99 Tcm-DX直肠淋巴引流显像研究

目的 探讨^99Tc^m－右旋糖酐（DX）直肠淋巴引流显像术前诊断直肠癌淋巴结转移的临床价值。方法 直肠癌患者17例，正常对照者20例。肛镜引导下，分左右两侧直肠粘膜下注射^99Tc^m－DX，每点37MBq（0．5mL）。注射后不同时间行γ照相。结果 ①对照组直肠淋巴引流图：向头侧引流的淋巴链完整、对称，近似“八”字形、梯形。肠旁、肠外淋巴结向上引流至腹主动脉周围淋巴结；部分可以显示两侧髂内淋巴结；显影淋巴结数为7－16个。②直肠癌组术前直肠淋巴引流异常：向头侧引流的淋巴链不完整或不显影；淋巴结显影不清、缺损或增大，淋巴链呈“串珠”样。③直肠癌组术后行病理检查的207个淋巴结中，31个癌结节或癌转移。据Dukes分期法，直肠癌患者术前淋巴显像与术后病理检查结果对照，灵敏度为91．6％，准确性88．2％，特异性80．0％，假阳性率20．0％，假阴性率8．3％。结论 ^99Tc^m－DX直肠淋巴引流显像对直肠癌淋巴结转移的术前诊断有临床价值。     

骨显像评价高强度聚焦超声治疗原发恶性骨肿瘤疗效

目的：探讨骨显像评价高强度聚焦超声（HIFU）治疗原发性恶性骨肿瘤疗效的价值。方法：用^99Tc^m-亚甲基二膦酸（MDP）及^99Tc^m(V)-二巯基丁二酸钠（DMSA）分别对HIFU治疗原发性恶性骨肿瘤前后行全身及局部显像，观察其变化。结果：（1）常规^99Tc^m-MDP显像肿瘤部位呈异常放射性浓聚区，治疗后局部呈放射性减低或缺损区，病灶范围缩小，部分患者病灶周围呈放射性浓聚区；（2）部分患者^99Tc^m(V)-DMSA显像示原有病灶治疗后放射性减低或缺损区出现放射性浓聚，提示其局部复发；（3）治疗前后患者局部与对侧正常部位感兴趣区（ROI）分示示差异有极显著性。结论：^99Tc^m-MDP骨显像可灵敏地反映病灶部位、范围及HIFU的疗效；^99tc^m(V)-DMSA显像可反映局部病灶复发与否。     

应用γ探测仪探测乳腺癌前哨淋巴结的临床价值

目的 探讨应用γ探测仪探测乳腺癌前哨淋巴结活组织检查（SLNB）的临床价值。方法 53例乳腺癌患者，在肿块或活组织检查腔周围的乳腺实质内注射^99Tc^m－硫胶体，应用γ探测仪术中定位切除放射性浓聚的前哨淋巴结（SLN），再行腋窝淋巴结清扫（ALND）。SLN与腋窝淋巴结（ALN）同时行HE和免疫组织化学（IHC）检测，以及用逆转录多聚酶链反应（RT－PCR）检测CK19 mRNA的表达，观察SLN的检出率和用SLN预测ALN转移的准确性，评价SLN阴性的早期乳腺癌患者用SLNB代替ALND的可行性。结果 SLN检出灵敏度为91％（48／53例），共检出SLN91枚，平均1．9枚。SLN预测ALN转移准确性为100％，阳性预测值为0。结论 术中用γ探测仪进行乳腺癌SLNB是可行的，SLN可预测腋窝其余淋巴结的转移情况，并可作为早期乳癌患者用SLNB代替ALND的可靠指标。     

^18F-FDG PET／CT显像监测胃癌术后复发转移的价值

目的评价^18F-脱氧葡萄糖（FDG）PET／CT监测胃癌术后复发及转移的临床价值。方法回顾性分析胃癌术后临床疑复发或转移而行^18F-FDG PET／CT检查的45例患者临床资料,根据细胞学、病理或随访结果分析PET／CT检查结果,计算残胃及转移灶最大标准摄取值（SUVmax）。采用SPSS11．5软件进行数据处理,SUVmax两样本均数比较采用t检验。结果（1）45例中22例临床疑残胃复发,12例患者最终确定残胃复发,^18F-FDG PET／CT诊断残胃复发的灵敏度、特异性及准确性分别为100．0％（12／12）、70．0％（7／10）和86．4％（19／22）,12例复发病灶SUVmax为6．27±3．42（其中2例低分化腺癌的SUVmax较低,分别为2．5和3．3）,另10例无复发的残胃SUVmax为3．92±2．24（其中3例吻合口炎性病灶局部SUVmax较高,分别为8．3,5．2和6．3）,差异无统计学意义（t=1．862,P〉0．05）。（2）对残胃以外转移灶的检出：PET／CT灵敏度、特异性、准确性在区域淋巴结转移中分别为78．9％（15／19）、92．3％（24／26）和86．7％（39／45）,在腹膜转移中分别为6／9、97．2％（35／36）和91．1％（41／45）,在远处转移中分别为86．7％（13／15）、93．3％（28／30）和91．1％（41／45）。（3）PET／CT假阳性8处为炎性或肠管摄取,假阴性9处多为直径〈1．0cm的转移灶和低分化腺癌及印戒细胞癌的转移灶。结论^18F-FDG PET／CT虽然检测胃癌术后区域淋巴结和腹膜转移的灵敏度较低,但仍是监测其术后复发转移的有效手段。     

炎症显像剂99Tcm-HMPAO-WBC 的标记与临床应用

目的 探讨炎症显像剂^99Tc^m—六甲基丙二胺肟—白细胞(HMPA0—WBC)对腹腔内可疑感染灶的诊断价值。方法 分离21例可疑腹腔内感染灶患者的自体WBC，用^99Tc^m—HMPA0标记。静脉注射^99Tc^m—HMPA0—WBC后不同时间点行Y显像。结果 标记物^99Tc^m—HMPA0—WBC活度为296～444MBq，标记产率为55％～65％。21例患者^99Tc^m—HMPA0—WBC显像结果为阳性11例，阴性10例。对比手术或6个月随访结果，真阳性11例，真阴性9例，假阴性1例，无假阳性。^99Tc^m—HMPA0-WBC显像对腹腔内感染灶诊断的灵敏度为91．7％，特异性为100％，准确性为95．2％，阳性预测值100％，阴性预测值90％。结论 ^99Tc^m—HMPA0—WBC标记方法简便、安全、价优、可信。^99Tc^m—HMPA0—WBC显像可快速、准确地诊断腹腔内感染灶。     

99Tcm-DMSA肾皮质显像诊断小儿肾发育不良

目的 探讨^99Tc^m—二巯基丁二酸(DMSA)肾皮质显像诊断小儿肾发育不良的价值。方法 疑为肾发育不良患儿29例，行常规^99Tc^m—DMSA肾皮质显像和腹部B超检查。图像分析：将发育不良肾分为0～4级。结果 ^99Tc^m—DMSA肾皮质显像示29例患儿中24例为单侧肾发育不良，其中11例1级，7例2级，6例3级，余5例患肾未显影为0级，结合其他：检查诊断为肾发育不良。患肾分肾功能为0～24．9％(平均6．3％)。29例患儿中24例患肾肾皮质显像诊断为肾发育不良，5例患肾未显影，由其他影像学方法确诊，诊断灵敏度为82．76％。29例中19例经手术治疗，病理检查证实为肾发育不良。结论 ^99Tc^m—DMSA肾皮质显像诊断肾发育不良灵敏度高、可靠，可确定发育不良肾部位和判断肾功能。     

18F-FDG符合线路显像对食管癌术后复发转移的诊断价值

目的 探讨^18F-脱氧葡萄糖（FDG）符合线路显像对食管癌术后复发转移的诊断价值。方法 对29例临床怀疑复发转移的食管鳞状细胞癌术后患者行^18F-FDG符合线路显像，计算其诊断复发转移灶的灵敏度、特异性和准确性，并与CT诊断结果比较。结果 29例患者中符合线路显像真阳性19例，真阴性6例，假阳性、假阴性各2例，其诊断食管癌术后复发转移的灵敏度、特异性和准确性分别为90．5％（19／21例）、75．0％（6／8例）和86．2％（25／29例）；而CT诊断的灵敏度、特异性和准确性分别为71．4％（15／21例）、87．5％（7／8例）和75．9％（22／29例）。在符合线路显像与CT检查均阳性的13例患者中，CT检出病灶20个；而符合线路显像检出27个，比CT多检出的病灶包括食管癌复发，锁骨上、纵隔和肺门淋巴结及骨转移。结论 ^18F-FDG符合线路显像对食管癌术后复发转移的诊断具有较高的临床价值，尤其在临床疑有复发转移而常规影像学检查阴性时有重要意义。     

^99mTc（V）—DMSA骨显像诊断骨转移瘤的临床价值

目的：评价99mTc（V）－DMSA显像在骨转移瘤诊断中的意义。材料和方法：对91例疑骨转移瘤患者行99mTc（V）DMSA全身显像，并与99mTc-MDP全身骨显像及其它检查对比。结果：74例证实存在骨转移瘤者，99mTc．MDP骨显像均显示异常放射性浓聚，99mTc（V）-DMSA显像72例显示了与99mTc-MDP显像某些相同部位的放射性浓聚，2例99mTc（V）DMSA显像阴性。17例骨良性病变，99mTc－MDP骨显像显示轻度异常放射性浓聚，而99mTc（V）-DMSA显像却未见异常的放射性浓聚。结论：99mTc（V）－DMSA诊断骨转移瘤的特异性比99mTc-MDP骨显像高，在骨良恶性肿瘤鉴别诊断中具有重要的临床价值。     

^99Tc^m-HL91乏氧显像在恶性肿瘤治疗后随访中的应用

目的评价^99Tc^m-4,9-二氮-3,3,10,10-四甲基十二烷-2,11-二酮肟（HL91）乏氧显像在恶性肿瘤治疗后随访中的价值。方法37例胸部和头颈部恶性肿瘤患者在治疗结束后3—12个月的临床随访中,CT检查怀疑肿瘤残余、复发或转移,再行^99Tc^m-HL91乏氧显像。目测定性分析,判定乏氧显像阳性病例,再用感兴趣区（ROI）技术对阳性病例进行半定量分析,计算肿瘤部位（T）与对侧相应部位或头皮（NT）的放射性比值（T／NT）,并采用成组设计两样本均数t检验进行比较。以鼻咽内镜检查、病理活组织检查结果和12个月的临床随访资料作为判断肿瘤残余、复发或转移的依据,计算^99Tc^m-HL91显像和cT的诊断效能。结果37例患者中,无肿瘤局部残余或复发病灶者19例,存在肿瘤局部残余或复发病灶者11例,有远处转移病灶者7例。（1）无肿瘤局部残余或复发组与肿瘤局部残余或复发组的T／NT比值分别为1．18±0．14和1．58±0．16,两者差异有统计学意义（t=4．87,P〈0．001）。（2）^99Tc^m-HL91显像监测肿瘤局部残余或复发的灵敏度72．73％（8／11）,特异性89．47％（17／19）,准确性83．33％（25／30）;CT监测肿瘤局部残余或复发的灵敏度63．64％（7／11）,特异性84．21％（16／19）,准确性76．67％（23／30）。^99Tc^m-HL91显像与CT结果一致的有21例患者,^99Tc^m-HL91显像与CT联合监测此21例肿瘤残余或复发的灵敏度4／4,特异性94．12％（16／17）,准确性95．24％（20／21）。（3）7例转移患者,^99Tc^m-HL91显像阳性4例,CT均阳性。结论^99Tc^m-HL91乏氧显像对恶性肿瘤治疗后局部残余、复发或转移灶的鉴别有一定价值,与CT联合可有效提高对恶性肿瘤治疗后局部残余、复发或转移灶的早期诊断效能。     

hNIS基因的组织特异性表达介导肝癌细胞摄取99Tcm

目的探讨人钠／碘同向转运体（hNIS）基因在肝癌细胞中的组织特异性表达介导^99Tc^m摄取的可行性。方法构建鼠白蛋白基因启动子／增强子（mAlb）引导下hNIS和潮酶素共同表达的逆转录病毒载体，该重组逆转录病毒感染大鼠肝癌细胞MH3924A建立稳定表达细胞系，用^125I摄取实验证实hNIS基因的功能表达。建立肝癌移植瘤大鼠模型。在体内和体外水平评价重组肝癌细胞对^99Tc^m的摄取和流出。绘制时间-放射性曲线和体内外放射性分布图。结果重组质粒构建成功。体外培养条件下，hNIS基因稳定转染细胞系摄取^99Tc^m高出野生型肝癌细胞254倍。50μmol／L NaClO3和500μmol／L哇巴因（Ouabain）可分别使MHm AlbhNIS6细胞摄取^99Tc^m降低97．56％和88．20％（P均〈0．01）。而^99Tc^m流出迅速，有效半减期不足2min，应用^99Tc^m／γ相机系统获得了转染肿瘤的清晰图像及定量数据，注射^99Tc^m O4^-后30min，MHmAlbhNIS6细胞形成的移植瘤摄取^99Tc^m比对照组高4倍。结论证实hNIS基因在肝癌细胞中的组织特异性表达介导^99Tc^m摄取；利用^99Tc^m／γ相机系统可无创、简单、定量检测hNIS基因的表达。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

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.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

肾细胞癌的MRI研究进展

肾细胞癌是最常见的成人肾脏恶性肿瘤。近年来，多种功能MRI成像技术（如扩散加权成像、灌注加权成像等）、多参数MRI联合分析以及影像组学等新兴影像处理技术被证实在肾细胞癌的诊断中具有较大的价值。目前，研究热点多集中于良恶性肿瘤的鉴别、组织学亚型的区分、肿瘤分期、预测核分级及判断预后。就MRI新技术及图像处理技术在肾细胞癌中的研究进展予以综述。     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

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.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Dynamic MRI of the gallbladder lesions: Differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.