Microvascular permeability of brain astrocytoma with contrast-enhanced magnetic resonance imaging: correlation analysis with histopathologic grade / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain astrocytoma with the volume transfer constant (K(trans)) and volume of extravascular extracellular space per unit volume of tissue (Ve) from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and to evaluate the effectiveness of the K(trans) and Ve in the grading of astrocytoma.</p><p><b>METHODS</b>The highest values of the K(trans) and Ve of 67 patients with astrocytoma (27 with grade II, 12 with grade III, and 28 with grade IV) were obtained. The comparisons of the differences of the K(trans) and Ve between the different grades were conducted using the Mann-Whitney rank-sum tests. Spearman's rank correlation coefficients were determined between K(trans) values, Ve values and astrocytoma grades. Receiver operating characteristic (ROC) curve analyses were performed to determine the cut-off values for the K(trans) and Ve to distinguish between the different grades of astrocytoma.</p><p><b>RESULTS</b>There were significant differences (P < 0.001) between the different grades in the K(trans) values and Ve values, except for grades III and IV. The K(trans) values and Ve values were both correlated with astrocytoma grades (both P < 0.001). The ROC curve analyses showed that the cut-off values for the K(trans) and Ve provided the best combination of sensitivity and specificity in distinguishing between grade II and grade III or IV astrocytomas.</p><p><b>CONCLUSIONS</b>DCE-MRI can play an important role in assessing the microvascular permeability and the grading of brain astrocytoma.</p>

Kinematics of the triangular fibrocartilage complex during forearm rotation in vivo / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate three-dimensional kinematics of the superficial and deep portion of triangular fibrocartilage complex (TFCC) in different parts of the forearm rotation.</p><p><b>METHODS</b>Six wrists of 6 volunteers were used to obtain CT scans at different positions of the wrist. The wrists were scanned from 90 degrees of pronation to 90 degrees of supination at an interval of 30 degrees. The 3-dimensional radius and ulna were reconstructed with customized software and changes in length of the superficial and deep portion of TFCC during forearm rotation.</p><p><b>RESULTS</b>In forearm pronation, the superficial dorsal portion and the deep palmar portion of the TFCC were tight. While the superficial palmar portion and the deep dorsal potion of the TFCC were lax. In supination, the changes in length of all these fibers were reverse.</p><p><b>CONCLUSIONS</b>In forearm rotation one portion fibers of dorsal TFCC and one portion fibers of palmar TFCC are tight, and this mechanism controls stability during DRUJ rotation.</p>