Relation between cancer cellularity and apparent diffusion coefficient values using diffusion-weighted magnetic resonance imaging in breast cancer

PURPOSE: The purpose of this study was to examine the relation between cancer cellularity and the apparent diffusion coefficient (ADC) value using diffusion-weighted magnetic resonance imaging in breast cancer. MATERIALS AND METHODS: The subjects were 27 women who had undergone operation for breast cancer. There were 27 breast cancer lesions, 24 of which were invasive ductal carcinoma (IDC) and 3 of which were noninvasive ductal carcinoma (NIDC). RESULTS: The mean ADC values of IDC, NIDC, and normal breasts were 1.07 +/- 0.19 .10(-3), 1.42 +/- 0.17 .10(-3), and 1.96 +/- 0.21 .10(-3) mm(2)/s, respectively. The mean ADC values of IDC and NIDC were significantly different from that of normal breasts (P < 0.001 each). The mean ADC values were also significantly different between IDC and NIDC (P < 0.001). There was no correlation between the ADC value and cancer cellularity. CONCLUSION: The mean ADC values for breast cancer were significantly different from that of normal breasts. The mean ADC value for breast cancer did not significantly correlate with cancer cellularity but did correlate with histological types.     

Comparison of 3.0-and 1.5-tesla diffusion-weighted imaging in the visibility of breast cancer

Purpose The aim of this study was to compare diffusion-weighted imaging (DWI) at 3.0 T and 1.5 T by evaluating the apparent diffusion coefficient (ADC) value and visibility of breast cancer in the same patients. Materials and methods A total of 13 patients (16 lesions) with breast cancer underwent DWI at 3.0 T and 1.5 T. Tumors were classified into two groups based on the lesion size. The ADC values were measured, and visibility of the tumors was scored blindly. Results No significant difference was found for ADC values between 3.0 T and 1.5 T in either group (P > 0.05). All of the large lesions were visible clearly at both magnetic field strengths, and image scores were not different (P > 0.05). In contrast, small lesions were more clearly visible and had better image scores at 3.0 T than at 1.5 T (P < 0.001). Conclusion Small cancers were more clearly visible on DWI at 3.0 T than 1.5 T.     

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.

Diagnostic performance of diffusion-weighted magnetic resonance imaging in esophageal cancer

The purpose of this study was to assess the value of diffusion-weighted magnetic resonance imaging (DWI) in detecting esophageal cancer and assessing lymph-node status, compared with histopathological results. DWI was prospectively performed in 24 consecutive patients with esophageal cancer, using the diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) sequence. DWIBS images were fused with T2-weighted images, and independently and blindly evaluated by three board-certified radiologists, regarding primary tumor detectability and lymph-node status. Apparent diffusion coefficients (ADCs) of the primary tumor and lymph nodes were also measured. Average primary tumor detection rate was 49.4%, average patient-based sensitivity and specificity for the detection of lymph-node metastasis were 77.8 and 55.6%, and average lymph-node group-based sensitivity and specificity were 39.4 and 92.6%. There were no interobserver differences among the three readers (P < 0.0001). Mean ADC of detected primary tumors was 1.26 ± 0.29×10⁻³ mm²/s. Mean ADC of metastatic lymph nodes (1.46 ± 0.35×10⁻³ mm²/s) was significantly higher (P < 0.0001) than that of nonmetastatic lymph nodes (1.15 ± 0.24 mm²/s), but ADCs of both groups overlapped. In conclusion, this study suggests that DWI only has a limited role in detecting esophageal cancer and nodal staging.     

MR扩散成像对宫颈癌放化疗早期疗效的评价

目的：探讨MR扩散成像评价晚期宫颈癌放化疗早期疗效的价值。方法：对18例经病理证实为晚期宫颈癌并接受放化疗的患者,在治疗前和开始治疗后2周、及治疗结束后行常规MRI及DWI检查。测量治疗前和治疗后不同时间点肿瘤最大径和ADC值,按治疗后肿瘤直径的变化进行分组,分析各组治疗前和治疗后不同时间点ADC值差异。结果：治疗后2周ADC值升高,完全缓解（CR）组ADC值变化高于部分缓解（PR）组,差异具有统计学意义（P〈0.05）。结论：MR扩散成像可以作为晚期宫颈癌放化疗早期评价的指标,并可根据ADC值升高情况预测治疗效果。     

Whole-body diffusion-weighted magnetic resonance imaging

Diffusion-weighted magnetic resonance imaging (DWI) provides information on the diffusivity of water molecules in the human body. Technological advances and the development of the concept of diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) have opened the path for routine clinical whole-body DWI. Whole-body DWI allows detection and characterization of both oncological and non-oncological lesions throughout the entire body. This article reviews the basic principles of DWI and the development of whole-body DWI, illustrates its potential clinical applications, and discusses its limitations and challenges.     

Extracranial applications of diffusion-weighted magnetic resonance imaging

Diffusion-weighted MRI has become more and more popular in the last couple of years. It is already an accepted diagnostic tool for patients with acute stroke, but is more difficult to use for extracranial applications due to technical challenges mostly related to motion sensitivity and susceptibility variations (e.g., respiration and air-tissue boundaries). However, thanks to the newer technical developments, applications of body DW-MRI are starting to emerge. In this review, we aim to provide an overview of the current status of the published data on DW-MRI in extracranial applications. A short introduction to the physical background of this promising technique is provided, followed by the current status, subdivided into three main topics, the functional evaluation, tissue characterization and therapy monitoring.     

肺癌的MR全身DWI与PET成像的对照研究

目的：探讨MR DWI及PET成像在肺癌诊断及鉴别诊断中的应用价值。方法：26例临床高度怀疑为肺癌且接受了PET检查的患者行MR DWI检查,通过三维图像重组及黑白翻转技术,得到＂类PET＂图像,观察病变的形态、大小和分布,并与PET影像进行比较,在工作站上测量肺部病变的ADC值及SUV值,进行相关性分析。最终的诊断结果依据影像学检查、病理诊断和随访复查共同确定,其中肺癌19例,肺部炎性假瘤1例,慢性炎症4例,淋巴结反应性增生2例。结果：以病理结果为金标准,PET检出肺癌的敏感度为100%,特异度为57.1%;MR DWI的敏感度为94.7%,特异度为71.2%。肺癌与炎性病变的ADC值及SUV值差异均有统计学意义（P〈0.01）,肺癌病灶的ADC值与SUV值没有明显线性相关关系（r=-0.293,P〉0.05）。结论：MR DWI及PET成像对肺癌的诊断有较高的敏感度及特异度,两种方法互为补充,可为肺癌的诊断及鉴别诊断提供更多的信息。     

The use of magnetic resonance imaging in breast cancer screening

Screening mammography is a powerful tool for reducing breast cancer mortality. Mammography can often detect clinically occult, early-stage breast cancer that is amenable to successful treatment. However, mammography is not a perfect test and has lower sensitivity in young women and in those with dense breasts. Magnetic resonance imaging (MRI) has been shown to depict breast cancers that are occult to other forms of detection, including mammography. This has generated interest in the use of MRI for breast cancer screening. Although preliminary studies in highly selected populations show promise for the potential efficacy of breast cancer screening with MRI, there are many questions that should be addressed before this technique is offered to the general population.     

Comparison of diffusion-weighted images using short inversion time inversion recovery or chemical shift selective pulse as fat suppression in patients with breast cancer

Purpose  Fat suppression is essential for diffusion-weighted imaging (DWI) in the body. However, the chemical shift selective (CHESS) pulse often fails to suppress fat signals in the breast. The purpose of this study was to compare DWI using CHESS and DWI using short inversion time inversion recovery (STIR) in terms of fat suppression and the apparent diffusion coefficient (ADC) value. Materials and methods  DWI using STIR, DWI using CHESS, and contrast-enhanced T1-weighted images were obtained in 32 patients with breast carcinoma. Uniformity of fat suppression, ADC, signal intensity, and visualization of the breast tumors were evaluated. Results  In 44% (14/32) of patients there was insufficient fat suppression in the breasts on DWI using CHESS, whereas 0% was observed on DWI using STIR (P < 0.0001). The ADCs obtained for DWI using STIR were 4.3% lower than those obtained for DWI using CHESS (P < 0.02); there was a strong correlation of the ADC measurement (r = 0.93, P < 0.001). Conclusion  DWI using STIR may be excellent for fat suppression; and the ADC obtained in this sequence was well correlated with that obtained with DWI using CHESS. DWI using STIR may be useful when the fat suppression technique in DWI using CHESS does not work well.     

Updates in advanced diffusion-weighted magnetic resonance imaging techniques in the evaluation of prostate cancer

Diffusion-weighted magnetic resonance imaging (DW-MRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer. It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DW-MRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the non-mono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging (DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.     

Monitoring ankylosing spondylitis therapy by dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging

Objective The effects of different therapies on enthesitis/osteitis in active ankylosing spondylitis (AS) were evaluated by magnetic resonance imaging (MRI). The aim was to assess the role of quantitative MRI in the evaluation of AS treatment efficacy. Materials and methods Thirty patients with active spondylitis or bilateral sacroilitis were selected and followed up for 1 year. Ten of the patients were treated only with non-steroidal anti-inflammatory drugs, 10 patients additionally received at baseline an intravenous pulse of glucocorticoids and 10 patients were treated with regular infusions of infliximab. Disease activity was measured according to clinical instruments and laboratory tests. For each patient, one selected inflamed lesion was followed from baseline through control visits quantitatively by diffusion-weighted imaging (DWI) measuring the apparent diffusion coefficient (ADC) and by dynamic contrast-enhanced imaging (DCEI) with evaluation of the enhancement factor (f_enh) and enhancement gradient (g_enh). Results Clinical and quantitative MRI parameters diminished significantly with regression of the inflammatory activity. The improvement in AS was most pronounced in patients treated with infliximab; after 12 months the ADC diminished from an average of 1.31 to 0.88 × 10⁻³ mm²/s, f_enh from 1.85 to 0.60, and g_enh from 3.09 to 1.40 %/s. Conclusion Diffusion-weighted imaging and DCEI were shown to be effective in quantifying changes in inflammation in skeletal lesions during the treatment of AS, and could therefore be convenient for assessing treatment efficacy. To the best of our knowledge this is the first time DWI was used to evaluate the activity of skeletal inflammation in rheumatic diseases such as AS.     

Role of diffusion-weighted imaging as an adjunct to contrast-enhanced breast MRI in evaluating residual breast cancer following neoadjuvant chemotherapy

Objective

To investigate whether the addition of diffusion-weighted imaging (DWI) to dynamic contrast-enhanced MRI (DCE-MRI) improves diagnostic performance in predicting pathologic response and residual breast cancer size following neoadjuvant chemotherapy.

Materials and methods

A total of 78 consecutive patients who underwent preoperative breast MRI with DWI following neoadjuvant chemotherapy were enrolled. DWI was performed on a 1.5 T system with b values of 0 and 750 s/mm. or on a 3 T system with b values of 0 and 800 or 0 and 1000 s/mm. The images on DCE-MRI alone, DWI alone, and DCE-MRI plus DWI were retrospectively reviewed. We evaluated the diagnostic performances of the three MRI protocols for the detection of residual cancer. The tumor size as predicted by MRI was compared with histopathologic findings. Apparent diffusion coefficient (ADC) values were also compared between the groups with and without residual cancer.

Results

Of the 78 patients, 59 (75.6%) had residual cancer. For detection of residual cancer, DCE-MRI plus DWI had higher specificity (80.0%), accuracy (91.0%), and PPV (93.2%) than DCE-MRI or DWI alone (P = 0.004, P = 0.007, and P = 0.034, respectively). The ICC values for residual cancer size between MRI and histopathology were 0.891 for DCE-MRI plus DWI, 0.792 for DCE-MRI, and 0.773 for DWI. ADC values showed no significant differences between residual cancer and chemotherapeutic changes (P = 0.130).

Conclusions

The addition of DWI to DCE-MRI significantly improved diagnostic performance in predicting pathologic response and residual breast cancer size after neoadjuvant chemotherapy.     

Sandwich sign of Borrmann type 4 gastric cancer on diffusion-weighted magnetic resonance imaging

Objective

To assess the appearance of Borrmann type 4 (BT-4) gastric cancer on diffusion-weighted magnetic resonance imaging (DWI) and to investigate the potential of qualitative and quantitative DW images analysis to differentiate BT-4 gastric cancer from poorly distended normal stomach wall.

Materials and methods

DWI was performed on 23 patients with BT-4 gastric cancer and 23 healthy volunteers. The signal characteristics and correlated histopathological basis of the cancers on DWI were investigated. The contrast-to-noise ratios (CNR) of cancer were compared between DWI and T1WI/T2WI_. The thickness and apparent diffusion coefficient (ADC) of cancer and normal stomach wall were compared.

Results

All of the gastric cancers displayed hyperintensity compared to the nearby normal gastric wall on DWI. A three-layer sandwich sign that demonstrated high signal intensity in the inner and outer layer, and low signal intensity in the intermediate layer was observed in 69.6% of cancers on DWI. The low signal intensity represents the muscularis propria through the comparison with pathology, and it is postulated that scattering distribution of the cancer cells in this layer causes less damage and subsequently less restriction of water movement, which causes the low signal intensity on DWI. The CNR obtained with DWI was higher than that with T1WI and T2WI (P < 0.001). The mean ADC value of BT-4 gastric cancer was significantly lower than the poorly distended normal stomach wall (1.12 ± 0.23 × 10⁻³ mm²/s vs. 1.93 ± 0.22 × 10⁻³ mm²/s, P < 0.01).

Conclusion

DWI can highlight the signals of BT-4 gastric cancer which may present a characteristic three-layer sandwich sign, and ADC values are helpful in the discrimination of gastric cancer from poorly distended stomach wall.     

磁共振弥散加权成像预测食管癌移植瘤放疗反应的实验研究

目的 探讨磁共振弥散加权成像（DWI）在预测食管癌放疗反应的应用价值。方法 将人食管癌Eca-109裸鼠皮下移植瘤模型按随机数表法分为实验组（14只,接受单次剂量15 Gy 6 MV X射线照射）和对照组（10只,无治疗）,均在实验组照射前及之后的1、6、13 d行DWI检测。比较不同时间点两组表观弥散系数（ADC）值及体积差异。结果 两组ADC值在第1天均下降,在第6、13天时实验组逐渐升高,并高于照射前,而对照组持续下降,两组比较,差异有统计学意义（F=6.178、16.181、58.733,P<0.05）,且ADC值的变化率差异有统计学意义（F=9.038、12.360、35.140,P<0.05）;而照射前两组ADC值差异无统计学意义（P>0.05）。与对照组比较,移植瘤体积在照射前及照射后的前4 d差异无统计学意义（P>0.05）,从第5天开始增长明显慢于对照组（F=28.587,P<0.05）。对照组移植瘤实验前的ADC、实验后第1天的ADC与其体积的后期变化存在线性相关关系,放疗后0~24 d,r值从-0.118逐渐升高至0.896。结论 磁共振ADC值可在食管癌移植瘤受照射后早期先于形态学发生变化,并且与肿瘤后期的体积变化存在相关关系。     

Magnetic resonance imaging of breast vascularity in medial versus lateral breast cancer

Objective

Breasts with malignant tumors can demonstrate a general increased vascularity compared to the contralateral breast and a prominent blood vessel adjacent to the tumor on magnetic resonance imaging (MRI). The aim of the study was to further characterize these alterations in blood supply by location of the tumor within the breast using MRI.

Materials and methods

The study group included 105 patients who underwent breast MRI for suspicion of a malignancy over a 2-year period. Fifty-one had pathologically verified malignant tumors (study group), 11 had pathologically verified benign lesions (control), and 43 had negative scans (control). The malignant lesions were distinguished by location, medial or lateral, within the breast. Origin of the vascular supply and vessel diameter was recorded in a blinded manner. When available, MRI scans performed 2 years after treatment were reviewed as well.

Results

Of the 24 medial malignant tumors, 21 (87%) had a predominantly medial vascular supply and 3 (13%), a predominantly lateral supply; of the 23 lateral tumors, 11 (48%) had a predominantly medial vascular supply and 8 (35%), a predominantly lateral supply (p = 0.03). In 4 cases, no dominant vessel was noted. Maximum vessel diameter was 3.6 ± 1.1 mm in the patients with malignancy and 2.6 ± 0.8 mm in the controls (p < 0.0005). General increased vascularity was demonstrated in 91% of the medial tumor subgroup and 83% of the lateral tumor subgroup, as opposed to 36-37% in the control groups (p < 0.0005). Follow-up MRI, performed in 8 patients in the malignant-tumor group after treatment, revealed a considerable decrease in the prominent vessels, to a size close to that of the controls.

Conclusion

Breasts with malignant tumors are characterized by an altered general vascular supply, a prominent feeding vessel, and increased regional vascularity. Both the presence and location of the tumor affect the vascular supply. The vascular change apparently diminishes after treatment, although this finding requires further investigation in a larger sample.     

磁共振扩散加权成像在乳腺病变诊断中的应用

目的：探讨单纯磁共振扩散加权成像对诊断乳腺病变的临床应用价值。方法：对临床拟诊为乳腺肿块的37例患者行磁共振扩散加权成像检查,并获得病理证实,其中良性病灶18个,恶性病灶19个。描记扩散图像上病变的兴趣区,由软件计算获得表观扩散系数（ADC）值。对获取数据进行统计分析,采用t检验对良性和恶性病变的ADC值进行比较。结果：12例良性病变在DWI上呈等信号或高信号,但ADC值升高或下降不明显,6例良性病变DWI上呈高信号,ADC值明显下降;19例恶性肿瘤DWI上呈高信号,ADC值明显下降。良性病变组ADC值为（1.474±0.441）×10^-3mm^2/s,恶性病变组ADC值为（1.082±0.160）×10^-3mm^2/s,两者间差异有显著性意义（P=0.002）。结论：MR扩散加权成像ADC值测量在乳腺病变定性诊断中有一定的辅助诊断价值。     

The role of diffusion-weighted imaging and the apparent diffusion coefficient (ADC) values for breast tumors.

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89+/-0.18 x 10(-3)mm(2)/second) and DCIS (1.17+/-0.18 x 10(-3)mm(2)/ second) are significantly lower than those of the benign lesions (1.41+/-0.56 x 10(-3)mm(2)/second) and the normal fibroglandular tissue (1.51+/-0.29 x 10(-3)mm(2)/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.     

Abdominal applications of diffusion-weighted magnetic resonance imaging: Where do we stand

Diffusion-weighted imaging (DWI) is one of the magnetic resonance imaging (MRI) sequences providing qualitative as well as quantitative information at a cellular level. It has been widely used for various applications in the central nervous system. Over the past decade, various extracranial applications of DWI have been increasingly explored, as it may detect changes even before signal alterations or morphological abnormalities become apparent on other pulse sequences. Initial results from abdominal MRI applications are promising, particularly in oncological settings and for the detection of abscesses. The purpose of this article is to describe the clinically relevant basic concepts of DWI, techniques to perform abdominal DWI, its analysis and applications in abdominal visceral MR imaging, in addition to a brief overview of whole body DWI MRI.     

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.