Posterior nutcracker syndrome associated with interrupted left inferior vena cava with azygos continuation and retroaortic right renal vein.

Various anatomic anomalies have been considered the causes of nutcracker syndrome (NCS). Posterior NCS refers to the condition, in which vascular narrowing was secondary to the compression of the retroaortic left renal vein while it is crossing between the aorta and the vertebral column. Here, we report an unusual case of posterior NCS associated with a complicated malformation of the interrupted left inferior vena cava with azygos continuation and retroaortic right renal vein, diagnosed by both color Doppler ultrasonography and CT angiography.

Visual pathway lesion and its development during hyperbaric oxygen treatment: a bold- fMRI and DTI study.

PURPOSE: To characterize and evaluate functional and anatomic changes of visual pathway lesions during hyperbaric oxygen (HBO) treatment with blood-oxygenation-level-dependent functional MRI (BOLD-fMRI) and diffusion tensor imaging (DTI). MATERIALS AND METHODS: Sixteen patients with visual pathway lesions received HBO treatment. Both BOLD-fMRI and DTI were performed before and after the treatment, while 12 healthy subjects were also studied with 2 examinations as control. The t-tests were used for the comparison of number of activated voxels (AVs) and fractional anisotropy (FA) between the two groups, and within the patient group before and after HBO treatment. Visual acuity of the patient group before and after the treatment was compared using Wilcoxon signed-rank test. RESULTS: Before the treatment, both AVs (P < 0.01) and FA (P < 0.05) in the bilateral cortexes of occipital lobes were significantly less in the patient group than in the control group. After the treatment, both AVs (P < 0.05) and FA (P < 0.05) were significantly increased. Moreover, The FA of 6 patients with lesions in the optical nerve was greater than the FA of the other 10 patients with lesions in the optic radiation (P < 0.05). CONCLUSION: BOLD-fMRI combined with DTI was useful for the characterization and evaluation of anatomic and functional changes of visual pathway lesions and their development during HBO treatment.

Evaluating ischemic stroke with diffusion tensor imaging.

INTRODUCTION: In recent years, diffusion tensor imaging (DTI) has emerged as a promising tool to study ischemic stroke. The aim of this study is to evaluate the anisotropic changes of cerebral white matter tracks in patients with ischemic stroke using DTI, and investigate the correlation between corticospinal tract damage and muscle strength in such patients during acute ischemia. METHODS: Nine patients with acute ischemic stroke and nine healthy subjects were examined with T1 weighted magnetic resonance imaging (MRI), T2 weighted MRI and DTI. Fractional anisotropy (FA) was measured and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. The muscle strength of the affected hand was assessed by Brunnstorm standard. RESULTS: In the control group, there was no significant difference in FA between the bilateral corticospinal tracts, but FA in different white matter structures of the same side was significantly different (t=3.12, p<0.05); while in the patient group, FA of the infarcted sites was significantly lower than the contralateral ones (t=5.570, p<0.01). The ipsilateral corticospinal tract demonstrated continuous interruption and the loss of consistent anatomic structure. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand (r=1.30, p<0.01). CONCLUSION: This study shows that DTI can be used to investigate ischemic stroke and assess ischemic stroke-induced damage. The damaged severity of corticospinal tracts is correlated with that of muscle strength.

[Clinical application of 16-slice spiral CT coronary angiography].

OBJECTIVE: To assess the clinical value of multislice spiral CT coronary angiography (MSCTCA). METHODS: Totally 79 patients were examined with MSCTCA and the CT images were reconstructed by several methods to analyze the factors crucial for the image quality, the ability of MSCT displaying the coronary artery vessels, along with the nature and calcification degrees of the plaques. The presence as well as the degree of vascular stenosis, visualization of the bypass graft, implanted stents and patency of the vessels were evaluated. RESULTS: The left main coronary artery and the left anterior descending artery were all best visualized in 75% R-R phases while the right coronary artery and the left circumflex artery in 62.5% R-R phases. CT images obtained by volume rendering showed the best quality at 75% R-R phases. 16-slice spiral CT was able to display from the primary to the tertiary, and even the quaternary branches of the coronary artery, and clearly displayed the coronary plaques, stenosis, implanted stents and bypass grafts. CONCLUSION: MSCTCA has a good clinical value in the primary identification of coronary heart disease and reexamination after revascularization.