螺旋CT增强扫描在肾盂癌诊断中的应用价值

目的 探讨螺旋CT增强扫描在肾盂癌诊断中的应用价值.方法 经手术病理证实的肾盂癌35例,术前均行螺旋CT平扫,增强扫描分为皮质期、实质期、排泄期、延迟期,将扫描结果进行分析.结果 CT表现分3型:病灶局限于肾盂内者25例;超出肾盂范围与肾实质分界不清6例;4例仅表现为肾孟肾盏积水扩张,但壁不规则增厚.增强扫描皮质期肿瘤轻度不均匀强化,实质期及排泄期13例病灶强化程度几乎没有改变,与相邻肾实质相比肿瘤呈低密度,14例延迟增强扫描见肾盂内不规则强化.结论 螺旋CT双期扫描可提高肾盂移行上皮癌的诊断正确率,但更应重视肾延迟期的CT扫描.     

肾脏恶性肿瘤的MRI诊断(附15例报告)

目的 :探讨肾脏恶性肿瘤的MRI诊断价值。方法 :回顾性分析和比较 15例经手术病理证实的肾脏恶性肿瘤患者的MRI检查资料 ,其中 13例行增强扫描。结果 :术前MR诊断正确的 13例 ,2例分别误诊为肾周陈旧性血肿、肾血管源性肿瘤。 12例为肾细胞癌 ,3例为肾移行细胞癌。病变大多边缘光整 ,有完整包膜 ,T1 WI为等或低信号 ,T2 WI大多为高信号 ,仅 1例T2 WI为低信号 ,若伴囊变者为混杂信号。病变强化无明显特征 ,仅有 1例肾盂癌明显强化 ,不符合其常见的乏血管特征。 1例肾上盏的 2cm× 2cm的肿瘤CT平扫和增强扫描均漏诊 ,MR信号特征可鉴别之。结论 :MRI具有良好的软组织分辨率、多方位成像的技术特点 ,在诊断肾脏恶性肿瘤中 ,对明确诊断和确定手术范围有重要的价值     

CT增强延时扫描在泌尿系病变诊断中的价值

目的 探讨CT增强延时扫描在泌尿系统疾病诊断中的临床价值。资料与方法 对25例泌尿系统疾病患者(包括肾损伤7例，肾盏憩室2例，膀胱憩室2例，肾脏输尿管先天发育异常6例，肾盂输尿管连接部梗阻2例，输尿管中段梗阻2例，巨输尿管1例，单纯输尿管囊肿1例，肾上极大盏结石合并小盏囊状扩张1例，肾盂内血凝块1例)行螺旋CT乎扫、增强扫描和增强延时扫描。结果 CT增强延时扫描能明确显示肾脏集合系统的损伤、肾盂输尿管连接部破裂所致的尿外渗及肾内血肿形成引起的肾收集系统的梗阻、移位、变形等继发病堑；显示憩室内囊液的延迟强化和持续长时间强化；显示发育异常的肾脏、输尿管的结构、位置和功能；显示尿路梗阻所致的尿外渗；显示肾盂内血凝块。结论 CT增强延时扫描在泌尿系病变的诊断中有重要价值，对某些疾病的诊断是十分必要的。     

多层螺旋CT尿路造影诊断泌尿系病变的价值(附40例分析)

目的：探讨多层螺旋CT尿路造影(blsort7)技术对泌尿系病变的临床诊断价值。方法：对40例泌尿系病变患者行CT平扫、肾实质期扫描(80s开始)或直接行肾实质期扫描，根据肾脏积水程度决定延迟扫描时问，无积水者延迟10～15rain，积水者延迟30一120min扫描，将原始资料传送至工作站进行图像后处理，获得尿路立体图像。结果：40例中，肾癌3例，肾盂癌7例，输尿管癌7例，结石5例，炎症6例，先天性发育异常11例，膀胱阴道瘘1例。33例经手术病理，7例经临床证实，术中所见与多层螺旋CT显示的病变部位、形态、大小均一致。结论：多层螺旋CT尿路造影具有扫描速度快、覆盖范围广、图像质量高及薄层扫描的特点，对泌尿系病变的诊断具有重要价值。     

肾盂癌的影像学分析

目的 讨论各种影像检查对肾盂癌的诊断价值.方法 对经影像检查并得到病理证实的肾盂癌19例进行分析,比较各种检查方法对肾盂癌的检出率.结果 静脉肾盂造影(IVP)显示肾盂、肾盏内不规则充盈缺损,肾盏积水.CT平扫见肾盂、肾盏内软组织肿块;当肿瘤侵犯肾实质时,显示肾盂及肾实质内软组织肿块,病灶密度不均匀,内有液化坏死.增强扫描病灶呈轻中度强化.19例患者中,术前IVP检查12例,9例IVP显示病灶,B超检查16例,10例显示病灶,CT扫描19例,18例显示病灶,MRI检查3例,3例显示病灶.结论 影像学检查对肾盂癌的诊断有一定价值.IVP和CT是诊断肾盂癌的首选方法,B超可作为普查手段.当肿瘤侵犯肾实质或有远处转移时,CT和MRI明显优于IVP.     

肾脏集合管癌的CT诊断

目的　提高对肾脏集合管癌CT表现的认识。方法　报告 3例经病理证实的肾脏集合管癌的螺旋CT所见 ,并作文献复习。结果　男 2例 ,女 1例 ,肿瘤位于右肾者 2例 ,左肾 1例。位于右肾的 1例 ,肿瘤累及肾皮质和髓质 ,并突出于肾轮廓之外 ,大小约 8 0cm× 8 0cm ,平扫CT值约37～ 4 5HU ,其内见高密度的斑点状钙化灶。增强动脉期 (皮质期 )及静脉期 (髓质期 )扫描示病变呈不均匀性强化 ,无包膜 ,CT值约 5 2～ 10 7HU ,CT诊断为右肾癌 ,但不排除肾结核。另外 2例肿瘤同时累及肾皮质、髓质及肾盂 ,其中位于左肾的 1例 ,肿瘤大小约 7 0cm× 7 5cm ,平扫病变区CT值约2 2HU ,增强动脉期 (皮质期 )扫描示肾皮、髓分界不清 ,病变区CT值约 70HU ,静脉期 (髓质期 )示肾静脉内癌栓形成 ,排泄期 (肾盂期 )扫描示左肾盂、肾盏未见显影 ,CT诊断为左肾癌 (集合管癌可能性大 )。另外 1例位于右肾 ,肿瘤大小约 8 0cm× 14 0cm ,平扫CT值约 32HU ,增强动脉期 (皮质期 )及静脉期 (髓质期 )扫描示肿瘤与正常的肾组织无明显分界 ,CT值约 4 5～ 72HU ,排泄期 (肾盂期 )扫描示左肾盂、肾盏未见显影 ,CT诊断为右肾癌 ,但不排除肾结核。 3例中 2例可见肾周脂肪囊及肾筋膜受侵犯 ,2例有局部淋巴结转移 ,1例有肋骨转移。结论　CT对肾脏集     

实体性肾肿瘤的CT诊断（附30例分析）

目的：探讨不同类型实体性肾肿瘤的CT表现特征。方法：回顾性分析30例经手术病理证实的实体性肾肿瘤的CT表现,其中肾透明细胞癌24例,肉瘤样癌1例,肾盂癌2例,嗜酸细胞瘤2例,血管瘤1例。所有病例均行CT平扫和多期增强扫描。结果：2例肾盂癌和1例肾血管瘤主体位于肾髓质,其余肾肿瘤主体均位于肾皮质。增强扫描24例透明细胞癌中21例在动脉期呈不均质显著强化,类似DSA中见到的“肿瘤染色”,而在静脉期和排泄期则呈低密度。3例Ⅰ级透明细胞癌和2例嗜酸细胞瘤类似肾脏的强化形式,即动脉期周边部与肾皮质同等强化,而中央部强化较晚,强化程度也较低。2例肾盂癌1例在动脉期呈不均质明显强化,另1例则始终无明显强化。1例血管瘤在3期均强化不明显。1例肉瘤样癌呈延迟强化,以周边部及类似房隔处强化明显。结论：不同类型的实体性肾肿瘤在CT上有其特殊的表现形式,但分化程度好的透明细胞癌与良性肾肿瘤鉴别较困难,有待于进行更深入细致的研究。     

肾窦区囊肿的MSCT表现分析

目的:探讨MSCT增强扫描对肾窦区囊肿的诊断及鉴别诊断价值。方法:回顾性分析18例肾窦区囊肿的CT增强扫描图像,应用MPR和VR观察其图像特点。结果:18例中,10例肾盂旁囊肿,CT示肾窦区圆形或椭圆形囊性病变,无强化,排泄期无对比剂进入,相邻肾盂、肾盏受压移位;6例肾盂周围囊肿,CT示沿肾盂、肾盏周围分布的多发囊性病变,呈不规则分支状,无增强效应,排泄期显示肾盂、肾盏被包绕,受压变细拉长;2例肾盂源性囊肿,CT示肾窦区圆形囊性病变,增强扫描无强化,可见通道与肾盂或肾盏相通,排泄期有对比剂充填。结论:CT增强扫描联合多种后处理方法对肾窦区囊肿的诊断及治疗有重要价值。     

肾脏浸润性病变:CT-超声-病理的相关性

作者研究了23例病理证实为肾脏实质内浸润的肿瘤。7例移行细胞癌,6例淋巴瘤,肾转移瘤和急性细菌性肾炎各3例,2例为肾胚胎瘤,肾盂鳞状细胞癌和肾细胞癌各1例。20例行CT检查,15例行超声检查。作者见到,肾脏浸润性病变初期,肾脏轮廓和大小正常,呈豆形。随着病变发展,肾脏完全或局限性增大,但仍保持豆形。肾脏横断面扫描常不能正确地反映肾脏的增大,而冠状面重建CT是显示肾脏纵轴方向增大的最佳方法,超声很容易显示肾脏纵切面的图像。病变区域的密度较正常肾实质的密度低,密度均一,边缘模糊。急性细菌性肾炎可见突出的带状影。肿瘤细胞沿肾盂肾盏系统的     

螺旋CT增强多期扫描对肾盂旁囊肿的诊断价值

目的：探讨多时相螺旋CT增强扫描对肾盂旁囊肿的诊断价值。方法：对病理证实的23例肾盂旁囊肿的CT平扫及增强表现进行回顾性的分析总结。结果：肾盂旁囊肿表现为肾窦内元强化效应的囊性病灶,延迟期扫描无对比剂进入囊肿内,而周边肾盏及肾盂受压变形,其内可见有对比剂进入。结论：CT增强扫描辅以适当的延时扫描能对肾盂旁囊肿做出准确的诊断。     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.     

Interventional procedures in the upper urinary tract

The introduction and acceptance of percutaneous nephrostomy as a safe and effective alternative to surgical nephrostomy served as the impetus for the development and expansion of an ever-increasing number of techniques that are encompassed by the term “interventional uroradiology.” This article reviews many of the non-vascular interventional techniques that have proliferated during the past decade and that are currently used in the kidney, ureter, and perinephric space. The authors emphasize those procedures that are most frequently employed, as well as their own preferences and perspectives on these procedures.     

Imaging in spinal trauma

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.     

MR imaging of blood oxygenation-dependent changes in focal renal ischemia and transplanted liver tumor in rat

The potential of using fast magnetic resonance (MR) imaging in conjunction with apnea-induced blood deoxygenation for the noninvasive monitoring of relative perfusion in the rat abdomen has been studied with two experimental models: glycer-ol-induced focal renal ischemia and transplanted liver tumor. Gradient-echo echo-planar imaging (GRE-EPI) (TE of 20 msec at 2 T) of liver and kidney was performed before, during, and after a 60-second apnea episode and then was followed in the same rat by contrast-enhanced (a) GRE-EPI and (b) T1-weighted spin-echo imaging (TR msec/TE msec = 200/6) with polylysine-(gadolmium-DTPA [diethylenetriaminepentaacetic acid]). The results indicate that a noninvasive vascular challenge due to apnea can be used for the detection of focal tissue perfusion abnormalities in rat kidney and liver tumor.