Patterns of peripheral enhancement in breast masses: correlation of findings on contrast medium enhanced MRI with histologic features and tumor angiogenesis

DCE-MRI Performance in Triple Negative Breast Cancers: Comparison with Non-Triple Negative Breast Cancers

BACKGROUND

Triple negative breast cancers is considered to have the worst prognosis in breast cancer. Dynamic contrast enhanced magnetic resonance imaging has been widely used in the diagnosis of breast cancer because that is more sensitive to breast cancer. However, there are few reports about the MRI characteristics of triple negative breast cancers.

OBJECTIVE

The aim of the study was to evaluate the imaging finding in triple negative breast cancers compared with non-TNBC and attempt to predict it.

METHOD

In total, 223 patients with a preoperative diagnosis of breast cancer were enrolled in the study. Dynamic contrast enhanced magnetic resonance imaging was performed before being diagnosed with breast cancer, and histopathological assessment was confirmed after biopsy or operation. The patients were divided into 2 groups based on immunohistochemical, namely the triple negative breast cancers or non-triple negative breast cancers.

RESULTS

The 2 groups demonstrated significant differences regarding the tumor size, margin, outline, burr sign, enhancement, inverted nipple(P<0.05). A multivariate logistic regression analysis was performed to further validate the association of these features, however, only margin [odds ratio (OR), 0.038; 95% confidence interval (CI), 0.014-0.100; <0.001], outline [odds ratio (OR), 0.039; 95% confidence interval (CI), 0.008-0.200; <0.001], burr sign [odds ratio (OR), 2.786; 95% confidence interval (CI), 1.225-6.333; 0.014] and enhancement [odds ratio (OR), 0.131; 95% confidence interval (CI), 0.037-0.457; P=0.001] were associated with TNBC.

CONCLUSION

The results indicated that the specific dynamic contrast enhanced magnetic resonance imaging features can be possible predictors of pathological results, with a consequent prognostic value.

What's Hot in Breast MRI

Several articles in the literature have demonstrated a promising role for breast MRI techniques that are more economic in total exam time than others when used as supplement to mammography for detection and diagnosis of breast cancer. There are many technical factors that must be considered in the shortened breast MRI protocols to cut down time of standard ones, including using optimal fat suppression, gadolinium-chelates intravascular contrast administrations for dynamic imaging with post processing subtractions and maximum intensity projections (MIP) high spatial and temporal resolution among others. Multiparametric breast MRI that includes both gadolinium-dependent, i.e., dynamic contrast-enhanced (DCE-MRI) and gadolinium-free techniques, i.e., diffusion-weighted/diffusion-tensor magnetic resonance imaging (DWI/DTI) are shown by several investigators that can provide extremely high sensitivity and specificity for detection of breast cancer. This article provides an overview of the proven indications for breast MRI including breast cancer screening for higher than average risk, determining chemotherapy induced tumor response, detecting residual tumor after incomplete surgical excision, detecting occult cancer in patients presenting with axillary node metastasis, detecting residual tumor after incomplete breast cancer surgical excision, detecting cancer when results of conventional imaging are equivocal, as well patients suspicious of having breast implant rupture. Despite having the highest sensitivity for breast cancer detection, there are pitfalls, however, secondary to false positive and false negative contrast enhancement and contrast-free MRI techniques. Awareness of the strengths and limitations of different approaches to obtain state of the art MR images of the breast will facilitate the work-up of patients with suspicious breast lesions.

BI-RADS 4 breast lesions: could multi-mode ultrasound be helpful for their diagnosis?

Background

The malignant probability of Breast Imaging Reporting and Data System (BI-RADS) 4 breast lesions is 3-94%, which is a very large span, and thus leads to a high rate of unnecessary biopsy. Therefore, the differential diagnosis of benign and malignant BI-RADS 4 breast lesions has become extremely important. Thus, in this paper, we investigated the diagnostic value of conventional ultrasonography (US), contrast-enhanced ultrasound (CEUS) and shear wave elastography (SWE) for BI-RADS 4 breast lesions, and tried to figure out a multi-mode ultrasonic method for them.

Methods

From March 2016 to May 2017, 118 breast lesions that were categorized as BI-RADS 4 lesions by US were studied with CEUS and SWE. All the lesions were confirmed by pathology via surgery or vacuum-assisted biopsy. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US, CEUS and SWE were analyzed. Then the diagnostic efficacies of US, CEUS, SWE and the combination of these modalities were compared. Logistic regression analysis was performed to identify the independent risk factors. A multi-mode method to evaluate BI-RADS 4 lesions based on the logistic regression was developed.

Results

Of the 118 BI-RADS 4 lesions, 74 lesions (62.7%) were benign and 44 lesions (37.3%) were malignant. The diagnostic sensitivity and specificity for US, US + CEUS, US + SWE, US + CEUS + SWE were 88.6% and 75.7%, 86.4% and 94.6%, 88.6% and 90.5%, 97.7% and 93.2%, respectively. The area under the ROC curve (AUC) of US + SWE + CEUS was significantly higher than that of US (P<0.0001), US + CEUS (P=0.020), but there was no significant difference between the AUC of US + SWE + CEUS and the AUC of US + SWE.

Conclusions

US + CEUS + SWE and US + SWE could significantly improve the diagnostic efficiency and accuracy of US in the diagnosis of BI-RADS 4 breast lesions.

The role of MRI in predicting Ki-67 in breast cancer: preliminary results from a prospective study

Purpose:

In the last decade contrast-enhanced magnetic resonance imaging (MRI) has gained a growing role as a complementary tool for breast cancer diagnosis. Currently the relationship between the kinetic features of a breast lesion and pathologic prognostic factors has become a popular field of research. Our aim is to verify whether breast MRI could be considered a useful tool to predict Ki-67 score, thus resulting as a breast cancer prognosis indicator.

Methods:

From June to December 2014, we enrolled patients with breast cancer who underwent preoperative dynamic contrast-enhanced MRI at the local health agency. We analyzed the time-signal intensity curves calculating the mean values of the following parameters: the basal enhancement (Ebase), the enhancement ratio (ENHratio), the maximum enhancement (Emax), and the steepest slope of the contrast enhancement curve (Smax). Scatterplots and Pearson correlation test were used to investigate the eventual associations among these parameters.

Results:

A total of 27 patients underwent breast MRI during the study period. The mean ± SD Ki-67 percentage was 27.03 ± 16.8; the mean Emax, Smax, Ebase, and ENHratio were 433.9 ± 120.2, 267.3 ± 96.8, 165.5 ± 77.1, and 187.1 ± 94.8, respectively. Scatterplots suggest a positive correlation between Ki-67 and both Emax and Smax. The correlation tests between Ki-67 and Emax, Ki-67 and Smax showed statistical significance.

Conclusions:

Our preliminary data suggest that enhancement pattern is closely linked to breast cancer proliferation, thus proving the relationship between more proliferating tumors and more rapidly enhanced lesions. This is hypothesis-generating for further studies aimed at promoting breast MRI in the early estimation of cancer prognosis and tumor in vivo response to chemotherapy.

Assessment of Tumor Vascularization: Immunohistochemical and Non-Invasive Methods

Growth of solid tumors beyond a certain mass is dependent on the vascular bed from pre-existing host vasculature. The process of angiogenesis is essential not only for primary tumor growth but also for metastasis. The number of microvessels within the invasive component of a primary tumor reflects the degree of tumor angiogenesis. At present the most widely used method to assess neovascularization is the quantitation of intratumoral microvessel density (IMD) by immunohistochemical methods in which specific markers for endothelial cells are employed. In this paper we analyze the different methods used to assess IMD, as well as their advantages and potential methodological pitfalls. Several studies have shown a close correlation between IMD, tumor growth and the occurrence of metastasis, suggesting that IMD is a prognostic indicator of clinical relevance. Furthermore, preliminary studies suggest that determination of angiogenesis may predict responsiveness to some forms of conventional anticancer therapy. Although the histological microvessel density technique is the current gold standard to characterize tumor angiogenesis, it may not be the ideal tool for clinical purposes because it needs to be performed on biopsy material and does not assess the functional pathways involved in the angiogenic activity of tumors. Non-invasive assessment of tumor vascularity is possible in vivo by means of Doppler sonography, dynamic contrast-enhanced magnetic resonance imaging (MRI) and positron emission tomography (PET). These methods may be preferable to histological assay because they are non-invasive, survey the entire tumor, reflect both anatomic and physiologic characteristics, and may be useful to monitor the activity of antiangiogenic therapies.

Correlation of MRI features and pathohistological prognostic factors in invasive ductal breast carcinoma

OBJECTIVE

The aim of this study was to correlate magnetic resonance imaging (MRI) features of invasive ductal carcinomas (IDC) with pathohistological prognostic factors. Such an association, if present, could have significant translational implications for early identification of aggressive types of breast cancer.

MATERIALS AND METHODS

One hundred and fourteen consecutive women with IDC who underwent breast MRI within one month prior to surgery were included in this retrospective study. MRI features were analyzed and then interpreted with a Göttingen score (GS) that included morphological (shape, margins, and pattern of enhancement) and kinetic characteristics (initial signal increase and post-initial behavior of the time-signal intensity curve). Histological specimens were analyzed for tumor size, axillary lymph node status, histological grade, estrogen receptors (ER), progesterone receptors (PR), HER2, and Ki-67.

RESULTS

By multivariate analysis, a smooth margin was a significant, independent predictor of a larger tumor size (p = 0.041), lymph node invasion (p = 0.013), and lower expression of ER (p = 0.022). High GS was a significant, independent predictor of a higher histological grade (p = 0.022) while round or oval shape of lesion was independent predictor of a higher PR expression (p = 0.027).

CONCLUSION

A smooth margin of breast cancer on breast MRI was able to predict positive axillary lymph nodes, larger tumor size, and lower expression of ER. Except for a higher histological grade, GS was not able to predict other unfavorable prognostic factors, probably due to the fact that smooth margins were assigned fewer points than spiculated margins.

Preoperative MRI features associated with lymphovascular invasion in node-negative invasive breast cancer: A propensity-matched analysis

PURPOSE

In node-negative disease, the presence of lymphovascular invasion (LVI) is reported to be an unfavorable prognostic factor. Thus, the aim of this study was to evaluate whether preoperative breast MRI features are associated with LVI in patients with node-negative invasive breast cancer by a propensity-matched analysis.

MATERIALS AND METHODS

Among 389 patients with node-negative invasive ductal breast cancer who had preoperative breast 3.0 Tesla MRI with precontrast T2-weighted fat-suppressed, pre- and dynamic postcontrast T1-weighted fat-suppressed sequences, 61 patients with LVI (LVI group) were matched with 183 patients without LVI (no LVI group) at a ratio of 1:3 in terms of age, histologic grade, tumor size, and hormone receptor status. Two radiologists reviewed the MRI features, following profiles of focal breast edema (peritumoral, prepectoral, subcutaneous), intratumoral T2 signal intensity, adjacent vessel sign, and increased ipsilateral whole-breast vascularity, in addition to 2013 Breast Imaging Reporting and Data System lexicon.

RESULTS

The presence of peritumoral edema (45.9% [28/61] versus 30.6% [56/183], P = 0.030) and adjacent vessel sign (82.0% [50/61] versus 68.3% [125/183], P = 0.041) was significantly associated with LVI. Prepectoral edema was also more frequently observed in the LVI group than in the no LVI group with borderline significance (26.2% [16/61] versus 15.3% [28/183], P = 0.055). In cases of nonmass enhancement, regional enhancement was more frequently found in the LVI group than in the no LVI group (60.0% [3/4] versus 5.9% [1/4], P = 0.042).

CONCLUSION

Preoperative breast MRI features may be associated with LVI in patients with node-negative invasive breast cancer.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1037-1044.

Association between dynamic contrast enhanced MRI imaging features and WHO histopathological grade in patients with invasive ductal breast cancer

The present study aimed to investigate the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and World Health Organization (WHO) histopathological grade in patients with invasive ductal breast cancer. A retrospective analysis on the results of DCE-MRI of 92 patients, who were diagnosed with invasive ductal breast cancer following surgery or biopsy, and these results were correlated with WHO histopathological grade. The statistical analysis demonstrated that the tumor size, shape and characteristics of early enhancement were associated with the WHO histopathological grade: The larger the lesion's long diameter, the higher the WHO histopathological grade; the WHO histopathological grades of round and oval masses were relatively lower, while those of lobulated and irregular masses were higher; and tumors with heterogeneous and ring-like enhancement exhibited higher WHO histopathological grades, while those of homogeneous enhancement were lower. The lesion's margin shape was not associated with the WHO histopathological grade. The present study demonstrates that features of DCE-MRI and WHO histopathological grade in patients with invasive ductal breast cancer are correlated, and these MRI features could be used to evaluate the biological behavior and prognosis of lesions.

Association of Different MRI BIRADS Descriptors With Malignancy in Non Mass-Like Breast Lesions

Background:

Several studies on the diagnostic efficacy of MRI has not real consensus for the accuracy of MRI characteristics in non mass like breast lesions, and the number of malignant lesions in different studies is insufficient.

Objectives:

In this study we aimed to analyze the diagnostic role of MRI BIRADS features for diagnosis of malignancy in non mass like breast lesions.

Patients and Methods:

All patients with positive findings (BIRADS 3, 4, 5), which had either biopsy proved pathology or follow-up MRI data at least for 12 months were included in the study. Finally, 213 breasts MRI that showed non mass like enhancing lesions among our patients were assessed in study. One experienced breast radiologist who was unaware of any clinical information or the histopathologic diagnosis evaluated all images retrospectively. The morphologic parameters evaluated consisted of distribution modifiers and pattern of internal enhancement. The kinetic enhancement parameters were assessed as showing washout, plateau, or persistent patterns. In the enhancement kinetic analysis, thew most worrisome curve type in each lesion was considered for interpretation, if it was more than 2% enhancement. We have evaluated the visual findings by comparison of the signal intensity on the first and third dynamic series. Data for the study were extracted from the breast MRI database and analyzed using SPSS version 16 statistical software.

Results:

Totally 188 patients had 213 non mass like lesions. Mean age of the patients was 44.9 ± 8.3 years (24-63). Totally 46 of lesions were malignant (21.6%). The most common BIRADS score was 4 (116; 54.5%). The most prevalent feature of distribution, internal enhancement and curve type were focal (59.2%), clumped (27.2%) and washout (34.3%). Distribution of different subgroups of MR BIRADS features was different among benign and malignant lesions (All Pvalues < 0.05). Regarding association with malignancy, odds ratio of lesions with segmental or ductal linear distribution was 3.4 (95% CI = 1.7-6.8), Clumped, Reticular and Dendritic internal enhancement was 2.5 (95% CI = 1.3-5) and wash out curve type was 5.4 (95% CI = 2.7-10.9). Sensitivity of higher MR BIRADS (4,5) for diagnosis of malignancy was 100%. Specificity of segmental or ductal linear distribution in diagnosis of malignancy was 81%. Specificity of BIRADS 5 for diagnosis of malignancy was 98%. In a multivariate logistic regression analysis for diagnosis of malignancy in which distribution, internal enhancement and curve type were considered as independent variables, distribution and curve type remained significant in the model while the internal enhancement showed a borderline P-value.

Conclusions:

Although in our study washout pattern was the most powerful indicator for malignant pathology in non mass like enhancing lesions, more studies with larger sample size needs in this regard.

Association between rim enhancement of breast cancer on dynamic contrast-enhanced MRI and patient outcome: impact of subtype

The heterogeneous nature of breast cancer is represented by three breast cancer subtypes associated with different patient outcome. However, within subtypes, variations still exist. Additional stratification is necessary for more individualized therapy. Functional tumor characteristics on dynamic contrast-enhanced (DCE)-MRI may play a role. Rim enhancement of breast cancers has been associated with unfavorable pathology characteristics in the context of outcome. However, existence of a direct link is unknown. The purpose was to retrospectively determine the association between rim enhancement on DCE-MRI and long-term patient outcome, and whether it has complementary value to subtype. Preoperative DCE-MRI was performed in 556 consecutive female patients who were eligible for breast-conserving therapy. Presence of rim enhancement was assessed. Tumor characteristics were derived from resection specimens. Patients were stratified according to subtype. Association was assessed between rim enhancement and patient, pathology and treatment characteristics, recurrence-free interval and invasive disease-free survival. Median follow-up was 84 months. Patients were stratified into ER-positive/HER2-negative (N = 416), HER2-positive (N = 75), or triple-negative (N = 65) subtypes. Rim enhancement was seen in 29.0% (N = 161/556) of tumors and was associated with higher histologic grade, negative ER-status, and triple-negative subtype. Only within triple-negative tumors, an association was seen with outcome. Recurrence was lower in non-rim-enhancing tumors (N = 1/36; 2.8%) compared to rim-enhancing tumors (N = 9/28; 32.1%) (p = 0.001). Survival was higher in non-rim-enhancing tumors (N = 34/36; 94.4%) compared to rim-enhancing tumors (N = 18/28; 64.3%) (p = 0.001). Rim enhancement on DCE-MRI is associated with long-term outcome of patients with triple-negative breast cancer and may potentially serve as a prognostic biomarker in these patients.

A rim-enhanced mass with central cystic changes on MR imaging: how to distinguish breast cancer from inflammatory breast diseases?

Objective

To evaluate the capacity of magnetic resonance imaging (MRI) to distinguish breast cancer from inflammatory breast diseases manifesting as a rim-enhanced mass with central cystic changes.

Materials and Methods

Forty cases of breast cancer and 52 of inflammatory breast diseases showing a rim-enhanced mass with central cystic changes were retrospectively reviewed. All cases underwent dynamic contrast-enhanced MRI and 31 of them underwent diffusion-weighted imaging (DWI). Morphological features, dynamic parameters and apparent diffusion coefficient (ADC) values were comparatively analyzed using univariate analysis and binary logistic regression analysis.

Results

Breast cancer had a significantly thicker wall than the inflammatory breast diseases (P<0.001) while internal enhancing septa were more common in inflammatory breast diseases (P = 0.003). On DWI, 86.7% of breast cancers demonstrate a peripheral hyperintensity whereas 93.8% of inflammatory breast diseases had a central hyperintensity (P<0.001). Compared to the inflammatory breast diseases, breast cancers had a lower ADC value for the wall (1.09×10⁻³ mm²/s vs 1.42×10⁻³ mm²/s, P<0.001) and a higher ADC value for the central part (1.94×10⁻³ mm²/s vs 1.05×10⁻³ mm²/s, P<0.001).

Conclusions

Both breast cancer and inflammatory breast diseases could present as a rim-enhanced mass with central cystic changes on MRI. Integrated analysis of the MR findings can allow for an accurate differential diagnosis.

Rim sign in breast lesions on diffusion-weighted magnetic resonance imaging: diagnostic accuracy and clinical usefulness

PURPOSE

To investigate the diagnostic accuracy and clinical usefulness of the rim sign in breast lesions observed in diffusion-weighted magnetic resonance imaging (DWI).

MATERIALS AND METHODS

The magnetic resonance imaging (MRI) findings of 98 pathologically confirmed lesions (62 malignant and 36 benign) in 84 patients were included. Five breast radiologists were asked to independently review the breast MRI results, to grade the degree of high peripheral signal, the "rim sign," in the DWI, and to confirm the mean apparent diffusion coefficient (ADCmean ) values. We analyzed the diagnostic accuracy and compared the consensus (when ≥ 4 of 5 independent reviewers agreed) results of the rim sign with the ADCmean values. Additionally, we evaluated the correlation between the dynamic contrast-enhanced (DCE)-MRI morphologic appearance and DWI rim sign.

RESULTS

According to the consensus results, the rim sign in DWI was observed on 59.7% of malignant lesions and 19.4% of benign lesions. The sensitivity, specificity, and area under the curve (AUC) value for the rim sign in DWI were 59.7%, 80.6%, and 0.701, respectively. The sensitivity, specificity, and AUC value for the ADCmean value (criteria ≤ 1.46 × 10(-3) mm(2) /sec) were 82.3%, 63.9%, and 0.731, respectively. Based on consensus, no correlation was observed between the DCE-MRI and DWI rim signs.

CONCLUSION

In DWI, a high-signal rim is a valuable morphological feature for improving specificity in DWI.

Practical dynamic contrast enhanced MRI in small animal models of cancer: data acquisition, data analysis, and interpretation

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) consists of the continuous acquisition of images before, during, and after the injection of a contrast agent. DCE-MRI allows for noninvasive evaluation of tumor parameters related to vascular perfusion and permeability and tissue volume fractions, and is frequently employed in both preclinical and clinical investigations. However, the experimental and analytical subtleties of the technique are not frequently discussed in the literature, nor are its relationships to other commonly used quantitative imaging techniques. This review aims to provide practical information on the development, implementation, and validation of a DCE-MRI study in the context of a preclinical study (though we do frequently refer to clinical studies that are related to these topics).

Diagnostic efficacy of contrast-enhanced sonography by combined qualitative and quantitative analysis in breast lesions: a comparative study with magnetic resonance imaging

OBJECTIVES

The purpose of this study was to evaluate the diagnostic efficacy of contrast-enhanced sonography for differentiation of breast lesions by combined qualitative and quantitative analyses in comparison to magnetic resonance imaging (MRI).

METHODS

Fifty-six patients with American College of Radiology Breast Imaging Reporting and Data System category 3 to 5 breast lesions on conventional sonography were evaluated by contrast-enhanced sonography and MRI. A comparative analysis of diagnostic results between contrast-enhanced sonography and MRI was conducted in light of the pathologic findings.

RESULTS

Pathologic analysis showed 26 benign and 30 malignant lesions. The predominant enhancement patterns of the benign lesions on contrast-enhanced sonography were homogeneous, centrifugal, and isoenhancement or hypoenhancement, whereas the patterns of the malignant lesions were mainly heterogeneous, centripetal, and hyperenhancement. The detection rates for perfusion defects and peripheral radial vessels in the malignant group were much higher than those in the benign group (P < .05). As to quantitative analysis, statistically significant differences were found in peak and time-to-peak values between the groups (P < .05). With pathologic findings as the reference standard, the sensitivity, specificity, and accuracy of contrast-enhanced sonography and MRI were 90.0%, 92.3%, 91.1% and 96.7%, 88.5%, and 92.9%, respectively. The two methods had a concordant rate of 87.5% (49 of 56), and the concordance test gave a value of κ = 0.75, indicating that there was high concordance in breast lesion assessment between the two diagnostic modalities.

CONCLUSIONS

Contrast-enhanced sonography provided typical enhancement patterns and valuable quantitative parameters, which showed good agreement with MRI in diagnostic efficacy and may potentially improve characterization of breast lesions.

Tumor accumulation of NIR fluorescent PEG-PLA nanoparticles: impact of particle size and human xenograft tumor model

Cancer therapies are often terminated due to serious side effects of the drugs. The cause is the nonspecific distribution of chemotherapeutic agents to both cancerous and normal cells. Therefore, drug carriers which deliver their toxic cargo specific to cancer cells are needed. Size is one key parameter for the nanoparticle accumulation in tumor tissues. In the present study the influence of the size of biodegradable nanoparticles was investigated in detail, combining in vivo and ex vivo analysis with comprehensive particle size characterizations. Polyethylene glycol-polyesters poly(lactide) block polymers were synthesized and used for the production of three defined, stable, and nontoxic near-infrared (NIR) dye-loaded nanoparticle batches. Size analysis based on asymmetrical field flow field fractionation coupled with multiangle laser light scattering and photon correlation spectroscopy (PCS) revealed narrow size distribution and permitted accurate size evaluations. Furthermore, this study demonstrates the constraints of particle size data only obtained by PCS. By the multispectral analysis of the Maestro in vivo imaging system the in vivo fate of the nanoparticles next to their accumulation in special red fluorescent DsRed2 expressing HT29 xenografts could be followed. This simultaneous imaging in addition to confocal microscopy studies revealed information about the accumulation characteristics of nanoparticles inside the tumor tissues. This knowledge was further combined with extended size-dependent fluorescence imaging studies at two different xenograft tumor types, the HT29 (colorectal carcinoma) and the A2780 (ovarian carcinoma) cell lines. The combination of two different size measurement methods allowed the characterization of the dependence of nanoparticle accumulation in the tumor on even rather small differences in the nanoparticle size. While two nanoparticle batches (111 and 141 nm in diameter) accumulated efficiently in the human xenograft tumor tissue, the slightly bigger nanoparticles (diameter 166 nm) were rapidly eliminated by the liver.

Application of Benchtop-magnetic resonance imaging in a nude mouse tumor model

Background

MRI plays a key role in the preclinical development of new drugs, diagnostics and their delivery systems. However, very high installation and running costs of existing superconducting MRI machines limit the spread of MRI. The new method of Benchtop-MRI (BT-MRI) has the potential to overcome this limitation due to much lower installation and almost no running costs. However, due to the low field strength and decreased magnet homogeneity it is questionable, whether BT-MRI can achieve sufficient image quality to provide useful information for preclinical in vivo studies. It was the aim of the current study to explore the potential of BT-MRI on tumor models in mice.

Methods

We used a prototype of an in vivo BT-MRI apparatus to visualise organs and tumors and to analyse tumor progression in nude mouse xenograft models of human testicular germ cell tumor and colon carcinoma.

Results

Subcutaneous xenografts were easily identified as relative hypointense areas in transaxial slices of NMR images. Monitoring of tumor progression evaluated by pixel extension analyses based on NMR images correlated with increasing tumor volume calculated by calliper measurement. Gd-BOPTA contrast agent injection resulted in a better differentiation between parts of the urinary tissues and organs due to fast elimination of the agent via kidneys. In addition, interior structuring of tumors could be observed. A strong contrast enhancement within a tumor was associated with a central necrotic/fibrotic area.

Conclusions

BT-MRI provides satisfactory image quality to visualize organs and tumors and to monitor tumor progression and structure in mouse models.

Two different types of ring-like enhancement on dynamic MR imaging in breast cancer: correlation with the histopathologic findings

PURPOSE

To describe two different types of "ring-like enhancement" seen on dynamic magnetic resonance imaging (MRI) of breast cancer, and compare their histopathological features.

MATERIALS AND METHODS

A total of 326 breast carcinomas in 311 patients were evaluated regarding the existence and appearance of "ring-like enhancement" in comparison to other MR imaging and histopathological findings.

RESULTS

Early peripheral enhancement (EPE) was observed in 81 of 326 lesions (24.8%) and delayed rim enhancement (DRE) in 110 (33.7%). Spiculated mass, invasive ductal carcinoma with abundant stroma, central fibrosis/necrosis, and a higher degree of fat invasion correlated with EPE (P < 0.001). DRE correlated with lobulated or round mass with a smooth border, invasive ductal carcinoma with scanty stroma, higher degrees of inflammatory change and surrounding compressed tissue, and less fat invasion (P <0.001). EPE correlated with the ratio of the peripheral to central blood vessel density (P = 0.0036) and DRE with the ratio of the peritumoral to peripheral lymph vessel density (P = 0.0298).

CONCLUSION

The appearance of two different types of ring-like enhancement on dynamic MRI in breast cancers was affected by the morphologic features, various histological factors reflecting the growth pattern of the mass, and angiogenesis and lymphangiogenesis.

MR imaging of medullary carcinoma of the breast

PURPOSE

To examine the magnetic resonance imaging (MRI) findings of medullary carcinoma of the breast and to correlate them with histopathologic features.

MATERIALS AND METHODS

Eight patients were retrospectively evaluated with pathologically confirmed medullary carcinoma of the breast. T1-weighted fat-saturated, T2-weighted fast spine echo, and gadolinium-enhanced fat-saturated fast spoiled gradient-echo images were obtained. Interpretation of the MRI findings was based on evaluation of the configuration, internal signal intensity, contrast enhancement, and type of the time-intensity curve.

RESULTS

Medullary carcinoma showed a lobular shape and a smooth margin, either homogenous or heterogeneous enhancement and delayed peripheral enhancement in the late phase on contrast-enhanced MRI, and either a plateau or washout type with rapid initial rise on the time-intensity curve of the dynamic study.

CONCLUSION

Although the MRI findings showed a close relationship with histopathologic features of medullary carcinoma, it was difficult to differentiate medullary carcinoma from other histologic types of invasive breast carcinomas.

Contrast kinetics of the malignant breast tumour—Border versus centre enhancement on dynamic midfield MRI

PURPOSE

To quantify the border versus centre enhancement of malignant breast tumours on dynamic magnetic resonance mammography.

MATERIALS AND METHODS

Fifty-two women diagnosed with primary breast cancer underwent dynamic magnetic resonance mammography (Omniscan 0.2 mmol/kg bodyweight) on a midfield scanner (0.6 T), prior to surgery. The following five variables were recorded from the border and centre regions of the tumours: Early Enhancement, Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Information on histology type, oestrogen and progesterone receptor status was collected. Statistical analysis was performed in SAS 9.1 as paired samples t-tests.

RESULTS

Fifty of 52 malignant tumours displayed a faster Early Enhancement in the border region compared to the centre (p<0.0001). Significant differences between the border and centre values were found for Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Hormone receptor positive tumours displayed an over-all highly significant difference between border and centre enhancement, whereas no significant differences for any of the five variables were recorded in neither oestrogen nor progesterone hormone receptor negative tumours.

CONCLUSION

The border/centre enhancement difference in malignant breast tumours is easily visualized on midfield dynamic magnetic resonance mammography. The dynamic behaviour is significantly correlated to histological features and receptor status of the tumours.

A wide variety of dynamic contrast-enhanced MR appearances of breast cancer: pathologic correlation study

PURPOSE

The aim of this study was to elucidate the characteristic magnetic resonance (MR) appearance of breast cancers, as well as, its variations and to investigate the pathology providing different patterns of dynamic-MR appearances.

MATERIALS AND METHODS

Fifty-two women with cancer underwent mastectomy (52 tumors resected) and had MR imaging at our institution between April 2001 and March 2004. MR images of T1WI, T2WI, dynamic-MRI and contrast-enhanced T1WI were obtained and evaluated. Dynamic-MR images were correlated with pathological findings.

RESULTS

Common MR appearance of breast cancer was a focal mass either with irregular or spiculated margins with similar signal intensity on T1WI as and similar to higher signal intensity on T2WI compared to the normal mammary gland. On static contrast-enhanced T1WI, apparent enhancement was typically observed. On dynamic MRI, tumor-rim-enhancement on an early phase image and washout enhancement pattern on dynamic images, both characteristic for breast cancer, were observed, however, the prevalence of them was relatively low, which could be explained by the variation of histopathology among breast cancer nodules.

CONCLUSION

In diagnosing breast masses on MRI, as well as the common and characteristic findings of breast cancer, the variations of MR findings and their underlying histopathology should also be considered.

Quantitative diffusion imaging in breast cancer: a clinical prospective study

PURPOSE

To study the correlation between apparent diffusion coefficient (ADC) and pathology in patients with undefined breast lesion, to validate how accurately ADC is related to histology, and to define a threshold value of ADC to distinguish malignant from benign lesions.

MATERIALS AND METHODS

Seventy-eight patients (110 lesions) were referred for positive or dubious findings. Three-dimensional fast low-angle shot (3D-FLASH) with contrast injection was applied. EPI diffusion-weighted imaging (DWI) with fat saturation was performed, and ROIs were selected on subtraction 3D-FLASH images before and after contrast injection, and copied on an ADC map. Inter- and intraobserver analyses were performed.

RESULTS

At pathology 22 lesions were benign, 65 were malignant, and 23 were excluded. The ADCs of malignant and benign lesions were statistically different. In malignant tumors the ADC was (mean +/- SEM) 0.95 +/- 0.027 x 10(-3)mm(2)/second, and in benign tumors it was 1.51 +/- 0.068 x 10(-3)mm(2)/second. According to receiver operating characteristic (ROC) curves, we found a threshold between malignant and benign lesions for highest sensitivity and specificity (both 86%) around 1.13 +/- 0.10 x 10(-3)mm(2)/second. For a threshold of 0.95 +/- 0.10 x 10(-3)mm(2)/second, specificity was 100% but sensitivity was very low. Inter- and intraobserver studies showed good reproducibility.

CONCLUSION

The ADC may help to differentiate benign and malignant lesions with good specificity, and may increase the overall specificity of breast MRI.

Correlation between numeric gadolinium-enhanced dynamic MRI ratios and prognostic factors and histologic type of breast carcinoma

OBJECTIVE

The purpose of this study was to assess the usefulness of numeric ratios from dynamic contrast-enhanced MRI in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma.

MATERIALS AND METHODS

A total of 104 patients with breast carcinoma were included in the study. Dynamic contrast-enhanced MR images were obtained every 30 seconds during the first 4.5 minutes after administration of contrast material, and peripheral contrast enhancement ratio and central contrast enhancement ratio were calculated in the early phase (1 minute after contract injection) and in the delayed phase (4 minutes after injection). Four contrast enhancement ratios were used for quantitative analysis of the following numeric ratios: early peripheral/early central, delayed peripheral/delayed central, delayed peripheral/early peripheral, and delayed central/early central. The four ratios were compared with histologic type. For invasive ductal carcinoma, the ratios were then compared with modified Scarff-Bloom-Richardson histologic grade, microvessel density, and fibrotic focus.

RESULTS

Mucinous carcinoma had significantly higher mean early peripheral/early central and delayed central/early central ratios than other types of tumors (p< 0.0001). For invasive ductal carcinoma, the mean early peripheral/early central ratio was significantly lower for modified Scarff-Bloom-Richardson grade 1 tumors than for grades 2 and 3 tumors (p < 0.0001). Early peripheral/early central ratio had a significant correlation with the ratio of peripheral to central mean microvessel density (p < 0.0001). There was also a significant difference in early peripheral/early central ratio (p < 0.0001) between tumors with a fibrotic focus and those without a fibrotic focus.

CONCLUSION

Numeric ratios obtained on gadolinium-enhanced dynamic MRI of the breast may be useful in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma: modified Scarff-Bloom-Richardson grade, microvessel density, and fibrotic focus.

The adjacent vessel on dynamic contrast-enhanced breast MRI

OBJECTIVE

The purpose of this study was to investigate whether an adjacent vessel leading to an enhancing lesion seen on subtraction images can help differentiate malignant from benign breast lesions and therefore increase the specificity of breast MRI.

MATERIALS AND METHODS

The study included 132 histologically verified lesions (71 malignant lesions, 10 pure carcinoma in situ, and 51 benign lesions) enhancing on dynamic breast MRI before biopsy. The lesions were evaluated by three radiologists in a double-blinded manner. The presence of an adjacent vessel was supposed if at least two observers voted positively.

RESULTS

Sixty-one (85.9%) of 71 malignant lesions, six (60%) of 10 carcinomas in situ, and 10 (19.6%) of 51 benign lesions were associated with an adjacent vessel, which differed significantly (p < 0.001) between benign and malignant lesions (the latter with and without including pure carcinoma in situ), leading to a positive predictive value of 85.9% (87% including pure carcinomas in situ), a negative predictive value of 80.4% (74.5% including pure carcinomas in situ), an accuracy of 83.2% (81.6% including pure carcinomas in situ), a sensitivity of 85.9% (82.7% including carcinomas in situ), and a specificity of 80.4% for this sign concerning malignancy.

CONCLUSION

The presence of an adjacent vessel seen on subtraction images promises to be a good marker for malignancy and can therefore help increase the specificity of breast MRI.

Breast MRI Using the VIBE Sequence: Clustered Ring Enhancement in the Differential Diagnosis of Lesions Showing Non-Masslike Enhancement

OBJECTIVE

The purpose of this study was to assess the frequency of a finding in which minute ring enhancements are clustered (defined as clustered ring enhancement) in lesions showing non-masslike enhancement and to evaluate the clinical usefulness of this sign, in addition to that of the BI-RADS MRI descriptors, in the differentiation between benign and malignant lesions.

MATERIALS AND METHODS

Retrospective review was performed of 61 consecutive lesions showing non-masslike enhancement. MRI was performed on a 1.5-T system using the volumetric interpolated breath-hold examination (VIBE) sequence. The kinetic parameter was visually assessed as follows: washout, plateau, and persistent.

RESULTS

The most frequent morphologic finding among the malignant lesions was heterogeneous internal enhancement (69%) (p = 0.003), followed in frequency by segmental distribution (54%) (p < 0.001); whereas, stippled internal enhancement was the most frequent finding in benign lesions (50%) (p < 0.001). The presence of clustered ring enhancement was found in 63% of the malignant lesions and only 4% of the benign lesions (p < 0.001). The features with the highest positive predictive value for malignancy were a segmental distribution (100%), clustered ring enhancement (96%), and a washout pattern (94%). The specificity of clustered ring enhancement was 96% (25/26). In cases showing focal and regional enhancement, the combination of clumped internal architecture and clustered ring enhancement showed a statistically significant association with malignant lesions (p < 0.001).

CONCLUSION

Clustered ring enhancement is thought to be a useful sign to differentiate between benign and malignant lesions, in addition to the BI-RADS MRI descriptors.

Dynamic contrast-enhanced magnetic resonance imaging as an imaging biomarker

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is being used in oncology as a noninvasive method for measuring properties of the tumor microvasculature. There is potential for DCE-MRI to be used as an imaging biomarker to measure antiangiogenic effects of cancer treatments. This article reviews the general methodology for performing DCE-MRI and discusses existing data and challenges to applying DCE-MRI for treatment response assessment in clinical trials.

Secondary breast, pancreatic, and renal involvement with non-Hodgkin's lymphoma: Imaging findings

The radiologic features in a patient with breast, pancreatic, and renal non-Hodgkin's lymphoma are presented in this paper. Although diagnosis of lymphoma is based on histologic criteria, radiologic techniques may be helpful in the evaluation and follow-up of masses in patients with lymphoma.

Rim enhancement of breast cancers on contrast-enhanced MR imaging: relationship with prognostic factors

BACKGROUND

There is little evidence regarding associations between magnetic resonance imaging (MRI) features and other important histopathological prognostic factors of breast cancer. The purpose of our study was to investigate the relationship between rim enhancement on MRI and common histopathological prognostic factors of breast cancers.

METHODS

We reviewed the contrast-enhanced MR images of 106 consecutive women with histopathologically verified invasive breast carcinomas. Three radiologists assessed the images of each lesion for the presence of rim enhancement on early and delayed images, which were classified into four patterns. Statistical analyses were performed to explore the associations of these patterns with common histopathological prognostic factors and patient age.

RESULTS

Positive ratios of lymph node metastasis and blood vessel invasion and negative ratios of hormone receptors were higher in the invasive cancers with rim enhancement than those without rim enhancement. Rim enhancement was more frequent in invasive ductal cancers with a higher histological grade and larger invasive cancers. The pattern of rim enhancement with centripetal progression showed a significantly increased risk of lymph node metastasis and was associated with a larger size of invasive lesion when compared with the other patterns. Invasive cancers with rim enhancement and little change between the early and delayed images and with centrifugal progression showed significantly less hormone receptor positivity than those without rim enhancement.

CONCLUSIONS

Rim enhancement patterns of breast cancers on contrast-enhanced MRI are related to common histopathological prognostic factors and these patterns may be valuable in the preoperative evaluation of breast cancers.

Solitary pulmonary nodules: association between signal characteristics in dynamic contrast enhanced MRI and tumor angiogenesis

PURPOSE

To estimate the association between signal characteristic of dynamic enhanced MRI using curve types and angiogenesis in solitary pulmonary nodules.

MATERIALS AND METHODS

Thirty-six patients with a solitary pulmonary nodule (SPN) ranging in size from 6 to 37 mm (median 17 mm) underwent dynamic contrast enhanced MRI with a time interval of 10 s over a total period of 4 min. Resulting from the time-intensity curves four different enhancement curve profiles (A-D) were defined: type A with strong increase followed by early washout, type B with strong increase without washout, type C with slow increase and type D without relevant increase. Maximum peak (Pmax), slope of the first bolus transit (slope) and washout were calculated. Microvessel densities (MVD) were counted at the margins and at the center of the nodules. The mean MVD of each nodule was calculated. Enhancement characteristics were correlated with MVD grouped by diagnosis and by curve types. Curve types were correlated with the score of vascular endothelial growth factor (VEGF).

RESULTS

The frequency of malignancy was 55% (20/36). Using curve types for differentiation between malignant and benign SPN, the sensitivity, specificity and accuracy were 100%, 75% and 89%, respectively. The correlation between Pmax and MVD(mean) for all nodules was moderate (r(s)=0.4, P=0.02). A relevant correlation was found between Pmax and MVD(margin) in curve type A (r(s)=0.63; P=0.04) and Pmax and MVD(mean) in curve type C (r(s)=0.86; P=0.006). No positive correlation was found between Pmax and MVD (mean, center and margin) in curve type B. No significant correlation was found for slope and washout. VEGF score correlated positively with curve types (r(s)=0.67; P<0.001).

CONCLUSION

A relevant association between perfusion curve profiles and angiogenesis was found in malignant nodules having early washout and in benign lesion with a slow increase of enhancement. In cases of strong signal increase without washout additional factors for enhancement must be considered. The use of curve profiles could allow for the estimation of the extent of VEGF.

Dynamic MR imaging of breast lesions: correlation with microvessel distribution pattern and histologic characteristics of prognosis

PURPOSE

To evaluate the association of dynamic enhancement parameters of benign and malignant breast lesions at magnetic resonance (MR) imaging with microvessel distribution and histologic prognostic tumor characteristics.

MATERIALS AND METHODS

Regional review board approval and informed consent were obtained. Surgical resection specimens of breast lesions (32 benign, 86 malignant) in 118 patients (age range, 28-86 years; mean, 58 years) who had undergone dynamic T1-weighted MR imaging of both breasts were included in the study. Different MR enhancement parameters and microvessel density (MVD) distribution were determined. In malignant lesions, TNM stage, tumor grade, proliferative activity, and hormone receptor expression were determined. Spearman correlation coefficients; Wilcoxon, Fisher exact, Kruskal Wallis, and chi(2) tests; and logistic regression analysis were used for evaluation.

RESULTS

Malignant lesions exhibited a higher ratio of microvessels in tumor periphery versus tumor center than did benign lesions (P < .0005). High vessel ratios (P = .001) and low central vessel numbers (P = .007) were associated with high tumor grade. In malignant lesions, initial enhancement ratios of periphery to center of lesion correlated with the corresponding microvessel ratios (r = 0.61). Yet, a high peripheral MVD was not associated with strong peripheral enhancement (r = -0.09). High enhancement ratios, washout rates, and early enhancement peaks were associated with unfavorable, albeit not significant, prognostic indicators. Visible rim enhancement was the most accurate prognostic enhancement criterion for estrogen receptor status (P = .007), tumor grade (P = .06), and lymph node status (P = .046). Washout was the best discriminating criterion for proliferative activity.

CONCLUSION

The different enhancement behaviors of malignant and benign breast lesions cannot be explained by MVD alone; however, a low MVD in the center of carcinoma is reflected quantitatively by a high enhancement ratio and qualitatively by rim enhancement, with an implication of adverse prognosis.

Dynamic High-Spatial-Resolution MR Imaging of Invasive Ductal Carcinoma: Influence of Histological Scirrhous Component on MR Descriptors

PURPOSE

The purpose of this study was to assess the relationship between the amount of scirrhous component in invasive ductal carcinoma and its MR characteristics.

MATERIALS AND METHODS

We retrospectively reviewed 71 consecutive patients with invasive ductal carcinoma smaller than 25 mm (average, 16.6 mm) in diameter. The scirrhous component was defined as invasive foci in small clusters of cancer cells showing desmoplasia. Invasive ductal carcinoma was subclassified into 3 groups in accordance with the amount of the scirrhous component (scirrhous component degree; SCD): SCD I (scirrhous component less than 20%), SCD II (intermediate), and SCD III (more than 80%). Dynamic magnetic resonance (MR) imaging was performed using volumetric interpolated sequence. Prior to dynamic study, T2*-weighted first-pass perfusion images were obtained before, during, and after bolus injection of 0.1 mmol Gd-DTPA/kg.

RESULTS

Twenty-eight lesions were classified as SCD I, 14 as SCD II, and 29 as SCD III. Mass margin and signal intensity loss in the perfusion study were significantly different among the 3 SCD groups (P<0.001). The kinetic patterns were significantly different among the 3 SCD groups (P=0.04), and between SCD I/II and SCD III (P=0.03). The presence of enhancing internal septations was significantly different between SCD I/II and SCD III carcinomas (P=0.05). Central enhancement was only observed in SCD I carcinoma (4%; 3/71).

CONCLUSION

The histological predominance of the scirrhous component in invasive ductal carcinoma may be one explanation for the differences in morphologic and kinetic patterns on MR imaging.

Positive and Negative Predictive Values of BI-RADS®-MRI Descriptors for Focal Breast Masses

PURPOSE

The purposes of this study were to evaluate the positive and negative predictive values of the BI-RADS-MR descriptors of focal masses and to develop an interpretation model based on the kinetic and morphologic parameters.

METHODS

Retrospective review was performed of 171 consecutive focal breast masses. MR imaging was performed on a 1.5T system using the volumetric interpolated breath-hold examination sequence (mean partition thickness, 1.2 mm; time of acquisition, 35 s). Kinetic enhancement patterns were assessed by visually comparing signal intensity on the dynamic images acquired at 60 s and 4 min (washout, plateau, and persistent).

RESULTS

There were 126 malignant and 45 benign lesions. The most frequent morphological finding among the malignant lesions was heterogeneous internal enhancement in the delayed phase (96%; P<0.001); the most frequent finding in benign lesions was smooth margin or smooth shape/margin (80 to 82%; P<0.001). The features with the highest positive predictive value for carcinoma were spiculated margin (100%), delayed central enhancement (100%), delayed enhancing internal septations (97%), and irregular shape (97%). The characteristics with the highest diagnostic accuracy for malignancy were spiculated margin (100%) and heterogeneous enhancement following washout in the smooth shape/margin group (100%). The sensitivity, specificity, and positive and negative predictive values of an interpretation model based on a combination of the morphologic characteristics and kinetic information were 99%, 89%, 96%, and 98%, respectively.

CONCLUSION

A combination of morphologic criteria, particularly lesion shape/margin and internal heterogeneity, and kinetic information is useful for differentiating benign and malignant lesions.

Interpretation of breast MRI: correlation of kinetic and morphological parameters with pathological findings

Breast MRI (magnetic resonance imaging) has emerged as a highly sensitive modality for imaging of breast tumors. Differences in MR enhancement characteristics between benign and malignant lesions are believed to reflect differences in vascularity, vessel permeability, and extracellular diffusion space. However, interpretation of breast MRI remains a challenging task. Precise MR-pathologic correlations may also lead to an improved understanding of the histological heterogeneity of breast cancers and definitions of diagnostic criteria.

Contrast-Enhanced High-Resolution MRI of Invasive Breast Cancer:Correlation with Histopathologic Subtypes

OBJECTIVE

We sought to determine whether contrast-enhanced MRI could aid in the identification of the histopathologic subtypes of invasive ductal carcinoma.

MATERIALS AND METHODS

We evaluated the contrast-enhanced MR images obtained in 62 women with invasive ductal carcinoma of no special type. The presence or absence of three distinct MRI findings-linear enhancement, a serrated border, and delayed rim enhancement-was evaluated. Classification and regression tree analyses were performed to construct the most efficient algorithm for predicting histopathologic subtype on the basis of dynamic MRI features.

RESULTS

Histopathologic subtypes of the invasive ductal carcinomas were scirrhous carcinoma in 22 patients, solid tubular carcinoma in 14, and papillotubular carcinoma in 26. A lesion with a serrated border was observed in 28 (45.2%) of the 62 patients. Delayed rim enhancement was seen in 23 (37.1%) and linear enhancement in 20 (32.3%). Scirrhous carcinomas were closely associated with a serrated border (20/22 or 90.9%, p < 0.0001). Delayed rim enhancement was frequently observed in solid tubular carcinomas (12/14 or 85.7%, p < 0.0001) but was not typically seen in scirrhous carcinomas (1/22 or 4.5%, p < 0.0001). Linear enhancement showed relatively high prevalence in papillotubular carcinomas (13/26 or 50%) and low prevalence in solid tubular carcinomas (1/22 or 7%, p < 0.02). Histopathologic subtypes of invasive breast carcinoma of no special type could be correctly identified in 47 (75.8%) of 62 lesions using the diagnostic algorithm generated by the classification and regression tree analyses.

CONCLUSION

MRI features showed a close relationship with histopathologic subtypes of invasive ductal carcinoma of no special type. Contrast-enhanced MRI can be a noninvasive diagnostic tool for histopathologic subtypes of invasive breast cancer.

Evaluation of tumor angiogenesis with contrast-enhanced dynamic magnetic resonance mammography

The goal of this research was to correlate dynamic magnetic resonance (MR) mammographic contrast enhancement and microvessel densities in breast masses. Forty-six female patients with breast masses detected by mammography and/or ultrasonography were included in the study. MR contrast enhancements of the lesions were investigated dynamically using axial three-dimensional fast low-angle shot sequences. After excisional biopsy or mastectomy, immunohistochemical staining with factor VIII-RA was performed, followed by microvessel density measurements. Contrast enhancement patterns in dynamic MR mammography were compared with microvessel density measurements using Student's t-test, Pearson's moment correlation coefficients, and one-way analysis of variance (ANOVA). Malignant lesions exhibited three different enhancement patterns: 1) a peak enhancement within 120 seconds (early phase), followed by a decrease in the delayed phase (25 cases); 2) an increase in the early phase, followed by a plateau in the delayed phase (9 cases); and 3) an increase throughout the examination without any peak (5 cases). In benign lesions, signal intensity did not exhibited a peak in five cases, whereas in two cases enhancement was increased in the early phase and made a plateau in the delayed phase. A significant correlation was found between microvessel density and the percentage of maximal signal increase following paramagnetic contrast administration (r=0.322, p<0.05). Dynamic enhancement patterns and rates of maximal signal increase predict microvessel density in breast malignancies and may possibly be used as prognostic indicators.

Hemodynamic parameters by color Doppler ultrasound and dynamic enhanced magnetic resonance imaging in palpable T1 breast cancers

Prospective study in 31 women with T1 breast cancers (24 invasive breast cancers and 7 in situ breast cancers) consisting of no vessel or a single vessel as demonstrated by color Doppler ultrasound (US), CDUS, who received dynamic enhanced magnetic resonance (eMRI). The flow parameters measured by CDUS and dynamic eMRI were statistically correlated and analyzed in distinguishing the invasive or in situ breast cancers and in predicting the axillary nodal status. All of the cancers were enhanced by dynamic eMRI; however, only 22 had color flow demonstrated by CDUS; 9 invasive cancers had metastasized to the lymph node. There was no correlation between the flow indices on CDUS and signal intensities on dynamic eMRI. Patterns of the signal-time curves of invasive and in situ cancers were statistically distinguishable and the correlation between lymph node status and peak systolic velocity was statistically significant. Hemodynamic parameters measured by CDUS and dynamic eMRI carry independent values in evaluating T1 breast cancers. With the knowledge of hemodynamic information, a more comprehensive approach to the treatment of these cancers can be achieved.

MR imaging features of breast lymphoma

Mammographic, ultrasonographic and MR imaging features in a patient with non-Hodgkin's lymphoma are reported in this paper. Mammography and ultrasonography revealed ill-defined, round masses with skin thickening. Precontrast T1W images demonstrated multiple well-defined, hypointense masses, which showed rapid rim enhancement in dynamic postcontrast sequence. The enhancement rate indicated malignant pathology. MR imaging demonstrated the extent of involvement more apparently than conventional imaging. Although, not pathognomonic for lymphoma, MR imaging may be helpful in evaluation and follow-up of breast masses in patients with previous lymphoma.

Observer variability and applicability of BI-RADS terminology for breast MR imaging: invasive carcinomas as focal masses

OBJECTIVE

The purpose of this study was to assess whether the descriptive terminology and final assessment categories of the Breast Imaging Reporting and Data System (BI-RADS) lexicon can be used for breast carcinomas detected on MR imaging and to assess the inter- and intraobserver variabilities in the use of the descriptors and final assessment categories.

MATERIALS AND METHODS

In 82 patients, 101 masses, including 68 infiltrating carcinomas and 33 benign lesions, were interpreted independently by four radiologists and described by BI-RADS terminology with respect to mass shape and margin and BI-RADS final assessment categories. The enhancement pattern of the mass was also reported. In addition, two radiologists interpreted each case twice to evaluate intraobserver variability. The final case set for analysis was the 68 infiltrating carcinomas.

RESULTS

Most of the infiltrating carcinomas were described as irregular, spiculated, and heterogeneously enhancing masses. The final impression of the 68 carcinomas was BI-RADS category 5 (highly suggestive of malignancy) in 41 (61%), category 4 (suspicious abnormality) in 24 (35%), and category 3 (probably benign) in three (4%). Enhancement pattern was heterogeneous in 40 (59%), homogeneous in 14 (21%), and rim in 14 (21%). Interobserver agreement was moderate for mass margin, shape, enhancement, and final assessment category.

CONCLUSION

This study suggests that the mammographic BI-RADS lexicon with some modifications may be applied to describe the features of infiltrating carcinoma seen on breast MR imaging.