肿瘤样钙质沉着症临床病理分析

目的　加深对肿瘤样钙质沉着症 (TC)临床病理特征的认识 ,提高确诊率。方法　分析 9例TC的临床、影像学、组织病理学资料。结果　TC临床诊断误诊率较高 ,9例患者中仅有 1例术前诊断正确 ,余者分别误诊为良性肿瘤 4例、异物 3例、恶性肿瘤 1例 ;而且 9例钙化区均具有典型的影像学和组织病理学特征。结论　在诊断TC过程中 ,只要注意X线摄片检查或进行病理组织活检 ,完全可以避免漏诊或误诊 ,必要时可行特殊染色或偏振光显微镜检查     

Nonlinear sensory cortex response to simultaneous tactile stimuli in writer's cramp.

Writer's cramp is a task-specific dystonia that leads to involuntary hand postures during writing. Abnormalities of sensory processing may play a pathophysiological role in this disorder. Electrophysiology studies in a monkey model of focal dystonia have revealed de-differentiation of sensory maps and the existence of single cells in hand regions of area 3b with enlarged receptive fields that extend to the surfaces of more than one digit. These changes may lead to abnormal processing of simultaneous sensory inputs. To study abnormal processing of simultaneous sensory information in adult humans with writer's cramp, we used functional magnetic resonance imaging to compare the response in primary sensory cortex with simultaneous tactile stimulation of the index and middle finger, with the response to stimulation of each finger alone. We tested five patients with writer's cramp and seven unaffected (normal) subjects. In the normal subjects, a linear combination of the activation patterns for individual finger stimulation predicts the pattern of activity for combined stimulation with 12% error. In writer's cramp patients, the linear combination predicted the combined stimulation pattern with 30% error. Results indicate a nonlinear interaction between the sensory cortical response to individual finger stimulation in writer's cramp. This altered interaction may contribute to the motor abnormalities.     

腮腺显像对鼻咽癌放疗后腮腺功能的评价

目的利用腮腺显像研究鼻咽癌放疗后腮腺的摄取与排泄功能.方法48例鼻咽癌患者中,对38例肿瘤和肿大淋巴结行加速调强放疗（SMART）,其亚临床灶和预防照射区接受常规照射;余10例行常规放疗.放疗前后均行腮腺显像,计算腮腺的放射性摄取指数（UI）及酸性刺激后排泌指数（EI）,对腮腺功能损伤情况进行分析;同时记录患者口干程度并分级.结果鼻咽癌SMART组放疗后腮腺UI和EI分别下降21.9%和37.3%,中重度口干者12例;而常规放疗组腮腺功能明显下降,UI和EI分别下降56.1%和96.1%,中重度口干者9例,两者比较差异均有显著性（P＜0.05）.结论腮腺显像可灵敏地监测鼻咽癌放疗后腮腺功能.     

乳腺影像学报告及数据系统:超声良恶性病变鉴别诊断初探

1992年美国放射学会制定了乳腺影像学报告及数据系统(breast imaging reporting and data system,BI-RADS),2003年第四版修订时包括了超声诊断(BI-RADS-US)。本文旨在初步探讨BI-RADS-US对于乳腺良恶性病变鉴别诊断的能力。我们收集了2006年1月至2007年3月期间、获得病理诊断的乳腺占位性病变共69例72灶。均为女性,年龄14-83岁,平均41.6岁。首先根据一般的非BI-RADS标准,做出良恶性鉴别。然后用BI-RADS-US标准进行鉴别和分级(0-6级),其中2级和3级为良性和良性可能性大,4级为性质待定,5级为恶性可能性大。计算并比较上述两种方法的准确性、敏感性、特异性。结果在72病灶中,根据非BI-RADS标准,诊断为良性者40灶,符合病理诊断者38灶(95.0%),诊断为恶性者23灶,符合病理者18灶(78.3%);诊断为性质待定者9灶。根据BI-RADS-US标准和分级,2级和3级共有37灶,与病理结果符合者为36灶(97.2%);5级有31灶,与病理符合者为22灶(71.0%);4级有4灶。非BI-RADS和BI-RADS-US的准确性各为83.3%和81.9%(P=1.000),敏感性各为91.7%和95.8%(P=1.000),特异性各为79.2%和75.0%(P=0.754)。总之,第一版BI-RADS-US在乳腺良恶性病变鉴别诊断方面的初步应用表现出较高的敏感性,而与非BI-RADS方法比较则尚无明显差别。     

New insights on COPD imaging via CT and MRI

Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD.     

Sodium MRI of the human kidney at 3 Tesla.

The sodium concentration gradient in the kidney (from the cortex to the medulla) serves to regulate fluid homeostasis and is tightly coupled to renal function. It was previously shown that renal function and pathophysiology can be characterized in rat kidneys by measuring the sodium gradient with (23)Na MRI. This study demonstrates for the first time the ability of (23)Na MRI to map the distribution of sodium in the human kidney and to quantify the corticomedullary sodium gradient. The study was performed on a 3T Signa LX scanner (GE) using an in-house-built quadrature surface coil. (23)Na images of volunteers were acquired using a 3D coronal gradient-echo sequence at a spatial resolution of 0.3 x 0.3 x 1.5 cm(3) in a 25-min scan time. The signal intensity (relative to the noise) increased linearly from the cortex to each of the medullae with a mean slope of 1.6 +/- 0.2 in relative arbitrary units per mm (Rel.u./mm, N = 6) and then decreased, as expected, toward the renal pelvis. Water deprivation (12 hr) induced a significant increase of 25% (P < 0.05) in this gradient. Based on these results, we suggest that sodium MRI can serve as a valuable noninvasive method for functional imaging of the human kidney.     

11^C-蛋氨酸的体内生物学分布和初步临床应用

目的研究新型脑肿瘤显像剂：11^C-蛋氨酸（11^C-MET）的体内生物学分布，探讨11^C—MET的临床显像方法及其在脑肿瘤显像中的应用．方法测定11^C—MET在小鼠体内的分布，对健康志愿者和病理证实胶质瘤患者进行PET脑显像．结果小鼠体内分布实验和脑PET显像发现，11^C—MET在血液中清除较慢，在肿瘤内有较长的滞留时问，平台期位于30—45min之间，延迟相对有利于脑瘤的显像，其余放射性主要集中在消化系统．结论11^C—MDT有较高的肿瘤／脑比值，是理想的脑肿瘤显像剂．     

Influence of SENSE on image properties in high-resolution single-shot echo-planar DTI.

Limited spatial resolution is a key obstacle to the study of brain white matter structure with diffusion tensor imaging (DTI). In its frequent implementation with single-excitation spin-echo echo-planar sequences, DTI's ability to resolve small structures is strongly restricted by T2 and T2* decay, B0 inhomogeneity, and limited signal-to-noise ratio (SNR). In this work the influence of sensitivity encoding (SENSE) on diffusion-weighted (DW) image properties is investigated. Computer simulations showed that the PSF becomes narrower with increasing SENSE reduction factors, R, enhancing the intrinsic resolution. After a brief theoretical discussion, we describe the estimation of SNR on a pixel-by-pixel basis as a function of R. The mean image SNR behavior is manifold: SENSE is capable of increasing SNR efficiency by reducing the echo time (TE). Each SNR(R) curve reveals a maximum that depends on the amount of partial Fourier encoding used. The overall best SNR efficiency for an eight-element head coil array and a b-factor of 1000 s/mm2 is achieved at R = 2.1 and partial Fourier encoding of 60%. In vivo tensor maps of volunteers and a patient, with an in-plane resolution of 0.78 x 0.78 mm2, are also presented to demonstrate the practical implementation of the parallel approach.     

屈颈MRI对青年性上肢远端肌萎缩症的诊断价值

目的评价屈颈MRI对青年性上肢远端肌萎缩症的诊断价值。方法男性患者5例，平均年龄21岁，临床表现为一侧或两侧上肢远端肌萎缩。对照组为健康志愿者，21岁男性8例。2组均行常规及屈颈颈椎MR平扫，矢状、轴面SET1WI、T2WI、液体衰减反转恢复（FLAIR）序列扫描。结果常规颈椎扫描：5例患者下段颈髓变细；屈颈位MR扫描：下颈段颈6以下脊髓前屈、变扁平，矢状径4～6mm，硬膜囊后壁前移，硬膜后间隙明显增宽，可见多发条状、迂曲流空信号影及软组织信号。对照组：常规扫描，下颈段脊髓（颈6～胸2）可见颈膨大，屈颈位脊髓略变细（6～7mm），硬膜囊后壁无前移，硬膜后间隙未见扩张血管影。结论屈颈MRI有助于显示下颈段脊髓及硬膜囊改变，结合临床资料可准确诊断青年性上肢远端肌萎缩症。