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. J. Magn. Reson. Imaging 2008;28:1435–1443. © 2008 Wiley‐Liss, Inc.     

Enhanced mass on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Purpose

To evaluate the diagnostic accuracy of a combination of dynamic contrast‐enhanced MR imaging (DCE‐MRI) and diffusion‐weighted MR imaging (DWI) in characterization of enhanced mass on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy.

Materials and Methods

We analyzed consecutive breast MR images in 270 patients; however, 13 lesions in 93 patients were excluded based on our criteria. We analyzed tumor size, shape, margin, internal mass enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators of malignancy and calculate a predictive probability for malignancy. We added the corresponding categories to these prediction probabilities for malignancy and calculated diagnostic accuracy when we consider category 4b, 4c, and 5 lesions as malignant and category 4a, 3, and 2 lesions as benign. In a validation study, 75 enhancing lesions in 71 patients were examined consecutively.

Results

Irregular margin, heterogeneous internal enhancement, rim enhancement, plateau time–intensity curve (TIC) pattern, and washout TIC pattern were the strongest indicators of malignancy as well as past studies, and ADC values less than 1.1 × 10^?3 mm²/s were also the strongest indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 92% (56/61), 86% (12/14), 97% (56/58), 71% (12/17), and 91% (68/75), respectively.

Conclusion

The combination of DWI and DCE‐MRI could produce high diagnostic accuracy in the characterization of enhanced mass on breast MR imaging. J. Magn. Reson. Imaging 2008;28:1157–1165. © 2008 Wiley‐Liss, Inc.

     

Non-mass-like enhancement on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Purpose

To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of lesions showing non-mass-like enhancement on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy.

Materials and methods

We analyzed consecutive MR images in 45 lesions showing non-mass like enhancement in 41 patients. We analyzed lesion size, distribution, internal enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators for malignancy. In a validation study, 22 non-mass-like enhancement lesions in 21 patients were examined. We calculated diagnostic accuracy when we presume category 4b, 4c, and 5 lesions as malignant or high to moderate suspicion for malignancy, and category 4a and 3 as low suspicion for malignancy or benign.

Results

Segmental distribution (P = 0.018), clumped internal enhancement (P = 0.005), and ADC less than 1.3 × 10⁻³ mm²/s (P = 0.047) were the strongest MR indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87% (13/15), 86% (6/7), 93% (13/14), 75% (6/8) and 86% (19/22), respectively.

Conclusion

The combination of DCE-MRI and DWI showed high diagnostic accuracy in characterization of non-mass-like enhancement lesions on breast MR images.     

Quantification of background enhancement in breast magnetic resonance imaging

Purpose:

To present a novel technique for measuring tissue enhancement in breast fibroglandular tissue regions on contrast‐enhanced breast magnetic resonance imaging (MRI) aimed at quantifying the enhancement of breast parenchyma, also known as “background enhancement.”

Materials and Methods:

Our quantitative method for measuring breast MRI background enhancement was evaluated in a population of 16 healthy volunteers. We also demonstrate the use of our new technique in the case study of one subject classified as high risk for developing breast cancer who underwent 3 months of tamoxifen therapy.

Results:

We obtained quantitative measures of background enhancement in all cases. The high‐risk patient exhibited a 37% mean reduction in background enhancement with treatment.

Conclusion:

Our quantitative method is a robust and promising tool that may allow investigators to quantify and document the potential adverse effect of background enhancement on diagnostic accuracy in larger populations. J. Magn. Reson. Imaging 2011;33:1229–1234. © 2011 Wiley‐Liss, Inc.     

DCE-MRI和DWI对乳腺腺病和乳腺癌的诊断价值

目的 探讨动态增强磁共振成像(DCE-MRI)和扩散加权成像(DWI)对乳腺腺病和乳腺癌的诊断价值.方法 回顾性分析手术后病理证实的30例乳腺腺病和45例乳腺癌的MRI影像资料,包括病灶的形状、边缘、强化方式、T2WI信号特点、时间-信号强度曲线(TIC)类型、早期强化率(EER)、达峰时间、背景强化程度及病灶的表观扩散系数(ADC)值.结果 在形态学特征中,乳腺癌多表现为边缘不规则,伴或不伴有毛刺,差异有统计学意义(P=0.002);同时多表现为不均匀强化,差异有统计学意义(P=0.009).在动态强化特征上,乳腺癌多表现为TIC流出型,EER多表现为快速流入,达峰时间多在2 min以内,以上差异均有统计学意义(P<0.001).在ADC值上,乳腺癌为(1.03±0.24)×10-3mm2/s,低于乳腺腺病的(1.34±0.30)×10-3mm2/s,差异有统计学意义(P<0.001).乳腺腺病和乳腺癌的形状特点、T2WI信号特点、背景强化程度比较差异无统计学意义(P>0.05).结论 DCE-MRI和DWI联合应用对于鉴别诊断乳腺腺病和乳腺癌具有重要的价值.     

Kinetic assessment of breast tumors using high spatial resolution signal enhancement ratio (SER) imaging.

The goal of this study was to investigate the relationship between an empirical contrast kinetic parameter, the signal enhancement ratio (SER), for three-timepoint, high spatial resolution contrast-enhanced (CE) MRI, and a commonly analyzed pharmacokinetic parameter, kep, using dynamic high temporal resolution CE-MRI. Computer simulation was performed to investigate: 1) the relationship between the SER and the contrast agent concentration ratio (CACR) of two postcontrast timepoints (tp1 and tp2); 2) the relationship between the CACR and the redistribution rate constant (kep) based on a two-compartment pharmacokinetic model; and 3) the sensitivity of the relationship between the SER and kep to native tissue T1 relaxation time, T10, and to errors in an assumed vascular input function. The relationship between SER and kep was verified experimentally using a mouse model of breast cancer. The results showed that a monotonic mathematical relationship between SER and kep could be established if the acquisition parameters and the two postinjection timepoints of SER, tp1, tp2, were appropriately chosen. The in vivo study demonstrated a close correlation between SER and kep on a pixel-by-pixel basis (Spearman rank correlation coefficient=0.87+/-0.03). The SER is easy to calculate and may have a unique role in breast tissue characterization.     

Correlation of perfusion parameters on dynamic contrast-enhanced MRI with prognostic factors and subtypes of breast cancers

Purpose:

To investigate whether a correlation exists between perfusion parameters obtained from dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and prognostic factors or immunohistochemical subtypes of breast cancers.

Materials and Methods:

Quantitative parameters (K^trans, k_ep, and v_e) of 70 invasive ductal carcinomas were obtained using DCE‐MRI as a postprocessing procedure. Correlations between parameters and prognostic factors, including tumor size, axillary nodal status, histologic grade, nuclear grade, expression of estrogen receptor (ER), progesterone receptor (PR), Ki‐67, p53, bcl‐2, and human epidermal growth factor receptor 2 (HER2) and subtypes categorized as luminal (ER or PR‐positive), triple negative (ER or PR‐negative, HER2‐negative), and HER2 (ER and PR‐negative, HER2 overexpression) were analyzed.

Results:

Mean K^trans was higher in tumors with a high histologic grade than with a low histologic grade (P = 0.007), with a high nuclear grade than with a low nuclear grade (P = 0.002), and with ER negativity than ER positivity (P = 0.056). Mean k_ep was higher in tumors with a high histologic grade than with a low histologic grade (P = 0.005), with a high nuclear grade than with a low nuclear grade (P = 0.001), and with ER negativity than with ER positivity (P = 0.043). Mean v_e was lower in tumors with a high histologic grade than with a low histologic grade (P = 0.038) and with ER negativity than with ER positivity (P = 0.015). Triple‐negative cancers showed a higher mean k_ep than the luminal type (P = 0.015).

Conclusion:

Breast cancers with higher K^trans and k_ep, or lower v_e, had poor prognostic factors and were often of the triple‐negative subtype. J. Magn. Reson. Imaging 2012;36:145–151. © 2012 Wiley Periodicals, Inc.     

Incidentally detected lesions on contrast-enhanced MR imaging in candidates for breast-conserving therapy: correlation between MR findings and histological diagnosis

PURPOSE: To investigate the correlation between MR findings and the histological diagnosis of incidentally detected lesions in candidates for breast-conserving therapy. MATERIALS AND METHODS: MR images of 299 patients with breast cancer were reviewed. Incidentally detected lesions were noted in 59 of 299 (20%) patients, and a histological diagnosis was obtained in 48 of 59 (81%) patients. There were 25 benign and 23 malignant lesions. The number, size, location, morphologic character, and kinetic curve assessment of the MR findings were analyzed. Statistical analyses were performed to determine whether any differences could be observed between benign and malignant lesions. RESULTS: Lesions of over 10 mm tended to be malignant (11/16; 69%), whereas those equal or less than 5 mm tended to be benign (12/17; 71%; P < 0.05). Lesions in the same quadrant as the main lesion tended to be malignant (20/27.5; 73%), whereas those in a different quadrant tended to be benign (17.5/20.5; 85%; P < 0.001). Lesions with early peak of enhancement tended to be malignant (20/25; 80%), whereas those with persistent enhancement tended to be benign (20/23; 87%; P < 0.001). CONCLUSION: Incidentally detected lesions that are found in a different quadrant from the main lesion, are smaller than 10 mm in diameter, and show persistent enhancement on MR imaging suggest benign lesions. Therefore, patients with such lesions should avoid unnecessary surgical procedures unless lesions are proved to be malignant by cytology or biopsy.     

Relationship of temporal resolution to diagnostic performance for dynamic contrast enhanced MRI of the breast

Purpose:

To investigate the relationship between temporal resolution of dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and classification of breast lesions as benign versus malignant.

Materials and Methods:

Patients underwent T₁‐weighted DCE MRI with 15 s/acquisition temporal resolution using 1.5 Tesla (n = 48) and 3.0T (n = 33) MRI scanners. Seventy‐nine patients had pathologically proven diagnosis and 2 had 2 years follow‐up showing no change in lesion size. The temporal resolution of DCE MRI was systematically reduced as a postprocessing step from 15 to 30, 45, and 60 s/acquisition by eliminating intermediate time points. Average wash‐in and wash‐out slopes, wash‐out percentage changes, and kinetic curve shape (persistently enhancing, plateau, or wash‐out) were compared for each temporal resolution. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to compare kinetic parameters and diagnostic accuracy.

Results:

Sixty patients (74%) had malignant lesions and 21 patients (26%) had benign lesions. All temporal‐resolution parameters significantly predicted benign versus malignant diagnosis (P < 0.05). However, 45 s/acquisition and higher temporal‐resolution datasets showed higher accuracy than the 60 s/acquisition dataset by ROC curve analysis (0.72 versus 0.69 for average wash‐in slope; 0.85 versus 0.82, for average wash‐out slope; and 0.88 versus 0.80 for kinetic curve shape assessment, for 45 s/acquisition versus 60 s/acquisition temporal‐resolution datasets, respectively (P = 0.027).

Conclusion:

DCE MRI data with at least 45‐s temporal resolution maximized the agreement between the kinetic parameters and correct classification of benign versus malignant diagnosis. J. Magn. Reson. Imaging 2009;30:999–1004. © 2009 Wiley‐Liss, Inc.     

The diverse pathology and kinetics of mass, nonmass, and focus enhancement on MR imaging of the breast

Purpose:

To compare the pathology and kinetic characteristics of breast lesions with focus‐, mass‐, and nonmass‐like enhancement.

Materials and Methods:

A total of 852 MRI detected breast lesions in 697 patients were selected for an IRB approved review. Patients underwent dynamic contrast enhanced MRI using one pre‐ and three to six postcontrast T₁‐weighted images. The “type” of enhancement was classified as mass, nonmass, or focus, and kinetic curves quantified by the initial enhancement percentage (E₁), time to peak enhancement (T_peak), and signal enhancement ratio (SER). These kinetic parameters were compared between malignant and benign lesions within each morphologic type.

Results:

A total of 552 lesions were classified as mass (396 malignant, 156 benign), 261 as nonmass (212 malignant, 49 benign), and 39 as focus (9 malignant, 30 benign). The most common pathology of malignant/benign lesions by morphology: for mass, invasive ductal carcinoma/fibroadenoma; for nonmass, ductal carcinoma in situ (DCIS)/fibrocystic change(FCC); for focus, DCIS/FCC. Benign mass lesions exhibited significantly lower E₁, longer T_peak, and lower SER compared with malignant mass lesions (P < 0.0001). Benign nonmass lesions exhibited only a lower SER compared with malignant nonmass lesions (P < 0.01).

Conclusion:

By considering the diverse pathology and kinetic characteristics of different lesion morphologies, diagnostic accuracy may be improved. J. Magn. Reson. Imaging 2011;33:1382–1389. © 2011 Wiley‐Liss, Inc.     

Segmental enhancement on breast MR images: differential diagnosis and diagnostic strategy

The histopathological variations of segmental enhancement on breast magnetic resonance imaging (MRI) were investigated, with the aim of identifying imaging characteristic clues to their differential diagnosis. We reviewed 70 breast MRI examinations demonstrating segmental enhancement, classified them based on their histopathology, and assessed their MRI findings as follows: (1) confluent or not confluent, (2) late enhancement pattern, and the absence or presence of (3) clustered ring enhancements and (4) surrounding high signal intensity (SI) on T2-weighted imaging. Thirteen lesions (18.5%) were benign, eight (11.5%) were high risk, 25 (36%) were ductal carcinoma in situ (DCIS) and 24 (34%) were infiltrating mammary carcinomas (IMC). Clustered ring enhancements were demonstrated in 74% of malignancies (high risk, DCIS and IMC) but no benign lesions (P = 0.0001). The surrounding high SI on T2-weighted imaging was seen in four of five IMC with marked lymphatic involvement. Clustered ring enhancement was not demonstrated in six of seven IMC of tubular and/or lobular types. Segmental enhancement was seen in not only DCIS but also IMC, high-risk and benign lesions. Clustered ring enhancement and surrounding high SI on T2-weighted imaging were clues to their differential diagnosis and helpful to decide their diagnostic strategy.     

Triple negative breast cancer: MRI features in comparison to other breast cancer subtypes with correlation to prognostic pathologic factors

Objective

This study aimed at determination of the MRI predictors of triple negative breast cancer (TNBC) in comparison to other breast cancer subtypes.

Materials and methods

The study retrospectively enrolled 185 female patients with 206 pathologically confirmed invasive breast cancers with different subtypes by immunohistochemistry. Histopathological analysis as well as MRI features of TNBC was compared to those of other breast cancer subtypes. MRI features included the tumor size, shape, margin, internal enhancement, intratumoral signal intensity on T2-WI, detectability by DW-MRI and ADC values.

Results

TNBCs showed higher histological grades (p < 0.0001) and younger patient age group (p = 0.006) compared to other tumor subtypes. At MRI, TNBCs were of larger size (p < 0.0001), round shape (p < 0.0001), smooth margin (p < 0.0001), with rim enhancement (p < 0.0001) and higher incidence of T2-WI tumoral hyperintensity (p = 0.0002) and intratumoral necrosis (p < 0.0001). No significant difference in tumor detectability was found by DW-MRI, however, TNBCs had higher ADC values (p < 0.0001).

Conclusion

In our study, TNBC patients were of younger age with higher grade malignancy. TNBC MRI predictors were unifocal rim enhancing mass with round shape, smooth margin, higher signal intensity on T2-WI, in addition to relatively larger sizes of tumors associated with high incidence of intratumoral necrosis and higher ADC values.     

Microcirculation and microvasculature in breast tumors: pharmacokinetic analysis of dynamic MR image series.

The purpose of this study was to quantify microcirculation and microvasculature in breast lesions by pharmacokinetic analysis of Gd-DTPA-enhanced MRI series. Strongly T1-weighted MR images were acquired in 18 patients with breast lesions using a saturation-recovery-TurboFLASH sequence. Concentration-time courses were determined for blood, pectoral muscle, and breast masses and subsequently analyzed by a two-compartment model to estimate plasma flow and the capillary transfer coefficient per unit of plasma volume (F/VP, KPS/VP) as well as fractional volumes of the plasma and interstitial space (fP, fI). Tissue parameters determined for pectoral muscle (fP = 0.04 +/- 0.01, fI = 0.09 +/- 0.01, F/VP = 2.4 +/- 1.3 min(-1), and KPS/VP = 1.2 +/- 0.5 min(-1)) and 10 histologically proven carcinomas (fP = 0.20 +/- 0.07, fI = 0.34 +/- 0.16, F/VP = 2.4 +/- 0.7 min(-1), and KPS/VP = 0.86 +/- 0.62 min(-1)) agreed reasonable well with literature data. Best separation between malignant and benign lesions was obtained by the ratio KPS/F (0.35 +/- 0.17 vs. 1.23 +/- 0.65). The functional imaging technique presented appears promising to quantitatively characterize tumor pathophysiology. Its impact on diagnosis and therapy management of breast tumors, however, has to be evaluated in larger patient studies.     

Combined quantitative dynamic contrast-enhanced MR imaging and (1)H MR spectroscopic imaging of human prostate cancer

PURPOSE: To differentiate prostate carcinoma from healthy peripheral zone and central gland using quantitative dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and two-dimensional (1)H MR spectroscopic imaging (MRSI) combined into one clinical protocol. MATERIALS AND METHODS: Twenty-three prostate cancer patients were studied with a combined DCE-MRI and MRSI protocol. Cancer regions were localized by histopathology of whole mount sections after radical prostatectomy. Pharmacokinetic modeling parameters, K(trans) and k(ep), as well as the relative levels of the prostate metabolites citrate, choline, and creatine, were determined in cancer, healthy peripheral zone (PZ), and in central gland (CG). RESULTS: K(trans) and k(ep) were higher (P < 0.05) in cancer and in CG than in normal PZ. The (choline + creatine)/citrate ratio was elevated in cancer compared to the PZ and CG (P < 0.05). While a (choline + creatine)/citrate ratio above 0.68 was found to be a reliable indicator of cancer, elevated K(trans) was only a reliable cancer indicator in the diagnosis of individual patients. K(trans) and (choline + creatine)/citrate ratios in cancer were poorly correlated (Pearson r(2) = 0.07), and thus microvascular and metabolic abnormalities may have complementary value in cancer diagnosis. CONCLUSION: The combination of high-resolution spatio-vascular information from dynamic MRI and metabolic information from MRSI has excellent potential for improved localization and characterization of prostate cancer in a clinical setting. J. Magn. Reson. Imaging 2004;20:279-287. Copyright 2004 Wiley-Liss, Inc.