Neuroimaging techniques in epilepsy

Objective: To review state-of-the-art neuroimaging modalities in epilepsy and their clinical applications. Data sources and study selection: PubMed literature searches to March 2010, using the following key words: 'epilepsy', 'positron emission tomography (PET)', 'single photon emission computed tomography (SPECT)', 'MR volumetry', 'diffusion tensor imaging', and 'functional MR imaging'. Data extraction All articles including neuroimaging techniques in epilepsy were included in the review. Data synthesis High-field magnetic resonance imaging is fundamental for high-resolution structural imaging. Functional radionuclide imaging (positron emission tomography/single-photon emission computed tomography) can provide additional information to improve overall accuracy, and show good results with high concordance rates in temporal lobe epilepsy. Magnetic resonance spectroscopy is a useful adjunct consistently demonstrating changing metabolites in the epileptogenic region. Magnetic resonance volumetric imaging shows excellent sensitivity and specificity for temporal lobe epilepsy but thus far it has been inconsistent for extratemporal epilepsy. Diffusion tensor imaging with tractography allows visualisation of specific tracts such as connections with the language and visual cortex to enhance preoperative evaluation. Functional magnetic resonance imaging using blood oxygen level-dependent activation techniques is mainly used in presurgical planning for the high-sensitivity mapping of the eloquent cortex. Both contrast-bolus and arterial spin labelling magnetic resonance perfusion imaging show good correlation with clinical lateralisation of seizure disorder. Conclusion Structural imaging is essential in localisation and lateralization of the seizure focus. Functional radionuclide imaging or advanced magnetic resonance imaging techniques can provide complementary information when an epileptogenic substrate is not identified or in the presence of non-concordant clinical and structural findings.link_to_subscribed_fulltex

Quantum metrology and its application in biology

Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance to biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context, focusing on optical techniques due to their particular relevance for biological imaging, sensing, and stimulation. Our understanding of quantum mechanics has already enabled important applications in biology, including positron emission tomography (PET) with entangled photons, magnetic resonance imaging (MRI) using nuclear magnetic resonance, and bio-magnetic imaging with superconducting quantum interference devices (SQUIDs). In quantum metrology an even greater range of applications arise from the ability to not just understand, but to engineer, coherence and correlations at the quantum level. In the past few years, quite dramatic progress has been seen in applying these ideas into biological systems. Capabilities that have been demonstrated include enhanced sensitivity and resolution, immunity to imaging artifacts and technical noise, and characterization of the biological response to light at the single-photon level. New quantum measurement techniques offer even greater promise, raising the prospect for improved multi-photon microscopy and magnetic imaging, among many other possible applications. Realization of this potential will require cross-disciplinary input from researchers in both biology and quantum physics. In this review we seek to communicate the developments of quantum metrology in a way that is accessible to biologists and biophysicists, while providing sufficient detail to allow the interested reader to obtain a solid understanding of the field. We further seek to introduce quantum physicists to some of the central challenges of optical measurements in biological science.Comment: Submitted review article, comments and suggestions welcom

Peripheral vascular malformations : modern imaging

Currently the major aim in peripheral vascular malformation diagnosis, crucial for subsequent management and treatment, is to identify its haemodynamic characteristics. Other significant features that should be specified by a radiologist are the exact location of the anomaly, its size, and its morphology. Until recently the diagnostic methods available for comprehensive evaluation of malformations have been rather limited. Moreover, they were often associated with the necessity of exposing the patient to X-ray radiation and with invasive procedures, as for example in angiography. The development of imaging techniques used in the diagnosis of vascular abnormalities in recent years, especially magnetic resonance imaging, has contributed to improved diagnostic value of the tests. In this article we review the currently available imaging modalities with particular consideration of magnetic resonance imaging and its capability to distinguish between high- and low-flow malformations

Role of multi-parametric (mp) MRI in prostate cancer

Multi-parametric magnetic resonance imaging is increasingly being recommended as standard imaging modality for prostate cancer diagnosis and staging. It comprises structural T2 and T1 sequences supplemented by functional imaging techniques, i.e. diffusion-weighted, dynamic contrast enhanced and spectroscopic imaging. Pre-biopsy multi-parametric magnetic resonance imaging is recommended for both detection and staging as it avoids biopsy artefact, and when normal, has a negative predictive value of 95% for significant cancer. Magnetic resonance imaging-guided prostate biopsy targets only area(s) considered to be suspicious for prostate cancer, hence resulting in improved accuracy. Dynamic contrast enhancing helps in the detection of cancer and for the assessment of extra-capsular extension, distal urethral sphincter and seminal vesicles involvement. The role of multi-parametric magnetic resonance imaging in follow-up of patients on active surveillance is also increasingly recognised. Its role is now further expanded to facilitate targeted therapies. This review focuses on the evolving role of multi-parametric magnetic resonance imaging in diagnosis and management of prostate cancer

Current status of hepatocellular carcinoma detection: screening strategies and novel biomarkers.

Hepatocellular carcinoma (HCC) remains a major cause of cancer-related mortality worldwide. Delayed diagnosis is a major factor responsible for the poor prognosis of HCC. Several advances have been made in the field of liver imaging with the use of novel imaging contrasts, improving current imaging techniques with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), introduction of new technologies such as contrast liver ultrasound, and development of novel biomarkers with the goal of early detection of HCC and improving outcomes of patients with HCC. This review focuses on current surveillance strategies and development of biomarkers with the goal of early detection of HCC

IMAGING TECHNIQUES USED IN MULTIPLE MYELOMA

Multiple myeloma (MM) is a plasma cell disorder, characterised by bone marrow infiltration with clonal plasma cells; production of monoclonal immunoglobulin (paraprotein); end-organ damage; lytic lesions in the bones; renal impairment; hypercalcaemia and anaemia. Skeleton evaluation in MM is necessary not only for staging purposes but also to detect serious complications such as fractures. Skeletal survey is an established rst-line investigation for this purpose. However, in recent years, new imaging techniques such as whole-body magnetic resonance imaging and 2- uoro-2-deoxy-D-glucose positron emission tomography computed tomography have been used widely. In this article, we review different imaging techniques used in MM and their impact on patient management. Key words: Imaging techniques, magnetic resonance imaging, multiple myeloma, osteolytic lesions, positron emission tomography/computed tomography, skeletal survey

A review of imaging techniques for systems biology

This paper presents a review of imaging techniques and of their utility in system biology. During the last decade systems biology has matured into a distinct field and imaging has been increasingly used to enable the interplay of experimental and theoretical biology. In this review, we describe and compare the roles of microscopy, ultrasound, CT (Computed Tomography), MRI (Magnetic Resonance Imaging), PET (Positron Emission Tomography), and molecular probes such as quantum dots and nanoshells in systems biology. As a unified application area among these different imaging techniques, examples in cancer targeting are highlighted

Cardiovascular MRI in clinical trials: expanded applications through novel surrogate endpoints

Recent advances in cardiovascular magnetic resonance (CMR) now allow the accurate and reproducible measurement of many aspects of cardiac and vascular structure and function, with prognostic data emerging for several key imaging biomarkers. These biomarkers are increasingly used in the evaluation of new drugs, devices and lifestyle modifications for the prevention and treatment of cardiovascular disease. This review outlines a conceptual framework for the application of imaging biomarkers to clinical trials, highlights several important CMR techniques which are in use in randomised studies, and reviews certain aspects of trial design, conduct and interpretation in relation to the use of CMR

Fatty images of the heart: spectrum of normal and pathological findings at computed tomography and cardiac magnetic resonance imaging.

Ectopic cardiac fatty images are not rarely detected incidentally at computed tomography and cardiac magnetic resonance, either in exams focused on the heart as in general thoracic imaging evaluations. A correct interpretation of these findings is essential in order to recognize their normal or pathological meaning, focusing on the eventually associated clinical implications. The development of techniques such as computed tomography and cardiac magnetic resonance allowed a detailed detection and evaluation of adipose tissue within the heart. This pictorial review illustrates the most common characteristics of cardiac fatty images at computed tomography and cardiac magnetic resonance, in a spectrum of normal and pathological conditions ranging from physiological adipose images to diseases presenting with cardiac fatty foci. Physiologic intramyocardial adipose tissue may normally be present in healthy adults, being not related to cardiac affections and without any clinical consequence. However cardiac fatty images may also be the expression of various diseases, comprehending arrhythmogenic right ventricular dysplasia, post-myocardial infarction lipomatous metaplasia, dilated cardiomyopathy and lipomatous hypertrophy of the inter-atrial septum. Fatty neoplasms of the heart as lipoma and liposarcoma are also described

Emerging methods for prostate cancer imaging: evaluating cancer structure and metabolic alterations more clearly

Imaging plays a fundamental role in all aspects of the cancer management pathway. However, conventional imaging techniques are largely reliant on morphological and size descriptors that have well-known limitations, particularly when considering targeted-therapy response monitoring. Thus, new imaging methods have been developed to characterise cancer and are now routinely implemented, such as diffusion-weighted imaging, dynamic contrast enhancement, positron emission technology (PET) and magnetic resonance spectroscopy. However, despite the improvement these techniques have enabled, limitations still remain. Novel imaging methods are now emerging, intent on further interrogating cancers. These techniques are at different stages of maturity along the biomarker pathway and aim to further evaluate the cancer microstructure (vascular, extracellular and restricted diffusion for cytometry in tumours) magnetic resonance imaging (MRI), luminal water fraction imaging] as well as the metabolic alterations associated with cancers (novel PET tracers, hyperpolarised MRI). Finally, the use of machine learning has shown powerful potential applications. By using prostate cancer as an exemplar, this Review aims to showcase these potentially potent imaging techniques and what stage we are at in their application to conventional clinical practice