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

Modelling of increased homocysteine in ischaemic stroke: post-hoc cross-sectional matched case-control analysis in young patients Aumento de homocisteína em acidente vascular cerebral isquêmico: análise post-hoc com casos controles em pacientes jovens

BACKGROUND & PURPOSE: Hyperhomocysteinaemia has been postulated to participate in pathogenesis of ischaemic stroke (IS). However, especially in young adults, there is possibility of significantly increased IS risk due to increased ‘normal’ homocysteinaemia, i.e., ‘hidden’ (‘pathologically dormant’) prevalence within a healthy, normally-defined range. We performed a post-hoc modelling investigation on plasma total homocysteinaemia (THCY) in gender- and age-matched young patients in the acute IS phase. We evaluated relationships between THCY and prevalence of other potential risk factors in 41 patients vs. 41 healthy controls. METHOD: We used clinical methods, instrumental and neuroimmaging procedures, risk factors examination, total plasma homocysteine measurements and other laboratory and statistical modelling techniques. RESULTS: IS patients and healthy controls were similar not only for matching variables, but also for smoking, main vitamin status, serum creatinine and lipid profile. Patients with IS, however, had lower vitamin B6 levels and higher THCY, fibrinogen and triglycerides (TGL). At multivariate stepwise logistic regression only increased THCY and TGL were significantly and independently associated with the risk for stroke (72% model accuracy, p model=0.001). An increase of THCY with 1.0 µmol/L was associated with 22% higher risk of ischaemic stroke [adjusted OR=1.22 (95%CI 1.03?1.44)]. In this way, novel lower cut-off value for HCY of 11.58 µmol/L in younger patients has been revealed (ROC AUC= 0.67, 95CI% 0.55-0.78, p=0.009). CONCLUSION: The new THCY cut-off clearly discriminated between absence and presence of IS (sensitivity>63%, specificity>68%) irrespectively of age and gender and may be applied to better evaluate and more precisely define, as earlier as possible, the young patients at increased IS risk.<br>OBJETIVO: Hiperhomocisteinemia tem sido postulada como um dos fatores de risco na patogênese do acidente vascular cerebral isquêmico (AVCI). Todavia, em adultos jovens existe a possibilidade de aumento significativo de risco de AVCI devido a aumento "normal" da homocisteinemia, "oculta" (patologicamente adormecida) dentro de uma variação definida como normal. Neste trabalho foi investigado um modelo post-hoc de dosagem de homocisteina no plasma (HC) em pacientes jovens com AVCI agudo pareados por gênero e idade. Foi avaliado também relações entre HC e prevalência de outros fatores de risco para AVCI em 41 pacientes e 41 controles normais. MÉTODO: Foi utilizado exame clínico, procedimentos instrumentais e de neuroimagem, exame de fatores de risco, dosagem da homocisteína no plasma, outros exames laboratoriais e análise estatística. RESULTADOS: Não foram encontradas diferenças quanto a presença de fumantes, dosagem de vitaminas, creatinina sérica e perfil lipídico entre os pacientes com AVCI e os controles normais. Todavia os pacientes com AVCI apresentaram diminuição de níveis de vitamina B6 e aumento de homocisteína, fibrinogênio e trigliceridios. A análise multivariada de regressão logística mostrou diferenças significativas apenas para HC e trigliceridios independentemente associadas para fatores de risco para AVCI (72% acuracia, p= 0,001). Um aumento de homocisteína de 1,0 µmol/L estava associado com aumento de 22% de risco de AVCI [OR=1,22 (95%IC 1,03-1,44)]. Foi evidenciado portanto um novo valor de cut-off para HC de 11,58 µmol/L em pacientes jovens com AVCI (ROC auc=0,67, 95% IC 0,55-0,78, p= 0,009). CONCLUSÃO: Este novo valor de cut-offpara a homocisteína discrimina claramente a ausência ou presença de AVCI (sensibilidade >63%, especificidade >68%) independente do gênero ou idade e deve ser aplicado para uma melhor avaliação precoce de pacientes jovens com risco de AVCI

Dysphagia evaluation and treatment after head and neck surgery and/or chemoradiotherapy of head and neck malignancy

Tumors of the head and neck represent 3.2% of newly diagnosed cancer; both surgery and chemoradiotherapy are valid treatment options for head and neck cancer. In many head and neck cancer patients dysphagia, malnutrition, and aspiration pneumonia are found and significantly impact the quality of life. Dysphagia is related to the tumor itself or its treatment consequences. A large number of surgical procedures according to tumor site and extension, patient age, and general conditions have been developed and are reviewed in this chapter. Swallowing disorders are related to both the surgical approach (open or endoscopic) and the tissue removed; while surgery of oral and oropharyngeal cancers mainly impact the oral control, oral peristalsis, and mastication, partial laryngeal surgery interferes with airway protection mechanisms, and complete laryngeal removal may be complicated with hypopharyngeal strictures. Different chemoradiotherapy protocols are available nowadays and are here reviewed; dysphagia may arise in the first 2 years as well as many years afterwards and is mainly related to increased oropharyngeal transit time, reduced tongue and pharyngeal strength, restricted laryngeal and hyoid elevation, poor vestibule and true vocal fold closure, and possibly abnormal upper esophageal sphincter function. The primary treatment goal of dysphagia in head and neck cancer patients is to maintain functional oral feeding and prevent aspiration and thoracic complications. All patients treated for a head and neck cancer should have access to a dysphagia specialist and to an instrumental investigation in order to establish adequate treatment