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<p>In order to improve the diagnosis of coronary artery disease, better methods for detection of myocardial perfusion defects would be useful. One of the methods used for myocardial perfusion evaluation today is magnetic resonance imaging. </p><p>This method could be improved if a contrast agent that induced long-lasting contrast enhancement in the myocardium could be developed. The paramagnetic manganese(II) ion has promising properties for meeting this need, since it enters cardiomyocytes through voltage-gated calcium channels and remains inside the cells for a long time after an intravenous injection. If these properties can be utilized, manganese-enhanced MRI has potential for detecting transient periods of ischemia in a manner similar to the conventional SPECT stress test.</p><p>To investigate the contrast-enhancing properties of the manganese(II) ion, a series of experiments was performed in pigs, using a manganese salt (MnCl₂) and two manganese-based chelates (MnDPDP and MnHPTA) and measuring the longitudinal relaxation rates before and after contrast agent administration. This was done in normal pig myocardium at rest and during dobutamine-induced stress with several different doses of contrast agent, and in a model for coronary artery stenosis using MnCl₂ administered during dobutamine stress to determine whether transient ischemia could be detected with this contrast agent.</p><p>The results of these experiments showed that of the three contrast agents, MnCl₂ induces the greatest increase in ΔR1, followed by MnHPTA. Using MnCl₂ it was possible to produce images on which transient myocardial ischemia was visible, but only during the first 30 minutes after contrast agent injection.</p><p>The stenosis model is still far from the clinical situation and several complications, including the potential toxicity of the manganese(II) ion, remain to be overcome. However, the results from this model are promising for the future development of manganese- enhanced magnetic resonance imaging of transient myocardial ischemia.</p>

In order to improve the diagnosis of coronary artery disease, better methods for detection of myocardial perfusion defects would be useful. One of the methods used for myocardial perfusion evaluation today is magnetic resonance imaging. This method could be improved if a contrast agent that induced long-lasting contrast enhancement in the myocardium could be developed. The paramagnetic manganese(II) ion has promising properties for meeting this need, since it enters cardiomyocytes through voltage-gated calcium channels and remains inside the cells for a long time after an intravenous injection. If these properties can be utilized, manganese-enhanced MRI has potential for detecting transient periods of ischemia in a manner similar to the conventional SPECT stress test. To investigate the contrast-enhancing properties of the manganese(II) ion, a series of experiments was performed in pigs, using a manganese salt (MnCl2) and two manganese-based chelates (MnDPDP and MnHPTA) and measuring the longitudinal relaxation rates before and after contrast agent administration. This was done in normal pig myocardium at rest and during dobutamine-induced stress with several different doses of contrast agent, and in a model for coronary artery stenosis using MnCl2 administered during dobutamine stress to determine whether transient ischemia could be detected with this contrast agent. The results of these experiments showed that of the three contrast agents, MnCl2 induces the greatest increase in ΔR1, followed by MnHPTA. Using MnCl2 it was possible to produce images on which transient myocardial ischemia was visible, but only during the first 30 minutes after contrast agent injection. The stenosis model is still far from the clinical situation and several complications, including the potential toxicity of the manganese(II) ion, remain to be overcome. However, the results from this model are promising for the future development of manganese- enhanced magnetic resonance imaging of transient myocardial ischemia.

During fetal development, the hippocampal structures are folded forming the hippocampal sulcus which penetrates into the temporal lobe and then the entity rotates.  During this process, the hippocampal sulcus will be closed and the inverted hippocampus takes a rounded form. After complete inversion, the hippocampus has an oval form in a plane perpendicular to its long axis. If this process has not been completed the hippocampus remains the rounded form. That condition is called incomplete hippocampal inversion (IHI). The aims of this study was to evaluate the frequency of IHI in non-epileptic and epileptic children and adults and to explore the development of the hippocampal region by studying premature neonates and fetuses. Magnetic resonance (MR) images of 201 epilepsy patients and 150 non-epileptic subjects were evaluated without knowing clinical data. IHI was found in 19 % in seizure free controls (20 left-sided and 8 bilateral). 30% of the 201 epilepsy patients had IHI (40 left-sided, 4 right-sided, 16 bilateral). The difference was statistically significant (p&lt;0.02). 25% of the temporal lobe epilepsy patients had IHI. The frequency was not significantly higher than in controls. There is no causality between temporal lobe epilepsy and IHI. 44% of the Rolandic epilepsy patients and 57% of the cryptogenic generalized epilepsy patients had IHI. IHI can be a sign of possible disturbed cerebral development in other parts of the brain. Cranial ultrasound examinations of 160 premature children were analyzed. The age at examination was 23-24 GW in 24 children, 25-28 GW in 72 children, and 29-36 GW in 64 children. IHI was found in 50%, 25% and 14%, respectively. The frequency difference between the children &lt; 25 GW and &gt; 25 GW was statistically significant (p&lt; 0.001). From 25 GW onwards, the frequency and laterality of IHI is similar to that in the adult population. MRIs of 63 fetuses without intracranial pathology were reviewed independently by two radiologists. Three MRIs were performed post mortem at gestation week (GW) 17-18 and 60 in utero at GW 19-35. The hippocampal sulcus was open, bi- or unilaterally, in 35 fetuses at GW 17-32. The oldest of them was at GW 32.  The sulcus was closed at GW 21 at the earliest, unilaterally, and always from GW 33 onwards bilaterally. In 26/63 fetuses (41%), the hippocampal development was asymmetric and in 23 fetuses, the right side had developed faster.