外照射治疗部位软组织浓聚骨显像剂的影像表现探讨

目的：探讨恶性肿瘤患者放射治疗局部软组织浓聚骨显像剂的影像变化。材料与方法：53例乳腺癌、30例鼻咽癌、49例肺癌、22例食管癌患者行99Tc—MDP全身骨显像，观察放射治疗局部软组织浓聚骨显像剂的情况。结果：154例患者中47例（30．5％）局部软组织浓聚。照射剂量＜30Gy组，16．1％（10／62）出现软组织浓聚，照射剂量≥30Gy组，40．2％（37／92）出现软组织浓聚，两者差异有显著性。结论：放射治疗可引起软组织弥漫性浓聚骨显像剂，软组织浓聚骨显像剂与放射治疗受照剂量有关。     

Prostate cancer detection with 3-T MRI: comparison of diffusion-weighted and T2-weighted imaging

OBJECTIVE: To compare the clinical value of diffusion-weighted (DW) and T2-weighted (T2W) imaging in detecting prostate cancer using a 3-Tesla (3T) magnetic resonance (MR) system. MATERIALS AND METHODS: Thirty-seven patients with suspected prostate cancer underwent T2W and DW imaging at 3T using an 8-channel phased-array coil. These images and apparent diffusion coefficient (ADC) maps were read retrospectively and blindly. The results were compared with histopathologic findings, and receiver operating characteristic (ROC) analysis was used to compare the cancer detection performance of T2W and DW imaging. RESULTS: The areas under the ROC curves for DW imaging and T2W imaging were 0.89 and 0.82, respectively. The performance of DW imaging in prostate cancer detection was significantly better than that of T2W imaging (P=0.0371). CONCLUSION: With a 3T MR system, the performance of DW imaging in detecting prostate cancer was better than that of T2W imaging. DW imaging appears to be a robust and reliable method to examine the whole prostate within an acceptable scan time in clinical settings.     

Imaging Assessment of Visceral Pleural Surface Invasion by Lung Cancer: Comparison of CT and Contrast-Enhanced Radial T1-Weighted Gradient Echo 3-Tesla MRI

ObjectiveTo compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura.Materials and MethodsThirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed. Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT).ResultsAt the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI.ConclusionThe diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.     

Echo-planar imaging for MRI evaluation of intrathoracic tumors in murine models of lung cancer

PURPOSE: To evaluate the efficacy of fast cardiac- and respiratory-gated MRI acquisition methods for noninvasive assessment of tumor volume in murine models of lung cancer. MATERIALS AND METHODS: A total of 21 mice bearing either human small-cell (N417) or non-small-cell (H460) lung tumors were scanned using combinations of respiratory-gated computed tomography (CT) imaging, cardiac- and respiratory-gated multishot spin-echo echo-planar imaging (SE-EPI), and cardiac- and respiratory-gated spoiled gradient echo (SPGR). Tumor depiction at 4.7T was qualitatively and quantitatively compared with CT and tissue cross sections. MRI-based measures of tumor volume were compared with ex vivo measurement of tumor mass. RESULTS: Tumors appeared hyperintense on T(2)-weighted EPI images, providing positive intrinsic contrast between tumors and surrounding tissues. Tumor boundaries were better distinguished by EPI and SPGR with T(1)-reducing contrast enhancement when tumor abutted other tissues than by CT or SPGR without contrast. Tumor volumes measured from EPI images correlate well with ex vivo measurements of tumor mass (P < 0.001, r(2) = 0.99) and volume (P < 0.01, r(2) = 0.98) over a wide range of tumor sizes. CONCLUSION: Respiratory- and cardiac-gated multishot EPI enables accurate, noninvasive assessment of tumor in murine models of lung cancer using a sequence that requires approximately two minutes to complete.     

15例前列腺癌侵犯膀胱误诊为膀胱癌的MRI表现

目的分析膀胱受累的前列腺癌的MRI表现,评价MRI对前列腺癌的定性诊断价值,避免伴膀胱受累的前列腺癌误诊为膀胱肿瘤。资料与方法回顾性分析15例行MRI检查前曾误诊为膀胱癌的前列腺癌患者的临床及MRI资料。结果 15例误诊病变MRI均明确诊断为前列腺癌,其中C期10例,D期5例。结论 MRI是诊断前列腺癌良好的影像学方法,特别是当病变累及膀胱时,可很好地避免误诊为膀胱肿瘤,再结合其他检查方法,可提高前列腺癌的诊断准确率。     

磁共振灌注成像在前列腺癌诊断中的应用

目的探讨前列腺癌的磁共振灌注成像的强化特征及前列腺不同组织灌注指标的差异。材料与方法回顾分析经组织病理学证实的前列腺癌49例,记录病人的临床资料。使用GE Echo-speed1.5T超导成像设备,联合应用盆腔相控阵线圈和直肠内表面线圈,采用单次激发平面回波序列进行灌注成像。通过GE高级工作站4.2进行数据处理,得到不同感兴趣区的灌注相关指标:负增强积分、增强平均时间、达峰值时间、信号降低最大斜率及血流速度,用闭孔内肌作为灌注指标的内参照,计算不同感兴趣区的相对灌注指标。结果前列腺癌信号-时间曲线为快速出现的信号降低倒置峰。前列腺癌(PCa)、前列腺增生(BPH)及正常前列腺外周带(PZ)的相对负增强积分(rNEI)、增强平均时间(rMTE)、达峰值时间(rTTM)、信号降低最大斜率(rMSD)及血流速度(rBF)的平均数值分别为6.44、0.71、0.68、1.93、8.17;3.01、0.82、0.83、1.33、3.64;1.29、0.95、0.94、0.64、1.43。前列腺癌的rNEI、rMSD和rBF明显高于前列腺增生的和正常前列腺外周带的(P<0.05)。前列腺癌的rMTE、rTTM低于前列腺增生的和正常前列腺外周带的(P<0.05)。结论磁共振灌注成像能有效反映出前列腺不同组织的微循环灌注差异,有助于提高前列腺癌的检出率。     

前列腺癌及直肠癌对盆腔筋膜侵犯的MRI表现

目的 探讨前列腺癌及直肠癌对盆腔主要筋膜侵犯的MRI表现特点.资料与方法 回顾性分析5例前列腺肿瘤侵犯尿生殖膈及Denonvilliers筋膜患者、4例直肠肿瘤侵犯直肠系膜或直肠系膜筋膜患者的MRI表现特点.结果 肿瘤对筋膜侵犯的MRI表现可分为直接征象和间接征象,直接征象为筋膜连续性中断,局限结节样侵犯；间接征象为脂肪间隙消失,周围淋巴结肿大.结论 MRI可以清晰地显示盆腔筋膜受累情况,对确定肿瘤分期有意义.     

前列腺中央腺体癌的MRS及DWI表现并误诊分析

目的探讨前列腺中央腺体癌的磁共振波谱分析(MRS)及扩散加权成像(DWI)表现,并对误诊病例进行分析。资料与方法回顾性研究术前MR诊断为前列腺中央腺体癌的患者共58例,术后确诊为癌40例、非癌18例,比较两组间的(胆碱+肌酸)/枸橼酸盐(CC/C)值和表观扩散系数(ADC)值。结果中央腺体癌组CC/C值及最小ADC值分别为2.89±1.26、(0.81±0.16)×10-3mm2/s,非癌组CC/C值及最小ADC值分别为1.28±0.59、(1.02±0.18)×10-3mm2/s,中央腺体癌组与非癌组之间的CC/C值及最小ADC值差异均有统计学意义(t值分别为5.994、-3.862,P值均<0.05)。结论 MRS和DWI对于前列腺中央腺体癌的诊断具有一定的价值。     

3.0 T MR及DWI在宫颈癌放射治疗中的应用研究

目的 探讨3.0 T MR及扩散加权成像(diffusion weighted imaging,DWI)在宫颈癌放射治疗(放疗)中的应用价值.资料与方法 16例宫颈癌患者放疗前及放疗40 Gy后均进行MR平扫及自由呼吸状态下轴位DWI,b值取0、1000 s/mm~2,分别测量放疗前后肿瘤区表观扩散系数(ADC)值,并作统计学分析.结果 宫颈癌放疗前T_1 WI示病灶呈等信号、T_2WI呈较高信号,DWI呈均匀明显高信号,ADC值平均约(0.99±0.07)×10~(-3)mm~2/s;放疗后病灶明显缩小,DWI信号减低,呈低信号或高低混杂信号,ADC值平均约(1.52 ±0.08)×10~(-3)mm~2/s.放疗前后ADC值差异具有统计学意义(P<0.01).结论 宫颈癌放疗前DWI呈明显高信号,放疗后DWI信号减低,且不均匀,ADC值较放疗前明显增高,DWI可以作为官颈癌放疗监测的理想手段之一.     

直肠癌MRI术前评估价值与术后病理对比研究

目的 探讨MRI对直肠癌术前评估的价值。方法 选取84例行外科手术治疗的直肠癌患者的MRI、病理、临床资料。用卡方检验评价MRI对诊断肿瘤T分期、N分期、环周切缘（CRM）受累情况、壁外血管浸润的准确性,用配对t检验评估MRI分析病灶与齿状线位置关系的准确性。结果 MRI可较准确地评估对诊断肿瘤T分期、N分期、环周切缘受累情况、壁外血管浸润状态（P<0.01）,可大致评估低位直肠癌病灶距齿状线距离（P> 0.05）。结论 MRI可较准确地评估对诊断肿瘤T分期、N分期、环周切缘受累情况、壁外血管浸润状态。受测量习惯、测量误差、肠管走行等因素的影响,MRI可大致评估病灶距齿状线距离,且测量误差在外科可接受范围内。MRI为临床手术选择及术前评估提供了有价值的影像学依据。     

Dynamic optical breast imaging: a novel technique to detect and characterize tumor vessels

Purpose

To prospectively determine the diagnostic accuracy of optical absorption imaging in patients with Breast Imaging Reporting and Data System (BI-RADS) 3–5 breast lesions.

Materials and methods

Forty-six patients with BI-RADS classification 3 (11%), 4 (44%) or 5 (44%) lesions, underwent a novel optical imaging examination using red light to illuminate the breast. Pressure was applied on the breast, and time-dependent curves of light absorption were recorded. Curves that consistently increased or decreased over time were classified as suspicious for malignancy. All patients underwent a core or surgical biopsy.

Results

Optical mammography showed a statistical difference in numbers of suspect pixels between benign (N = 12) and malignant (N = 35) lesions (respectively 1325 vs. 3170, P = 0.002). In this population, optical imaging had a sensitivity of 74%, specificity of 92%, and diagnostic accuracy of 79%. The optical signal did not vary according to any other parameter including breast size or density, age, hormonal status or histological type of lesions.

Conclusion

Optical imaging is a low-cost, non-invasive technique, yielding physiological information dependent on breast blood volume and oxygenation. It appears to have a good potential for discriminating benign from malignant lesions. Further studies are warranted to define its potential role in breast cancer imaging.     

Dynamic breast magnetic resonance imaging without complications in a patient with dual-chamber demand pacemaker

Mammography and ultrasound indicated a cancer of the right breast in a 77-year-old woman with a dual-chamber demand pacemaker. The patient was not pacemaker-dependent. She underwent breast 1.5T magnetic resonance imaging (MRI) (dynamic gradient echo sequence with Gd-DOTA 0.1 mmol/kg). Before the patient entered the MR room, the configuration of the device was changed (the response to magnet was switched from asynchronous to off and the rate-responsive algorithm was disabled). No relevant modifications of heart rhythm or rate were observed during the MR examination. No symptom was reported. Immediately after the examination, the pacemaker interrogation showed neither program changes nor alert warnings. MRI detected a bifocal cancer in the right breast which allowed tailored breast-conserving treatment to be initiated. Histopathology confirmed a bifocal invasive ductal carcinoma.     

单指数、双指数模型多b值DWI在胰腺癌的应用价值

目的 探讨单指数、体素内不相干运动成像(IVIM)双指数模型多b值扩散加权成像(DWI)定量参数在胰腺癌的应用价值.方法 应用3.0T磁共振扫描仪对临床或手术证实的37例胰腺癌患者行胰腺多b值DWI.应用单指数、IVIM双指数模型分析多b值DWI,测量胰腺癌和癌周胰腺组织的标准化表观扩散系数(ADCstandard)、纯扩散系数 (ADCslow)、假扩散系数(ADCfast) 和灌注分数(f),并应用独立样本t检验进行统计学分析.结果 胰腺癌的ADCslow值高于癌周胰腺组织的ADCslow值(0.611×10-3 mm2/s vs 0.521×10-3 mm2/s,P=0.037),而胰腺癌的ADCfast和f值低于癌周胰腺组织的ADCfast和f值(5.066×10-3 mm2/s vs 7.188×10-3 mm2/s,P=0.035;55.8% vs 64.0%,P=0.016),差异均有统计学意义.胰腺癌的ADCstandard值和ADCslow值显著正相关(r =0.824,P=0.000);ADCfast值和f值显著负相关(r=-0.558,P=0.000).结论 IVIM-DWI的灌注相关参数(ADCfast、f)和扩散相关参数(ADCslow)可以有效鉴别胰腺癌和癌周胰腺组织,IVIM-DWI是无创性早期诊断和鉴别胰腺癌与癌周胰腺组织的理想方法之一.     

3.0TMRI多期增强扫描术前评估胰腺癌可切除性

目的：探讨3.0T MRI多期增强扫描在胰腺癌可切除性评估中的价值。方法对行3.0T MRI 多期增强扫描并经手术病理证实为胰腺癌的38例患者,分析 MRI图像,观察肿瘤对周围血管及邻近器官侵犯、远处转移和腹膜后淋巴结转移情况,作出能否切除的术前评估;并与手术结果比较。结果38例胰腺癌中,32例位于胰头,4例位于胰体,2例位于胰尾。19例术前 MRI认为肿瘤可切除,实际成功切除17例,可切除的阳性预测值为89.5%。另外19例术前MRI认为无法切除,实际手术探查后发现均无法切除。不可手术切除的主要原因包括胰周主要血管受侵、肝转移、淋巴结转移及腹膜种植转移。结论 MRI多期增强在胰腺癌可切除性评估中具有重要价值,可为临床选择合适的治疗方案提供参考依据。