Current Medical Imaging - Volume 2, Issue 1, 2006

Two observations emerge from a review of the articles contained in this issue of CMIR. The first and perhaps most important is the remarkable growth in diagnostic technology. PET imaging has increased in utilization during the past several years so that it is now a part of the state-of-the-art of cancer care. The increased availability of combined PET/CT imaging has greatly fostered its growth and increased the specificity and Read More

During the last two decades, functional brain imaging using positron emission tomography (PET) has advanced elegantly, and steadily gained importance in the clinical and research arenas. Significant progress has been made by different scanner manufacturers and research groups in the design of dedicated high-resolution three-dimensional (3-D) PET units; however, emerging clinical and research applications of functiona Read More

Inferences about brain function, using functional neuroimaging data, require models of how the data were derived. A variety of models are used in practice that range from conceptual models of functional anatomy to nonlinear mathematical models of hemodynamic responses (e.g. as measured by functional magnetic resonance imaging, fMRI) and neuronal responses. In this review, we discuss the most important mod Read More

During the past years brain imaging techniques like positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) became more and more important for gaining new insights into processes of and circuits for memory encoding and retrieval. These findings also had a great impact on a better understanding of memory dysfunctions and their underlying brain mechanisms. In the present review, d Read More

Functional neuroimaging has provided a new view of the activity in the human cortex. The understanding of the relationship between functional signals, particularly functional MRI, clinical disorders and cognitive functions has increased. This article reviews selected contributions of positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) with a focus on Read More

During the last five years, neuroimaging techniques such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) appeared as new tools to study the neural correlates of human male sexual arousal (SA). In this paper, some of the main methodological aspects of these studies will be summarized, including the participants, the way to induce sexual arousal within the scanner and the diffe Read More

The clinical use of ultrashort echo time (UTE) pulse sequences for imaging tissues or tissue relaxation components with short T2s is described. Tissues are divided into those with a majority of short T2 components and those with a minority. Disease processes which increase or decrease the signal from short T2 components are described. Features of the basic physics are described including the fact that when the radiofreque Read More

Accurate segmentation of magnetic resonance (MR) images of the brain is of interest in the study of many brain disorders. In this paper, we provide a review of some of the current approaches in the tissue segmentation of MR brain images. We broadly divided current MR brain image segmentation algorithms into three categories: classificationbased, region-based, and contour-based, and discuss the advantages and di Read More

Approximately half of all strokes result in moderate-to-severe disability, making stroke the leading cause of long-term disability in North America. Functional magnetic resonance imaging (fMRI) has emerged as a powerful tool to investigate functional reorganization, temporary or permanent, during the recovery of motor and cognitive functions following stroke, as a means to potentially predict patient outcome and guide reha Read More

The pulsation of the cerebrospinal fluid (CSF) has fascinated investigators of the intracranial physiology since it was first documented by invasive CSF pressure measurements. Advances in dynamic Magnetic Resonance Imaging (MRI) now enable visualization of and quantitation the CSF flow dynamics and has contributed to our understanding of the origin of CSF pulsation and its relation to the pulsatile blood flow. This, in turn, Read More

Magnetic Resonance Imaging (MRI) machines are invariably grouped according to their main magnetic field strength. Yet far more important to their overall performance are their gradient coils. For it is these that determine the limitations of the crucial parameters, TE, image speed, even the acoustic noise produced, in every imaging sequence. To some degree, the gradients even determine what imaging sequences are possi Read More

During the past few years, Multi-Slice Computed Tomography (MSCT) has emerged as a rapidly progressing technique with a high potential for non-invasive angiography. Recent studies using the latest 16-slice technology have demonstrated that the technique can detect coronary artery lesions with sensitivities and specificities of approximately 92% and 95%, respectively. In particular, the negative predictive value of the techniq Read More

Magnetic Resonance Angiography (MRA) with intravenous paramagnetic agent has recently evolved as an accurate non invasive method, for the imaging of the aorta and its major branches, the carotid, the renal and pelvic arteries. The first report of contrast enhanced MRA was published at 1993. Recently a new method was developed, employing the motion of the MR table, during the examination (Moving bed - bolus chase Read More

Ultrasonic elasticity imaging is a promising new tool for breast cancer diagnosis and management. Ultrasound is applied to sense small local tissue deformations noninvasively to image stiffness and thus exploit the large intrinsic stiffness contrast generated during the progression of many diseases in vivo. This paper briefly reviews several related approaches to breast elasticity imaging to explain some of the observed varia Read More