normal CT scans. EEG topography and positron emission tomography have not been evaluated as fully as computerized tomography. However, preliminary studies indicate some functional abnormalities in schizophrenia and affective disorders compared to normal controls. Magnetic resonance imaging shows promise but has had only a limited application to date in psychiatry.


2020 ◽  
Author(s):  
Nitesh Pradhan ◽  
Vijaypal Singh Dhaka ◽  
Geeta Rani ◽  
Himanshu Chaudhary

Abstract Imaging techniques such as X-ray, computerized tomography scan and magnetic resonance imaging are useful in the correct diagnosis of a disease or deformity in the organ. Two-dimensional imaging techniques such as X-ray give a clear picture of simple bone deformity but fail in visualizing multiple fractures in a bone. Moreover, these lack in providing a multi-angle view of a bone. Three-dimensional techniques such as computerized tomography scan and magnetic resonance imaging present a correct orientation of fracture geometry. Computerized tomography scan is a collection of multiple slices of an image. These slices provide a fair idea about a fracture but fail in the measurement of correct dimensions of a fractured fragment and to observe its geometry. It also exposes a patient with carcinogenic radiations. Magnetic resonance imaging induces a strong magnetic field. So, it becomes ineffective for organs containing metallic implants. The high cost of three-dimensional imaging techniques makes them inaccessible for economic weaker section of society. The limitations of two- and three-dimensional imaging techniques motivate researchers to propose an innovative machine learning model ‘CT slices to $3$-D convertor’ that accepts multiple slices of an image and yields a multi-dimensional view at all possible angles from 0 degree to 360 degree for an input image.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sang Wha Kim ◽  
Adams Hei Long Yuen ◽  
Cherry Tsz Ching Poon ◽  
Joon Oh Hwang ◽  
Chang Jun Lee ◽  
...  

AbstractDue to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.


2004 ◽  
Vol 18 (2) ◽  
pp. 80-87 ◽  
Author(s):  
Archie Heddings ◽  
Mehmet Bilgen ◽  
Randolph Nudo ◽  
Bruce Toby ◽  
Terence McIff ◽  
...  

Objectives. It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury. Methods. Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms. Results. Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations. Conclusion. Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.


1994 ◽  
Vol 23 (6) ◽  
pp. 1379-1382 ◽  
Author(s):  
Hitoshi Imaizumi ◽  
Masamitsu Kaneko ◽  
Satoshi Nara ◽  
Hiroko Saito ◽  
Koji Asakura ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jae Heon Kim ◽  
Hong J. Lee ◽  
Yun Seob Song

A reliablein vivoimaging method to localize transplanted cells and monitor their viability would enable a systematic investigation of cell therapy. Most stem cell transplantation studies have used immunohistological staining, which does not provide information about the migration of transplanted cellsin vivoin the same host. Molecular imaging visualizes targeted cells in a living host, which enables determining the biological processes occurring in transplanted stem cells. Molecular imaging with labeled nanoparticles provides the opportunity to monitor transplanted cells noninvasively without sacrifice and to repeatedly evaluate them. Among several molecular imaging techniques, magnetic resonance imaging (MRI) provides high resolution and sensitivity of transplanted cells. MRI is a powerful noninvasive imaging modality with excellent image resolution for studying cellular dynamics. Several types of nanoparticles including superparamagnetic iron oxide nanoparticles and magnetic nanoparticles have been used to magnetically label stem cells and monitor viability by MRI in the urologic field. This review focuses on the current role and limitations of MRI with labeled nanoparticles for tracking transplanted stem cells in urology.


Soft Matter ◽  
2021 ◽  
Author(s):  
Yunhao Ding ◽  
Dianjinfeng Gong ◽  
Jing Yang ◽  
Zhen Xu ◽  
Zhichao Wang ◽  
...  

Packing structures of granular cylinders with aspect ratio close to one have been reconstructed with the help of magnetic resonance imaging techniques. By controlling the container boundary condition and preparation...


2017 ◽  
Author(s):  
Gerald W. Staton Jr ◽  
Phuong-Anh T. Duong

Chest imaging techniques are evolving with recent advances in computed tomography, magnetic resonance imaging, and ultrasonography. While conventional radiography remains an important screening tool because of its low relative cost, ease of acquisition, general availability, and familiarity, physicians must understand all techniques so as to provide patients with the most appropriate diagnostic imaging. Consultation with radiologists, use of online clinical decision support, and adherence to national guidelines such as the American College of Radiology Appropriateness Criteria®, can help clinicians make imaging decisions, especially in light of medical imaging risks that are of concern in the medical community and the general population. Choosing appropriate imaging, including whether or not to image, requires careful consideration. This review contains 6 figures, 3 tables, and 6 references. Key Words: Chest Radiographs, Dual-Energy Chest Radiographs, Computed Tomography, High-Resolution Chest Computed Tomography, Multidetector Row Computed Tomography, Computed Tomographic Angiography for Pulmonary Embolism, Magnetic Resonance Imaging, Single-Photon Emission Tomography (SPECT), Ultrasonography 


2021 ◽  
Vol 25 (02) ◽  
pp. 346-354
Author(s):  
Alain G. Blum ◽  
Marnix T. van Holsbeeck ◽  
Stefano Bianchi

AbstractThe unique anatomical characteristics of the thumb offer a broad range of motion and the ability to oppose thumb and finger, an essential function for grasping. The motor function of the thumb and its orientation make it particularly vulnerable to trauma. Pathologic lesions encountered in this joint are varied, and imaging techniques play a crucial role in injury detection and characterization. Despite advances in diagnostic accuracy, acute thumb injuries pose a challenge for the radiologist. The complex and delicate anatomy requires meticulous and technically flawless image acquisition. Standard radiography and ultrasonography are currently the most frequently used imaging techniques. Computed tomography is most often indicated for complex fractures and dislocations, and magnetic resonance imaging may be useful in equivocal cases. In this article, we present the relevant anatomy and imaging techniques of the thumb.


Author(s):  
Thu Hien Trinh Thi

TÓM TẮT U mỡ trong xương là khối u lành tính hiếm gặp, thường gặp ở các xương dẹt, hiếm gặp ở xương nền sọ, đặc biệt là xương bướm. Trong đa số các trường hợp, u mỡ trong xương bướm thường được phát hiện tình cờ qua chụp cắt lớp vi tinh (CLVT) hoặc cộng hưởng từ (CHT) sọ não. Đây là một khối u phát triển chậm, ít gây ra triệu chứng, một số trường hợp gây triệu chứng khi khối u to chèn ép vào cấu trúc lân cận như tuyến yên hoặc dây thần kinh thị. Trong bài này, chúng tôi báo cáo một trường hợp u mỡ trong xương bướm không triệu chứng được phát hiện tình cờ và được chẩn đoán dựa vào phim chụp cộng hưởng từ sọ não. Bệnh nhân được khuyến nghị theo dõi định kỳ bằng cộng hưởng từ mà không phải tiến hành bất kỳ phương pháp điều trị nào. Từ khóa: U mỡ, xương bướm, MRI, cộng hưởng từ sọ não, chẩn đoán hình ảnh. ABSTRACT INTRAOSSEOUS LIPOMA OF SPHENOID BONE: A RARE CASE REVIEW Intraosseous lipoma is very rare, usually benign tumor of flat bones. The incidence of an intraosseous lipomalocated basal skull bones is extremely rare, especially in sphenoid bone. Radiological imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) are used to detect the intraosseous lipoma by accident. These tumors are slow growing and usually asymptomatic, in some cases causing symptoms when the large tumor presses on nearby structures such as pituitary gland or the optic nerve. We present a rare case of lipomaof the sphenoid bone discovered incidentally with brain magnetic resonance imaging. The patient has been followed-up by magnetic resonance imaging without the need for surgery. Keywords: Intraosseous lipoma, sphenoid bone, MRI, brain MRI, diagnostic radiology


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