Intravoxel Incoherent Motion Diffusion-weighted Imaging: Evaluation of the Differentiation of Solid Hepatic Lesions

PURPOSE: To evaluate whether intravoxel incoherent motion (IVIM)–related parameters could be used to differentiate malignant from benign focal liver lesions (FLLs) and to improve diagnostic efficiency. METHODS: Seventy-four patients with 75 lesions, including 51 malignant FLLs and 24 benign FLLs, underwent liver 3.0-T magnetic resonance imaging for routine examination sequences. IVIM diffusion-weighted imaging (DWI) with 11 b values (0-800 s/mm²) was also acquired concurrently. Apparent diffusion coefficient (ADC_total) and IVIM-derived parameters, such as the pure diffusion coefficient (D), the pseudodiffusion coefficient (D^?), and the perfusion fraction (f), were calculated and compared between the two groups. A receiver operating characteristic curve analysis was performed to assess their diagnostic value. RESULTS: ADC_total, D, and f were significantly lower in the malignant group than in the benign group, whereas D^? did not show a statistical difference. D had a larger area under the curve value (0.968) and higher sensitivity (92.30%) for differentiation. CONCLUSION: IVIM is a useful method to differentiate malignant and benign FLLs. The D value showed higher efficacy to detect hepatic solid lesions.     

3.0 T磁共振扩散加权成像在乳腺良恶性病变鉴别中的价值及较优b值下ADC值与预后因子相关性研究

摘要 目的：研究3.0 T磁共振扩散加权成像在乳腺良恶性病变鉴别中的价值及较优b值下ADC值与预后因子的相关性。方法：选取2017年11月～2019年11月于我院接受诊治的乳腺病变患者50例进行研究,将其按照良恶性差异分成恶性组40例与良性组10例,另取同期于我院体检的健康志愿者50例作为对照组。对所有人员均进行3.0 T磁共振扩散加权成像,比较不同b值下ADC值在不同乳腺组织中的差异,比较不同b值下诊断乳腺良恶性病变的效能,分析较优b值下ADC值和乳腺癌患者各项预后因子的相关性。结果：对照组、良性组、恶性组在不同b值下的ADC值均呈逐渐降低趋势（P＜0.05）;对照组、良性组、恶性组b值为1000 s/mm²下的ADC值均低于b值为600 s/mm²（P＜0.05）。b值为1000 s/mm²时诊断乳腺恶性病变的敏感度、特异度、准确度分别为92.50%、100.00%、94.00%,高于b值为600 s/mm²的70.00%、60.00%、68.00%（P＜0.05）。b值为1000 s/mm²下雌激素受体、孕激素受阳性患者的ADC值低于阴性患者,而人类表皮生长因子受体2阳性患者的ADC值高于阴性患者（P＜0.05）。经Spearman相关性分析可得,b值为1000 s/mm²下ADC值与雌激素受体、孕激素受体阳性表达均呈负相关关系,而与人类表皮生长因子受体2阳性表达呈正相关关系（P＜0.05）。结论：3.0 T磁共振扩散加权成像在乳腺良恶性病变鉴别中的价值较高,且以b值为1000 s/mm²的诊断能效较优。此外,b值下ADC值和乳腺癌部分预后因子表达状态密切相关。     

The Value of Diffusion-Weighted Imaging in the Differential Diagnosis of Ovarian Lesions: A Meta-Analysis

Objectives

The ability of contrast-enhanced MRI to distinguish between malignant and benign ovarian masses is limited. The aim of this meta-analysis is to evaluate the diagnostic performance of diffusion-weighted imaging (DWI) in differentiating malignant from benign ovarian masses.

Methods

A comprehensive literature search was performed in several authoritative databases to identify relevant articles. The weighted mean difference (WMD) and corresponding 95% confidence interval (95% CI) were calculated. We also used subgroup analysis to analyze study heterogeneity, and evaluated publication bias.

Results

The meta-analysis is based on 21 studies, which reported the findings for 731 malignant and 918 benign ovarian masses. There was no significant difference in apparent diffusion coefficient (ADC) values for DWI between benign and malignant lesions (WMD = 0.22, 95% CI = -0.02–0.47, p = 0.08). Subgroup analysis by benign tumor type revealed higher ADC values (or a trend toward higher values) for cysts, cystadenomas and other benign tumors compared to malignant masses (cyst: WMD = 0.54, 95% CI = -0.05–1.12, p = 0.07; cystadenoma: WMD = 0.73, 95% CI = 0.38–1.07, p < 0.0001; other benign tumor: WMD = 0.16, 95% CI = -0.13–0.46, p = 0.28). On the other hand, lower ADC values (or a trend toward lower values) were observed for endometrioma and teratoma compared to malignant masses (endometrioma: WMD = -0.09, 95% CI = -0.47–0.29, p = 0.64; teratoma: WMD = -0.49, 95% CI = -0.85–0.12, p = 0.009). Subgroup analysis by mass property revealed higher ADC values in cystic tumor types than in solid types for both benign and malignant tumors. Significant study heterogeneity was observed. There was no notable publication bias.

Conclusions

Quantitative DWI is not a reliable diagnostic method for differentiation between benign and malignant ovarian masses. This knowledge is essential in avoiding misdiagnosis of ovarian masses.     

The Predictive Value of Golgi Protein 73 in Differentiating Benign from Malignant Liver Tumors

Introduction

In the work up of primary solid liver lesions it is essential to differentiate correctly between benign and malignant tumors, such as hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) respectively. A promising new marker to detect HCC is Golgi Protein 73 (GP73). Studies comparing patients with HCC and cirrhosis with normal controls suggested that GP73 is specific for patients with HCC; however, patients with other liver tumors were not included. We therefore studied the predictive value of GP73 in differentiating between solid benign and malignant liver tumors.

Materials and Methods

This study included 264 patients: 88 patients with HCC, 88 with hepatocellular adenoma (HCA), and 88 with focal nodal hyperplasia (FNH). A blood sample was collected from each patient to measure GP73 levels using a quantitative ELISA assay and differences in outcome between subgroups were compared. The receiver operating characteristic (ROC) curve, sensitivity and specificity of GP73 were calculated and compared to alpha-fetoprotein (AFP) levels.

Results

When comparing malignant and benign liver tumors the area under ROC was 0.701 and 0.912 for GP73 and AFP respectively. Test characteristics revealed a sensitivity of 60% for GP73 and 65% for AFP; in addition the specificity was 77% for GP73 and 96% for AFP.

Conclusion

Although the literature suggests that GP73 is a valuable serum marker in patients with HCC, the serum concentration may also be increased in patients with solid benign liver tumors. Therefore, a GP73 assay is less suitable for discriminating between primary malignant and benign tumors of the liver.     

Comparison of Dynamic and Liver-Specific Gadoxetic Acid Contrast-Enhanced MRI versus Apparent Diffusion Coefficients

Background

Hepatic lesions often present diagnostic connundrums with conventional MR techniques. Hepatobiliary phase contrast-enhanced imaging with gadoxetic acid can aid in the characterization of such lesions. However, quantitative measures describing late-phase enhancement must be assessed relative to their accuracy of hepatic lesion classification.Purpose: To compare quantitative parameters in gadoxetic acid contrast-enhanced dynamic and hepatobiliary phase imaging versus apparent diffusion coefficients in hepatic lesion characterization.

Material and Methods

57 patients with focal hepatic lesions on gadoxetic acid MR were included. Lesion enhancement at standard post-contrast time points and in the hepatobiliary phase (HB; 15 and 25 minutes post-contrast) was assessed via calculation of contrast (CR) and enhancement ratios (ER). Apparent diffusion coefficient (ADC) values were also obtained. Values for these parameters were compared among lesions and ROC analyses performed.Results: HB enhancement was greatest with FNH and adenomas. HB ER parameters but not HB CR could distinguish HCC from benign entities (0.9 ER ROC AUC versus 0.5 CR ROC AUC). There was no statistically significant difference found between the 15 and 25 minutes HB time points in detection of any lesion (p>0.4). ADC values were statistically significantly higher with hemangiomas (p<0.05) without greater accuracy in lesion detection relative to HB phase parameters.

Conclusion

Hepatobiliary phase gadoxetic acid contrast-enhanced MR characterizes focal hepatic lesions more accurately than ADC and conventional dynamic post-contrast time point enhancement parameters. ER values are generally superior to CR. No discernible benefit of 25 minute versus 15 minute delayed imaging is demonstrated.     

Characterization of Breast Tumors Using Diffusion Kurtosis Imaging (DKI)

Aim

The aim of this study was to investigate and evaluate the role of magnetic resonance (MR) diffusion kurtosis imaging (DKI) in characterizing breast lesions.

Materials and Methods

One hundred and twenty-four lesions in 103 patients (mean age: 57±14 years) were evaluated by MR DKI performed with 7 b-values of 0, 250, 500, 750, 1,000, 1,500, 2,000 s/mm² and dynamic contrast-enhanced (DCE) MR imaging. Breast lesions were histologically characterized and DKI related parameters—mean diffusivity (MD) and mean kurtosis (MK)—were measured. The MD and MK in normal fibroglandular breast tissue, benign and malignant lesions were compared by One-way analysis of variance (ANOVA) with Tukey''s multiple comparison test. Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of MD and MK in the diagnosis of breast lesions.

Results

The benign lesions (n = 42) and malignant lesions (n = 82) had mean diameters of 11.4±3.4 mm and 35.8±20.1 mm, respectively. The MK for malignant lesions (0.88±0.17) was significantly higher than that for benign lesions (0.47±0.14) (P<0.001), and, in contrast, MD for benign lesions (1.97±0.35 (10⁻³ mm²/s)) was higher than that for malignant lesions (1.20±0.31 (10⁻³ mm²/s)) (P<0.001). At a cutoff MD/MK 1.58 (10⁻³ mm²/s)/0.69, sensitivity and specificity of MD/MK for the diagnosis of malignant were 79.3%/84.2% and 92.9%/92.9%, respectively. The area under the curve (AUC) is 0.86/0.92 for MD/MK.

Conclusions

DKI could provide valuable information on the diffusion properties related to tumor microenvironment and increase diagnostic confidence of breast tumors.     

Whole-Body Diffusion-Weighted Imaging in Chronic Recurrent Multifocal Osteomyelitis in Children

Objective

Chronic recurrent multifocal osteomyelitis/ chronic non-bacterial osteomyelitis (CRMO/ CNO) is a rare auto-inflammatory disease and typically manifests in terms of musculoskeletal pain. Because of a high frequency of musculoskeletal disorders in children/ adolescents, it can be quite challenging to distinguish CRMO/ CNO from nonspecific musculosketetal pain or from malignancies. The purpose of this study was to evaluate the visibility of CRMO lesions in a whole-body diffusion-weighted imaging (WB-DWI) technique and its potential clinical value to better characterize MR-visible lesions.

Material and Methods

Whole-body imaging at 3T was performed in 16 patients (average: 13 years) with confirmed CRMO. The protocol included 2D Short Tau Inversion Recovery (STIR) imaging in coronal and axial orientation as well as diffusion-weighted imaging in axial orientation. Visibility of lesions in DWI and STIR was evaluated by two readers in consensus. The apparent diffusion coefficient (ADC) was measured for every lesion and corresponding reference locations.

Results

A total of 33 lesions (on average 2 per patient) visible in STIR and DWI images (b = 800 s/mm² and ADC maps) were included, predominantly located in the long bones. With a mean value of 1283 mm²/s in lesions, the ADC was significantly higher than in corresponding reference regions (782 mm²/s). By calculating the ratio (lesion to reference), 82% of all lesions showed a relative signal increase of 10% or higher and 76% (25 lesions) showed a signal increase of more than 15%. The median relative signal increase was 69%.

Conclusion

This study shows that WB-DWI can be reliably performed in children at 3T and predominantly, the ADC values were substantially elevated in CRMO lesions. WB-DWI in conjunction with clinical data is seen as a promising technique to distinguish benign inflammatory processes (in terms of increased ADC values) from particular malignancies.     

肿瘤/肝脏比值在~(18)F-FDG符合线路SPECT/CT显像在肺癌诊断中的价值

目的:探讨18F-FDG符合线路SPECT/CT显像在肺癌病灶的检测能力以及肿瘤/肝脏比值对肺部良恶性病灶及胸部小病灶诊断的临床价值。方法:回顾性分析2011年6月至2013年4月期间于西安交通大学第一附属医院行18F-FDG符合线路SPECT/CT显像的肺癌疑诊患者41例CT测量肺部原发病灶最大直径4.16±2.81厘米(最小直径1.3厘米,最大直径16厘米),以病理结果作为判断标准,通过t检验及接受者操作特征曲线(receiver operating characteristic,ROC)研究18F-FDG符合线路SPECT/CT显像对肺部病灶、肺及纵膈小病灶的诊断价值。结果:18F-FDG符合线路SPECT/CT显像肺部良恶性病灶的肿瘤/肌肉(T/N)、肿瘤/肝脏(T/L)比值差异均具有显著统计学意义(P0.01),T/L比值在肺部良恶性病灶和肺及纵膈最大横径小于3 cm的病灶ROC曲线的曲线下面积分别为0.857、0.810,均大于T/N比值相应的ROC曲线下面积(分别为0.825、0.760)。T/N=3.5为界值时,诊断肺部病灶的灵敏度为90%,特异度为71.4%,准确度为0.614;诊断最大横径小于3 cm病灶的灵敏度为70%,特异度为80%,准确度为0.50。T/L=2.3时诊断肺部病灶的灵敏度为80%,特异度为85.7%,准确度为0.657。T/L=1.6时诊断最大横径小于3 cm病灶的灵敏度为90%,特异度为80%,准确度为0.70。结论:T/N=3.5为界值时,对于肺部病灶及肺及最大横径小于3 cm病灶良恶性的鉴别能力较好。T/L比值对于肺部良恶性病灶和肺及纵膈最大横径小于3 cm的病灶诊断价值均高于传统常用的T/N比值,具有较高的准确性,可以良好的应用于18F-FDG符合线路SPECT/CT显像对肺癌的诊断中。     

剪切波弹性成像在乳腺实性病变良恶性鉴别中的诊断价值

目的:探讨剪切波弹性成像在乳腺实性病变良恶性鉴别中的诊断价值。方法:收集2012年3月-2013年6月于我院收治的乳腺实性病变患者54例,共65个病灶,先后给予乳腺二维超声检查与剪切波弹性成像检查,采用弹性模量值与钼靶BI-RADS分级方法诊断,比较两种方法诊断的准确性。结果:良性病灶组弹性最小、最大值以及平均值、标准差与恶性病灶组比较差异具有统计学意义(P0.05);ROC曲线分析显示,在乳腺实性病变良恶性的鉴别中,弹性最大值明显优于平弹性均值;剪切波弹性成像对乳腺实性病变良恶性鉴别的敏感度、特异度、准确度、阳性预测值、阴性预测值高于二维超声技术(P0.05)。结论:剪切波弹性成像在乳腺实性病变良恶性鉴别中具有良好的诊断价值,能够提高诊断的准确性。     

Morphometric analysis of AgNORs in thin-layer, liquid-based liver specimens

OBJECTIVE: To detect argyrophilic nucleolar organizer regions (AgNORs) in ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) liver fine needle aspiration (FNA) specimens and to define the diagnostic value of their quantitative analysis in the evaluation of hepatic lesions. STUDY DESIGN: ThinPrep liquid-based FNA biopsy specimens from 49 malignant and benign liver lesions were resampled, fixed in 95% ethanol and stained with the AgNOR technique in accordance with the 1-step colloid method. The specimens included 11 benign and 38 malignant lesions (23 poorly differentiated hepatocellular carcinomas [HCCs] and 15 poorly differentiated metastatic adenocarcinomas [MCs]). Morphometric analysis was performed using a Zeiss Axiolab microscope (Carl Zeiss GmbH, Jena, Germany) with a mechanical stage fitted with a Sony-iris CCD videocamera (Tokyo, Japan). The videocamera was connected to a Pentium III P/C (Intel Corp., Santa Clara, California, U.S.A.) loaded with the appropriate image analysis software. The measurements were performed with ImageScan software (Jandel Scientific, Erkrath, Germany). The number of AgNORs per nucleus (NN) and the total area per nucleus occupied by AgNORs (AR) were calculated semiautomatically. Statistical analysis was performed using the SPSS software package (Chicago, Illinois, U.S.A.). RESULTS: The least significant deviance test for multiple comparisons revealed that NN differed significantly between the 3 groups of samples examined (P < .0001). The mean NN values in HCCs and MCs were significantly different (P < .0001). Logistic regression model demonstrated that as NN increased, the probability of a MC diagnosis decreased (<4%). AR values were different at a statistically significant level only between benign and malignant specimens (P = .00006), not between HCCs and MCs (P = .933). CONCLUSION: Quantitative analysis of AgNORs in ThinPrep specimens could be a diagnostically useful method in liver disease.     

Characterization of Incidental Liver Lesions: Comparison of Multidetector CT versus Gd-EOB-DTPA-Enhanced MR Imaging

As a result of recent developments in imaging modalities and wide spread routine medical checkups and screening, more incidental liver lesions are found frequently on US these days. When incidental liver lesions are found on US, physicians have to make a decision whether to just follow up or to undergo additional imaging studies for lesion characterization. In order to choose the next appropriate imaging modality, the diagnostic accuracy of each imaging study needs to be considered. Therefore, we tried to compare the accuracy of contrast-enhanced multidetector CT (MDCT) and Gd-EOB-DTPA-enhanced MRI for characterization of incidental liver masses. We included 127 incidentally found focal liver lesions (94 benign and 33 malignant) from 80 patients (M∶F = 45∶35) without primary extrahepatic malignancy or chronic liver disease. Two radiologists independently reviewed Gd-EOB-DTPA-enhanced MRI and MDCT. The proportion of confident interpretations for differentiation of benign and malignant lesions and for the specific diagnosis of diseases were compared. The proportion of confident interpretations for the differentiation of benign and malignant lesions was significantly higher with EOB-MRI(94.5%–97.6%) than with MDCT (74.0%–92.9%). In terms of specific diagnosis, sensitivity and accuracy were significantly higher with EOB-MRI than with MDCT for the diagnosis of focal nodular hyperplasia (FNH) and focal eosinophilic infiltration. The diagnoses of the remaining diseases were comparable between EOB-MRI and MDCT. Hence, our results suggested that Gd-EOB-MRI may provide a higher proportion of confident interpretations than MDCT, especially for the diagnosis of incidentally found FNH and focal eosinophilic infiltration.     

Tubo-Ovarian Abscess (with/without Pseudotumor Area) Mimicking Ovarian Malignancy: Role of Diffusion-Weighted MR Imaging with Apparent Diffusion Coefficient Values

Objective

To assess the added value of diffusion-weighted magnetic resonance imaging (DWI) with apparent diffusion coefficient (ADC) values compared to MRI, for characterizing the tubo-ovarian abscesses (TOA) mimicking ovarian malignancy.

Materials and Methods

Patients with TOA (or ovarian abscess alone; n = 34) or ovarian malignancy (n = 35) who underwent DWI and MRI were retrospectively reviewed. The signal intensity of cystic and solid component of TOAs and ovarian malignant tumors on DWI and the corresponding ADC values were evaluated, as well as clinical characteristics, morphological features, MRI findings were comparatively analyzed. Receiver operating characteristic (ROC) curve analysis based on logistic regression was applied to identify different imaging characteristics between the two patient groups and assess the predictive value of combination diagnosis with area under the curve (AUC) analysis.

Results

The mean ADC value of the cystic component in TOA was significantly lower than in malignant tumors (1.04 ± 0 .41 × 10⁻³ mm²/s vs. 2.42 ± 0.38 × 10⁻³ mm²/s; p < 0.001). The mean ADC value of the enhanced solid component in 26 TOAs was 1.43 ± 0.16×10⁻³mm²/s, and 46.2% (12 TOAs; pseudotumor areas) showed significantly higher signal intensity on DW-MRI than in ovarian malignancy (mean ADC value 1.44 ± 0.20×10⁻³ mm²/s vs.1.18 ± 0.36 × 10⁻³ mm²/s; p = 0.043). The combination diagnosis of ADC value and dilated tubal structure achieved the best AUC of 0.996. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRI vs. DWI with ADC values for predicting TOA were 47.1%, 91.4%, 84.2%, 64%, and 69.6% vs. 100%, 97.1%, 97.1%, 100%, and 98.6%, respectively.

Conclusions

DW-MRI is superior to MRI in the assessment of TOA mimicking ovarian malignancy, and the ADC values aid in discriminating the pseudotumor area of TOA from the solid portion of ovarian malignancy.     

Diagnosis of Breast Masses from Dynamic Contrast-Enhanced and Diffusion-Weighted MR: A Machine Learning Approach

Purpose

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is increasingly used for breast cancer diagnosis as supplementary to conventional imaging techniques. Combining of diffusion-weighted imaging (DWI) of morphology and kinetic features from DCE-MRI to improve the discrimination power of malignant from benign breast masses is rarely reported.

Materials and Methods

The study comprised of 234 female patients with 85 benign and 149 malignant lesions. Four distinct groups of features, coupling with pathological tests, were estimated to comprehensively characterize the pictorial properties of each lesion, which was obtained by a semi-automated segmentation method. Classical machine learning scheme including feature subset selection and various classification schemes were employed to build prognostic model, which served as a foundation for evaluating the combined effects of the multi-sided features for predicting of the types of lesions. Various measurements including cross validation and receiver operating characteristics were used to quantify the diagnostic performances of each feature as well as their combination.

Results

Seven features were all found to be statistically different between the malignant and the benign groups and their combination has achieved the highest classification accuracy. The seven features include one pathological variable of age, one morphological variable of slope, three texture features of entropy, inverse difference and information correlation, one kinetic feature of SER and one DWI feature of apparent diffusion coefficient (ADC). Together with the selected diagnostic features, various classical classification schemes were used to test their discrimination power through cross validation scheme. The averaged measurements of sensitivity, specificity, AUC and accuracy are 0.85, 0.89, 90.9% and 0.93, respectively.

Conclusion

Multi-sided variables which characterize the morphological, kinetic, pathological properties and DWI measurement of ADC can dramatically improve the discriminatory power of breast lesions.     

DCE-MRI参数与肿瘤新生血管的相关性的研究

目的:研究DCE-MRI(dynamic contrast-enhanced magnetic resconance imaging,DCE-MRI)参数与肿瘤新生血管的相关性。方法:应用3.0T磁共振仪对124例乳腺肿瘤患者行DCE-MR检查,经手术病理证实恶性59例;良性65例。并计算血流动力学参数K~(trans)、K_(ep)、Ve以及ADC(apparent diffusion cofficient,ADC)值。运用Person检验分析磁共振各参数值与CD31、CD105表达的微血管密度(MVD)之间的相互关系,以及与细胞增殖Ki-67的相关性。结果:K~(trans)、K_(ep)以及ADC值在恶、良性病变、正常腺体组之间两两比较有统计学差异,K~(trans)、K_(ep)值在恶性病变组最高,高于正常组织、良性病变组(P0.05)。而Ve值正常腺体、良性病变以及正常腺体组与恶性病变组两两比较有统计学意义(P0.05),良性病变与恶性病变组比较无统计学差异(P0.05)。并且K~(trans)和K_(ep)值在浸润性导管癌和导管原位癌组明显高于不典型增生组(P0.001)。相反ADC值浸润性癌和导管原位癌低于不典型增生(P0.001)。而Ve值在各组间无统计学差异(P0.05)。另外CD105、Ki-67与磁共振参数K~(trans)、K_(ep)和ADC值之间具有相关性(P0.05,r=0.563,r=-0.566)。结论:DCE-MRI成像中K~(trans)、K_(ep)和ADC值可以定量评估乳腺癌微血管密度。     

Comparative studies of nuclear DNA content in benign and malignant thyroid lesions

Currently available data suggest that DNA aneuploidy is associated with aggressive behavior of and unfavorable prognosis in several malignant human tumors as compared with diploid malignancies. However, the diagnostic and prognostic importance of flow cytometric DNA measurements in the case of thyroid neoplasms remains controversial. Therefore, the aim of our study was to evaluate utility of DNA index (DI) and proliferative index (PI) in distinguishing benign from malignant thyroid lesions taking into account the possible influence of intra-tumor heterogeneity and tissue preparation mode on DNA flow-cytometry measurements. A retrospective study was performed on 71 paraffin-embedded specimens from 57 patients with benign and malignant thyroid pathologies: 13 colloid goitres, 12 parenchymatous goitres, 19 adenomas and 13 carcinomas. In 14 of 57 cases two separate specimens taken from different areas of the same lesion were analysed and DNA parameters were compared. Additionally, flow cytometry DNA analysis was parallelly performed on 3 adjacent but differently processed tissue sections (fresh, formalin-fixed and paraffin-embedded) taken from each of 26 surgically excised thyroid lesions. DNA content was also analysed in both fresh and formalin-fixed twin specimens of normal pig thyroid glands (N = 6). We demonstrated that all tumors diagnosed as thyroid carcinomas were associated with abnormal nuclear DNA content although aneuploidy was not found specific to malignant thyroid tumors. Aneuploid samples of benign thyroid lesions exhibited higher proliferative activity, expressed as mean PI values, than diploid ones. In carcinomas the mean PI values were significantly higher than in benign lesions, independently whether they concerned aneuploid or diploid tissues. Considering intra-tumor heterogeneity, the flow cytometric DNA parameters can be assumed as reproducible despite differences in the mode of tissue fixation and preparation for analysis.     

Differentiating Laryngeal Carcinomas from Precursor Lesions by Diffusion-Weighted Magnetic Resonance Imaging at 3.0 T: A Preliminary Study

Background

Diffusion-weighted magnetic resonance imaging (DWI) has been introduced in head and neck cancers. Due to limitations in the performance of laryngeal DWI, including the complex anatomical structure of the larynx leading to susceptibility effects, the value of DWI in differentiating benign from malignant laryngeal lesions has largely been ignored. We assessed whether a threshold for the apparent diffusion coefficient (ADC) was useful in differentiating preoperative laryngeal carcinomas from precursor lesions by turbo spin-echo (TSE) DWI and 3.0-T magnetic resonance.

Methods

We evaluated DWI and the ADC value in 33 pathologically proven laryngeal carcinomas and 17 precancerous lesions.

Results

The sensitivity, specificity, and accuracy were 81.8%, 64.7%, 76.0% by laryngostroboscopy, respectively. The sensitivity, specificity, and accuracy of conventional magnetic resonance imaging were 90.9%, 76.5%, 86.0%, respectively. Qualitative DWI analysis produced sensitivity, specificity, and accuracy values of 100.0, 88.2, and 96.0%, respectively. The ADC values were lower for patients with laryngeal carcinoma (mean 1.195±0.32×10⁻³ mm²/s) versus those with laryngeal precancerous lesions (mean 1.780±0.32×10⁻³ mm²/s; P<0.001). ROC analysis showed that the area under the curve was 0.956 and the optimum threshold for the ADC was 1.455×10⁻³ mm²/s, resulting in a sensitivity of 94.1%, a specificity of 90.9%, and an accuracy of 92.9%.

Conclusions

Despite some limitations, including the small number of laryngeal carcinomas included, DWI may detect changes in tumor size and shape before they are visible by laryngostroboscopy. The ADC values were lower for patients with laryngeal carcinoma than for those with laryngeal precancerous lesions. The proposed cutoff for the ADC may help distinguish laryngeal carcinomas from laryngeal precancerous lesions.     

Ultrasound-guided fine needle aspiration cytology of impalpable breast lesions in a rural setting. Comparison of cytology with imaging and final outcome

OBJECTIVE: To analyze the effectiveness of fine needle aspiration (FNA) cytology in a multidisciplinary setting in rural Australia and to compare the imaging (mammographic and ultrasound) appearances and cytomorphologic findings with the final outcome. STUDY DESIGN: Prospective analysis of ultrasound-guided FNA cytology results from 426 women, aged 40-86 years, with screening-detected mammographic abnormalities. Cases of microcalcification, assessed mainly by stereotactatic core biopsy, were not included in the study. The FNAs were performed at a rural breast screening and assessment program in New South Wales, Australia, over a three-year period between May 1993 and May 1996. RESULTS: Imaging, FNA and combined imaging and FNA results from 426 women were as follows. The imaging diagnoses included 176 (41%) benign, 34 (8%) probably benign, 17 (4%) equivocal, 104 (24%) suspicious and 95 (23%) malignant cases. The FNA findings showed 59 (14%) no epithelial cells seen (nondiagnostic), 175 (41%) benign, 36 (8%) atypical, 41 (10%) suspicious and 115 (27%) malignant. Combined imaging and cytologic results comprised 224 (52.6%) benign, 10 (2.3%) atypical/equivocal, 59 (13.9%) suspicious and 133 (31.2%) malignant cases. All the malignant cases, by combined assessment, had malignant histology, and all the benign cases behaved in a benign fashion. In 80% of the suspicious lesions, the histologic diagnosis was malignant, but only 10% of the atypical/equivocal lesions had malignant histology. The positive predictive value of diagnosis of malignancy by combined imaging and FNA was 100%, and the false negative rate was 0%. CONCLUSION: Despite the recent surge in the popularity of core biopsy, FNA cytology of impalpable, mammographically detected lesions, when practiced in a multidisciplinary setting, is an extremely accurate test with high sensitivity, specificity, predictive values and efficacy. FNA cytology of the breast is a well-tolerated, relatively noninvasive test with a very low risk of complications. The sensitivity and positive predictive values for malignant and suspicious mammographic categories are also very high.     

Diffusion-Weighted Imaging in 3.0 Tesla Breast MRI: Diagnostic Performance and Tumor Characterization Using Small Subregions vs. Whole Tumor Regions of Interest

Introduction

Apparent diffusion coefficient (ADC) values are increasingly reported in breast MRI. As there is no standardized method for ADC measurements, we evaluated the effect of the size of region of interest (ROI) to diagnostic utility and correlation to prognostic markers of breast cancer.

Methods

This prospective study was approved by the Institutional Ethics Board; the need for written informed consent for the retrospective analyses of the breast MRIs was waived by the Chair of the Hospital District. We compared diagnostic accuracy of ADC measurements from whole-lesion ROIs (WL-ROIs) to small subregions (S-ROIs) showing the most restricted diffusion and evaluated correlations with prognostic factors in 112 consecutive patients (mean age 56.2±11.6 years, 137 lesions) who underwent 3.0-T breast MRI.

Results

Intra- and interobserver reproducibility were substantial (κ = 0.616–0.784; Intra-Class Correlation 0.589–0.831). In receiver operating characteristics analysis, differentiation between malignant and benign lesions was excellent (area under curve 0.957–0.962, cut-off ADC values for WL-ROIs: 0.87×10⁻³ mm²s^-1; S-ROIs: 0.69×10⁻³ mm²s^-1, P<0.001). WL-ROIs/S-ROIs achieved sensitivities of 95.7%/91.3%, specificities of 89.5%/94.7%, and overall accuracies of 89.8%/94.2%. In S-ROIs, lower ADC values correlated with presence of axillary metastases (P = 0.03), high histological grade (P = 0.006), and worsened Nottingham Prognostic Index Score (P<0.05). In both ROIs, ADC values correlated with progesterone receptors and advanced stage (P<0.01), but not with HER2, estrogen receptors, or Ki-67.

Conclusions

ADC values assist in breast tumor characterization. Small ROIs were more accurate than whole-lesion ROIs and more frequently associated with prognostic factors. Cut-off values differed significantly depending on measurement procedure, which should be recognized when comparing results from the literature. Instead of using a whole lesion covering ROI, a small ROI could be advocated in diffusion-weighted imaging.     

Radiofrequency Ablation of Liver VX2 Tumor: Experimental Results with MR Diffusion-Weighted Imaging at 3.0T

Purpose

To evaluate the value of DWI in detecting the lesions of pre- and post-radiofrequency ablation (RFA) of the rabbit liver VX2 tumors.

Materials and Methods

Twenty-two New Zealand White rabbits were tested. The protocol was approved by the Committee on the Ethics of Animal Experiments. Twenty separate tumor fragments were implanted into the livers of 20 rabbits, the liver was exposed by performing midline laparotomy. 3.0T MR DWI (b = 0, 200, 400, 600, 800,1000 s/mm²) were performed 14–21 days after tumor implantation (mean, 17 days) in the 18 tumor-bearing animals. Then RFA was performed in the 18 tumor-bearing animals and in the two healthy animals. 3.0T MR DWI was performed 7–10 days after RFA (mean, 8 days). Pathology exam was performed immediately after the completion of post- RFA MR imaging. Analyzing the features of MRI and ADC values in the pre- and post- RFA lesions of the VX2 tumors, and histopathologic results were compared with imaging findings.

Results

The difference of ADC value between viable tumor and normal liver parenchyma was significant (P<.001). After RFA, when b = 200, 400, 600, 800, 1000 s/mm², the differences of ADC values of viable tumor, granulation tissue, necrosis, normal liver parenchyma were significant (P<.001). At the time the animals were sacrificed after RFA and MR imaging, histopathologic results of local viable tumors were found in 9 (50%) of the 18 treated tumors. Macroscopic viable tumors were found at the RFA sites in 3 (17%), all 3 macroscopic viable tumors were visualized at the periphery of the RFA areas.

Conclusions

3.0T MR DWI can be used to follow up the progress of the RFA lesion, it is useful in detecting different tissues after RFA, and it is valuable in the further clinical research.     

超声多技术联合在良恶性甲状腺结节鉴别诊断中的应用价值

摘要 目的：分析超声剪切波弹性成像（SWE）、超声造影（CEUS）、声触诊组织成像及定量（VTIQ）、促甲状腺激素（TSH）多技术联合在甲状腺结节良恶性鉴别诊断中的应用价值。方法：选取宁德市医院甲状腺不确定性质结节患者120例,以病理结果为金标准将其分为良性组和恶性组,分析两组SWE、CEUS、VTIQ各影像参数及术前TSH水平差异,绘制受试者工作特征曲线（ROC）评估上述技术联合对甲状腺结节良恶性的鉴别诊断价值。结果：120例患者共检出128个结节,其中良性47个,恶性81个;恶性组SWE中弹性模量值（Emax、Emin、Emean）均大于良性组（P＜0.01）;恶性组、良性组在CEUS中强化差异有显著性（P＜0.05）;VTIQ中恶性组剪切波速度（SWV）最大值、最小值、平均值均大于良性组（P＜0.01）;恶性组患者术前TSH水平高于良性组（P＜0.01）;ROC曲线分析显示,SWE、CEUS、VTIQ、TSH联合检测诊断甲状腺结节良恶性的效能最高,其灵敏度、特异度、准确度、曲线下面积（AUC）分别为85.19%、89.36%、86.72%、0.873。结论：SWE、CEUS、VTIQ、TSH联合对区分甲状腺结节良恶性有较高价值。