STIR turbo SE MR imaging vs. coregistered FDG-PET/CT: quantitative and qualitative assessment of N-stage in non-small-cell lung cancer patients

PURPOSE: To conduct a prospective comparison of the accuracy of short inversion time (TI) inversion-recovery (STIR) turbo spin-echo (SE) imaging and coregistered 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (coregistered FDG-PET/CT) to assess the N-stage in non-small-cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: A total of 115 consecutive NSCLC patients prospectively underwent CT, STIR turbo SE imaging, and FDG-PET, as well as surgical and pathological examinations. All STIR turbo SE images were obtained with a 0.9% saline phantom, which was placed alongside the chest wall of each patient, and coregistered FDG-PET/CTs were reconstructed using commercially available software. For quantitative assessments, the ratio of signal intensity (SI) of each lymph node to that of 0.9% saline phantom (lymph node-saline ratio [LSR]) and maximal standardized uptake value (SUV(max)) of each lymph node were calculated. Feasible threshold values were determined by using the receiver operating characteristic (ROC) curve-based positive test, and diagnostic capabilities of N-stage were compared by McNemar's test on a per patient basis. RESULTS: When feasible, threshold values were adopted, quantitative sensitivity (90.1%) and accuracy (92.2%) of STIR turbo SE imaging were significantly higher than those of quantitative and qualitative sensitivities (76.7% and 74.4%) and accuracies (83.5% and 82.6%) of coregistered FDG-PET/CT on a per patient basis (P < 0.05). CONCLUSION: STIR turbo SE imaging is at least as valid as coregistered FDG-PET/CT for quantitative and qualitative assessment of the N-stage for NSCLC patients.     

Metastases in mediastinal and hilar lymph nodes in patients with non-small cell lung cancer: quantitative and qualitative assessment with STIR turbo spin-echo MR imaging

PURPOSE: To evaluate short inversion time inversion-recovery (STIR) turbo spin-echo (TSE) magnetic resonance (MR) imaging for detection of metastases in lymph nodes by using quantitative and qualitative analyses. MATERIALS AND METHODS: One hundred ten patients (68 men and 42 women) with non-small cell lung cancer who ranged in age from 36 to 82 years (mean age, 64 years) were examined with respiratory-triggered STIR TSE MR imaging. Ratios of signal intensity in a lymph node to that in a 0.9% saline phantom (lymph node-saline ratios [LSRs]) for all lymph nodes were classified into three groups according to nodal short-axis diameter. LSRs of each group were compared by using pathologic diagnosis as the standard of reference. For quantitative analysis, the LSR threshold value for a positive test was determined on a per-node basis and tested for ability to enable a correct diagnosis on a per-patient basis. For qualitative analysis, signal intensities of lymph nodes were assessed by using a five-point visual scoring system. Results of quantitative and qualitative analyses were compared on a per-patient basis with McNemar testing. RESULTS: In 110 patients, 92 of 802 lymph nodes were pathologically diagnosed as containing metastases, while 710 lymph nodes did not contain metastases. Mean LSR in the lymph node group with metastasis was higher than that in the group without metastasis (P <.05). When an LSR of 0.6 was used as the positive-test threshold at quantitative analysis, sensitivity was 93% (37 of 40 patients) and specificity was 87% (61 of 70 patients) on a per-patient basis. With a score of 4 as the positive-test threshold at qualitative analysis, sensitivity was 88% (35 of 40 patients) and specificity was 86% (60 of 70 patients) on a per-patient basis. There was no significant difference (P >.05) between results of quantitative and those of qualitative analysis. CONCLUSION: Quantitative and qualitative analyses of STIR TSE MR images enable differentiation of lymph nodes with metastasis from those without. Qualitative analysis can substitute for quantitative analysis of STIR TSE MR imaging data.     

Turbo short tau inversion recovery imaging for metastatic node screening in patients with head and neck cancer

BACKGROUND AND PURPOSE: A rapid and sensitive MR imaging technique would be beneficial for screening of metastatic nodes in the neck. We preliminarily evaluated the coronal MR imaging with a turbo short tau inversion recovery (STIR) sequence for that purpose. METHODS: The coronal turbo STIR imaging (repetition time [TR]/echo time [TE]/inversion time [TI] = 3850 ms/20 or 80 ms/180 ms) and axial fat-suppressed spectral presaturation with inversion recovery (SPIR) T2-weighted imaging (fsT2WI) (TR/TE = 3500 ms/80 ms) were performed on 29 patients with head and neck cancer. We obtained coronal turbo STIR images and axial fsT2WI of the necks. The section thickness, intersection gap, matrix size, and field of view were the same in both techniques. The diagnostic ability for metastatic nodes was assessed at each neck level by using various cutoff size criteria. The nodal involvement was confirmed by histologic examination. RESULTS: The image acquisition time for the whole neck by coronal turbo STIR and axial fsT2WI techniques was approximately 2 minutes and 4 minutes, respectively. When the size criteria (cutoff sizes of short axis diameter were 8 mm at level I and 5 mm at levels II and III) were used, the STIR imaging yielded compromised diagnostic ability having 100% sensitivity and 100% negative predictive value (NPV). fsT2WI technique yielded 100 sensitivity and 100% NPV by using cutoff sizes of 6 mm at levels I and II and 5 mm at level III. CONCLUSION: Coronal STIR imaging provided a rapid screening technique for cervical metastatic nodes and could be a diagnostic tool before detailed MR studies of the neck.     

Feasibility of diffusion-weighted imaging in the differentiation of metastatic from nonmetastatic lymph nodes: early experience

PURPOSE: To investigate the feasibility of diffusion-weighted imaging (DWI) in the differentiation of metastatic from nonmetastatic lymph nodes. MATERIALS AND METHODS: In 125 patients who underwent lymph node dissection for uterine cervical cancer, DWI was performed at b value of 0 and 1000 s/mm2. By referring to the surgical maps of the pelvic lymph nodes, the apparent diffusion coefficient (ADC) was compared in the metastatic and nonmetastatic lymph nodes, and receiver-operating-characteristics analysis was performed to evaluate the diagnostic performance of the ADC in differentiating metastatic from nonmetastatic lymph nodes. RESULTS: The ADC were significantly lower in the metastatic lymph nodes (0.7651x10(-3) mm2/s+/-0.1137) than in the nonmetastatic lymph nodes (1.0021x10(-3) mm2/s+/-0.1859; P<0.001). The area-under-the-curve of ADC for differentiating metastatic from nonmetastatic lymph nodes, was 0.902. The sensitivity and specificity of ADC for differentiating metastatic from nonmetastatic lymph nodes, were 87% for the ADC and 80%, respectively. CONCLUSION: DWI is feasible for differentiating metastatic from nonmetastatic lymph nodes in patients with uterine cervical cancer.     

Non-small cell lung cancer: Spectral computed tomography quantitative parameters for preoperative diagnosis of metastatic lymph nodes

ObjectiveTo investigate the application value of spectral computed tomography (CT)quantitative parameters for preoperative diagnosis of metastatic lymph nodes in patients with non-small cell lung cancer (NSLC).Methods84 patients with suspected lung cancer who underwent chest dual-phase enhanced scan with gemstone spectral CT imaging (GSI) mode were selected. GSI quantitative parameters including normalized iodine concentrations (NIC), water concentration, slope of the spectral Hounsfield unit curve (λHU) were measured. The two-sample t test was used to statistically compare these quantitative parameters. Receiver operating characteristic (ROC) curves were drawn to establish the optimal threshold values.ResultsA total of 144 lymph nodes were included, with 48 metastatic lymph nodes and 96 non-metastatic lymph nodes. The slope of the spectral Hounsfeld unit curve (λHU) measured during both arterial and venous phases were signifcantly higher in metastatic than in benign lymph nodes (P < 0.05). The area under the ROC curve (AUC = 0.951) of λHU of the arterial phase (AP) was the largest. When the optimal threshold values of λHU was 2.75, the sensitivity, specificity, and overall accuracy in the diagnosis of metastatic lymph nodes were 88.2%, 88.4%, 87.0%, respectively.ConclusionConventional CT diagnostic criteria established in accordance with size (lymph node maximal short axis diameter ≥10 mm) as the basis for judging metastatic lymph node. In quantitative assessment using spectral CT imaging, quantitative parameters showed higher accuracy than qualitative assessment of conventional CT based on the size for preoperative diagnosis of metastatic lymph nodes.     

MR imaging of infradiaphragmatic lymphadenopathy in children and adolescents with Hodgkin disease: Comparison with lymphography and CT

The ability of short-inversion-time inversion recovery (STIR) magnetic resonance imaging to depict infradiaphragmatic lymphadenopathy was evaluated in 25 consecutive patients with newly diagnosed Hodgkin disease. All patients underwent computed tomography (CT) and multiplanar STIR imaging prior to lymphography (LAG). The STIR and CT images were evaluated for paraaortic and parailiac node enlargement. Findings were compared with LAG findings, which showed the architectural pattern of the opacified lymph nodes. In the upper paraaortic region, STIR imaging showed more abnormal nodes than did CT or LAG. In the lower paraaortic and parailiac regions, lymph node enlargement was shown equally well with STIR and LAG, whereas CT showed fewer enlarged lymph nodes. LAG showed paraaortic or parailiac focal tumor infiltration in three patients with normal-size nodes, and hyperplasia in two patients with enlarged nodes. STIR imaging showed more abnormal infradiaphragmatic nodes than did CT because of improved lymph node conspicuity. STIR imaging may be a useful addition to CT for staging pediatric Hodgkin disease.     

MR IVIM-DWI 及 DCE-MRI 对直肠癌系膜淋巴结良恶性的诊断价值

目的：探讨 MR 体素内不相干运动扩散加权成像(IVIM-DWI)及动态增强磁共振成像(DCE-MRI)在鉴别直肠癌直肠系膜淋巴结转移的应用价值。方法38例经病理确诊为直肠癌的患者,术前行 IVIM-DWI 及 DCE-MRI 检查。比较转移性淋巴结(n=28)与非转移性淋巴结(n=27)的短径、短径-长径比、IVIM-DWI 参数值[表观扩散系数(ADC)、单纯扩散系数(D)、伪扩散系数(D?)和灌注分数(f)]及 DCE-MRI 半定量参数值[曲线上升斜率(Slope)、最大上升斜率(Maxslope)、对比增强比(CER)、对比剂清除率(Washout)、达峰时间(TTP)、前90 s 增强曲线下面积(iAUC90)和前180 s 增强曲线下面积(iAUC180)]。结果转移性与非转移性淋巴结在平均短径(8.87 mm±2.829 mm vs 6.83 mm±1.075 mm)、D 值[(0.824±0.113)×10-3 mm2/s vs (1.033±0.244)×10-3 mm2/s)]、CER(1.588±0.664 vs 1.054±0.419)、iAUC90(22.89±9.83 vs 13.59±5.34)和 iAUC180(49.38±20.19 vs 30.31±11.67)上差异有统计学意义(P ≤0.001);在短径-长径比、ADC 值、D?值、f 值及 Slope、Maxslope、Washout、TTP 上无统计学差异(P >0.05)。鉴别转移性及非转移性淋巴结的最佳阈值(各自的曲线下面积、敏感性、特异性)分别为：短径=7.1 mm(0.744、64.2%、85.1%)、D=0.906×10-3 mm2/s (0.821、81.5%、75.0%)、CER=1.05(0.749、85.7%、62.9%)、iAUC90=13.42(0.780、85.7%、62.9%)及 iAUC180=49.65(0.770、50.0%、100%)。结论IVIM-DWI 及 DCE-MRI 在鉴别直肠癌直肠系膜转移性及非转移性淋巴结的诊断中具有一定的意义。     

MR imaging of focal lung lesions: elimination of flow and motion artifact by breath-hold ECG-gated and black-blood techniques on T2-weighted turbo SE and STIR sequences.

Respiratory and cardiac motion correction may result in better turbo spin-echo (SE) imaging of the lung. To compare breath-hold cardiac-gated black-blood T2-weighted turbo SE and turbo short-inversion-time inversion-recovery (STIR) magnetic resonance (MR) imaging pulse sequences with conventional breath-hold turbo SE and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences for lesion conspicuity of focal lung lesions, 42 patients with focal lung lesions were prospectively studied with MR imaging at 1.5 T. Helical computed tomography was used as a reference. In comparison with the conventional breath-hold turbo SE sequence, all black-blood sequences had fewer image artifacts arising from the heart and blood flow. The overall image quality for the black-blood turbo SE and turbo STIR sequences was superior to that for the breath-hold turbo SE and HASTE sequence (P < 0.01). Not only focal lung lesions but also surrounding inflammatory changes were clearly visualized with these two sequences. With the HASTE sequence, although several slices could be obtained in one breath-hold, both the tumor and vessels appeared blurred. We conclude that T2-weighted turbo SE and turbo STIR imaging of the lung with effective suppression of flow and motion artifacts provide high-quality images in patients with focal lung lesions.     

18F-FDG PET-CT显像在预测肺癌淋巴结分期中的价值

目的:探究18F-FDG PET-CT显像在肺癌患者淋巴结分期中的预测价值。方法:以35例经手术病理证实为肺癌患者的PET-CT资料及临床资料为研究对象。在PET-CT原发灶及纵隔淋巴结各区最浓聚的部位勾画感兴趣区,得出SUVmax.以淋巴结转移进行分组,采用t检验、Wilcoxon rank-sum检验及四格表资料的Fisher确切概率法分析组间淋巴结SUVmax、淋巴结与原发灶SUVmax的比值(SUVratio)及临床特征的差异。用ROC曲线对PET/CT的预测价值进行分析。结果:患者年龄、性别、吸烟史、组织类型与肺门、纵隔淋巴结转移无显著相关(P>0.05)。转移淋巴结的SUVmax较非转移淋巴结显著升高,差异有统计学意义(P<0.05),而淋巴结的SUVratio与淋巴结转移无明显相关(P>0.05)。取淋巴结SUVmax的最佳阈值,假阴性患者中的肺癌原发灶SUVmax偏低,假阳性患者比假阴性患者中的吸烟率高,但不具有显著统计学意义(P>0.05)。结论:淋巴结SUVmax可以为临床判断淋巴结转移提供定量指标。结合患者的临床病理特征判断淋巴结的转移可能从--定程度上减少假阳性率及假阴性率。     

Gd-DTPA-enhanced short repetition time and short inversion time inversion recovery magnetic resonance imaging. Experimental and clinical assessment

To suppress both water and fat signal while retaining the high signal of Gd-DTPA enhancement, magnetic resonance imaging (MRI) of phantoms and 28 patients with mass lesions was done using short repetition time (TR) and short inversion time inversion recovery (STIR) sequences. Optimal STIR pulse sequences of 500 to 1000/80-100/20-30 (TR/TI/TE) were determined by an experimental study. In most instances, a signal bandwidth of +/- 8 kHz was used to increase the signal-to-noise ratio. The authors measured image contrast between lesions and adjacent fatty tissue and compared postcontrast STIR and T1-weighted spin-echo (T1-W SE) images. When the signal intensity of a lesion is 80% of adjacent fatty tissue on postcontrast T1-W SE, short TR STIR images provide better tumor delineation.     

Computed tomography lymphography with intrapulmonary injection of iopamidol for sentinel lymph node localization

PURPOSE: Experimental and clinical evaluation of the potential utility of indirect computed tomographic lymphography (CT-LG) with intrapulmonary injection of iopamidol for preoperative localization of sentinel lymph node station in non-small cell lung cancer. METHODS: CT-LG with intrapulmonary injection of 0.5 mL of undiluted iopamidol was performed in 10 dogs using a multidetector-row CT unit, followed by postmortem examination of enhanced lymph nodes in 5 of these dogs. The CT-LG with peritumoral injection of 1 mL of the contrast agent was also performed in 9 patients with non-small cell lung cancer without lymphadenopathy. At surgery, enhanced lymph nodes were resected under CT-LG guide, followed by standard lymph node dissection with macroscopic and histologic examination. A significant enhancement of lymph nodes was determined when CT attenuation value was increased with 30 Hounsfield units (HU) compared with precontrast images. RESULTS: CT-LG visualized a total of 15 enhanced lymph nodes (on average, 1.5 nodes per animal) within 2 minutes after contrast injection in the 10 dogs, with average size of 6.7+/- 1.9 mm and average maximum CT attenuation of 149 +/- 41 HU. All the 8 enhanced nodes in 5 dogs were found in the appropriate anatomic locations in postmortem examinations. Without noticeable complications, CT-LG visualized 30 ipsilateral intrathoracic lymph nodes including 19 hilar/pulmonary and 11 mediastinal nodes in the 9 patients (on average, 2.2 hilar/pulmonary and 1.1 mediastinal nodes per patient) within 2 minutes after contrast injection, with average size of 4.7+/- 0.4 mm and average maximum CT attenuation of 134 +/- 52 HU. At surgery, all these enhanced nodes could be accurately found and resected under CT-LG guidance. Metastasis was not evident in either of these enhanced lymph nodes or the remaining distant nodes in all patients. CONCLUSION: Quick and accurate localization of sentinel lymph node station on detailed underlying lung anatomy by using indirect CT-LG may be of value to guide selective lymph node dissection for minimally invasive surgery in non-small cell lung cancer.     

Effectiveness of the STIR turbo spin–echo sequence MR imaging in evaluation of lymphadenopathy in esophageal cancer

Purpose

We have investigated the utility of the STIR TSE sequence in the differentiation of benign from malignant mediastinal lymph nodes in patients with esophageal cancer.

Patients and methods

This study included 35 consecutive patients who were diagnosed as esophageal cancer and were undergone surgery. STIR TSE sequences were obtained as the ECG trigger. The signal intensity of the benign and malign lymph nodes, normal esophagus, and pathologic esophagus can be calculated on STIR sequence.

Results

Pathologically, the number of total lymph nodes in 35 operated cases was 482. Approximately 152 lymph nodes were detected with MR imaging. Of these, 28 were thought to be malignant, and 124 were thought to be benign, although 32 were malignant and 120 were benign according pathological results. The ratio of benign lymph node intensity value to normal esophagus intensity value was 0.73 ± 0.3. The ratio of malignant lymph node intensity value to normal esophagus intensity value ratio was 2.03 ± 0.4. According to these results, the sensitivity of MR was 81.3%, the specificity was 98.3%.

Conclusion

We think that if motionless images can be obtained with MRI, we may be able to differentiate benign lymph nodes from malignant ones.     

MR-guided RF thermal ablation of the kidney in a porcine model.

OBJECTIVE: The purpose of the study was to evaluate the ability of MR imaging to reveal RF interstitial thermotherapy in the porcine kidney, as a model for future human trials, and to provide guidance for RF probe insertion. SUBJECTS AND METHODS: Ten MR-guided RF ablations were performed in the kidneys of three pigs. A 17-gauge monopolar RF probe electrode was inserted into the renal cortex using MR guidance, and RF was applied for 10 min. After postprocedure imaging (T2-weighted, turbo short inversion time inversion recovery [STIR], and T1-weighted sequences), the kidneys were harvested for pathologic examination. RESULTS: Successful RF probe placement was accomplished in all cases; the interventional procedure time for probe insertion ranged from 4 to 15 min. The thermal lesion size varied from 7 to 14 mm perpendicular to the probe track and was best seen on turbo STIR images. Turbo STIR had the highest renal cortex-to-RF thermal lesion contrast-to-noise ratio with an average of 4.4 +/- 3.5. Turbo STIR imaging never overestimated pathologic lesion diameter with a mean difference of 1.5 +/- 1.4 mm. Three subcapsular hematomas occurred. which could be detected immediately on postprocedure imaging. CONCLUSION: MR-guided RF thermal ablation in the porcine kidney was found to be feasible, but minor complications occurred. Induced thermal lesion size was best monitored using turbo STIR images. In the future, RF ablation may offer an alternative treatment option for renal cancer.     

MR evaluation of vertebral metastases: T1-weighted,short-inversion-time inversion recovery,fast spin-echo,and inversion-recovery fast spin-echo sequences.

PURPOSETo compare the detectability of vertebral metastatic disease on T1-weighted, short-inversion-time inversion recovery (STIR), fast spin-echo (FSE), fat-saturated FSE, and inversion recovery FSE (IRFSE) MR sequences using percent contrast and contrast-to-noise ratios.METHODSPatients with proved metastatic disease underwent imaging on a 1.5-T MR system with sagittal T1-weighted (800/20/2 [repetition time/echo time/excitations]) (91 patients), STIR (1400/43/2; inversion time, 140) (91 patients), FSE (4000/180/2) (46 patients), fat-saturated FSE (4000/180/2) (16 patients), and IRFSE (29 patients) sequences. Percent contrast and contrast-to-noise ratio were calculated for the lesions. The number of metastatic lesions detected with each of the pulse sequences was also calculated.RESULTSMean percent contrast was, for T1-weighted sequence, -42.2 +/- 1%; STIR, 262 +/- 34%; FSE, 121 +/- 21%; fat-saturated FSE, 182 +/- 6%; and IRFSE, 272 +/- 47%. The mean contrast-to-noise ratio for T1-weighted was -4.63 +/- 1.7; STIR, 10.8 +/- .98; FSE, 4.16 +/- .76; fat-saturated FSE, 4.87 +/- .19; and IRFSE, 5.2 +/- .87. STIR and IRFSE showed the highest number of lesions, followed by T1-weighted, fat-saturated FSE, and FSE sequences. T1-weighted sequences showed 94%, FSE 55%, and fat-saturated FSE 78% of the lesions detected. Epidural metastatic lesions were better depicted on T1-weighted, FSE, and fat-saturated FSE sequences.CONCLUSIONSTIR was superior to both T1-weighted and FSE (with and without fat saturation) for detection of metastatic lesions, in terms of both percent contrast and contrast-to-noise ratio and visibility. IRFSE was equal to STIR for the detection of metastasis by both subjective and objective criteria. T1-weighted, FSE, and fat-saturated FSE sequences were superior to STIR and IRFSE in the detection of epidural metastatic disease. IRFSE provided faster scanning time, which could be translated into greater resolution.     

Whole-body fast inversion recovery MR imaging of small cell neoplasms in pediatric patients: a pilot study

OBJECTIVE. The purpose of this study was to assess the ability of whole-body turbo short tau inversion recovery (STIR) MR imaging to detect metastases in children with small cell tumors and to compare its performance with that of conventional imaging. CONCLUSION. Early data suggest that whole-body turbo STIR MR imaging is as reliable as other conventional imaging studies for staging newly diagnosed small cell tumors in pediatric patients.     

Multicenter clinical trial of ultrasmall superparamagnetic iron oxide in the evaluation of mediastinal lymph nodes in patients with primary lung carcinoma.

The purpose of this study was to evaluate the clinical efficacy of ultrasmall superparamagnetic iron oxide particles as a magnetic resonance (MR) contrast agent in differentiating metastatic from benign lymph nodes. Eighteen patients with primary lung malignancy and suspected regional lymph node metastases underwent MR imaging before and after Combidex(R) infusion in a multi-institutional study. All MR sequences were interpreted by one or more board-certified radiologists experienced in imaging thoracic malignancy. Each patient was evaluated for the number and location of lymph nodes, homogeneity of nodal signal, and possible change of MR signal post contrast. All patients underwent resection or sampling of the MR-identified lymph node(s) 1-35 day(s) post contrast MR imaging. In all, 27 lymph nodes or nodal groups were available for histopathologic correlation. Combidex had a sensitivity of 92% and a specificity of 80% in identifying pathologically confirmed metastatic mediastinal lymph nodes. Based on our preliminary data, Combidex MR imaging may provide additional functional information useful in the staging of mediastinal lymph nodes.     

非小细胞肺癌30例术中应用~(99m)Tc标记前哨淋巴结的临床观察

目的探讨非小细胞肺癌术中应用99mTc探测肺癌前哨淋巴结,以提高术中清除前哨淋巴结的准确性。方法 30例非小细胞肺癌患者,术中将99mTc硫胶体溶液在肺部肿瘤环周的4～6个部位分别注射,用便携式γ射线探测器探测肺门及纵隔各部位淋巴结的放射活性计数值。常规行肺癌肺叶切除、淋巴结清除术并行常规病理检查。结果 30例患者共清除淋巴结395枚,其中前哨淋巴结即阳性转移淋巴结112枚,阳性转移率为28.3%。前哨淋巴结的99mTc放射活性计数值为15321.85±5945.28,阴性淋巴结的计数值为8479.26±3201.37(P<0.01)。结论对于非小细胞肺癌患者,术中应用99mTc标记前哨淋巴结能够更准确地提示肺癌纵隔转移淋巴结,有效提高转移淋巴结的检出率。     

Value of whole-body turbo short tau inversion recovery magnetic resonance imaging with panoramic table for detecting bone metastases: comparison with 99MTc-methylene diphosphonate scintigraphy

OBJECTIVE: The objectives of this study were to assess the efficacy and reliability of whole-body turbo short tau inversion recovery (STIR) magnetic resonance imaging (MRI) for detecting skeletal metastasis and to compare the results with those of bone scintigraphy. METHODS: Twenty-six patients with primary cancer (mean age=56 years, age range: 34-75 years) were assessed for bone metastasis with whole-body MRI and bone scintigraphy. Eight bone regions in each patient were assessed (total of 208 sites) with each of these 2 techniques. A turbo STIR sequence and panoramic table were used during MRI. Whole-body MRI and scintigraphy findings were compared with biopsy or follow-up imaging results. RESULTS: After at least 12 months of follow-up, 9 patients had bone metastases in a total of 31 sites. Whole-body MRI showed 29 metastases (94%) in the total 208 skeletal sites investigated in the 26 patients. Bone scintigraphy revealed metastases in 16 (52%) of the 208 sites. CONCLUSION: Whole-body turbo STIR MRI is a reliable method for screening patients with suspected skeletal metastases. This technique is also advantageous in that it reveals extraskeletal organ and soft tissue metastases.     

3.0T MR多b值DWI对鼻咽癌患者颈部良恶性淋巴结的鉴别诊断价值

目的探讨3.0T磁共振多b值扩散加权成像(DWI)对鼻咽癌患者颈部良恶性淋巴结的鉴别和诊断价值。方法收集本院66例鼻咽癌患者的临床资料,并以35例良性淋巴结肿大患者为对照。所有患者均行MR常规平扫、增强和多b值DWI影像学检查,比较不同b值下鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结与良性淋巴结肿大患者表观扩散系数(ADC)值的差异。通过绘制受试者工作特征(ROC)曲线计算诊断阈值、ROC曲线下面积、敏感度和特异度,评价不同b值下ADC值对鼻咽癌颈部良恶性淋巴结的鉴别和诊断价值。结果随着b值的增加,鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结与良性淋巴结肿大患者ADC值呈现减少的趋势;鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结之间ADC值的比较,差异均无统计学意义(P>0.05);鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结ADC值均显著低于良性淋巴结肿大患者(P<0.05)。在b值分别取400、600、800、1000s/mm^2时,其对应的ROC曲线下面积分别为0.77、0.82、0.91、0.87。当b=800s/mm^2时,其鉴别和诊断淋巴结良恶性的价值最高,此时ADC值诊断鼻咽癌颈部转移性小淋巴结的阈值为0.945×10^-3mm^2/s,诊断敏感度为98.49%,特异度为79.63%,约登指数为0.78。结论3.0T MR多b值DWI检查可有效区分良恶性淋巴结的性质,并且在b值为800s/mm^2时,其鉴别和诊断不同淋巴结性质的能力最强,可用于临床鉴别和诊断鼻咽癌患者颈部淋巴结转移瘤。     

Preoperative staging of pelvic lymph nodes in prostate cancer by 11C-choline PET.

Prostate cancer is known for its difficulties in preoperative staging of pelvic lymph nodes by conventional imaging techniques. Thus, a histopathologic examination of the pelvic lymphadenectomy specimen is mandatory for patients at risk for metastatic disease. The aim of this study was to evaluate the strength and accuracy of (11)C-choline PET in preoperative noninvasive staging of pelvic lymph nodes in prostate cancer. METHODS: In a prospective study we examined 67 consecutive patients with histologically proven prostate cancer with (11)C-choline PET. The results of PET were compared with the results of histology of the pelvic lymph nodes and with the follow-up data. Conventional axial imaging was routinely performed using MRI or CT. The sensitivity, specificity, and accuracy of (11)C-choline PET were calculated. RESULTS: Fifteen patients had histologically proven lymph node metastases. (11)C-Choline PET was true-positive in 12 of 15 patients and false-negative in 3 patients. Fifty-two patients had no lymph node metastases. (11)C-Choline PET was true-negative in 50 of 52 patients and false-positive in 2 patients. We calculated a sensitivity of (11)C-choline PET for staging metastatic lymph node disease of 80%, a specificity of 96%, and an accuracy of 93%. Next, (11)C-choline PET detected solitary extraregional lymph node metastases in 5 of 12 patients with nodal metastases. CONCLUSION: This study showed that (11)C-choline PET is sensitive and accurate in preoperative staging of pelvic lymph nodes in prostate cancer.