Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging

Endoscopic Spinal Fusion

Spinal fusion surgery has the potential to alleviate pain, improve functional ability, and maximize overall quality of life. Recognizing not only the importance to preserve as much normal human anatomy and physiology as possible but also to take into account the overwhelming economic, social, and psychological burden that open surgery may place on both patient and society, the concept of minimally invasive surgery (MIS) was born. The goals of MIS are to achieve the same results as conventional open surgery while striving to minimize soft tissue destruction, decrease intraoperative blood loss, reduce postoperative pain and hospital length of stay, and most importantly accelerate return to preoperative functional status. Endoscopic spinal fusion represents a step in the evolution of minimally invasive spine surgery that now allows us to even perform procedures such as the transforaminal lumbar interbody fusion (TLIF) without general anesthesia, removing yet another possible cause of surgical morbidity. Endoscopic techniques for fusion in the lumbar spine have been developed for every approach, and techniques also exist for both cervical and thoracic applications

In vitro modulation of oral bacterial adhesion to saliva-coated hydroxyapatite beads by milk casein derivatives

Bovine caseinate, derivatives of its glycosylated moiety [caseinoglycomacropeptide (CGP)], and caseinophosphopeptides were evaluated as inhibitors of adhesion of oral bacteria to saliva‐coated hydroxyapatite beads (S‐HA). All milk casein‐derived components behaved as potent inhibitors of Streptococcus sanguis OMZ 9 and Streptococcus sobrinus OMZ 176 adhesion to S‐HA, whereas neither bovine serum albumin nor polyethyleneglycol were able to interfere with the adhesion of these strains. By contrast, none of the molecular species tested was able to inhibit the attachment of Actinomyces viscosus Ny 1 to S‐HA. On the other hand, casein derivatives were shown to displace human serum albumin from S‐HA beads. They were also able to bind to the bacterial cell surface of all strains examined. Collectively, these findings suggest that interactions between acidic casein‐derived milk components and the biological surfaces involved in bacterial adhesion to S‐HA result in an inhibitory effect that is selective for the oral streptococci examined. </p