Changes in Right Ventricular Dysfunction After Balloon Pulmonary Angioplasty in Patients With Chronic Thromboembolic Pulmonary Hypertension.

The aim was to investigate the effect of balloon pulmonary angioplasty (BPA) on right ventricular (RV) function in chronic thromboembolic pulmonary hypertension. Twenty-six patients with chronic thromboembolic pulmonary hypertension were enrolled and were divided into 2 groups, group H with high (>30 mm Hg) mean pulmonary arterial pressure and group L with low (25 to 30 mm Hg) mean pulmonary arterial pressure. RV function was assessed using 2-dimensional speckle-tracking echocardiography as well as 3-dimensional echocardiography, and RV dyssynchrony was assessed by the RV strain curves. Exercise capacity was evaluated by the 6-minute walk distance. RV dilatation was significantly reduced after BPA. In group H, RV ejection fraction, RV free wall longitudinal strain and RV dyssynchrony were all impaired before BPA and were ameliorated after BPA. In group L, RV ejection fraction as well as RV dyssynchrony were impaired without the reduction of RV free wall longitudinal strain and were improved after BPA, indicating that RV dysfunction may be attributable to the RV dyssynchrony in group L. Furthermore, RV dyssynchrony at baseline was the only parameter that was correlated with improvement in the 6-minute walk distance after BPA. RV dyssynchrony may affect RV function and could be the useful parameter for clinical outcome after BPA.

Detection of changes in the ventral tegmental area of patients with schizophrenia using neuromelanin-sensitive MRI.

The ventral tegmental area (VTA), one of the neuromelanin-containing dopaminergic nuclei in the midbrain, is closely related to the pathogenesis of schizophrenia, but its imaging findings remain unclear. Here, we investigated whether neuromelanin-sensitive MRI can detect alterations in the signals of the VTA of patients with schizophrenia. Neuromelanin-sensitive T1-weighted images at 3 T were obtained in 14 patients with schizophrenia and 22 healthy individuals. After signal inhomogeneity correction, brain signal rescaling of the images, and spatial normalization, signal intensity of the VTA and substantia nigra pars compacta (SNc) was automatically measured using the regions-of-interest constructed from the images of the healthy individuals. The normalized signal intensity of the VTA in patients with schizophrenia (median ± quartile deviation, 998 ± 10) was significantly decreased compared with that in healthy controls (1018 ± 15) (P=0.010), whereas that of the SNc was not significantly different between the groups (1093 ± 6 and 1098 ± 10, respectively, P=0.84). The VTA/SNc ratio was also significantly lower in patients with schizophrenia (0.916 ± 0.007) than in the control participants (0.934 ± 0.010) (P=0.010). In addition, the scores of the Scale for the Assessment of Positive Symptoms showed an independent negative correlation with VTA signaling (r=-0.69, P=0.012). Neuromelanin-sensitive MRI enables direct visualization of the selective signal attenuation in the VTA, which was correlated with positive symptoms, in patients with schizophrenia.

Visual discrimination among patients with depression and schizophrenia and healthy individuals using semiquantitative color-coded fast spin-echo T1-weighted magnetic resonance imaging.

INTRODUCTION: Fast spin-echo (FSE) T1-weighted (T1W) magnetic resonance imaging (MRI) at 3T, which is sensitive to neuromelanin-related contrast, can quantitatively detect signal alterations in the locus ceruleus (LC) and the substantia nigra pars compacta (SNc) of depressive and schizophrenic patients; however, its qualitative diagnostic performance remains unknown. We investigated whether visual interpretation of semiquantitative color maps can be used for discriminating between depressive and schizophrenic patients and healthy individuals. METHODS: We retrospectively examined 23 patients with major depression, 23 patients with schizophrenia, and 23 age-matched healthy controls by using a FSE-T1W MRI technique. Semiquantitative color maps of sections through the LC and SNc were visually interpreted by nine raters using a continuous confidence rating scale for receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve (Az), which reflects the performance in differentiating between depressive patients and controls, was 0.88, and the sensitivity and specificity at the maximum likelihood were 76% and 83%, respectively. In contrast, the Az value, sensitivity, and specificity values between schizophrenics and controls and between depressives and schizophrenics were 0.66 and 0.69, 42% and 48%, and 82% and 84%, respectively. CONCLUSION: Semiquantitative, color-coded FSE-T1W MRI at 3T can be used for visually differentiating depressive patients from healthy individuals with a substantially high likelihood, but this technique cannot be applied to distinguish schizophrenic patients from the other two groups.

Monoamine neurons in the human brain stem: anatomy, magnetic resonance imaging findings, and clinical implications.

By using high-resolution, conventional, and neuromelanin-sensitive magnetic resonance imaging techniques, we reviewed the normal anatomy of the nuclei consisting of monoamine neurons such as dopaminergic, noradrenergic, and serotoninergic neurons and noted the changes in these nuclei that occur in some degenerative and psychiatric disorders. Multimodal MR images can directly or indirectly help in identifying the substantia nigra, locus ceruleus, and raphe nuclei that contain monoamine neurons. Neuromelanin-sensitive magnetic resonance imaging can detect signal alterations in the substantia nigra pars compacta and/or locus ceruleus that occur in Parkinson's disease and psychiatric disorders such as depression and schizophrenia. This technique seems to be promising for the noninvasive evaluation of the pathological or functional changes in the monoamine system that occur in degenerative and psychiatric disorders.

Use of neuromelanin-sensitive MRI to distinguish schizophrenic and depressive patients and healthy individuals based on signal alterations in the substantia nigra and locus ceruleus.

BACKGROUND: We investigated alterations in the substantia nigra pars compacta (SNc) and locus ceruleus (LC) in schizophrenic and depressive patients by using a neuromelanin-sensitive magnetic resonance imaging (MRI) technique that enables direct visualization of these nuclei and examined whether this technique could distinguish between these disorders and healthy subjects. METHODS: Using a neuromelanin-sensitive T1-weighted MRI technique, we examined 20 schizophrenia patients, 18 depressive patients, and 34 healthy control subjects. The signal intensities of the areas corresponding to the SNc and LC were measured, and the contrast ratios (CR) to the adjacent white matter were calculated. RESULTS: The CR of the SNc was significantly higher in schizophrenic patients (22.6 +/- 5.6) than in depressive patients (19.2 +/- 4.7) and healthy control subjects (19.6 +/- 3.8), whereas the CR of the LC in depressive patients (7.7 +/- 2.4) was significantly lower than that in healthy control subjects (11.0 +/- 3.9) and schizophrenic patients (10.0 +/- 3.1). Further, the difference in the CR between the SNc and LC was significantly greater in schizophrenic patients (12.6 +/- 6.7) than in control subjects (8.6 +/- 4.1). CONCLUSIONS: Neuromelanin-sensitive MRI enables visualization of alterations in the SNc and LC that are observed in schizophrenia and depression.