The significance of added ADC value to conventional MR imaging in differentiation between benign and malignant ovarian neoplasms

Purpose

To highlight the role of ADC value measurement in differentiating benign from malignant ovarian tumors.

Materials and methods

Twenty patients with ovarian neoplasms underwent conventional MRI including ADC value calculation before surgery. Retrospective analysis of the pathological specimen with lesion morphology, signal characteristics, enhancement criteria and correlation with the appearance at DWI followed by ADC value measurement were obtained.

Results

Twenty patients with ovarian mass lesions were included. They were divided into purely solid, purely cystic and complex solid/cystic lesions. All solid malignant lesions showed diffusion restriction as well as the wall and septations of most malignant cystic lesion however, except one case. All benign lesions did not display diffusion restriction in DWI. The best cut off value of ADC to discriminate between benign and malignant lesions was 0.9 with specificity of 100%, sensitivity of 88.9%, NPV of 75%, PPV of 100% and accuracy of 91.7%.

Conclusion

Addition of ADC value measurement to conventional MRI increases its specificity from 78.6% to 85.7% which could be useful in differentiating benign from malignant lesions.     

Role of DW-MRI and ADC value in monitoring therapy of head and neck squamous cell carcinoma

Aim

To evaluate role of DW-MRI and ADC value in monitoring therapy of head and neck squamous cell carcinoma (HNSCC).

Diffusion weighted (DW) MRI role in characterization of breast lesions using absolute and normalized ADC values

Introduction

Diffusion-weighted imaging (DWI) is a modality that depicts the diffusivity of water molecules. This technique has the potential to play an adjunct role to conventional and dynamic MRI in the assessment of breast tissue.

Combined apparent diffusion coefficient value (ADC) and 1H magnetic resonance spectroscopy (MRS) in breast lesions: Benefits and limitations

Objective

This study aimed to assess the diagnostic value of a combined imaging protocol of diffusion-weighted MRI, apparent diffusion coefficient (ADC) values, and MR spectroscopy(MRS) in discriminating benign and malignant breast lesions.

Characterization of orbital masses by diffusion-weighted Magnetic Resonance Imaging (DWI) and Apparent Diffusion Coefficient (ADC) value

Objective

To assess DWI and ADC value in characterization of orbital masses (differentiation of benign, inflammatory and malignant orbital masses).

Diffusion-weighted MRI in prostatic lesions: Diagnostic performance of normalized ADC using normal peripheral prostatic zone as a reference

Aim of study

Evaluate the potential value of the normal peripheral zone as a reference organ to normalize prostatic lesion apparent diffusion coefficient (ADC) to improve its evaluation of prostatic lesions.

The utility of DW-MRI in the diagnosis of pancreatic focal lesions

Background

Early diagnosis is crucial in management of pancreatic malignancy. DWMRI could be used in differentiating pancreatic lesions and judge about tumor aggressiveness.

DWI及ADC值在肝脏弥漫性疾病诊断中的应用价值

目的:探讨肝脏常见弥漫性疾病的ADC值及DWI上信号强度与相应血供相关性。方法:共110例(19例肝硬化癌变结节、20例肝转移性肿瘤、35例海绵状血管瘤和36例肝囊肿)弥漫性肝占位进行磁共振扫描并计算感兴趣区ADC值、信号强度及增强率。结果:癌变结节与DN及正常肝组织间ADC值相比明显高于后两者,P<0.05。肝囊肿、海绵状血管瘤、肝硬化癌变结节及转移性肝癌在DWI上均为明显高信号。结论:DWI及ADC值对于鉴别弥漫分布的肝脏恶性实质肿块与肝硬化再生结节及良性富水肿块(血管瘤及囊肿)有重要的诊断价值,尤其是在弥漫分布的肝硬化再生结节中发现癌变结节,有其重大的临床意义。     

DWI in breast MRI: Role of ADC value to determine diagnosis between recurrent tumor and surgical scar in operated patients

Introduction

Purpose of our study is to evaluate the role of the apparent diffusion coefficient (ADC) in the diagnosis of recurrent tumor on the scar in patients operated for breast cancer. Assess, therefore, the weight of diagnostic diffusion echo-planar sequence, in association with the morphological and dynamic sequences in the diagnosis of tumor recurrence versus surgical scar.

Materials and methods

From September 2007 to March 2009, 72 patients operated for breast cancer with suspected recurrence on the scar were consecutively subjected to magnetic resonance imaging (MRI), including use of a diffusion sequence. All patients with pathological enhancement in the scar were then subjected to histological typing. MRI was considered negative in the absence of areas of suspicious enhancement. In all cases it was measured the ADC value in the scar area or in the area with pathological enhancement. The ADC values were compared with MRI findings and histological results obtained.

Results

26 cases were positive/doubtful at MRI and then subjected to histological typing: of these recurrences were 20 and benign were 6. 46 cases were judged negative at MRI and therefore not sent to cyto-histology. The average ADC value of recurrences was statistically lower of scarring (p < 0.001).

Conclusions

ADC value can be a specific parameter in differential diagnosis between recurrence and scar. The diffusion sequence, in association with the morphological and dynamic sequences, can be considered a promising tool for the surgical indication in suspected recurrence of breast cancer.     

磁共振扩散加权成像在直肠肿瘤性病变诊断中的价值

目的：通过对不同类型直肠肿瘤病例DWI图像分析和ADC值的测量探讨扩散加权成像对直肠肿瘤性病变的诊断价值。方法比较8例直肠腺瘤,30例中分化腺癌,6例低分化腺癌,7例黏液腺癌,6例淋巴瘤及5例间质瘤的ADC值的差异。结果①直肠淋巴瘤的ADC值明显低于直肠癌、直肠腺瘤,差异有统计学意义（ P＜0．05）,淋巴瘤与间质瘤之间差异无统计学意义（ P ＞0．05）;②直肠腺瘤ADC值低于粘液腺癌（ P ＜0．05）,与间质瘤、腺癌之间差异无统计学意义（ P＞0．05）;③间质瘤 ADC值低于粘液腺癌（ P ＜0．05）,与淋巴瘤、腺癌、腺瘤之间差异无统计学意义（ P ＞0.05）;④粘液腺癌ADC值高于中分化腺癌（ P ＜0．05）,与低分化腺癌之间差异无统计学意义（ P ＞0．05）,中分化、低分化腺癌之间差异无统计学意义（ P ＞0．05）。结论扩散加权成像对不同类型直肠肿瘤、不同类别的直肠腺癌具有一定的鉴别诊断价值,联合MR常规扫描可提高诊断效能。     

The added value of qualitative and quantitative diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating benign from malignant breast lesions

Objective

To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) with calculation of the apparent diffusion coefficient (ADC) value in characterizing benign and malignant breast lesions.

探讨双b值对比法在肝脏局灶性病变诊断中的作用

目的：探讨双b值对比法在肝脏局灶性病变诊断中的价值.方法：回顾性分析108例行肝脏MRI平扫及动态增强扫描患者的病例（肝癌44例.转移瘤4例,血管瘤40例,囊肿18例,局灶性结节增生2例）,分为良恶性两组（恶性组48例,A组;良性组60例,B组）.均行b值为500和800 s/mm2的DWI扫描,测量肝脏病变的信号强度值,计算相对信号比R500、R800（R=病灶信号/背景信号）,观察不同b值时病变的信号变化情况△R（△R=R800-R500）.采用X2检验分析采用△R值诊断良恶性病变与病理结果的一致性.结果：△R≥0.25有42例（PA组）,△R〈0.25（PB组）有66例,其中PA中有4个为良性病变（均为血管瘤）,PB中有10个为恶性病变（2个转移瘤,8个肝癌）,差异无统计学意义（X2=1.786,P〉0.05）.结论：双b值对比法在肝脏局灶性病变的定性诊断中具有可行性.     

DWI在肝脏占位病变诊断和疗效评估中的应用价值

弥散加权成像（diffusion weighted imaging,DWI）是一种能反映活体水分子弥散特性的功能成像技术,能提供反映细胞水平组织改变和肿瘤细胞构成及细胞膜完整性的重要信息。MRI的技术进步使DWI在腹部应用成为现实。现就DWI在肝脏占位病变诊断和疗效评估中的应用现状和面临的困难及发展方向予以综述。     

Usefulness of apparent diffusion coefficient value and proton magnetic resonance spectroscopy as a noninvasive techniques in recurrent cerebral gliomas

Objective

Conventional MRI does not provide sufficient information to differentiate post-radiotherapy necrosis from brain tumor recurrence, recent studies have investigated the use of more advanced imaging modalities that are able to differentiate between the two entities.

Correlation of measurements from diffusion weighted MR imaging and FDG PET/CT in GIST patients: ADC versus SUV

Purpose

We investigated the correlation relationship between ADCs measured by MRI and SUVs measured by PET/CT of lesions on GIST (gastrointestinal stromal tumor) patients to verify if MR is able to replace or serve as an alternative to PET/CT in GIST staging and treatment monitoring.

Materials and methods

Between September 2010 and January 2011, five patients with histologically proven metastatic GIST in Queen Mary Hospital, Hong Kong were enrolled into our study. All patients underwent both MRI and PET/CT scans at prognosis. Pearson's correlations of twenty-nine lesions were conducted between 5 pairs of ADCs and SUVs values.

Results

Lesions in the liver, peritoneum or bowel loops were found by PET/CT and no extra-abdominal lesion was identified. All twenty-nine lesions are identifiable by MRI with sensitivity of 100%. Significant inverse correlation were found between ADC_mean and SUV_mean (P = 0.006), ADC_mean and SUV_max (P = 0.010), ADC_min and SUV_max (P = 0.014), ADC_min and SUV_mean (P = 0.026), rADC_min and rSUV_max (P = 0.047).

Conclusion

DWI is comparable to PET/CT in visually detecting the GIST lesions’ location. Significant inverse correlations were found between ADCs from DWIBS and SUVs from PET/CT on data of GIST patients. This finding demonstrates that DWI is potentially capable of offering similar information for diagnosis and treatment response evaluating in GIST's patients as PET/CT does. Furthermore, ADC_min, which is determined by single pixel, is not as reliable as ADC_mean, which is weighted average value of the whole lesion volume.     

3T diffusion-weighted MRI in the response assessment of colorectal liver metastases after chemotherapy: Correlation between ADC value and histological tumour regression grading

PurposeThe purpose of the study was to correlate the apparent diffusion coefficient (ADC) values of diffusion-weighted MR imaging (DW-MRI) by 3T device with the histological tumour regression grading (TRG) analysis of colorectal liver metastases after preoperative chemotherapy.Materials and methodsOur study included thirty-five patients with colorectal liver metastases who had undergone MRI by 3T device (GE DISCOVERY MR750; GE Healthcare) after preoperative chemotherapy. DW-MRI was performed using a single-shot spin-echo echo-planar sequence with multiple b-values (0, 150, 500, 1000, 1500 s/mm²), thus obtaining an ADC map. For each liver lesion (more than 1 cm in diameter) the fitted ADC values were calculated by two radiologists in conference and three ROIs were drawn: around the entire tumour (ADC_e), at the tumour periphery (ADC_p) and at the tumour center (ADC_c). All ADC values were correlated with histopathological findings after surgery. Hepatic metastases were pathologically classified into five groups on the basis of TRG. Statistical analysis was performed on a per-lesion basis utilizing the one-way analysis of variance (ANOVA). This retrospective study was approved by our institutional review board; written informed consent was obtained from all patients.ResultsA total of 106 colorectal liver metastases were included for image analysis. TRG1, TRG2, TRG3, TRG4 and TRG5 were observed in 4, 14, 36, 35 and 17 lesions, respectively. ADC_e and ADC_p values were significantly higher in lesions classified as TRG1 (2.40 ± 0.12 × 10⁻⁹ m²/s and 2.28 ± 0.26 × 10⁻⁹ m²/s, respectively) and as TRG2 (1.40 ± 0.31 × 10⁻⁹ m²/s and 1.44 ± 0.35 × 10⁻⁹ m²/s), compared to TRG3 (1.16 ± 0.13 × 10⁻⁹ m²/s and 1.01 ± 0.18 × 10⁻⁹ m²/s), TRG4 (1.10 ± 0.26 × 10⁻⁹ m²/s and 0.97 ± 0.24 × 10⁻⁹ m²/s), and TRG5 (0.93 ± 0.17 × 10⁻⁹ m²/s and 0.82 ± 0.28 × 10⁻⁹ m²/s). ADC_e, ADC_p and ADC_c values were significantly different in TRG classes (p < 0.0001). Statistical correlations were found between the ADC_e, ADC_p, ADC_c values and the TRG classes (Spearman correlation coefficient were −0.568, −0.542 and −0.554, respectively).ConclusionOur study showed a significant correlation between ADC values of 3T DW-MRI and histological TRG of colorectal liver metastases after preoperative chemotherapy.     

兔VX2肝移植瘤TACE治疗前后ADC值与细胞密度的相关性研究

目的：探讨兔VX2肝移植瘤模型TACE治疗前后磁共振扩散加权成像的ADC值与细胞密度的相关性研究。方法：建立兔VX2肝移植瘤动物模型,并随机分为对照组（n=10）和TACE组（n=10）。接种后用二维超声监测肿瘤生长至1～2cm大小,对照组经肝动脉插管给予生理盐水10ml;TACE组给予超液化碘油2mg/kg和阿霉素2mg／kg。介入术前和术后第7天（处死动物前）行DWI检查,观察介入治疗前后肿瘤的磁共振信号及表观扩散系数（ADC值）变化情况。据常规HE染色计算细胞密度,分析肿瘤治疗前后的ADC值和细胞密度的变化及其相关性。结果：对照组不同b值所对应正常肝组织的ADC值明显高于肿瘤组织的ADC值（P〈0．05）,对照组在注人生理盐水前后的ADC值差别无统计学意义（P〉0．05）,肿瘤组织的ADC值与细胞密度呈负相关关系（P〈0．05）。TACE组介入治疗前ADC值高于治疗后的ADC值,差别有统计学意义（P〈0．05）,肿瘤TACE术后ADC值与细胞密度存在负相关性（P〈0．05）,且介入术后TACE组肿瘤细胞密度较对照组降低（P〈0．05）。结论：肿瘤组织与正常肝脏ADC值存在显著差异,ADC值能反映出肿瘤治疗前后组织微观结构的改变,可用于评估肿瘤增殖情况及治疗疗效。     

Diffusion-weighted imaging of the liver: optimizing b value for the detection and characterization of benign and malignant hepatic lesions

PURPOSE: To determine the optimal b values required for diffusion-weighted (DW) imaging of the liver in the detection and characterization of benign and malignant hepatic lesions. MATERIALS AND METHODS: MR images obtained in 76 patients including 28 malignant hepatic lesions (21 hepatocellular carcinomas and 7 metastases) and 27 benign lesions (12 hemangiomas and 15 cysts) were reviewed. DW-echo planner images (EPIs; b values with 100, 200, 400, and 800 s/mm2) were reviewed solely first, and then with T2-weighted EPIs (b=0 s/mm2). RESULTS: Sensitivity for malignant lesions (74%) was highest on DW-EPIs with b value of 100 s/mm2 and T2-weighted EPIs combined (P<0.05), and sensitivity for benign lesions (87%) was highest on DW-EPIs with b value of 800 s/mm2 and T2-weighted EPIs (P<0.05). Specificities were comparably high for all sequences. The Az values for malignant lesions were 0.94, 0.90, 0.87, and 0.89, and those for benign lesions were 0.91, 0.89, 0.87, and 0.94 on DW-EPIs with b values of 100, 200, 400, and 800 and T2-weighted EPIs combined, respectively. Hepatic cysts were clearly distinguished with the cutoff ADC value of 2.5x10(-3) mm2/s using a b value of 400 s/mm2 or greater. CONCLUSION: DW-EPIs with middle b values were not required in the detection and characterization of benign and malignant hepatic lesions.     

磁共振ADC值联合血液生化学指标诊断肝纤维化的临床初探

目的探讨磁共振表观扩散系数(ADC)值联合血液生化学指标诊断肝纤维化的临床价值。资料与方法利用扩散成像技术检测41例慢性肝病患者磁共振ADC值(b=600s/mm2),同时测量透明质酸(HA)并计算肝纤维化诊断预测模型Forns和APRI指数。以肝纤维化病理分期作为金标准,应用受试者工作特征(ROC)曲线分析以上指标诊断肝纤维化的价值。用Logistic回归综合两指标信息,根据ROC曲线确定诊断界值,分析其诊断肝纤维化的价值。结果在判断S≥2肝纤维化时,ADC值、HA、Forns和APRI的曲线下面积(Az)分别为0.88、0.80、0.72和0.76;在判断S≥3肝纤维化时,Az分别为0.93、0.84、0.77和0.74。而在判断S≥2肝纤维化时ADC+HA、ADC+Forns和ADC+APRI两两联合诊断时的Az分别为0.93、0.93和0.92;在判断S≥3肝纤维化时,Az分别为0.96、0.95和0.94,且Logistic回归方法的诊断敏感性和特异性比单个指标诊断均有所提高。结论ADC值与血液生化学多指标联合建立Logistic回归模型,和单独检测相比诊断准确性提高,可供临床参考。     

Diffusion-weighted echo-planar MR imaging and ADC mapping in the differential diagnosis of ovarian cystic masses: usefulness of detecting keratinoid substances in mature cystic teratomas

PURPOSE: To elucidate whether apparent diffusion coefficient (ADC) values calculated from echo-planar diffusion-weighted MR imaging (EPDWI) are useful in the differential diagnosis of ovarian cystic masses. MATERIALS AND METHODS: EPDWI was performed in 131 patients with ovarian cystic masses (54 mature cystic teratomas, 35 endometrial cysts, four other benign cysts, 14 benign neoplasms, and 24 malignant neoplasms). The areas of the highest signal intensity on EPDWI (b = 1000 seconds/mm(2)) and the lowest ADC values within the cystic component were evaluated. RESULTS: On qualitative and quantitative analyses, mature cystic teratomas tended to show higher signal intensity and had areas of lower ADC values than endometrial cysts and other benign and malignant neoplasms (P < .005). In vitro scanning of the cystic contents of mature cystic teratomas confirmed that high signal on DWI or low ADC value was attributable to the keratinoid substance within the tumors. The difference in ADC between malignant and benign lesions were significant when mature cystic teratomas and endometrial cysts were included, but was not significant when they were excluded. CONCLUSION: The ADC value may add useful information to the differential diagnosis of ovarian cystic masses in limited populations, such as those with mature cystic teratomas with a small amount of fat.