Quantitative cardiac MRI

Cardiac MRI has become an indispensable imaging modality in the investigation of patients with suspected heart disease. It has emerged as the gold standard test for cardiac function, volumes, and mass and allows noninvasive tissue characterization and the assessment of myocardial perfusion. Quantitative MRI already has a key role in the development and incorporation of machine learning in clinical imaging, potentially offering major improvements in both workflow efficiency and diagnostic accuracy. As the clinical applications of a wide range of quantitative cardiac MRI techniques are being explored and validated, we are expanding our capabilities for earlier detection, monitoring, and risk stratification of disease, potentially guiding personalized management decisions in various cardiac disease models. In this article we review established and emerging quantitative techniques, their clinical applications, highlight novel advances, and appraise their clinical diagnostic potential

Donor-acceptor complexes incorporating ferrocenes: Spectroelectrochemical characterisation, quadratic hyperpolarisabilities and the effects of oxidising and reducing agents

The donor-acceptor complexes [Fe(C5H5){C5H4QNHM(NO)(Tp Me,Me)X}] {TpMe,Me = tris(3,5-dimethylpyrazolyl)borate; Q = nothing, M = Mo, X = Cl, Br, I; M = W, X = Cl; Q = C6H4, M = Mo, X = Cl, Br, I; M = W, X = Cl; Q = CH=CHC6H4 or N=NC6H4, M = Mo, X = Cl), which contain 16-valence electron metal nitrosyl centres, [Fe(C5H5){C5H4QpyMo(NO)(Tp Me,Me)Cl}] (py = 4-pyridyl; Q = CH=CH, CH=CHCO, N=CH and C6H4CH=CH), [Fe(C5Me4H){C5H4CH=CHpyMo(NO) (TpMe,Me)Cl}] and [Fe(C5Me4H)(C5Me4QpyZ)] {Q = CH=CH or CH=N, Z = Mo(NO)(TpMe,Me)Cl or W(CO)5; Q=2,4-CH=CH(C4H2S)CH=CH, Z = W(CO)5 or Me+I-}, some of which contain 17-valence electron molybdenum nitrosyl centres, and [Fe(C5Me4H){C5Me4CH=CH(C 4H2S)CH=CHpy}], have been characterised electrochemically, by their electronic spectra, and spectroelectrochemically. Hyper-Rayleigh scattering was used to determine the first hyperpolarisability, β, the data showing that (a) β is dependent on the metal in the acceptor fragment, (b) β increased when Cl or Br was replaced by I and (c) β increased when the number of methyl groups on the cyclopentadienyl rings increased. The β-values for comparable complexes containing {Mo(NO)(TpMe,Me)Cl} and {W(CO)5} moieties were similar. Chemical oxidation of the ferrocenyl or chemical reduction of the molybdenum nitrosyl acceptor fragments in selected complexes caused a reduction of between 25% and 100% in the NLO response. X-Ray structural studies of [Fe(C5H5){C5H4NHMo(NO)(Tp Me,Me)Cl}] (P1̄) and [Fe(C5Me4H){C5Me4CH=CHpyMo(NO) (TpMe,Me)Cl}] (P1̄) are reported