肺癌脊椎骨转移（18）F-FDG PET/CT与MRI的对比分析

目的：比较分析18 F-FDG PET/CT与MRI在肺癌脊椎骨转移诊断方面的敏感性、特异性。方法：28例肺癌PET/CT疑脊椎转移患者行MRI检查,比较两种方法对脊椎转移的显示征象。统计学方法采用配对四格表资料2检验,P〈0.05被认为差异有显著性。结果：经病理或随访确诊脊椎骨转移22例。以受累椎体病灶个数为统计单位,脊椎范围内共700个椎体,153个为真阳性,574个为真阴性。PET/CT诊断正确143个病灶,假阴性10个,假阳性24个,其敏感性93.4%,特异性95.6%。MRI诊断正确145个病灶,假阴性8个,无假阳性,其敏感性94.7%,特异性100%。结论：在显示脊椎骨转移方面,MRI较PET/CT具有更高的敏感性、特异性。     

Added diagnostic value of T2-weighted MR imaging to gadolinium-enhanced three-dimensional dynamic MR imaging for the detection of small hepatocellular carcinomas

Purpose

To assess the added value of T2-weighted MRI to gadolinium-enhanced dynamic MRI for detection of HCCs.

Materials and methods

Two readers retrospectively analyzed MRIs of 115 patients with 131 HCCs (size; 0.6–2.0 cm) that had been diagnosed by histology (n = 41) or imaging findings (n = 90). Two separate blind image analyses of the gadolinium set and the combined T2-weighted imaging and gadolinium sets were performed. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic method with four-point scale. Sensitivity and positive predictive value were also calculated.

Results

For both observers, the Az values and sensitivities with the combined T2-weighed imaging and gadolinium set (mean Az 0.806, sensitivity 84.7) were significantly higher than those with the gadolinium set (mean Az 0.660, sensitivity 59.9) (p < 0.05). The addition of T2-weighted imaging led to a change in diagnosis for 27 lesions by both observers, which at gadolinium set were assigned a confidence level of 1 or 2 but at additional reading of T2-weighted imaging were assigned a confidence level of 3 or 4. For the positive predictive values, each image set showed a similar value for each observer.

Conclusion

The addition of T2-weighted imaging to gadolinium-enhanced 3D dynamic imaging could be helpful in the detection of HCC by increasing reader confidence for HCCs with equivocal findings on gadolinium-enhanced MRIs.     

Gadobenate dimeglumine-enhanced liver MR imaging: value of dynamic and delayed imaging for the characterization and detection of focal liver lesions

The aim of this study was to determine the value of delayed-phase imaging (DPI) of gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging for the evaluation of focal hepatic tumors compared with precontrast imaging and early dynamic phase imaging. The MR images were obtained in 48 patients with 98 focal hepatic tumors. Three-dimensional gradient-echo (GRE) imaging obtained before and 30, 60, and 1 h after administration of 0.1 mmol/kg of gadobenate dimeglumine. Each image set was analyzed qualitatively (lesion detection, conspicuity, delineation, and enhancement pattern on DPI) and quantitatively [signal-to-noise ratio (SNR), tumor–liver contrast-to-noise ratio (CNR)]. Improved lesion-to-liver contrast during the dynamic phase imaging was observed compared with precontrast images. The DPI showed a homogeneous enhancement of liver parenchyma and distinctive enhancement features of focal liver lesions: metastases (85%) showed a target shaped enhancement, and hepatocellular carcinomas (HCCs) showed an inhomogeneous (58%) or homogeneous enhancement (21%). The DPI showed better performance for the detection of metastases than other images by increasing lesion delineation (p<0.05). The absolute CNR of metastasis measured from periphery of the tumors on DPI was greater than precontrast and arterial phase imaging (p<0.05). The Gd-BOPTA during both dynamic and delayed phases provides valuable information for the characterization of focal liver lesions, and furthermore, Gd-BOPTA-enhanced DPI contributed to the improved detection of liver metastasis compared to precontrast and early dynamic imaging.     

Comparison of MR and PET imaging for the evaluation of liver metastases

PURPOSE: To compare the accuracy of fluoro-18-deoxyglucose positron emission tomography (FDG-PET) and dynamic-enhanced magnetic resonance imaging (MRI) scans in the diagnosis of liver metastatic lesions from colon and other sources. MATERIALS AND METHODS: Thirty consecutive patients with known or suspected metastatic lesions were scanned by both MRI and PET. Histopathology and/or clinical outcome, including cross-sectional imaging follow up, were used as a gold standard. RESULTS: Of 30 patients, 16 were positive by pathology and/or clinical outcome and 14 were negative for liver metastases. The sensitivity, specificity, and positive and negative predictive values on MRI were 85.7%, 100%, 100%, and 89%, respectively, compared to 71%, 93.7%, 90.9%, and 79% on FDG-PET. The difference between the two methods was not significant (X(2) = 0.2, P > 0.05). CONCLUSION: Our study showed no significant difference in detection of liver metastases using MRI or FDG-PET. However, MRI has advantages in spatial resolution and lesion characterization.     

PET/CT诊断恶性肿瘤及其转移灶的价值

目的探讨PET／CT对恶性肿瘤及其转移灶的检测效能。方法恶性肿瘤患者65例皆行PET／CT检查，原发灶皆经病理组织学确诊，转移灶的诊断综合组织病理学结果及多种影像学检查而定。行^18F-脱氧葡萄糖(FDG)PET／CT融合图像、唧图像和CT图像帧对帧对比分析。结果初诊恶性肿瘤患者59例，有恶性病灶264个。264个病灶中，唧与平扫CT阅片均有肯定诊断结论者128个，占48．4％；而唧有肯定诊断结论，但CT难以有肯定诊断结论者111个，占42．0％；唧显像为阴性或难以确定，而CT有肯定诊断结论者11例共25个病灶．占9．6％。PET／CT的总检出率高于PET和CT。6例治疗后患者，CT难以确定肿瘤残余和坏死区域，而PET／CT能清楚区分。结论PET／CT可提高对恶性肿瘤诊断及分期的准确性。     

The potential of PET/MR for brain imaging

Introduction  

The completion of an integrated PET/MR prototype system for brain imaging is the latest step in the evolution of positron emission tomography. Early images with this new imaging system demonstrate that high-resolution multiparametric studies can be combined without significant loss of performance of either imaging modality.     

PET/MR imaging of pelvic malignancies

Integrated PET/MRI is a new technology which allows simultaneous acquisition of positron emission tomography and magnetic resonance imaging data during one examination. The technique appears to be particularly appropriate for oncologic imaging of female and male pelvic malignancies, as these entities demand a high soft tissue contrast and might be further assessed metabolically with PET. The review article highlights recent developments of integrated PET/MRI in pelvic malignancies.     

46例癫痫患者发作间期^18F—FDG PET显像结果分析

探讨＾１８Ｆ－脱氧葡萄糖ＰＥＴ对发作间期癫痫灶的诊断价值。方法４６例癫痫患者于发作间期进行ＣＴ和（或）ＭＲＩ、头皮、ＥＥＧ及＾１８Ｆ－ＦＤＧ ＰＥＴ检查。结果４６例患者中８６．９５％（４０例）ＰＥＴ显像有异常代谢灶,低代谢灶３１例,高代谢灶９例。     

Improved detection of skull metastasis with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: Metastasis to the skull is clinically important, but routine MR imaging offers moderate sensitivity for skull-metastasis detection in our experience. We sought to determine if diffusion-weighted MR imaging (DWI) could improve the detection of skull metastasis in patients with primary carcinomas that metastasized to bone compared with conventional MR imaging. MATERIALS AND METHODS: Seventy-five patients from the tumor registry of our institution with extracranial primary malignancy who had brain MR imaging with DWI and radionuclide bone scanning (RNBS, gold standard) within a 6-week interval were evaluated. Thirty-eight patients demonstrated increased radiopharmaceutical uptake on RNBS, consistent with skull metastasis of any size, and the remaining 37 were control subjects. Two readers correlated the DWI and conventional MR imaging with RNBS. RESULTS: The overall sensitivity of DWI for detection of skull metastases was 68.4%-71.1% (kappa=0.68) versus 42.1%-55.3% (kappa=0.65) for conventional MR imaging. Breast cancer (n=20) was detected with greatest sensitivity of 86.7%-93.3% (kappa=0.80) for DWI versus 60%-80% (kappa=0.5) for conventional MR imaging. Lung cancer (n=32) was detected with 63.6%-72.7% sensitivity (kappa=0.56), and prostate cancer (n=8) with 14.3% sensitivity (kappa=0.5) for DWI versus 27.3%-36.4% (kappa=0.81) and 14.3-42.9% (kappa=0), respectively, for conventional MR imaging. CONCLUSIONS: DWI is a useful sequence for identifying focal skull metastases for breast and lung malignancies and, compared with conventional MR imaging, provides improved detection of these lesions. DWI is insensitive for detecting skull metastases from prostate carcinoma.     

PET/CT and MR imaging in myeloma

Myeloma is the most common primary bone malignancy. It accounts for 10% of all hematological malignancies and 1% of all cancers. In the United States, there are an estimated 16,000 new cases and over 11,000 deaths yearly due to myeloma. Plasma cell dyscrasias manifest themselves in a variety of forms that range from MGUS (monoclonal gammopathy of undetermined significance) and smoldering myeloma that require no therapy, to the “malignant” form of multiple myeloma. The role of imaging in the management of myeloma includes: an assessment of the extent of intramedullary bone disease, detection of any extramedullary foci, and severity of the disease at presentation; the identification and characterization of complications; subsequent assessment of disease status. This review will focus on the use of PET/CT and MR imaging for myeloma patients at the time of initial diagnosis and for follow-up management, based on current reports in the literature and our practice at the Marlene and Stewart Greenebaum Cancer Center, University of Maryland Medical Center in Baltimore, USA.     

18F-FDG PET/CT显像在肾上腺转移瘤中的诊断价值和预测分析

目的探讨18F-FDG PET/CT显像在肾上腺转移瘤中的诊断价值及预测价值。方法回顾性分析2012年12月至2016年10月行PET/CT检查的95例无症状的肾上腺病变患者,分为肾上腺转移瘤组（40例）和肾上腺良性病变组（55例）,分别测量肾上腺病灶大小、CT值、最大标准化摄取值（SUV_max）、肾上腺病灶SUV_max/肝脏本底SUV_max比值（SUV_max比值）,分别进行单因素检验、独立样本t检验、Mann-Whitney U秩和检验统计分析。采用多因素Logistic回归分析肾上腺转移瘤的危险预测因素,并采用受试者工作特征（ROC）曲线分析确定肾上腺转移瘤与良性病变鉴别诊断的最佳临界点。结果110个肾上腺病灶中良性病变60个,转移瘤50个,大小为0.65~5.70 cm,平均（1.65±0.82）cm。CT值-20.4~46.8 HU,平均（24.2±14.9）HU。SUV_max为1.1~31.9,平均4.5±4.6。SUV_max比值为0.44~14.5,平均1.99±2.15。单因素分析得出两者在病灶大小、CT值、SUV_max、SUV_max比值之间的差异均有统计学意义（Z=-4.908、-6.030、-7.966、-8.252,均P < 0.001）;多因素Logistic回归分析显示SUV_max比值是影响肾上腺转移瘤发生的独立因素,ROC曲线分析得出SUV_max比值=1.24为鉴别诊断肾上腺转移瘤与良性病变的最佳临界点,灵敏度和特异度分别为90.0%和93.3%。结论18F-FDG PET/CT显像对肾上腺转移瘤具有较高的诊断价值。SUV_max比值是肾上腺转移瘤的独立危险预测因素,鉴别诊断肾上腺良性病变与转移瘤的SUV_max比值最佳临界点为1.24。     

18F-FDG PET/CT显像对脊柱单发转移瘤的诊断价值

目的 评价18F-FDG PET/CT显像对脊柱单发转移瘤的诊断效能及优势.方法 回顾性分析67例[男41例,女26例,年龄40～83(61.5 ±10.2)岁]有恶性肿瘤病史且经局部CT和(或)MRI检查发现单个椎体病变,疑为骨转移瘤患者的资料.患者均行PET/CT显像,既往未行MRI检查者于PET/CT检查后1周内行病变椎体MRI检查.脊柱单发病灶以病理学诊断或6个月以上影像学及临床随访作为最终诊断依据,将PET/CT融合图像与单纯PET、CT及MRI图像分别对比,评价PET/CT显像对脊柱单发转移瘤的诊断效能及优势.对数据行x2检验.结果 PET/CT显像诊断脊柱单发转移瘤的灵敏度为96.3％(52/54),特异性为84.6％ (11/13),阳性预测值为96.3％(52/54),阴性预测值为84.6％ (11/13),准确性为94.0％(63/67).灵敏度、阴性预测值及准确性与PET[81.5％ (44/54)、44.4％ (8/18)、77.6％(52/67)]相比差异均有统计学意义(x2值分别为6.000、5.134、7.421,均P＜0.05);灵敏度、特异性、阴性预测值、准确性与CT[79.6％(43/54)、53.8％ (7/13)、38.9％(7/18)、74.6％(50/67)]相比差异有统计学意义(,值分别为7.083、4.248、6.482、9.543,均P＜0.05);准确性与MRI[80.6％ (54/67)]相比差异有统计学意义(x2=5.457,P＜0.05).结论 PET/CT对脊柱单发转移瘤有较高的诊断效能及优势.PET/CT准确性高于MRI,当在MRI怀疑脊柱单发转移难以明确性质时,可以通过PET/CT提高诊断准确性.     

胎盘植入的MRI诊断

_目的：探讨 MRI 对胎盘植入的诊断价值。方法：回顾性分析经临床综合诊断为胎盘植入的17例孕产妇的MRI 表现。结果：17例患者子宫均不同程度增大,结合带低信号影变薄或中断;胎盘不规则增厚,植入区域子宫壁明显变薄,两者分界不清,9例 T2 WI 上低信号的子宫肌壁内可见高信号的胎盘植入灶。DWI 上12例病灶呈明显高信号,且显示较 T2 WI 清楚,3例未见明显高信号,2例运动伪影较重,不能评价。17例 MRI 动态增强扫描示病灶显著强化,与子宫肌层强化程度类似,边缘强化明显,呈“花环”、“花瓣”样强化,中晚期持续、明显强化,5例病灶中央坏死区未见强化。结论：MRI 平扫结合 DWI 能明确诊断胎盘植入及判断肌层受侵情况,动态增强扫描则有利于明确血供及鉴别诊断,因此 MRI对于诊断胎盘植入具有重要价值。     

胼胝体梗死的MRI表现及其诊断价值

目的：探讨胼胝体梗死的MRI表现特征及其诊断价值。方法：在连续2年颅脑MRI检查中搜集569例脑梗死病例．对其中有胼胝体梗死的36例进行回顾性分析。全部病例均行sE与TSE序列T1WI、T2wI扫描，15例加FLAIR序列扫描，l3例行钆喷替酸葡甲胺(GdDTPA)增强扫描。结果：569例脑梗死中36例(6．3％)MRI确诊为胼胝体梗死。其中3例为单纯胼胝体梗死，33例同时伴其它部位脑梗死。36例共45个梗死灶，位于胼胝体膝部19个，体部15个，压部10个，膝体部1个。T1WI呈略低信号26个，低信号19个，T2wI均呈高信号；15例FLAIR序列11例呈高信号，4例呈低信号；13例增强扫描9例强化。结论：胼胝体梗死少见。MRI可清楚显示胼胝体梗死的存在、部位与范围，但缺乏特征性，结合临床及脑内其它部位梗死灶并存可确定诊断。     

Colorectal liver metastases: CT, MR imaging, and PET for diagnosis--meta-analysis

PURPOSE: To perform a meta-analysis to obtain sensitivity estimates of computed tomography (CT), magnetic resonance (MR) imaging, and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of colorectal liver metastases on per-patient and per-lesion bases. MATERIALS AND METHODS: MEDLINE, EMBASE, Web of Science, and CANCERLIT databases and Cochrane Database of Systematic Reviews were searched for relevant original articles published from January 1990 to December 2003. Criteria for inclusion of articles were as follows: Articles were reported in the English, German, or French language; CT, MR imaging, or FDG PET was performed to identify and characterize colorectal liver metastases; histopathologic analysis (surgery, biopsy, or autopsy), intraoperative observation (manual palpatation, intraoperative ultrasonography [US]), and/or follow-up US was the reference standard; and data were sufficient for calculation of true-positive or false-negative values. A random-effects linear regression model was used to obtain sensitivity estimates in assessment of liver metastases. RESULTS: Of 165 identified relevant articles, 61 fulfilled all inclusion criteria. Sensitivity estimates on a per-patient basis for nonhelical CT, helical CT, 1.5-T MR imaging, and FDG PET were 60.2%, 64.7%, 75.8%, and 94.6%, respectively; FDG PET was the most accurate modality. On a per-lesion basis, sensitivity estimates for nonhelical CT, helical CT, 1.0-T MR imaging, 1.5-T MR imaging, and FDG PET were 52.3%, 63.8%, 66.1%, 64.4%, and 75.9%, respectively; nonhelical CT had lowest sensitivity. Estimates of gadolinium-enhanced MR imaging and superparamagnetic iron oxide (SPIO)-enhanced MR imaging were significantly better, compared with nonenhanced MR imaging (P = .019 and P < .001, respectively) and with helical CT with 45 g of iodine or less (P = .02 and P < .001, respectively). For lesions of 1 cm or larger, SPIO-enhanced MR imaging was the most accurate modality (P < .001). CONCLUSION: FDG PET had significantly higher sensitivity on a per-patient basis, compared with that of the other modalities, but not on a per-lesion basis. Sensitivity estimates for MR imaging with contrast agent were significantly superior to those for helical CT with 45 g of iodine or less.     

SPECT/CT骨显像在肿瘤患者可疑脊柱转移灶中的诊断价值

目的 评价99Tcm-亚甲基二膦酸盐(MDP)SPECT/CT骨显像对肿瘤患者可疑脊柱转移灶的诊断价值.方法 选取76例99Tcm-MDP骨显像可疑脊柱转移灶患者,进行SPECT/CT同机融合显像.76例患者中,与病理(含术中病理)检查结果对照19例,与随访1年余(2006年6月至2006年12月患者,随访至2008年3月)结果对照14例,显像结果与CT及MRI的共同结果对照43例.结果 SPECT/CT显像诊断肿瘤脊柱转移灶的灵敏度为95.83%(23/24),特异性为90.38%(47/52),准确性为92.11%(70/76),阳性预测值为82.14%(23/28),阴性预测值为97.92%(47/48),阳性似然比为9.97,阴性似然比为0.05.结论 SPECT/CT提高了肿瘤可疑脊柱转移灶鉴别诊断的准确性和特异性.     

46例癫痫患者发作间期~(18)F-FDG PET显像结果分析

目的　探讨18F 脱氧葡萄糖 (FDG)PET对发作间期癫痫灶的诊断价值。方法　 4 6例癫痫患者于发作间期进行CT和 (或 )MRI、头皮EEG及18F FDGPET检查。结果　 4 6例患者中 86 95 %(40例 )PET显像有异常代谢灶 ,其中低代谢灶 3 1例 ,高代谢灶 9例。而CT和 (或 )MRI仅 5 6 5 2 % (2 6例 )异常 ,EEG 82 60 % (3 8例 )异常。 9例示局限性高代谢区患者 1周后在确认检查前后 12h均未发作的前提下再次行PET检查 ,结果发现其中 7例同一部位出现低代谢区 ,另 2例代谢也有所降低。结论　18F FDGPET对发作间期癫痫灶的诊断价值明显优于CT和 (或 )MRI和头皮EEG ,尤其在发作间期和发作期各检查 1次 ,或延长发作后检查时间 ,可提高灵敏度和特异性及诊断准确性。