Advances In Computed Tomography Research Articles

Advanced cardiovascular imaging: from patients to populations

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in both men and women in developed nations. Gender and population differences in the prevalence, presentation and prognosis of CVD, as well as in the role of traditional risk factors in determining its risk have been increasingly recognized. Thus, multi-ethnic studies are necessary to fully understand the basis for optimal prevention and management of CVD. Cardiovascular imaging is a well-validated form of non-invasive diagnostic and prognostic testing. Coronary artery calcium (CAC), carotid intima-media thickness (IMT), and elevated left ventricular (LV) mass and geometry as assessed by cardiac magnetic resonance (CMR) offer highly specific phenotype data on the extend of CVD. Due to their high sensitivity, these modalities are increasing used to characterize CVD risk in clinically asymptomatic individuals. Noninvasive imaging of the heart and blood vessels has the potential to replace invasive angiography for the evaluation of ischemic and nonischemic cardiomyopathy. Computed Tomography (CT) angiography allows coronary vessels to be accurately assessed for stenosis. Magnetic resonance imaging (MRI) at 1.5 Tesla and 3 Tesla offers superior evaluation of myocardial structure, function and perfusion, as well as atherosclerotic plaque and tissue composition. In summary, new imaging techniques for the heart and blood vessels offer the potential for advanced tools for patient diagnosis. The application of advanced cardiac CT and MRI to study numbers of patients is underway in epidemiologic studies to help understand risk factor effects and genetic relationships [1,2].

JS1-4 - Evolutional Drug Development with the Use of Microdosing and PET Imaging

ABSTRACT Microdose clinical trials can be utilized for the purpose to gain pharmacokinetic information on a tentative drug candidate in human using labelled compound(s) and AMS or imaging technology using PET, or non-labelled compound(s) and LC/MS/MS, and to select drug candidate by ensuring adequate properties in early stage. In 2008, the NEDO (New Energy and Industrial Technology Development Organization) project entitled ‘Establishment of Evolutional Drug development with the Use of Microdosing Clinical Trial’ was adopted. In this project, the quantitative prediction method on drug absorption, distribution, metabolism and excretion (ADME) using modeling and simulation will be applied to human to validate this methodology. That is, based on the in vitro data on metabolism, transport and binding with animal and human tissues, the drug concentration–time profiles in the plasma and target tissues such as the brain, tumor, liver and kidney will be predicted and the validity of the predictions will be investigated by using clinical studies under its microdose and therapeutic dose conditions. PET is a promising approach to determine the functional change of transporters associated with genetic polymorphisms or drug–drug interactions. Labeled PET probes have been developed for specific transporters in this NEDO project. In addition, in 2010, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) has launched its second program, the ‘J-AMP; Japan Advanced Molecular Imaging Program’, using the two major centers (RIKEN, NIRS). In this project, research is undertaken focusing on the cancer and dementia fields to contribute to the development of new drugs and biomarkers as diagnostic tools. Here, in this presentation, I will share with you our recent progress in the use of the analysis of plasma clearance of drugs and PET imaging to evaluate the transporter function in vivo.

Advances in CT and MR Technology

This article will review recent advances in computed tomography (CT) and magnetic resonance (MR) hardware and software techniques that have dramatically changed the use of CT and MR angiography. For CT angiography, technology has increased the speed of acquisition, reduced the radiation dose necessary to diagnose disease, and simplified the ability to characterize disease. Similarly, advances in MR angiography have focused on safer techniques that do not require the use of intravenous contrast agents, increased the speed of acquisition, and improved spatial resolution. In addition, new MR angiography methods have expanded the use of MR angiography beyond purely anatomical information toward quantitative hemodynamic analyses.

Pediatric Head Injury

1. Jeff E. Schunk, MD* 2. Sara A. Schutzman, MD† 1. *Professor, Division of Pediatric Emergency Medicine, Department of Pediatrics, University of Utah School of Medicine, Primary Children’s Medical Center, Salt Lake City, UT. 2. †Assistant Professor, Department of Pediatrics, Harvard Medical School, Senior Associate Physician in Medicine, Division of Emergency Medicine, Department of Medicine, Children’s Hospital Boston, Boston, MA. * Abbreviations: BSF: : basilar skull fracture CSF: : cerebrospinal fluid CT: : computed tomography EDH: : epidural hemorrhage GCS: : Glasgow Coma Scale ICI: : intracranial injury ICP: : intracranial pressure PECARN: : Pediatric Emergency Care Applied Research Network SAH: : subarachnoid hemorrhage SDH: : subdural hemorrhage TBI: : traumatic brain injury Recent studies have provided updated guidelines for the diagnosis of head injury and the management of patients who experience concussions. A multidisciplinary panel has recently issued new guidelines for return to play after head injury. After reading this article, readers should be able to: 1. Understand the anatomy and pathophysiology relevant to pediatric head injuries. 2. Take an appropriate history, perform an appropriate physical examination, and decide what imaging, if any, is warranted in the case of a child with a head injury. 3. Know the characteristics of the various types of intracranial injuries. 4. Understand the proper management of both minor and severe head injuries in children. Pediatric head injury is extremely common. Although the vast majority of children with head trauma have minor injuries, a small number, even among well-appearing children, will have more serious injuries with the potential for deterioration and significant sequelae. The clinician is challenged to discern which few among the many injured are at high risk for intracranial complications. Clinical symptoms are neither completely sensitive nor specific for significant injury: vomiting may be associated with intracranial injury (ICI), but most children who experience vomiting do not have a complication. Computed tomography (CT) accurately identifies ICIs requiring intervention, but also identifies minor lesions with unclear clinical importance (ie, not requiring intervention) and exposes developing brains to ionizing radiation with the associated risks. Although clinical decision rules determine which children are at highest risk and provide a useful clinical framework, they may not necessarily direct care. Additionally, in this era of reliance on imaging, it is important to remember what the clinical examination tells us regarding brain function, information that …

P2.13 Image-Guided and Targeted Therapy Using Theranostic Nanoparticles for Personalized Cancer Treatment

ABSTRACT Highly heterogeneous cancer cells represent the major challenge in clinical oncology for the treatment of human cancers. Novel therapeutic approaches that enable the application of personalized therapy for cancer patients hold great promise for effective treatment while minimizing systemic toxicity. We have developed an integrated cancer image-therapy protocol that takes advantages of multifunctionality of theranostic nanoparticles and advanced molecular imaging methods for biomarker-targeted tumor imaging and drug delivery, MRI monitoring therapeutic response, and optical image-guided surgery. Multifunctional magnetic iron oxide nanoparticles (IONPs) developed by our group are targeted to epidermal growth factor receptor, Her-2/Neu, and urokinase plasminogen activator receptor, which are biomarkers highly expressed in many types of human cancers. These receptor-targeted IONPs have capacity to carry single or multiple therapeutic agents for drug delivery, near infrared fluorescence and spectroscopic optical imaging, and magnetic resonance imaging (MRI). They are also designed to overcome physical and intrinsic barriers that reduce efficiency of drug delivery and confer drug resistance in human cancers. We have shown specificity and sensitivity of optical and MR imaging using the nanoparticles as targeted molecular contrast agents in orthotopic human breast, pancreatic, and ovarian cancer xenograft models. The development of biomarker targeted MRI nanoparticle probes should allow determining the level of biomarker expression in tumors using a non-invasive imaging approach for selection of the appropriate patients for targeted therapy. Based on the targeted imaging nanoparticles, we further developed methods to encapsulate or conjugate chemotherapy drugs into the nanoparticles. Efficacy of targeted therapy and MRI-monitoring drug delivery and response after systemic delivery of the theranostic nanoparticles has been demonstrated in orthotopic human breast, pancreatic and ovarian cancer xenograft models in nude mice. Since drug resistant residual tumors contain nanoparticles that produce optical signals, we applied hand-held optical imaging devices for detection and removal of drug resistant tumor lesions in the surgical cavity to prevent local recurrence and distant metastasis. The ultimate goal of our research is to translate this biomarker targeted therapy and image-guided treatment and surgery protocol into clinical applications for personalized management of cancer patients. Download : Download full-size image Fig. 1 . An integrated therapy-imaging approach for personalized therapy and effective treatment of drug-resistant cancers

Advances in molecular imaging for breast cancer detection and characterization

Advances in our ability to assay molecular processes, including gene expression, protein expression, and molecular and cellular biochemistry, have fueled advances in our understanding of breast cancer biology and have led to the identification of new treatments for patients with breast cancer. The ability to measure biologic processes without perturbing them in vivo allows the opportunity to better characterize tumor biology and to assess how biologic and cytotoxic therapies alter critical pathways of tumor response and resistance. By accurately characterizing tumor properties and biologic processes, molecular imaging plays an increasing role in breast cancer science, clinical care in diagnosis and staging, assessment of therapeutic targets, and evaluation of responses to therapies. This review describes the current role and potential of molecular imaging modalities for detection and characterization of breast cancer and focuses primarily on radionuclide-based methods.

Advances in Molecular Imaging: Targeted Optical Contrast Agents for Cancer Diagnostics

Over the last three decades, our understanding of the molecular changes associated with cancer development and progression has advanced greatly. This has led to new cancer therapeutics targeted against specific molecular pathways; such therapies show great promise to reduce mortality, in part by enabling physicians to tailor therapy for patients based on a molecular profile of their tumor. Unfortunately, the tools for definitive cancer diagnosis - light microscopic examination of biopsied tissue stained with nonspecific dyes - remain focused on the analysis of tissue ex vivo. There is an important need for new clinical tools to support the molecular diagnosis of cancer. Optical molecular imaging is emerging as a technique to help meet this need. Targeted, optically active contrast agents can specifically label extra- and intracellular biomarkers of cancer. Optical images can be acquired in real time with high spatial resolution to image-specific molecular targets, while still providing morphologic context. This article reviews recent advances in optical molecular imaging, highlighting the advances in technology required to improve early cancer detection, guide selection of targeted therapy and rapidly evaluate therapeutic efficacy.

Light emitting diodes: Light engines to simplify and economize advanced microscopy

THE old adage, ‘‘A picture is worth a thousand words,’’ is especially true in biological research, with microscopic images serving to mark the development of key concepts in biology since Hooke first described ‘‘cells’’ in thin slices of cork (1). More than 400 years later, microscopic imaging still serves as a primary data source for biological research, with increasingly advanced techniques that provide information on molecular scale interactions and dynamics. Such advanced molecular imaging techniques take advantage of ever more sophisticated light sources, optics, detectors, and image processing methods, many of which can be quite complex and expensive. At the same time, new technologies and production methods, many driven by the consumer market, have resulted in key components of imaging systems becoming smaller, simpler, and cheaper. The convergence of these effects is having profound effects on our options for light sources for microscopic imaging. The properties of the illumination source are critical to many advanced optical microscopy methods. Lasers play a key role in many of these owing to the monochromatic and coherent nature of their light, plus their ability to be pulsed and otherwise controlled. However, illumination with high-pressure mercury gas discharge or xenon lamps is still the standard for most imaging applications. These light sources provide bright, broad-spectrum excitation (300–900 nm) that can be easily selected by excitation filters for fluorescent imaging applications. However, there are quite a few disadvantages that limit the wide-spread of mercury or xenon lamps-based microscopy system in biological applications. First, sometimes these traditional light sources are too bright and harmful for the living organisms being studied. Excessive brightness can cause rapid photo-bleaching of the dyes used to stain the cells/ tissues. UV light especially, if not blocked, can have significant deleterious effects on live cells. Second, there are substantial costs involved in using mercury or xenon lamps because of their relatively short lifespan. The life of a mercury lamp is usually several hundred hours, and the intensity of these lamps decays progressively during this time. In addition, gas discharge lamps require some time to warm up before lamp intensity reaches steady state. Therefore, once mercury lamps are turned on, they have to be left on for hours to enable fluorescent measurements as needed without delay, thereby further shortening the lamp lifetime. Third, there are also some hazards issues of using mercury or xenon lamps. These lamps generate a significant amount of heat and therefore introduce complications when used in a confined space. When mercury lamps die, they can explode and damage the lenses or mirrors within the lamp housing. These factors combine to make gas discharge lamps inconvenient for lab-based applications and impractical for field applications, including use in portable, miniature, or low cost imaging devices. By contrast, light-emitting diodes (LEDs) show great pro

Stem Cells as a Tool for Breast Imaging

Stem cells are a scientific field of interest due to their therapeutic potential. There are different groups, depending on the differentiation state. We can find lonely stem cells, but generally they distribute in niches. Stem cells don't survive forever. They are affected for senescence. Cancer stem cells are best defined functionally, as a subpopulation of tumor cells that can enrich for tumorigenic property and can regenerate heterogeneity of the original tumor. Circulating tumor cells are cells that have detached from a primary tumor and circulate in the bloodstream. They may constitute seeds for subsequent growth of additional tumors (metastasis) in different tissues. Advances in molecular imaging have allowed a deeper understanding of the in vivo behavior of stem cells and have proven to be indispensable in preclinical and clinical studies. One of the first imaging modalities for monitoring pluripotent stem cells in vivo, magnetic resonance imaging (MRI) offers high spatial and temporal resolution to obtain detailed morphological and functional information. Advantages of radioscintigraphic techniques include their picomolar sensitivity, good tissue penetration, and translation to clinical applications. Radionuclide imaging is the sole direct labeling technique used thus far in human studies, involving both autologous bone marrow derived and peripheral stem cells.

Molecular Imaging of Stem Cells: Tracking Survival, Biodistribution, Tumorigenicity, and Immunogenicity

Being able to self-renew and differentiate into virtually all cell types, both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) have exciting therapeutic implications for myocardial infarction, neurodegenerative disease, diabetes, and other disorders involving irreversible cell loss. However, stem cell biology remains incompletely understood despite significant advances in the field. Inefficient stem cell differentiation, difficulty in verifying successful delivery to the target organ, and problems with engraftment all hamper the transition from laboratory animal studies to human clinical trials. Although traditional histopathological techniques have been the primary approach for ex vivo analysis of stem cell behavior, these postmortem examinations are unable to further elucidate the underlying mechanisms in real time and in vivo. Fortunately, the advent of molecular imaging has led to unprecedented progress in understanding the fundamental behavior of stem cells, including their survival, biodistribution, immunogenicity, and tumorigenicity in the targeted tissues of interest. This review summarizes various molecular imaging technologies and how they have advanced the current understanding of stem cell survival, biodistribution, immunogenicity, and tumorigenicity.

Fluorescent magnetoliposomes as a platform technology for functional and molecular MR and optical imaging

Here, we present a detailed characterisation of rhodamine B-containing magnetoliposomes (FLU-ML), emphasising the dependence of their fluorescence properties on the presence of iron oxide cores, and the molar fraction of the fluorophore. The magnetoliposome types used exist as colloidally stable, negatively charged clusters with an average hydrodynamic diameter of 95 nm. The molar rhodamine B fractions were 0.67 % and 1.97 %. Rhodamine B normalised fluorescence, quantum yields and fluorescence lifetimes were substantially reduced by inner filter effects as the magnetoliposome concentration is increased, by increasing molar rhodamine B fraction, and by quenching originating from the iron oxide cores. MR relaxometry at 3 T revealed extremely high r2 relaxivities (440 to 554 s-1mM-1) and moderately high r1 values (2.06 to 3.59 s-1mM-1). Upon incubating human prostate carcinoma (PC-3) cells with FLU-ML, a dose-dependent particle internalisation was found by MR relaxometry. In addition, the internalised FLU-ML were clearly visible by fluorescence microscopy. At the FLU-ML concentrations used (up to 3 × 10³ M Fe) cell viability was not substantially impaired. These results provide valuable insights on the fluorescence properties of bimodal magnetoliposomes and open promising perspectives for the use of these materials as a platform technology for advanced functional and molecular MR and optical imaging applications.

18F]fluoro-L-thymidine (FLT) uptake in baseline positron emission tomography (PET) as a prognostic marker in patients with advanced non-small cell lung cancer (NSCLC) treated first-line with erlotinib.

7591 Background: Since the introduction of targeted therapy into the treatment of advanced NSCLC molecular imaging tools gain in importance for assessment of pharmacodynamics, prognosis and prediction of therapeutic outcome. We evaluated the prognostic value of 3'-deoxy-3'-[18F]fluoro-L-thymidine (FLT) uptake measured by positron emission tomography (PET) as a noninvasive proliferation marker in patients with metastatic non-small cell lung cancer (NSCLC) prior to systemic therapy with erlotinib. Methods: We retrospectively analyzed FLT uptake in 41 chemonaive patients with advanced NSCLC (stage IV) treated with erlotinib first-line prior to systemic therapy. The peak SUV of the lesion with the highest SUV (SUVpeak) as well as sex, age, ECOG performance state at presentation, EGFR mutational status and adenocarcinoma/BAC histology were analyzed in univariate analysis using Kaplan-Meier statistics and log rank test for its association with survival. Multivariate analysis was performed using Cox regression. Results: Median follow-up was 21.9 months. In univariate analysis, patients with an SUVpeak ≤3.1 had a significantly better overall survival (15.67 months [95% CI 6.4 to 25 months]) compared to patients with an SUVpeak >3.1 (3.2 months [95% CI 0 to 8.2 months]) (p=0.008, log rank). In addition, age was significantly associated with overall survival (p=0.046 log rank test). In this cohort none of the clinical parameters gender, histology, ECOG performance status or EGFR mutational status were significantly associated with overall survival. In multivariate analysis including age and SUVpeak, SUVpeak was a significantly strong prognostic factor for overall survival (p=0.020). Conclusions: FLT uptake of the most active tumor manifestation site is a strong prognostic marker for overall survival among patients with advanced NSCLC treated with erlotinib first-line.

Spatial mapping by imaging mass spectrometry offers advancements for rapid definition of human skin proteomic signatures

Investigations into the human skin proteome by classical analytical procedures have not addressed spatial molecular distributions in whole-skin biopsies. The aim of this study was to develop methods for the detection of protein signatures and their spatial disposition in human skin using advanced molecular imaging technology based on mass spectrometry technologies. This technology allows for the generation of protein images at specific molecular weight values without the use of antibody while maintaining tissue architecture. Two experimental approaches were employed: MALDI-MS profiling, where mass spectra were taken from discrete locations based on histology, and MALDI-IMS imaging, where complete molecular images were obtained at various MW values. In addition, proteins were identified by in situ tryptic digestion, sequence analysis of the fragment peptides and protein database searching. We have detected patterns of protein differences that exist between epidermis and dermis as well as subtle regional differences between the papillary and reticular dermis. Furthermore, we were able to detect proteins that are constitutive features of human skin as well as those associated with unique markers of individual variability.

Multi-modal molecular imaging approaches to detect primary cells in preclinical models

The need to understand cellular trafficking in vivo in situ requires the development and application of novel methodologies for cellular labeling and cell tracking. Here we applied new technologies associated with advances in molecular imaging to demonstrate the feasibility of labeling primary immune cells. We demonstrate the utility of fluorescently tagged polystyrene microspheres, MRI susceptible emulsions and cell entry peptoids. The adaptation of these labeling agents will permit cell specific delivery, diagnostic sensing and the delivery of therapeutic agents to sites of inflammation and infection.

Molecular imaging of cell-based cancer immunotherapy

Cell-based cancer immunotherapy represents a new and powerful weapon in the arsenal of anticancer treatments. Non-invasive monitoring of the disposition, migration and destination of therapeutic cells will facilitate the development of cell based therapy. The therapeutic cells can be modified intrinsically by a reporter gene or labeled extrinsically by introducing imaging probes into the cells or on the cell surface before transplant. Various advanced non-invasive molecular imaging techniques are playing important roles in optimizing cellular therapy by tracking cells and monitoring the therapeutic effects of transplanted cells in vivo. This review will summarize the application of multiple molecular imaging modalities in cell-based cancer immunotherapy.

Advanced CT images reveal nonmetric cranial variations in living humans

Two mainland Japanese males were examined with a computer tomography (CT) X-ray scanner to reconstruct three-dimensional CT simulation images of their cranial anatomy and to check for the presence/absence of 23 nonmetric cranial traits. Surface anatomy for scoring 19 nonmetric cra- nial variations was clearly observed among the 23 variations. Evaluation of the four other traits might have been disturbed due to dental treatment history, small variations in the images, or X-ray radiation condition. However, these disturbances could be overcome by a combination of simple thin-sliced CT images and magnetic resonance imaging. We have thus developed a new anatomical field for eluci- dating human morphology.

PET/CT in paediatric oncology: clinical usefulness and dosimetric concerns

Childhood cancer, always particularly distressing, appears to be on the increase. The last quarter of the last century saw an approximately 25% rise in the incidence of diagnoses of malignancies (all forms) in children in the Western world (USA and Europe), the figure rising from around 12 per 100,000 in 1975 to 15 per 100,000 in 2,000. This corresponds to an average annual increase of approximately 1% for the whole period. Among the major types of childhood cancer, leukaemias and cancers of the central nervous system account for more than half of all new cases. Around a third of childhood cancers are leukaemias, the most common type being acute lymphoblastic leukaemia. The most common solid tumours in children are brain tumours (e.g. gliomas and medulloblastomas), while other solid cancers (e.g. neuroblastomas, Wilms tumours, and sarcomas such as rhabdomyosarcoma and osteosarcoma) are less common [2]. Due to significant advances in treatment, however, the same 25-year period also saw substantial improvements in survival, with 5-year survival rates for all childhood cancers (combined) rising from around 55–60% to around 75–80% percent, the average annual increase for the whole period being approximately 5%. Of course, the data vary around these values in relation to age, gender, geography and type of cancer. In short, in the face of a growing incidence of childhood cancer cases, therapeutic advances seem to be failing to make inroads. But, in this scenario, there emerges a question: could application of today’s most advanced molecular imaging techniques help to boost the effectiveness of childhood cancer diagnosis and treatment? This is clearly a hypothesis worth addressing, but given that these techniques, such as positron emission tomography (PET), used alone or in combination with x-ray computed tomography (CT), are based on use of ionising radiation, it is also one that immediately raises the problem of potential radiation burden, known to be a much more critical issue in children than in adults. Indeed, because of concerns over radiation exposure, but also problems linked to long scan acquisition times and the need for sedation in young children, imaging studies in children tend to be restricted to patients in whom the study is absolutely crucial for the diagnosis, treatment planning and follow-up, when other modalities have failed to provide conclusive information. “Focus on...” abridgements aim to highlight papers published within the past year and draw extensively on the texts and summaries of the articles referenced. Less recent citations are also included when deemed useful to provide background information on the topic reviewed.

Molecular imaging of HER2-positive breast cancer: a step toward an individualized 'image and treat' strategy.

HER2 overexpression is correlated with aggressive tumor behavior and poor clinical outcome. Therefore, HER2 has become an important prognostic and predictive factor, as well as a target for molecular therapies. The article reviews recent advances in molecular imaging of HER2 that could facilitate individual approaches to targeted therapy of HER2-positive breast cancers. Because of the heterogeneity of breast cancer and possible discordance in HER2 status between primary tumors and distant metastases, assessment of HER2 expression by noninvasive imaging may become an important complement to immunohistochemistry or fluorescence in-situ hybridization analyses of biopsied tissue. Monoclonal antibodies such as trastuzumab and pertuzumab, or small scaffold proteins such as affibody molecules are used as HER2-targeting agents. For imaging purposes, these agents are labeled with positron or gamma-emitting radionuclides, optical dyes, or paramagnetic contrast molecules for positron emission tomography single photon emission tomography optical, and magnetic resonance imaging, respectively. HER2-specific molecular probes, combined with modern imaging techniques to provide information on HER2 expression not only in primary tumors but also in distant metastases not amenable to biopsy, may reduce problems with false negative results and, thereby, influence patient management by selecting patients that would benefit from HER2-targeted therapies. The new 'image and treat' strategy, involving assessment of target presence and distribution in an individual patient followed by optimized, target-specific drug delivery, may potentially improve efficacy of cancer treatment while reducing side effects.

Optical molecular imaging and its emerging role in colorectal cancer.

Colorectal cancer remains a major cause of morbidity and mortality in the United States. The advent of molecular therapies targeted against specific, stereotyped cellular mutations that occur in this disease has ushered in new hope for treatment options. However, key questions regarding optimal dosing schedules, dosing duration, and patient selection remain unanswered. In this review, we describe how recent advances in molecular imaging, specifically optical molecular imaging with fluorescent probes, offer potential solutions to these questions. We begin with an overview of optical molecular imaging, including discussions on the various methods of design for fluorescent probes and the clinically relevant imaging systems that have been built to image them. We then focus on the relevance of optical molecular imaging to colorectal cancer. We review the most recent data on how this imaging modality has been applied to the measurement of treatment efficacy for currently available as well as developmental molecularly targeted therapies. We then conclude with a discussion on how this imaging approach has already begun to be translated clinically for human use.

Diagnostic and Therapeutic Joint Injections

Joint injection is a useful tool in the diagnosis of intra-articular pathology that may improve diagnostic performance of computed tomography (CT) and magnetic resonance (MR) imaging. Historically, conventional arthrography under fluoroscopy was the first method to be used to image indirectly the intra-articular soft tissues, but with the advent of CT, CT arthrography offered better soft tissue depiction. The development of conventional MR allowed even better visualization of soft tissues, and in the early 1990s, MR arthrography surpassed CT arthrography in popularity. Joint injections may also be performed for therapeutic reasons with different drugs, such as corticosteroids, anesthetics, or hyaluronic acid, which have been shown to provide pain relief in various circumstances. In this article, the technical principles for joint injection of the shoulder, knee, elbow, hip, ankle, and wrist, used for therapeutic or diagnostic reasons, are discussed. Indications, expected benefits, and risks are also analyzed.