C, N, and P stoichiometry for leaf litter of 62 woody species in a subtropical evergreen broadleaved forest.

To understand leaf litter stoichiometry in a subtropical evergreen broadleaved forest, we measured the contents of carbon (C), nitrogen (N) and phosphorus (P) in leaf litters of 62 main woody species in a natural forest of C. kawakamii Nature Reserve in Sanming, Fujian Province. Differences in leaf litter stoichiometry were analyzed across leaf forms (evergreen, deciduous), life forms (tree, semi-tree or shrub), and main families. Additionally, the phylogenetic signal was measured by Blomberg's K to explore the correlation between family level differentiation time and litter stoichiometry. Our results showed that the contents of C, N and P in the litter of 62 woody species were 405.97-512.16, 4.45-27.11, and 0.21-2.53 g·kg-1, respectively. C/N, C/P and N/P were 18.6-106.2, 195.9-2146.8, and 3.5-68.9, respectively. Leaf litter P content of evergreen tree species was significantly lower than that of deciduous tree species, and C/P and N/P of evergreen tree species were significantly higher than those of deciduous tree species. There was no significant difference in C, N content and C/N between the two leaf forms. There was no significant difference in litter stoichiometry among trees, semi-trees and shrubs. Effects of phylogeny on C, N content and C/N in leaf litter was significant, but not on P content, C/P and N/P. Family differentiation time was negatively correlated with leaf litter N content, and positively correlated with C/N. Leaf litter of Fagaceae had high C and N contents, C/P and N/P, and low P content and C/N, with an opposite trend for Sapidaceae. Our findings indicated that litter in subtropical forest had high C, N content and N/P, but low P content, C/N, and C/P, compared with the global scale average value. Litter of tree species in older sequence of evolutionary development had lower N content but higher C/N. There was no difference of leaf litter stoichiometry among life forms. There were significant differences in P content, C/P, and N/P between different leaf forms, with a characteristic of convergence.

Remodeling of occluded internal carotid artery in vessel wall magnetic resonance imaging.

OBJECTIVE: The purpose of the present study was to investigate the remodeling pattern of the extracranial occluded internal carotid artery (OICA) by vessel wall magnetic resonance imaging (VWI). METHODS: Thirty-nine atherosclerotic OICAs from 32 consecutive cases underwent 3-Tesla VWI to acquire pre- and post-contrast T1-weighted two-dimensional fluid-attenuated inversion recovery fast spin echo sequences. 25 symptomatic CAs exhibited ipsilateral downstream cerebral ischemia or ophthalmic artery embolism within last three months. The 14 remaining CAs were asymptomatic. Twenty-four CAs from 22 patients with atherosclerosis but no stenosis were recruited as control group. The outer wall area (OWA) was calculated based on the outer contour of the carotid artery drawn on the pre-contrast VWI. Negative remodeling was defined as a lower OWA compared to that of control group. RESULTS: Clinical characteristics including age, sex and vascular risk factors showed no significant difference between the occluded and control group. However, the OWA was lower in the occluded group than in the control group (0.63 versus 0.90 cm2, p = 0.004). For all OICAs, the OWA was larger in symptomatic cases than asymptomatic cases (0.71 versus 0.49cm2, p = 0.025). Using a cutoff value of 0.44, the sensitivity and specificity of OWA for detecting symptomatic OICA were 0.88 and 0.57, respectively. Heterogeneous signal intensity and enhancement were more often observed at the proximal than the distal segment of occlusion (p < 0.001). The inter-observer agreement regarding the evaluation of VWI characteristics was desirable (κ = 0.805 ∼ 0.847). CONCLUSIONS: Negative remodeling is prevalent in OICA, especially in asymptomatic cases.

Ultrasonic evaluation of congenital vaginal oblique septum syndrome: A study of 21 cases.

The aim of the present study was to investigate the ultrasound features and classify the lesion types of congenital vaginal oblique septum syndrome (CVOS) in 21 patients prior to surgery. Grey-scale pelvic ultrasound was performed to evaluate the uterus, vagina and kidneys in 21 patients with suspected CVOS. Ultrasound features, including the presence of a double uterus, hematocolpos masses and renal absence, in CVOS types I, II and III were studied and compared with intra-operative results and the results of surgery. Ultrasound identified the presence of double uteruses and cervices with ipsilateral renal agenesis on the oblique septum side in all 21 patients. There were 14 hematocolpos lesions on the right and 7 on the left of the vagina. Type I CVOS was diagnosed in 15 patients with a large hematocolpos mass (volume, 64-268 ml) and these diagnoses were confirmed by surgery. Furthermore, there were 4 patients with type II and 2 patients with type III CVOS exhibiting small hematocolpos lesions (volume, 5-36 ml) identified by ultrasound, which were all confirmed by surgery. Therefore, ultrasound imaging is useful tool to evaluate the abnormal features of CVOS and determine the type of CVOS in patients prior to surgical intervention.

Magnetic Resonance Venography Findings of Obstructed Hepatic Veins and the Inferior Vena Cava in Patients with Budd-Chiari Syndrome.

Objective: This study aimed to illustrate the magnetic resonance venography (MRV) manifestations of obstructed hepatic veins (HVs), the inferior vena cava (IVC), and accessory hepatic veins (AHVs) in patients with Budd-Chiari syndrome (BCS) and to evaluate the visualization capacity of MRV in the diagnosis of BCS. Materials and Methods: Fifty-two patients with chronic BCS were included in this study. All patients were examined via MRV performed with a 3T system following injections of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) or Gd-ethoxibenzyl-DTPA. HV and IVC lesions were classified, and their characteristics were described. HV cord-like occlusions detected via MRV were compared using ultrasonography (US). Digital subtraction angiography (DSA) was performed as a contrast in the MRV detection of IVC lesions. The HVs draining collaterals, mainly AHVs, were carefully observed. HV lesions were classified as segmental stenosis, segmental occlusion, membranous stenosis, membranous occlusion, cord-like occlusion, or non-visualized. Except for patent IVCs, IVC lesions were classified as segmental occlusion, segmental stenosis, membranous occlusion, membranous stenosis, and hepatomegaly-induced stenosis. Results: All patients (52/52, 100%) showed HV lesions of different degrees. MRV was inferior to US in detecting cord-like occlusions (6 vs. 19, χ2 = 11.077, p < 0.001). Dilated AHVs, including 50 (50/52, 96.2%) caudate lobe veins and 37 (37/52, 71.2%) inferior HV and AHV lesions, were well-detected. There were no significant differences in detecting segmental lesions and thrombosis between MRV and DSA (χ2 = 0.000, p1 = 1.000, p2 = 1.000). The capacity of MRV to detect membranous lesions was inferior to that of DSA (7 vs. 15, χ2 = 6.125, p = 0.013). Conclusion: In patients with BCS, MRV can clearly display the lesions in HVs and the IVC, as well as in AHVs, and it has diagnostic and therapeutic value.

Ultrasonographic Visualization of Accessory Hepatic Veins and Their Lesions in Budd-Chiari Syndrome.

The aim of this study was to investigate the ultrasonographic features of accessory hepatic veins (AHVs) and their lesions in Budd-Chiari syndrome (BCS). Three hundred patients with BCS were examined by ultrasonography with multifrequency (3-6 MHz) convex transducers. Sonography was performed 1 to 2 wk before digital subtraction angiography and computed tomography angiography or magnetic resonance imaging. Using sonograms, we evaluated the number, course, diameter, orifice, lesions and hemodynamics of patent and obstructed AHVs. Ultrasonography was superior to digital subtraction angiography, computed tomography angiography and magnetic resonance imaging in revealing AHV lesions and hemodynamics. Dilated AHVs were detected in 227 patients. There were 239 caudate lobe veins in 167 patients and 168 inferior right hepatic veins in 151 patients. Both caudate lobe veins and inferior right hepatic veins were found in 91 of the 227 patients. The inlets to AHVs were located mainly on the right lateral or right anterior wall of the inferior vena cava, and the remnant, on the left lateral wall. AHV lesions comprised mainly septal obstruction and segmental stenosis. The hemodynamics of AHVs varied with the condition of inferior vena cava and AHVs. Ultrasonic examination can reveal AHVs and their lesions in patients with BCS and is helpful in choosing and planning therapeutic approaches.

Computed tomography angiography manifestations of collateral circulations in Budd-Chiari syndrome.

The aim of this study was to assess the computed tomography angiography (CTA) manifestations of collateral circulations in patients with Budd-Chiari syndrome (BCS). Eighty patients with BCS were examined by CT scan. Using the CTA images of the relevant blood vessels, including the affected hepatic veins (HVs) and inferior venae cavae (IVCs), the collateral circulations were reconstructed. In addition to obstructed HVs and IVCs, collateral circulations were found in each of the patients. The collateral circulations were classified as intrahepatic, extrahepatic and portosystemic pathways. Intrahepatic collateral pathways were further classified as the following six types: HV-accessory HV (n=51, 63.8%), HV-HV (n=6, 7.5%), HV-accessory HV plus HV (n=6, 7.5%), IVC-HV/accessory HV-HV-right atrium (n=5, 6.3%), HV-umbilical vein (n=4, 5.0%) and HV-inferior phrenic vein (n=8, 10.0%). Extrahepatic collateral pathways included IVC-lumbar-ascending lumbar-hemiazygos/azygos vein (n=80, 100.0%), IVC-left renal-ascending lumbar-hemiazygos vein (n=75, 93.8%), IVC-left renal-inferior phrenic vein (n=49, 61.3%), IVC-renal -peri-renal -superficial epigastric vein (n=26, 32.5%) and superficial epigastric vein (n=12, 15.0%) types. The CTA characteristics of each type of collateral circulation were demonstrated. In conclusion, the present study revealed that CTA is able to show the intra- and extrahepatic collateral circulations of patients with BCS, which may be useful for therapeutic planning.

Diffusion-weighted imaging for the left hepatic lobe has higher diagnostic accuracy for malignant focal liver lesions.

BACKGROUND: This study was conducted to investigate whether apparent diffusion coefficient (ADC) measurements by dividing the liver into left and right hepatic lobes may be utilized to improve the accuracy of differential diagnosis of benign and malignant focal liver lesions. MATERIALS AND METHODS: A total of 269 consecutive patients with 429 focal liver lesions were examined by 3-T magnetic resonance imaging that included diffusion-weighted imaging. For 58 patients with focal liver lesions of the same etiology in left and right hepatic lobes, ADCs of normal liver parenchyma and focal liver lesions were calculated and compared using the paired t-test. For all 269 patients, ADC cutoffs for focal liver lesions and diagnostic accuracy in the left hepatic lobe, right hepatic lobe and whole liver were evaluated by receiver operating characteristic curve analysis. RESULTS: For the group of 58 patients, mean ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. For differentiating malignant lesions from benign lesions in all patients, the sensitivity and specificity were 92.6% and 92.0% in the left hepatic lobe, 94.4% and 94.4% in the right hepatic lobe, and 90.4% and 94.7% in the whole liver, respectively. The area under the curve of the right hepatic lobe, but not the left hepatic lobe, was higher than that of the whole liver. CONCLUSIONS: ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. Optimal ADC cutoff for focal liver lesions in the right hepatic lobe, but not in the left hepatic lobe, had higher diagnostic accuracy compared with that in the whole liver.

Diagnosis of the cavo-hepato-atrial pathway in Budd-Chiari syndrome by ultrasonography.

The aim of this study was to investigate the ultrasonic features of the cavo-hepato-atrial pathway in Budd-Chiari syndrome (BCS), by which blood is drained from the occluded inferior vena cava (IVC) to the right atrium via hepatic veins. Ultrasonograms from 11 patients with BCS with cavo-hepato-atrial pathways were retrospectively studied. Doppler ultrasound was used to observe the direction of the flow and measure the velocity of the blood-draining vessels. Blood flow in the draining vessels and the collaterals was shown as blue, red or bicolored depending on whether the flow direction was away from the transducer, towards the transducer or both. For measurement, the Doppler angle between the axis of the Doppler beam and that of the vein examined was always <60°. Ultrasonography was performed 1-2 weeks prior to digital subtraction angiography (DSA). All patients were confirmed by DSA. Membranous and segmental occlusions of IVCs were observed in seven and four cases, respectively. Blood flow from the IVC reversed to the hepatic/accessory hepatic vein, continued through the dilated intrahepatic collaterals, onward to the other hepatic vein and finally to the right atrium. The majority of the inlets (8/11) of hepatic veins above the occlusion were narrow compared with the dilated distant parts of the lumens. Accelerated blood flow in the inlets was detected in all patients regardless of the luminal diameter. In conclusion, the results from the present study suggest that the unusual cavo-hepato-atrial pathway can be diagnosed reliably by ultrasonography, which may be useful for clinical management.

Sonographic classification of draining pathways of obstructed hepatic veins in Budd-Chiari syndrome.

PURPOSE: To describe and propose a sonographic classification of the blood-draining pathways of obstructed hepatic veins in Budd-Chiari syndrome. METHODS: This retrospective study included 206 patients with hepatic vein obstructions who underwent sonographic examination. We evaluated the afflicted hepatic veins, as well as the course, orifice, blood flow direction of draining veins, and communicating branches. Results were classified and compared with digital subtraction angiography and computed tomography angiography. RESULTS: Of 618 hepatic veins in 206 patients, 542 were obstructed. The blood-draining pathways were classified as hepatic vein-accessory hepatic vein (131/206), hepatic vein-hepatic vein/accessory hepatic+hepatic vein (49/206), and, less frequently, collateral pathways (26/206). Blood was drained from obstructed hepatic veins to the inferior vena cava, right atrium, para-umbilical veins, or hepatic subcapsular veins through communicating branches of various number and diameters. Doppler signals were obtained from the draining veins. CONCLUSIONS: Sonography provides accurate information regarding the blood-draining pathways of obstructed hepatic veins in Budd-Chiari syndrome, which may be helpful for treatment and follow-up.