Imaging, arthroscopy, and markers in osteoarthritis.

Osteoarthritis is the most common form of arthritis occurring in humans, but its diagnosis in early stages continues to be elusive. Early diagnosis is of great potential importance because it would allow identification of individuals at risk for progressive disease and permit early intervention. At present, perhaps even more important, the ability to recognize patients with early, often asymptomatic, disease and the ability to monitor disease progression over time would be most useful for the evaluation of new forms of therapy to prevent, halt, or even reverse osteoarthritis. Thus, 1991 has witnessed the continued search for the ideal indicator of early osteoarthritis.     

Clinical Utility of Intravascular Imaging: Past,Present, and Future

Although it is the tool used by most interventional cardiologists to assess the severity of coronary artery disease and guide treatment, coronary angiography has many limitations because it is a shadowgraph, depicting planar projections of the contrast-filled lumen that are often foreshortened rather than imaging the diseased vessel itself. Currently available intravascular imaging technologies include grayscale intravascular ultrasound (IVUS), optical coherence tomography (OCT) (the light analogue of IVUS), and near-infrared spectroscopy that detects lipid within the vessel wall and that has been combined with grayscale IVUS in a single catheter as the first combined imaging device. They provide tomographic or cross-sectional images of the coronary arteries that include the lumen, vessel wall, plaque burden, plaque composition and distribution, and even peri-vascular structures—information promised, but rarely provided angiographically. Extensive literature shows that these tools can be used to answer questions that occur during daily practice as well as improving patient outcomes. Is this stenosis significant? Where is the culprit lesion? What is the anatomy of an unusual or ambiguous angiographic lesion? What is the right stent size and length? What is the likelihood of distal embolization or periprocedural myocardial infarction during stent implantation? Has the intervention been optimized? Why did this stent thrombose or restenose? This review summarizes these uses of intravascular imaging as well as the outcomes data supporting their incorporation into routine clinical practice.     

Renal Artery Stenosis: Imaging Options,Pitfalls, and Concerns

Renal artery stenosis can be diagnosed with multiple imaging modalities, each one having different risk vs accuracy tradeoffs. Catheter angiography with pressure gradient measurements is the definitive gold standard but also the most invasive and thus reserved primarily for imaging at the time of renal revascularization. Ultrasonography is the safest and least expensive but also the least accurate and most operator-dependent. Contrast-enhanced computed tomographic angiography and magnetic resonance angiography are intermediate (between ultrasound and catheter angiography) with respect to accuracy and expense. Exciting new advances in magnetic resonance that include new contrast agents, which eliminate nephrogenic systemic fibrosis risk, and techniques to characterize the hemodynamic significance of renal artery stenoses are now becoming available. In addition, magnetic resonance angiography without any contrast has become more accurate and rivals contrast-enhanced techniques in some patients. This review explores these techniques for renal artery stenosis imaging.     

Imaging the airways. Hemoptysis, bronchiectasis, and small airways disease

Advances in technology have increased the contribution of radiology in understanding and evaluating diseases of the airways. In patients with hemoptysis, CT is now established as a complementary technique to bronchoscopy, or as an alternative to bronchoscopy in selected cases. The introduction of high-resolution CT has improved the detection and assessment of bronchiectasis and small airways disease, allowed better correlation between pathologic changes and radiologic appearances, and provided new insights into possible links between small airways disease and bronchial disease.     

Evidence-based Imaging and Cost-effectiveness Analysis in Cardiopulmonary Imaging

Evidence-based imaging is a paradigm for using the best evidence to guide medical decision making. Evidence-based imaging centers on formulating a clinical question focused on a specific patient scenario, conducting a literature search and critical review, summarizing the evidence, and using the information to guide medical decision making. Additional tools important to evidence-based imaging are clinical prediction rules, designed to provide evidence for when imaging should be used, and cost-effectiveness analysis, designed to quantify the economic and patient outcomes from medical interventions.