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11.
Marcela Hernández Hoyos Piotr Orłowski Ewa Piątkowska-Janko Piotr Bogorodzki Maciej Orkisz 《International journal of computer assisted radiology and surgery》2006,1(1):51-61
The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and
the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one
acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed
based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction,
multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment
between its normal vector and the centerlines’ tangent vectors. The method was evaluated on a phantom and on 35 patients,
by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries.
In the phantom, difference of orientation and of height between known and calculated planes was 1.2° and 2.5 mm, respectively.
In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12° per artery.
Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby
permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA. 相似文献
12.
Yoshinobu Okabe Osamu Tsuruta Yoshiki Naito Hideya Suga Michio Sata 《Digestive endoscopy》2007,19(Z1):S121-S125
Regarding peroral cholangioscopy (POCS) for biliary disease, due to the recent appearance of a video cholangioscope that can obtain high‐quality images, it is possible to observe subtle changes of the biliary mucosa. In addition to the conventional observation method using POCS, the biliary mucosa with also observed with narrow band imaging (NBI) in one case of chronic cholangitis and four cases of extra hepatic bile duct tumor (three surgical cases). In the conventional observation method, the vessels in the surface layer of the biliary mucosa could be observed more clearly using NBI. In one case in which a tumor was observed, the irregularity of the biliary mucosa became clear on NBI, and the vessels inside a papillary tumor could also be easily observed. In another case of bile duct tumor, the conventional observation method showed a region in the proximity of the tumor where the vessels could not be seen clearly, but they could be seen clearly on NBI. In all of the cases, the bile juice was seen as red on NBI, which disturbed the observation. With POCS using NBI, it was possible to observe the vessels and irregularities in the surface layer of the biliary mucosa more clearly than with conventional observation methods. 相似文献
13.
作者通过对30例颅脑疾患冠状CT扫描资料进行研究,提出在一定情况下,在横断CT扫描的基础上,加用冠状CT扫描或冠矢重建图象,对病变的精确定位、病变的起源和发展方向以及病变与周围结构的关系等很有裨益。 相似文献
14.
K. OKAMURA I. KOBAYASHI K. MATSUO T. KIYOSHIMA K. YAMAMOTO A. MIYOSHI & H. SAKAI 《Histopathology》1997,31(6):540-548
Aims:
The purpose of this study is to examine the relationship between immunohistochemical localization of cathepsin D (CD), proliferating cell nuclear antigen (PCNA) and epidermal growth factor receptor (EGF-R) in 65 cases of breast carcinoma in Japanese women and traditional prognostic factors such as histological grade, lymph node status, mitotic rate and clinical stage, in order to possibly identify some indicator(s) that may be specifically associated with prognosis.
Methods and results:
Serial sections of 5-μm thick were cut from the archival formalin-fixed, paraffin-embedded tissue blocks, and processed for CD, PCNA and EGF-R immunostaining. The results were analysed by computer-based image analysis system. All samples showed a positive immunoreaction for cathepsin D in both the parenchyma and stroma. However, the staining area and intensity varied from cell to cell in the parenchyma and stroma as well as among samples. Subsequently, the evaluation of immunostaining for CD was separately performed in both the parenchyma and stroma (CDpar and CDstr, respectively) and the combination of both components (CDtotal). PCNA and EGF-R showed positive immunostaining almost exclusively in the parenchymal component of the carcinoma tissue specimens. CDtotal significantly correlated with the histological grade, PCNA index (PI), mitotic rate (MR), EGF-R and lymph node metastasis. Significant correlation was also demonstrated between CDpar and the histological grade, EGF-R and lymph node metastasis, or between CDstr and MR, EGF-R and lymph node metastasis. EGF-R correlated highly with the histological grade, MR score, lymph node metastases and recurrence-free survival.
Conclusions:
Both the CD parameters and EGF-R are valuable indicators for predicting the biological behaviour of human breast carcinoma. 相似文献
15.
Chretien Marie Francoise; Lebouvier Brigitte; Denis Alain; Chappard Daniel 《Human reproduction (Oxford, England)》1998,13(10):2767-2771
A cytomorphometric analysis of superficial vaginal cells inwomen in three groups of different types of hormonal concentrationwas made. There were 15 women in each group. Group I was studiedduring a natural cycle, group II under oral contraceptive therapyand group III during an in-vitro fertilization (IVF) stimulationprotocol. Morphometric parameters were measured on an imageanalyser. The area, perimeter and several form factors weremeasured separately for nuclei and cytoplasm. The nucleus:cytoplasmicratio was also determined. The cytoplasmic area was significantlyreduced in group II and was associated with a statisticallysignificant reduction of the nuclear area. The nucleus:cytoplasmicratio appeared significantly increased in group II and reducedin group III. Low oestradiol impregnation obtained with an oralminidosed contraceptive interfered with vaginal cell maturation.High oestradiol concentrations obtained during IVF protocolsinduced marked nuclear pycnosis but did not induce supra-physiologicalcell enlargement. Maximal cell size is genetically regulatedaccording to Driesch's law of volume invariance and hormonalover-stimulation has no effect on cell size. The nucleus:cytoplasmicratio appears to be a powerful parameter reflecting the oppositeeffects of hormones on cell compartments. 相似文献
16.
采用计算机图象纹理分析和相关点阵检测技术,对人食管正常粘膜、不典型增生上皮及原位癌的不同纹理特征进行了观察。观察样品为常规病理切片,用计算机图象分析系统检测了组织的纹理特征。对受检图象建立了三种灰色分层关系矩阵,同时计算了8种纹理测度。结果显示,在重度不典型增生上皮和原位癌之间,其纹理测度和相关点阵检测数据均有显著性差异(P<0.05)。全部测量数据经计算机多元逐步判别分析,其正判率达90%以上。本研究结果表明,计算机纹理分析方法可正确地判别食管癌前病变和原位癌的组织结构异型性。提示本技术在食管癌的早期诊断方面具有肯定的实用性价值。 相似文献
17.
Periannan Kuppusamy Penghai Wang Michael Chzhan Jay L. Zweier 《Magnetic resonance in medicine》1997,37(4):479-483
The application of electron paramagnetic resonance imaging (EPRI) to obtain information from biological samples has been limited by the lack of ideal single line radical labels. The commonly used nitroxides exhibit multiple lines causing either hyperfine-based limitations in the maximum obtainable image resolution or hyperfine-based artifacts in the reconstructed image. The use of a novel single-line triarylmethyl paramagnetic label that enables marked enhancement in image quality and resolution is reported. This label exhibits a single line EPR spectrum that is sharp (linewidth ~60 mG in the absence of oxygen) and relatively stable in tissues. The potential of this label in enabling high resolution EPR imaging of biological samples was demonstrated in a series of phantoms and isolated biological organs such as the rat kidney. The images demonstrate that resolutions better than 100 μm could be obtained at L-band on samples of up to 20 mm in size. 相似文献
18.
Flemming M. Nilsson Birgitte L. Hansen Christian Büchel Wagner F. Gattaz Jes Gerlach 《European archives of psychiatry and clinical neuroscience》1996,246(2):71-77
Digital movment analysis (DMA) is a new instrumental approach to assessing oral tardive dyskinesia (TD) by means of digital image processing of a video signal, tracking five paper dots placed around the patient's mouth. A total of 40 schizophrenic patients, 30 with and 10 without TD, were examined twice (with a 3-month interval) with this new device. The patients were further examined with two TD rating scales: the St. Hans Rating Scale for extrapyramidal syndromes (SHRS) and the Abnormal Involuntary Movement Scale (AIMS).The schizophrenic patients accepted the instrumental assessment without any anxiety or resistance. The internal relibility of the apparatus was high, with correlation coefficients of 0.80–0.99. The DMA TD values correlated with the SHRS and AIMS scores with correlation coefficients of 0.48–0.73 indicating an acceptable, although not strong, concurrent validity. Fluctuations occurred from the first to the second examination independent of medication. For these fluctuations no correlation was found between DMA values and rating scores. Finally, the DMA device was able to detect perioral tremor as a sign of parkinsonism.It has been concluded that DMA is a useful supplement to classical TD rating, although further validity evaluation is warranted. 相似文献
19.
The CellSoft computer-assisted sperm analysis system was evaluated as to the optimal setting of three components of the internal running conditions. These 'set up' parameters were the lower setting for cell size range (PIXMIN), threshold velocity (MINVEL) and maximum velocity (MAXVEL). The decision for the PIXMIN setting was founded on observed sizes of sperm with low instant velocities combined with a study of the relationship between false positive observations for sperm and the PIXMIN setting. Our recommendation for this setting is three pixels. From the observation that 97.5% of immobilized sperm exhibit instant velocities of less than 15 microns sec-1, this is our proposal for the MINVEL setting. Correspondingly, the 97.5 percentile for instantaneous velocities in a population of some 14,000 cells (30 men with type 'a' motility, WHO) was 168 microns sec-1. We recommend that MAXVEL be set at this limit. Alternative settings for both MINVEL and MAXVEL are presented as some users may wish to apply other percentiles. From the above results a setting for PIXMAX at 25 pixels could be inferred. We recommend that these settings be applied in semen laboratories analysing human native samples at room temperature. 相似文献
20.
MRI同层动态增强对垂体微腺瘤的诊断价值 总被引:3,自引:0,他引:3
目的:分析垂体微腺瘤的MPd同层动态增强特征。方法:对40例临床怀疑为垂体微腺瘤的病人行同层动态增强MPd扫描,并绘出时间一信号强度曲线图。结果:40例病人中共检出垂体微腺瘤26例。同层动态增强后垂体微腺瘤的MPd表现为圆或椭圆形的低或稍低信号,似“充盈缺损”;垂体微腺瘤的最大信号强度多出现在注入造影剂后32~96s,以64s最明显。结论:同层MPd动态增强对垂体微腺瘤的诊断有较高价值。 相似文献