肾上腺腺瘤和非腺瘤的动态增强CT检查

目的采用规范化的动态增强CT检查技术,对大样本病例进行深人地多角度评价．使肾上腺肿瘤动态增强CT检查能够在临床上广泛应用。资料与月法经手术和临床证实的70例共79个肾上腺肿块（腺瘤44个．非腺瘤35个）分别以相同的扫描条件行CT平扫和动态增强检查（静脉注人对比剂后30s开始扫描）,然后延时1、2、3、5．7min扫描。剂量1．2ml／kg体重,注射流率2．5ml／s。分析评价肾上腺肿块的T—D曲线和廓清率Wash（相对廓清率Washr和绝对廓清率Washa）。结果T—D曲线分为5种类型,即A、B、C、D和E各型。腺瘤的特征曲线为A、C型,非腺瘤为B、D、E型（P=0．000）。Washr和Washa于腺瘤和非腺瘤间存在显著性差异（P=0．000）,腺瘸的Washr和Washa均高于非腺瘤,并且Washr诊断效果优于Washa。7min延时点诊断价值较大．Washr≥34HU提示为腺瘤．反之提示为非腺瘤。结论肾上腺CT动态增强检查能够对腺瘤和非腺瘤尤其对乏脂性腺瘤与非腺瘤的鉴别诊断具有较大价值。     

肾上腺腺瘤和非腺瘤动态增强CT曲线与微血管超微结构的相关性研究

目的 探讨肾上腺腺瘤和非腺瘤动态增强CT曲线与微血管超微结构特点的相关关系,以进一步阐明其动态增强机制.资料与方法 经手术病理证实的42例46个肾上腺肿块(腺瘤23个、非腺瘤18个、增生结节5个)均行动态增强CT检查和病理学检查,而后分析肾上腺肿块动态增强CT表现特征[时间-密度(T-D)曲线]与微血管超微结构之间的相关关系.结果 肾上腺腺瘤和非腺瘤间微血管超微结构存在显著不同.肾上腺肿块T-D曲线廓清迅速组(A、C型)与廓清缓慢组(B、D、E型)间的微血管超微结构表现特点亦不同;T-D曲线廓清迅速组微血管超微结构表现为管腔规则,无狭窄;内皮细胞吞饮泡多,窗孔多;细胞间隙增宽;基底膜菲薄,厚薄均匀,有裂口;血管外间隙窄、规则且均匀一致,基质少等,与腺瘤表现一致;由此提示动态增强CT曲线与微血管超微结构存在相关关系.结论 微血管超微结构可能是导致腺瘤和非腺瘤具有不同的T-D曲线类型的主要因素之一.     

动态增强CT检查对肾上腺腺瘤与非腺瘤的鉴别诊断价值

目的探讨动态增强CT检查技术对肾上腺腺瘤与非腺瘤的鉴别诊断价值并优选出有意义的参数，以进一步明确两者的鉴别诊断标准。资料与方法对44例共49个肾上腺肿瘤先平扫再行动态增强CT检查，观察以肿瘤的CT绝对值、绝对开始廓清率及相对开始廓清率作为标准鉴别肾上腺腺瘤与非腺瘤的诊断价值。结果延时3min，以36％的绝对开始廓清率或35％的相对开始廓清率分别与CT绝对值58HU相结合作为标准，对腺瘤有较高的诊断价值，对于腺瘤中的乏脂质性腺瘤与非腺瘤的鉴别诊断也具有同样的价值。结论以肿瘤的廓清率与延时增强后的CT绝对值作为联合标准，能明显提高腺瘤的诊断价值。     

垂体腺瘤快速动态增强MRI表现与血管生成的相关性研究

目的 探讨垂体腺瘤快速动态增强与常规MRI的表现及其在评价肿瘤血管生成中的价值。资料与方法 对46例垂体腺瘤患者术前行超快速小角度激发（Turbo-FLASH）梯度回波序列T1WI动态增强和常规MRI，术后检测垂体腺瘤组织标本中的FⅧ-Rag的表达，分析动态增强及常规MRI表现与肿瘤微血管密度（MVD）之间的关系。结果垂体腺瘤动态增强时间．信号强度曲线（SI-TC）不同类型之间的MVD值有显著性差异，MVD值与最大斜率（SSmax）呈显著正相关，不同程度的肿瘤坏死或囊变的MVD值之间有显著性差异（P〈0．05）。结论 Turbo-FLASH T1WI动态增强MRI曲线的类型和增强参数SSmax与肿瘤的MVD关系密切，可用于无创性评价垂体腺瘤的血管生成。     

大肠腺瘤与非肿瘤性息肉中VEGF的表达差异及其与血管形成关系的研究

目的：探讨血管内皮生长因子（VEGF）在大肠腺瘤与非肿瘤性息肉中的表达差异及其与血管形成的关系。方法：采用免疫组化和原位杂交技术检测36例大肠腺瘤、36例非肿瘤性息肉、13例腺癌和11例正常黏膜组织中VEGF蛋白及其mRNA的表达，并计数微血管密度（MVD）。结果：大肠腺瘤组VEGF蛋白及其mRNA的表达和MVD值均高于非肿瘤性息肉组（P〈0．05）；大肠腺瘤组MVD值与VEGF的表达强度呈显著正相关（rs=0．640，P〈O．01）。结论：VEGF和血管形成密切相关，腺瘤的高表达和非肿瘤性息肉的低表达可能是两者恶变趋势差异的重要分子机理之一。     

肾上腺腺瘤与非腺瘤的CT鉴别诊断

目的 探讨肾上腺腺瘤与非腺瘤的CT鉴别诊断价值.方法 回顾性分析经手术和随访证实的56例(58个病灶)肾上腺肿瘤的CT表现及病理组织学特征,患者均行CT平扫及1 min、5 min增强扫描,对诊断参数进行分析并对照病理组织学表现,对肾上腺肿瘤做出正确的诊断.结果 腺瘤与非腺瘤在CT平扫及增强后1 min、5 min的CT值、相对廓清率和绝对廓清率的差异均有统计学意义(P＜0.05),以平扫时CT≤19 HU,延时5 min时CT≤46 HU,绝对廓清率≥63%,相对廓清率≥31%为阈值相结合作为诊断标准时,诊断腺瘤或乏脂性腺瘤的敏感性分别为96%或86%.结论 以肿瘤平扫及增强后的CT值与肿瘤的廓清率作为联合标准,对腺瘤(包括乏脂性腺瘤)与非腺瘤的鉴别诊断有较高的价值.     

垂体腺瘤MRI强化特征与VEGF、bFGF mRNA表达的关系

目的探讨垂体腺瘤T1W I动态增强及常规MR I表现与VEGF和bFGF mRNA表达的相关性。方法对30例垂体腺瘤患者术前行快速梯度回波序列(Turbo-FLASH)T1W I动态增强和常规MR I,术后应用逆转录PCR(RT-PCR)方法检测垂体腺瘤组织标本中VEGF和bFGF mRNA的表达,分析动态增强及常规MR I表现与VEGF和bFGF mRNA表达之间的关系。结果垂体腺瘤动态增强时间-信号强度曲线(SI-TC)不同类型之间的VEGF、bFGF mRNA值有显著性差异(Ρ<0.05)。VEGF和bFGF与SSm ax呈显著正相关(Ρ<0.05)。肿瘤强化率不同程度间的VEGF、bFGF值有显著性差异(Ρ<0.05)。结论垂体腺瘤MR I强化特征可一定程度反映VEGF和bFGF mRNA的表达。     

大肠癌肠外浸润螺旋CT征象与肿瘤血管生成的相关性

目的 探讨大肠癌肠外浸润的螺旋CT（SCT）征象与病理、肿瘤微血管密度（MVD）、血管内皮生长因子（VEGF）和基质金属蛋白酶-2（MMP-2）表达的关系。方法 40例大肠癌患者，术前均行SCT多期动态扫描，术后标本采用免疫组织化学方法染色，检测VEGF和MMP-2的表达和计数MVD。结果 螺旋CT判断大肠癌肠外、肠壁浸润的准确率为92．5％（37／40）。肠外、肠壁浸润组的转移率分别为75．0％（21／28）和33．3％（4／12），其差异有统计学意义（P〈0．05）。大肠癌肠壁、肠外浸润组间的CT强化程度、MVD、VEGF和MMP-2的表达比较差异有统计学意义（P〈0．05）。CT强化程度与MVD之间呈正相关（P〈0．05）。结论 SCT增强扫描能较准确地判断大肠癌的肠外浸润，且肠外浸润预示着更高的转移倾向；CT强化程度可作为定量分析指标初步判断肿瘤血管生成，MVD、VEGF、MMP-2表达与大肠癌浸润密切相关，肿瘤血管生成在大肠癌的浸润过程中起着促进作用。     

乳腺动态增强MRI表现与血管生成相关性的初步研究

目的 初步探讨乳腺动态增强MRI表现与微血管密度（MVD）和血管内皮生长因子（VGEF）表达的相关性.方法 选择我院2010年5月～2012年12月接受动态增强MRI检查的34例乳腺病变患者,观察患者动态增强MRI检查参数及病理检查结果,比较乳腺良性病变与恶性病变动态增强MIR表现、MVD和VEGF表达差异,分析乳腺动态增强MIR表现与MVD和VEGF表达的相关性.结果 本组34例经手术病理证实乳腺良性病变16例,乳腺恶性病变18例,乳腺良性病变与恶性病变患者动态增强MIR表现、MVD和VEGF表达比较显示,两组患者在早期增强率（EER）、时间-信号增强曲线（TIC）类型、MVD及VEGF有显著性差异,有统计学意义（P＜0.05）,两组信号增强峰值（SImax）无显著性差异,无统计学意义（P＞0.05）.乳腺动态增强MIR表现与MVD和VEGF表达相关性分析显示,MVD和VEGF与TIC类型显著相关,两两比较有统计学意义（P＜0.01）;MVD与EER显著相关,两两比较有统计学意义（P＜0.05）.结论 乳腺动态增强MRI可反映乳腺良性病变与恶性病变血管生成差异,对于乳腺病变诊断具有较高应用价值.     

肾细胞癌螺旋CT表现与肿瘤血管生成的相关性研究

目的 探讨肾细胞癌(RCC)螺旋CT同层动态扫描表现与癌组织微血管密度(MVD)、癌细胞血管内皮生长因子(VEGF)蛋白表达之间的相关关系。方法 对18例肾细胞癌患者行螺旋CT靶平面同层动态扫描,计算动态CT各指标,包括曲线升段斜率(S)、曲线下面积(AR)、增强后CT增加值(△HU)、组织血管比(TBR)。时间-密度曲线(T-DC)类型按升段斜率由小到大分为A、B、C型。组织切片经CD34单克隆抗体及VEGF多克隆抗体免疫组织化学染色。采用图像分析仪计数“热点”(hot spot)MVD、VEGF蛋白表达量,并观察肾细胞癌微血管分布。结果 (1)癌组织MVD与动态CT指标S、△HU、AR、肿瘤曲线分型之间呈极显著性相关(r=0.51、0.56、0.50、0.57,P<0.01),与TBR呈显著相关性(r=0.51,P<0.05)。VEGF蛋白表达量与MVD及动态CT各指标间均无显著相关性(r=0.30、0.03、0.12、0.08、0.10、0.01,P>0.05)。(2)据T-DC升段斜率不同,所分A、B、C型。RCC间增强CT表现差异有显著性意义(F=9.84、12.17、24.00,P<0.05)。结论 动态螺旋CT扫描可无创评价肿瘤血管生成。     

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.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

CT Arthrography and Virtual Arthroscopy in the Diagnosis of the Anterior Cruciate Ligament and Meniscal Abnormalities of the Knee Joint

Objective

To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology.

Materials and Methods

Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images.

Results

The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively.

Conclusion

CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.     

Treatment of biliary leaks and fistulae by simultaneous percutaneous drainage and diversion

Although biliary fistulae and bilomas are often adequately managed with percutaneous drainage, persistent bile duct leaks are difficult to control. The primary surgical goal in this situation is to decompress the biliary system through diversion of bile flow to facilitate healing of the defect in the bile ducts. We report 3 patients with large biliary duct defects who underwent percutaneous transhepatic cholangiography which demonstrated the site of the biliary leakage. Then, extrapolating the aforementioned surgical tenet to these patients, all 3 were successfully treated with interventional radiologic techniques: simultaneous percutaneous transhepatic biliary diversion to control biliary flow and percutaneous biloma drainage to facilitate closure of the cavity.     

CT and US of the pancreas

The diagnostic capabilities of pancreatic imaging continue to improve with technological advancements in computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). To update the practicing radiologist, this article summarizes the current literature on pancreatic imaging, with particular emphasis on CT and US. Pertinent clinical considerations of the disease entities are included, along with illustrative material from the authors' experience.     

Accuracy and precision of MR velocity mapping in measurement of stenotic cross-sectional area,flow rate,and pressure gradient

Reliability of magnetic resonance (MR) velocity mapping to assess severity of stenosis was assessed in vitro. Steady flow at different flow rates through five stenoses with a central orifice area ranging from 17 to 176 mm² was measured with velocity mapping performed perpendicular to the stenotic jet. Besides determination of the stenotic cross-sectional area and flow rate, the pressure gradient was calculated with the modified Bernoulli equation and compared with manometer measurements. Cross-sectional areas were measured with an accuracy of ?76%, a precision of ?91%, and an error of ?19 mm². Flow rates had an accuracy of ?72%, a precision of ?94%, and an error of ?1.4 L/min. The modification of the Bernoulli equation limited its reliability to stenoses with areas of 35-113 mm². Pressure gradients were calculated with an accuracy of ?80%, a precision of ?88%, and an error of ?15 mm Hg. The method was applied in a single patient with aortic stenosis and gave estimates that agreed with those obtained by heart catheterization.     

Lymphoepithelial cyst of the pancreas: radiological and pathological findings

We report a case of a rare lymphoepithelial cyst of the body of the pancreas that developed in a woman complaining of constipation for 15 years. Ultrasonography revealed a homogeneous isoechoic lesion, while CT demonstrated a polycystic homogeneous mass with central scar and calcification. Cytological investigation of a CT-guided biopsy permitted diagnosis of lymphoepithelial cyst. The patient was operated on and had an uneventful recovery. The histological finding was of a cyst wall lined with keratinised squamous epithelium surrounded by lymphoid tissue with reactive follicular hyperplasia. The radiological findings and differential diagnosis are discussed. Correspondence to: D. Regge     

T2-weighted MR imaging of the chest: Comparison of electrocardiograph-triggered conventional and turbo spin-echo and nontriggered turbo spin-echo sequences

In 22 patients with a diverse range of thoracic abnormalities, T2-weighted magnetic resonance (MR) images of the chest were obtained with electrocardiograph (ECG)-triggered turbo spin-echo (TSE), ECG-triggered conventional spin-echo (CSE), and nontriggered TSE sequences, and the images were compared. A 5-point rating scale was used by three radiologists experienced in MR imaging of the chest to Independently evaluate the images for (a) freedom from ghosting, (b) clarity of heart wall and cardiac chambers, (c) clarity of mediastinal structures, (d) conspicuity of abnormalities, and (e) overall image quality. Evaluations were analyzed with statistical methods. For freedom from ghosting, clarity of heart wall and cardiac chambers, clarity of mediastinal structures, and overall image quality, the ECG-triggered TSE images were rated higher than the TSE images, which. In turn, were rated higher than the ECG-triggered CSE images at the P=.05 level of significance. No significant differences were seen between the pulse sequences in the conspicuity of abnormalities, although some differences were observed in individual cases. Our results suggest that ECG-triggered TSE imaging provides improved, time-efficient T2-weighted images of the chest.     

Evaluation of adrenal masses with gadolinium enhancement and fat-suppressed MR imaging

A study was undertaken to determine the ability to characterize benign and malignant masses with unenhanced and contrast material-enhanced fast lowangle shot and fat-suppressed spin-echo magnetic resonance (MR) imaging. Thirty patients with adrenal masses detected at computed tomography (CT) underwent MR imaging within 14 days after CT. CT and MR images were interpreted in a prospective, blinded fashion. Sixteen patients had 20 benign adrenal masses, and 14 patients had 18 malignant masses. Quantitative measurements included percentage of contrast enhancement on immediate postcontrast dynamic images and periphery - center signal-to-noise ratio (S/N) on gadolinium-enhanced fat-suppressed images. Qualitative evaluation included determination of the regularity of lesion margins, homogeneity of signal intensity, and local extension. MR imaging depicted all adrenal masses discovered at CT examinations. Lesions ranged in diameter from 1 to 15 (mean, 4.4) cm. No significant difference was observed in percentage of contrast enhancement between benign (90.5% ± 59.0 [standard deviation]) and malignant (110.5% ± 116.4) masses. A difference was observed between periphery - center S/N for benign (?.05 ± 1.5) and malignant (7.7 ± 9.8) masses; overlap between the two, however, occurred. Qualitative evaluation allowed correct characterization of 32 of 38 masses, comparing favorably with CT, which allowed characterization of 30 lesions.     

MR detection of quantitative and structural changes in human aortic aneurysms

Collagen is a major component of the extracellular matrix and a determinant of the elastic behavior of the human aorta. To investigate the changes found in aneurysmal degeneration, the authors studied the solid-state hydrogen-1 nuclear magnetic resonance line shape of collagen in aneurysms and normal human aortas. A three-component decomposition of the free induction decay was performed, with collagen characterized by a T2 of about 18 μsec. The second moment of the collagen line shape was found to be increased in aneurysms (5.3 vs 4.8 G²), while, correspondingly, the T2 of collagen was lower in aneurysms (16.3 vs 17.7μsec). This corresponds to a modification of collagen structure and molecular motion. Collagen concentration was lower in nondiseased aortic walls (9.4% vs 7.3%). These results are discussed in reference to the contradictory conclusions in the current literature. The increase in collagen and the modification of its structure and molecular motion are explained by the need to resist an increasing tangential tension due to increased aortic diameter and diminished wall thickness in aneurysms and by intercalation or site binding in the helices or electric dipolar interactions in the less mobile side groups.