幕上星形细胞肿瘤MRI表现与VEGF、P16、Ki-67相关性研究

探讨星形细胞肿瘤MRI表现与P16、Ki—67、血管内皮生长因子(vascular endothelial growth factor，VEGF)表达的相关性。材料和方法：收集我院术前经MRI诊断并经手术病理证实的幕上星形细胞肿瘤53例，行常规平扫描后静脉注射Gd—DTPA增强成像；同时采用HE染色及链菌素生物素—过氧化酶连接法进行VEGF、Ki—67、P16的免疫组织化学染色，测定它们的表达指数。结果：星形细胞肿瘤的信号不均匀性、坏死、水肿、占位效应、强化程度与VEGF、Ki—67、P16的表达相关，且随着星形细胞肿瘤恶性程度的增高VEGF、Ki—67的表达增加；P16的表达率降低。结论：星形细胞肿瘤的MRI表现与VEGF、Ki—67、P16的表达密切相关，MRI可以间接判断星形细胞肿瘤的某些生物学行为。     

Efficacy evaluation of gadoteridol for MR angiography of intracranial vascular lesions

A phase III multicenter study was conducted in 89 patients with known intracranial vascular lesions to evaluate an extracellular gadolinium contrast agent, gadoteridol, for intracranial magnetic resonance (MR) angiography. The pre- and postcontrast MR angiograms of 82 patients were evaluated by the unblinded investigators and by two blinded readers (A and B) for visualization of lesions; arterial and venous anatomy; extent, size, and number of lesions; and disease classification. The unblinded readers indicated that lesions were visualized better on postcontrast images in the following categories: venous anatomy, 87 (81%) of 107 lesions; arterial anatomy, 43 lesions (40%); and extent or size of lesions, 38 lesions (36%). In 29 (35%) of 82 patients, the unblinded readers determined that enhanced MR angiography provided more diagnostic information than unenhanced MR angiography. The blinded readers determined that enhanced MR angiography provided more information for visualization of vascular anatomy in more than 60% of cases. The additional information provided with gadoteridol would have changed the diagnosis in nine (8%) of 107 lesions seen by the unblinded readers, 11 (12%) of 90 lesions seen by reader A, and three (3%) of 93 lesions seen by reader B. The results confirm that the use of gadoteridol improves the visualization of intracranial vascular lesions with MR angiography. The authors conclude that development of new postprocessing algorithms will improve the utility of contrast-enhanced MR angiography.     

Phase-derivative analysis in MR angiography: Reduced Venc dependency and improved vessel wall detection in laminar and disturbed flow

A problem of current MRA techniques is the inability to accurately depict the vascular anatomy, particularly in areas of disturbed flow. Various reasons, such as intravoxel phase dispersion, saturation, temporal variations, and maximum intensity projection (MIP) nonlinearity, cause a wrong delineation of vessel boundaries. A phase contrast (PC)-based postprocessing operation, the phase derivative (PhD), is introduced to detect phase fluctuations indicating flow. Two-dimensional and three-dimensional angiographic reconstruction algorithms are presented. Mathematical formulas are derived to predict the effect of sampling to flow profiles and the effect on the PhD of these profiles. Numerical, phantom, and preliminary in vivo experiments demonstrate that PhD images do not suffer from phase wraps and allow a velocity dynamic range extension only limited by a differential phase change. It is also shown that PhD MIPs produce higher signal-to-noise ratios than conventional PC angiograms and give a better impression of the anatomy of (stenotic) vessels and of their diameters for both laminar and disturbed flow.     

Velocity and flow quantitation in the superior sagittal sinus with ungated and cine (gated) phase-contrast MR imaging

Normal blood flow and velocity in the superior sagittal sinus were measured in 30 patients. A fast two-dimensional ungated phase-contrast (PC) pulse sequence was compared with a peripherally gated cine PC technique for velocity and flow quantitation. The same imaging parameters were used for both methods. Measured values for mean velocity and flow obtained with the two methods were compared by using regression analysis and t testing. For blood flow, the correlation coefficient was 0.976. For velocity measurements, r was 0.950. Mean flow was 285 mL/min ± 19 with the ungated PC method and 281 mL/min ± 19 with the cine PC method. The mean velocities measured with the two methods were 12.94 cm/sec ± 1.1 and 13.59 cm/sec ± 1.1, respectively. There was no significant difference (paired t test) between the methods for mean flow or velocity data. This was true even though flow in the superior sagittal sinus is moderately pulsatile, as shown with the cine PC technique. The ungated PC method provided these data in 13 seconds versus 3.5 minutes for the cine PC method.     

Vessel enhancement filtering in three-dimensional MR angiograms using long-range signal correlation

Small vessels in three-dimensional MR angiograms have low visibility in maximum-intensity projection images because of their low contrast. In a previous study, we had two nonlinear filters that appeared to give significant improvement in small vessel detail. In this paper, we report on a generalization of this filter that allows a more general modeling of the vessels and a more complete suppression of background. One implementation of the general filter gave a vessel mean contrast-to-noise ratio that is 2.52 and 3.51 times higher than the vessel mean contrast-to-noise ratio obtained using our previously reported maximum-minimum (max-min) filter and cross- section filter, respectively.     

Computed tomography in gunshot wounds to the neck: Can we predict vascular injury?

The purpose of this study was to evaluate the ability of helical computed tomography (CT) to detect arterial injuries in gunshot wounds to the neck. In a blinded retrospective review, 54 helical CT scans of the cervical spine were evaluated for bullet/bone fragments, subcutaneous air, bullet path, hematoma, spine fractures, and pharyngoesophageal compromise. The distance of fragments to a major vessel was calculated. CT findings that correlated significantly with major arterial injury included the presence of fragments (bullet/bone) close to a major vessel (2.5 mm) and spine fractures. Visualizing fragments <5 mm from a vessel or a transcervical bullet trajectory predicted 12 of 13 major arterial injuries. We conclude that CT clearly depicts anatomic damage. Specific findings, such as the location of fragments and bullet trajectory adjacent to a vessel and spine fractures, indicate a higher probability of vascular damage, thus directing more definitive evaluation.     

Stable Transfection of Nonosteogenic Cell Lines with Tissue Nonspecific Alkaline Phosphatase Enhances Mineral Deposition Both in the Presence and Absence of β-Glycerophosphate: Possible Role for Alkaline Phosphatase in Pathological Mineralization

It is documented that alkaline phosphatase (AP) plays an important role in bone mineralization. Considering that TN-AP is expressed in periodontal ligament fibroblasts, renal epithelial cells, and vascular endothelial cells, and that TN-AP is both a calcium-/phosphate-binding protein and a phosphohydrolytic enzyme, we hypothesize that membrane-bound AP also plays an important role in the initiation of physiological and pathological mineralizations in tissues other than bone and cartilage. To test this hypothesis, nonosteoblast cell lines, including a fibroblast line, a renal epithelial line, and a capillary endothelial line, were stably transfected to express high levels of rat bone AP on their cell surfaces. These rat bone AP-expressing cells were then cultured on filter membranes in the presence or absence of β-glycerol phosphate. von Kossa staining for calcium phosphate and transmission electron microscopy with electron diffraction analysis for minerals were employed to investigate the effect of membrane AP on extracellular calcium phosphate mineralization. Our results indicated that AP expression on these nonosteoblast-like cell surfaces have induced extracellular hydroxyapatite (HAP) mineralization. Our findings support the concept that membrane-bound AP contributes to extracellular apatitic mineralization by mechanisms that do not necessarily involve its hydrolase activity. They also suggest that AP might be important for the initiation of pathological mineralization in nonosteogenic tissues. Received: 11 January 1996 / Accepted: 31 October 1996     

In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

Ulnar distribution of reflex sympathetic dystrophy due to compression of the brachial plexus by a primary venous malformation

An atypical variant of reflex sympathetic dystrophy (RSD) is presented in a 45 year old female with a vascular malformation of the right arm and chest wall. The mechanism was thought to be compression of the brachial plexus by the malformation. The unique scintigraphic features of this presentation of RSD in the ulnar arterial distribution are illustrated.     

距骨的血液供应及其临床意义

本文观察了２４侧尸体足标本，均无已知临床血管疾病。在死后３６～４８小时之间行动脉灌注ＡＢＳ填充剂，以化学腐蚀和手工剔除的方法清除软组织。距骨的血供来自小腿下部三根主要动脉的分支，即跗骨管动脉和三角支、近端和远端跗骨窦动脉、颈上支及后结节血管丛。跗骨管动脉常发自足底内侧动脉，而三角支多单独自胫后动脉发出；跗骨管动脉通常比三角支和跗骨窦动脉都来得细小。以上的这些动脉相互吻合，形成了一个骨膜血管网，覆盖于全部的距骨非关节面上。而且，环绕着跗骨管、跗骨窦、距骨颈的上面和距骨体部的内侧面，由三角支、跗骨管动脉、跗骨窦动脉、颈上支及其相互之间的吻合血管网形成了一个不定形的距骨动脉环。本文还讨论了距骨缺血性坏死与动脉环的可能关系，距骨骨折脱位或手术后的缺血性坏死是由于距骨动脉环的毁损或功能受影响所致。三角支在距骨骨折脱位时具有重要意义，手术或手法复位时应注意保护。