Ultrasonography contrast media Levovist and power Doppler in the study of the breast. Methodology, vascular morphology and automatic enhancement quantification with wash-in and wash-out curves]

PURPOSE: To define the technique for contrast-enhanced power Doppler US studies of breast lesions and to identify possible clinical applications. MATERIAL AND METHODS: We studied 51 breast lesions detected at mammography and confirmed at cytology and/or surgical biopsy; 15 were benign lesions and 36 carcinomas, namely 14 T1ab, 29 T1c and 8 T2. We found 14 masses with regular margins, 28 with irregular margins, 1 asymmetric density, 2 architectural distortions and 6 clustered calcifications. US studies were performed with an AU5 Harmonic unit (Esaote Biomedica, Genoa, Italy) equipped with a software for online image storage, analysis and automatic quantification of US signal intensity changes after contrast agent injection, namely wash-in and wash-out contrast enhancement curves. The echocontrast agent Levovist (Schering AG, Berlin, Germany), 4.0 g preparation, was administered by i.v. injection (cubital vein) in two times at a concentration of 400 mg/mL. The first 4 mL of Levovist suspension were injected as a bolus at approximately .5 mL/s to evaluate lesion vascularization and choose the best scanning plane for wash-in and wash-out quantification. The remaining 6 mL of Levovist suspension were injected at approximately 1.0 mL/s and dedicated to wash-in and wash-out recording. RESULTS: The region of interest could not be identified in 2 of 6 calcifications. After Levovist administration, signal enhancement was seen in 36 lesions. Nonsignificant curves were obtained in 7 fibroadenomas, 1 fibrocystic mastopathy and 5 carcinomas. Pathology diagnosed an in situ component around the lesion core (true positives) in 12 carcinomas with perilesional vessels and also 3 more carcinomas with perilesional foci in situ missed at contrast-enhanced US (false negatives). The wash-in/wash-out curves of 30 carcinomas differed from those of the 6 fibroadenomas, in that the former had faster wash-in and an earlier enhancement peak, as well as longer enhancement than the latter. Moreover, fibroadenoma curves are regularly increasing, with moderate variations. As for wash-out, carcinomas exhibited three main patterns, namely a monophasic, a polyphasic and a plateau pattern. DISCUSSION: The pattern of enhancement curves in fibroadenomas is related to straight and regular vessels, while arteriovenous shunts in carcinomas cause early signal intensity peaks. Wash-out is longer in carcinomas than in fibroadenomas because the former present anarchic and tortuous vessels with slow flows. CONCLUSIONS: Levovist enhanced US is a complementary test to study known breast lesions which permits the differential diagnosis of carcinomas and fibroadenomas. Our results justify a larger clinical trial to assess the role of this technique for diagnosis, prognosis and staging purposes.     

MR imaging of the breast with Gd-DTPA enhancement: comparison with mammography and ultrasonography.

The accuracy of MR imaging with Gd-DTPA enhancement was compared with mammography and ultrasonography in 52 patients with clinically palpable benign and malignant breast masses (36 carcinomas, 2 malignant phyllodes tumors, 7 fibroadenomas, 7 cysts). On dynamic MR imaging, carcinomas and fibroadenomas were discriminated by their different dynamic enhancement profiles. In carcinomas, signal intensity increased rapidly, reaching a peak or plateau within 2 min after the injection of contrast medium. In fibroadenomas, signal intensity showed a much slower continuous increase without ceasing until about 8 min after injection. Malignant phyllodes tumors showed a dynamic enhancement profile identical to that of benign fibroadenomas. MR imaging correctly identified 84% of malignant tumors, 86% of fibroadenomas, and 100% of cysts, and was substantially more accurate in tissue characterization than mammography. The results of ultrasonography were highly similar to those of MR imaging. However, no single modality was infallible, and the three modalities were complementary rather than competitive. Considering the high cost and long examination time of MR imaging, mammography supplemented by ultrasonography seems to be the method of choice in the diagnosis of breast lesions. Nevertheless, MR imaging can add important information when the results of mammography and ultrasonography are insufficient or contradictory.     

Computer-assisted quantitative assessment of power Doppler US: effects of microbubble contrast agent in the differentiation of breast tumors

RATIONALE AND OBJECTIVES: To objectively quantify the effects of a microbubble contrast agent to differentiate breast tumors with power doppler ultrasound and to compare these results with color doppler ultrasound (CD US). METHODS: In 47 patients a microbubble contrast agent was injected intravenously. Computer-assisted quantitative assessment of the color pixel density was performed to evaluate the increase in Doppler signals. Results were compared to previously published results of a color Doppler ultrasound study. RESULTS: Peak color pixel density at contrast-enhanced power Doppler ultrasound was higher for carcinomas than for benign tumors (P < 0.03). Time to peak enhancement was shorter in carcinomas than in benign tumors (P < 0.01). For both parameters, diagnostic accuracy of power Doppler ultrasound was 69 and 78%, and for color Doppler ultrasound 62 and 76%, respectively. CONCLUSIONS: Quantitative assessment of contrast-enhanced power Doppler ultrasound showed significant differences in malignant and benign breast tumors. Diagnostic accuracy of contrast-enhanced power Doppler ultrasound was higher compared to color Doppler ultrasound.     

Differentiation of phyllodes breast tumors from fibroadenomas on MRI

OBJECTIVE: The purpose of our study was to evaluate the MRI appearance of phyllodes breast tumors and to differentiate them from fibroadenomas. MATERIALS AND METHODS: MR images were obtained on a 1.5-T imager. T1- and T2-weighted sequences and dynamic 2D fast-field echo T1-weighted sequences were performed. MR images of 23 patients with 24 phyllodes breast tumors (one malignant, 23 benign) were analyzed with respect to morphology and contrast enhancement. The tumors were compared with the MRI appearance of 81 fibroadenomas of 75 patients. RESULTS: Well-defined margins were seen in 87.5% of the phyllodes tumors and 70.4% of the fibroadenomas, and a round or lobulated shape in 100% and 90.1%, respectively. A heterogeneous internal structure was observed in 70.8% of phyllodes tumors and in 49.4% of fibroadenomas. Nonenhancing internal septations were found in 45.8% of phyllodes tumors and 27.2% of fibroadenomas. A significantly greater increase in signal was seen on T2-weighted images in the tissue surrounding phyllodes tumors (21%) compared with fibroadenomas (1.2%). Most of both lesions appeared with low signal intensity on T1- and T2-weighted images. After the administration of contrast material, 33.3% of phyllodes tumors and 22.2% of fibroadenomas showed a suspicious signal intensity-time course. CONCLUSION: Phyllodes breast tumors and other fibroadenomas cannot be precisely differentiated on breast MRI. Phyllodes tumors have benign morphologic features and contrast enhancement characteristics suggestive of malignancy in 33% of cases.     

Breast lesions: evaluation with dynamic contrast-enhanced T1-weighted MR imaging and with T2*-weighted first-pass perfusion MR imaging

PURPOSE: To evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced T1-weighted magnetic resonance (MR) imaging and T2*-weighted first-pass perfusion imaging in patients with breast tumors and to determine if T2*-weighted imaging can provide additional diagnostic information to that obtained with T1-weighted imaging. MATERIALS AND METHODS: One hundred thirty patients with breast tumors underwent MR imaging with dynamic contrast-enhanced T1-weighted imaging of the entire breast, which was followed immediately with single-section, T2*-weighted imaging of the tumor. RESULTS: With T2*-weighted perfusion imaging, 57 of 72 carcinomas but only four of 58 benign lesions had a signal intensity loss of 20% or more during the first pass, for a sensitivity of 79% and a specificity of 93%. With dynamic contrast-enhanced T1-weighted imaging, 64 carcinomas and 19 benign lesions showed a signal intensity increase of 90% or more in the first image obtained after the administration of contrast material, for a sensitivity of 89% and a specificity of 67%. CONCLUSION: T2*-weighted first-pass perfusion imaging can help differentiate between benign and malignant breast lesions with a high level of specificity. The combination of T1-weighted and T2*-weighted imaging is feasible in a single patient examination and may improve breast MR imaging.     

Breast carcinomas with strong high-signal intensity on T2-weighted MR images: pathological characteristics and differential diagnosis

PURPOSE: To investigate the histopathological characteristics of breast carcinomas with strong high-signal intensity (SHi) on T2-weighted (T2W) MR images (T2-SHi), and discuss the differential diagnosis between T2-SHi breast carcinomas and T2-SHi fibroadenomas. MATERIALS AND METHODS: Thirty of 480 breast carcinomas examined by MRI were defined as tumors with T2-SHi (defined as homogeneous higher signal intensity (SI) compared to surrounding normal breast tissue on fat-suppressed T2W imaging (T2WI). They included eight mucinous and 22 nonmucinous carcinomas. The histopathological characteristics of T2-SHi breast carcinomas, their signal-to-noise ratios (SNRs) on T2WI, contrast-enhancement patterns, and morphology were compared with those of 22 non-T2-SHi breast carcinomas and 19 T2-SHi fibroadenomas. RESULTS: In nonmucinous carcinomas T2-SHi was attributable to a mixture of background matrix, a higher proportion of cells than stroma, abundant cytoplasm, edematous stroma, and hemorrhage. The significantly high SNR (mean = 75) and enhancing internal septations seen in mucinous carcinomas, and the washout phenomenon, irregular border, absence of internal septation, and rim enhancement seen in nonmucinous carcinomas provide useful information for differentiating these tumors from T2-SHi fibroadenomas. CONCLUSION: A mixture of several histopathological characteristics was associated with T2-SHi breast carcinomas. The combined information from T2WI and contrast-enhanced (CE) imaging may help distinguish T2-SHi breast carcinomas from T2-SHi fibroadenomas.     

Diagnostic efficacy of SonoVue, a second generation contrast agent, in the assessment of extracranial carotid or peripheral arteries using colour and spectral Doppler ultrasound: a multicentre study

The purpose of this study was to demonstrate the improvement in diagnostic quality and diagnostic accuracy of SonoVue microbubble contrast-enhanced ultrasound (CE-US) versus unenhanced ultrasound imaging during the investigation of extracranial carotid or peripheral arteries. 82 patients with suspected extracranial carotid or peripheral arterial disease received four SonoVue doses (0.3 ml, 0.6 ml, 1.2 ml and 2.4 ml) with Doppler ultrasound performed before and following each dose. Diagnostic quality of the CE-US examinations was evaluated off-site for duration of clinically useful contrast enhancement, artefact effects and percentage of examinations converted from non-diagnostic to diagnostic. Accuracy, sensitivity and specificity were assessed as agreement of CE-US diagnosis evaluated by an independent panel of experts with reference standard modality. The median duration of clinically useful signal enhancement significantly increased with increasing SonoVue doses (p< or =0.002). At the dose of 2.4 ml of SonoVue, diagnostic quality evaluated as number of inconclusive examinations significantly improved, falling from 40.7% at baseline down to 5.1%. Furthermore, SonoVue significantly (p<0.01) increased the accuracy, sensitivity and specificity of assessment of disease compared with baseline ultrasound. SonoVue increases the diagnostic quality of Doppler images and improves the accuracy of both spectral and colour Doppler examinations of extracranial carotid or peripheral arterial disease.     

MR重T2W首次通过灌注成像鉴别乳腺良恶性肿瘤的价值初探

目的　评价在同 1次检查中T1W动态增强成像之后进行重T2 W (T 2 W )首次通过灌注成像的可行性 ,以及后者在鉴别乳腺良恶性肿瘤方面的诊断价值。方法　 2 9例乳腺病患者在T1W动态增强后进一步行病灶局部的T 2 W首次通过灌注成像 ,分别根据病灶T1W动态增强的早期强化程度和T 2 W首次通过灌注成像的早期信号丢失程度判定病灶的良恶性 ,计算其敏感度、特异度 ,以进行两方法间的比较。结果　应用T1W动态增强成像序列 ,良、恶性病变的信号强度增加率之间差异有显著性意义 (t=2 5 6 3,P =0 0 16 ) ,但两者的早期增强程度范围有很大的重叠 ;早期增强率诊断的敏感度为 94 % ,特异度仅为 2 5 %。应用T 2 W首次通过灌注成像序列 ,良、恶性病变之间的T2 信号强度丢失程度差异有非常显著性意义 (t=4 777,P <0 0 0 1) ,良、恶性病变的早期信号丢失率之间重叠很少 ;早期信号丢失率诊断的敏感度为 88% ,特异度为 75 %。结论　T 2 W首次通过灌注成像在鉴别良恶性乳腺肿瘤方面具有较高特异度 ;在同一患者中 ,T 2 W首次通过灌注成像结合T1W动态增强成像检查是可行的 ,可以提高乳腺MR成像的诊断准确性。     

Tumor vascularity of breast lesions: potentials and limits of contrast-enhanced Doppler sonography

OBJECTIVE: We investigated improving the evaluation of benignity in breast lesions using Doppler sonography with galactose palmitic acid-coated microbubbles. SUBJECTS AND METHODS: In 77 patients with 84 breast tumors scheduled for surgical tumor removal, color-coded duplex sonography was performed before and after administration of Levovist. Of the 77 patients, 25 with 28 lesions had been treated for prior breast carcinoma. The parameters investigated were the following: degree of enhancement, number of tumor vessels, time to maximum enhancement, and the pattern of vascular morphology and course. RESULTS: Findings in malignant tumors (n = 53) showed a greater number of vessels and a faster stronger enhancement after Levovist administration, whereas a definite partial overlap with results from benign tumors (n = 31) was found. The best distinction was produced by vascular morphology and course, with a sensitivity of 90% and a specificity of 81 %. In 23 of the 25 patients who previously underwent surgery, a clear distinction was possible between a postoperative scar (n = 11) and a tumor recurrence (n = 17). CONCLUSION: Although administration of the contrast agent clearly improved evaluation of benign features on Doppler sonography, absolute certainty cannot be achieved. The feasibility of making an otherwise difficult distinction between a scar and tumor recurrence on sonography and mammography appears to be promising, but further studies are necessary.     

Vascular patterns in nodules of intraductal papillary mucinous neoplasms depicted under contrast-enhanced ultrasonography are helpful for evaluating malignant potential

Objectives

The purpose of this study is to evaluate the feasibility of contrast-enhanced ultrasonography (CE-US) to differentiate between benign and malignant intraductal papillary mucinous neoplasms (IPMN).

Patients and methods

Contrast-enhanced ultrasonography with a contrast agent was performed on 22 consecutive patients with IPMN suspected of being malignant. This revealed 10 carcinomas, 1 borderline lesion and 11 adenomas. All patients underwent surgery, and the histological diagnosis was confirmed by examination of resected specimens. CE-US was performed using a contrast agent. The detection rates of mural nodules were compared between CE-US and contrast-enhanced computed tomography (CE-CT), and the imaging of mural nodules depicted under CE-US was analyzed.

Results

Seventeen of 22 resected specimens (77.3%) had mural nodules. There was no significant difference in the detection rate between CE-US (n = 15; 88.2%) and CE-CT (n = 12; 70.6%). In 12 (80.0%) of these patients, CE-US revealed small vessels in the mural nodule. The spotty or linear-shaped pattern was detected in 4 patients and the branch-shaped pattern in 8. The branch-shaped pattern lesion was associated with carcinoma. These mural nodules were 10 mm or more in height. In the perfusion image phase, cystic walls and mural nodules were also enhanced in all cases.

Conclusion

The vessel shapes of the mural nodules depicted under CE-US were associated with size and pathological findings. These results suggested that CE-US with a contrast agent is a powerful modality with which to evaluate the malignant potential of IPMN.     

The use of duplex Doppler ultrasound in the diagnosis of breast cancer

Duplex Doppler ultrasound was used to examine 50 breast lesions in 45 patients. Examination was confined to the region of interest, which in most cases was a palpable lump, and the corresponding area of the contralateral breast as a control. In only one patient was a Doppler signal obtained from a normal breast. Nine of the 50 lesions were believed to represent simple breast cysts at sonography and were not treated further. The remaining 41 lesions were excised; 22 were carcinomas and 19 benign (fibrocystic disease 7, fibroadenomas 5, miscellaneous 7). Doppler signals were obtained in 20 of the carcinomas and three of the benign lesions. In this series, the sensitivity of duplex Doppler ultrasound for the detection of breast carcinoma was 91%, and the specificity 89%. The positive predictive value was 87% and the negative predictive value 93%.     

Classification of hypervascularized lesions in CE MR imaging of the breast

The purpose of this paper is to define and evaluate a classification category for contrast-enhanced (CE) MR imaging of the breast based on the BI-RADS mammographic categories of the American College of Radiology. Using five evaluation criteria for MR findings (initial signal increase, post-initial signal behavior, shape, border, and contrast material distribution within enhancing tumors) 522 patients (1031 breasts) were analyzed. Scores were given from 0 to 8 points and classified into five categories (group I: 0 points, negative; group II: 1-2 points, benign; group III: 3 points, probably benign; group IV: 4-5 points, suspicious abnormality; group V: 6-8 points, highly suspicious for malignancy) to 265 focal hypervascularized breast lesions in 244 breasts (patient group A). These findings were correlated with histology or follow-up. Additionally, this classification was correlated to the contrast medium uptake within the parenchyma of the remaining 787 breasts without any focal lesion (patient group B). Two hundred sixty-five hypervascularized lesions in 238 patients (244 breasts, patient group A) were classified into group I: 0%; group II: 27.3%; group III: 22.3%; group IV: 18.6%; and group V: 31.8%. Histology revealed 115 benign and 134 malignant tumors in these groups. Sixteen benign lesions were controlled by follow-up. Sensitivity for the detection of malignancy using the presented multifactorial MRM classification was 92%, and specificity was 92%. Excluding cases of ductal carcinoma in situ specificity increased to 95%. Seven hundred eighty-seven breasts without any focal hypervascularized lesion (patient group B) were classified into groups I or II. Follow-up ( n=771) or histology ( n=14) confirmed the diagnosis in 785 of these breasts. Histopathology revealed, however, malignant tumors in the remaining two cases. The classification of lesions based on a multifactorial analysis is very helpful in the interpretation of CE MRI of the breast. The evaluation of all diagnostic imaging modalities, however, is essential in determining the correct diagnosis and/or in deciding on the appropriate therapeutic procedure.     

Ultrasonographic contrast agent: evaluation of time-intensity curves in the characterisation of solitary thyroid nodules

PURPOSE: To evaluate whether the time-intensity curve can improve characterisation of solitary thyroid nodules. MATERIAL AND METHODS: From June to December 2000 we studied 61 patients (16 men and 45 women, mean age 46 years) with solitary thyroid nodules that were not associated with any important hormonal alteration and that showed poor tracer uptake at scintigraphy. We evaluated the Power Doppler vascular pattern before and after a 60" intravenous injection of 2.5 g of Levovist (diluted in 7 ml). The study lasted 5 minutes from the beginning of the infusion. Finally, the time-intensity curves were processed. All the nodules underwent fine needle aspiration biopsy (FNAB) and excision biopsy. RESULTS: Histology revealed 43 benign lesions and 18 malignant lesions. At contrast-enhanced Power Doppler 83.4% (15/18) of the malignant nodules were found to be hypervascularized, while 16.6% (3/18) were hypovascularized. Of the benign lesions, 90.7% (39/43) were hypervascularized, 9.3% (4/43) were hypovascularized. All the nodules, both hyper- and hypovascularized, displayed rapid and intense wash-in curves. By contrast, the wash-out curves were regular and monophasic in 40/43 (93%) benign lesions (36 hypervascularized and 4 hypovascularized lesions) and irregular and polyphasic in 16/18 (89%) malignant lesions (13 hypervascularized and 3 hypovascularized lesions); 3/43 (7%) benign nodules showed polyphasic wash-out and 2/18 malignant lesions (11%) showed monophasic wash-out. DISCUSSION AND CONCLUSIONS: Time-intensity curves, and particularly wash-out curves, provide useful information for the characterisation of solitary thyroid nodules. 93% of benign nodules (with regular vascularization) showed a monophasic pattern of the wash-out curve, while 89% of malignant nodules ("anarchical" vascularization) had polyphasic wash-out curves. This behaviour was observed in both hypervascularized and hypovascularized lesions. Our method proved to have a sensitivity of 88% and a specificity of 93%. The study of time-intensity curves could therefore enable us to differentiate between benign and malignant lesions and characterise hypovascularized malignant nodules which would not be observed without contrast agent.     

Digital mammography using iodine-based contrast media: initial clinical experience with dynamic contrast medium enhancement

PURPOSE: We sought to evaluate the potential of dynamic contrast enhancement after the intravenous administration of an iodine-based contrast medium in full-field digital mammography. MATERIAL AND METHODS: A protocol for image acquisition was established for contrast-enhanced mammography and the mammography unit (Senographe 2000D, GE Healthcare, Buc, France) changed as required. The effect of the protocol parameters on imaging was investigated. Subsequently, 21 patients with 25 suspicious lesions of the breast (10 benign, 1 borderline, and 14 malignant) underwent mammography with administration of an iodine-based contrast medium (Ultravist 370, Schering AG, Berlin, Germany), after approval of ethical committee as well as permission of German federal office for Radiation protection, and informed consent from each patient was obtained. Three sequential digital mammographic images of the respective breast were acquired after administration of the contrast medium at a dose of 1 mL/kg body weight and a flow of 4 mL/s. The postcontrast images were acquired 60, 120, and 180 seconds after administration. Subsequently, the precontrast image was logarithmically subtracted from the postcontrast images. Enhancement of the lesions was measured in absolute terms as well as relative to the enhancement of the glandular tissue. The subtracted images were evaluated for lesion depiction and dynamic contrast enhancement. Lesion-enhancement kinetics were compared with the histologic findings. RESULTS: All malignant lesions were identified on the contrast-enhanced images of digital mammography. Three of the tumors (2 malignant, 1 benign) were detected only by contrast-enhanced mammography and not by standard mammography. Dynamic enhancement curves of benign and malignant tumors in contrast-enhanced mammography look similar to the curves known from gadolinium-enhanced magnetic resonance imaging. Nevertheless differentiation between malignant and benign tumors based on the enhancement patterns cannot be directly taken over from magnetic resonance imaging, as suggested by our initial results. The results are somewhat better when tumor enhancement relative to surrounding glandular tissue is used instead of absolute enhancement. CONCLUSION: The results of this preliminary study suggest that contrast-enhanced digital mammography is a potentially useful tool for the detection and the differentiation of benign and malignant breast lesions.     

Correlation of contrast agent kinetics between iodinated contrast-enhanced spectral tomosynthesis and gadolinium-enhanced MRI of breast lesions

Objectives

Assessment of contrast agent kinetics in contrast-enhanced MRI (CE-MRI) with gadolinium-containing contrast agents offers the opportunity to predict breast lesion malignancy. The goal of our study was to determine if similar patterns exist for spectral contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated contrast agent.

Methods

The protocol of our prospective study was approved by the relevant institutional review board and the German Federal Office for Radiation Protection. All patients provided written informed consent. We included 21 women with a mean age of 62.4 years. All underwent ultrasound-guided biopsy of a suspect breast lesion, spectral CE-DBT and CE-MRI. For every breast lesion, contrast agent kinetics was assessed by signal intensity–time curves for spectral CE-DBT and CE-MRI. Statistical comparison used Cohen’s kappa and Spearman’s rho test.

Results

Spearman’s rho of 0.49 showed significant (P?=?0.036) correlation regarding the contrast agent kinetics in signal intensity–time curves for spectral CE-DBT and CE-MRI. Cohen’s kappa indicated moderate agreement (kappa?=?0.438).

Conclusion

There is a statistically significant correlation between contrast agent kinetics in the signal intensity–time curves for spectral CE-DBT and CE-MRI. Observing intralesional contrast agent kinetics in spectral CE-DBT may aid evaluation of malignant breast lesions.

Key Points

? Contrast agent kinetics can be assessed using spectral digital breast tomosynthesis (DBT). ? Contrast agent kinetics patterns in spectral DBT are similar to those in contrast-enhanced MRI. ? Multiple contrast enhancement for spectral DBT gives additional diagnostic information.     

Prognostic value of contrast-enhanced MR mammography in patients with breast cancer

The objective of this study was to evaluate the prognostic value of contrast-enhanced MR mammography in patients with breast cancer. A total of 190 patients with breast cancer (37 noninvasive carcinomas, 153 invasive carcinomas) underwent dynamic contrast-enhanced MR mammography preoperatively. Using 1.5-T unit, T1-weighted sequences (2D FLASH) were obtained repeatedly one time before and five times after IV administration of 0.1 mmol gadopentetate-dimeglumine per kilogram body weight. The findings on MR imaging were correlated with histopathologically defined prognostic factors (histological type, tumor size, tumor grading, metastasis in lymph nodes). In addition, immunohistochemically defined prognostic factors (c-erbB-1,c-erbB-2, p53, Ki-67) were correlated with the signal increase on MR mammogram in 40 patients. There was no significant correlation between the findings on MR mammography and the histopathological type of carcinoma, the grading, and the lymphonodular status. Noninvasive carcinomas showed a higher rate of moderate (38 %) or low (27 %) enhancement on MR imaging than invasive carcinomas (6 and 3 %). The results on MR mammography and the results of immunohistochemical stainings did not correlate significantly. Noninvasive carcinomas showed significantly lower enhancement than invasive carcinomas. However, the signal behavior of contrast-enhanced MR mammography is not related to established histopathological prognostic parameters as subtyping, grading, nodal status, and the expression of certain oncogenes/tumor suppressor genes. Received 29 August 1996; Revision received 28 October 1996; Accepted: 29 November 1996     

Enhanced MRI of breast cancer smaller than 3 cm]

Twenty-two patients with breast cancers were studied using magnetic resonance (MR) imaging with a cylindrical surface coil at 1.5 Tesla. All were examined with the FE sequence and Gd-DTPA as a contrast medium. These images were compared with micrographs of the specimens. All cancers were enhanced clearly, and demarcated margins or spiculations of the tumors were seen as clearly on MR images as on micrographs of the specimens. In 12 patients (9 carcinomas, 2 fibroadenomas and 1 benign phyllodes tumor), dynamic studies were performed after the intravenous injection of Gd-DTPA. All nine carcinomas showed enhancement characterized by a sudden increase in signal intensity on the order of 100% or more within the first 2 minutes after injection. Two fibroadenomas were enhanced slowly. Thirteen patients with breast cancers were examined with several sequences (FE, T1-weighed SE, T2-weighed SE and STIR) with or without Gd-DTPA. The most clearly delineated images of the tumors were those of FE images with Gd-DTPA enhancement. A phantom constituted of various concentrations of Gd-DTPA in 20% albumin solution was measured by signal intensities with T1-weighted SE sequence and FE sequence. The ratio of enhancement of the 20% albumin solution relative to the Gd-DTPA concentration was higher with the FE sequence than with the SE sequence. The sensitivity of the FE sequence to Gd-DTPA enhancement was 1.5 times that of the SE sequence under the usual concentration of Gd-DTPA.     

Contrast-enhanced MR mammography for evaluation of the contralateral breast in patients with diagnosed unilateral breast cancer or high-risk lesions

PURPOSE: To prospectively evaluate accuracy of gadobenate dimeglumine-enhanced magnetic resonance (MR) mammography for depiction of synchronous contralateral breast cancer in patients with newly diagnosed unilateral breast cancer or high-risk lesions, with histologic analysis or follow-up as reference. MATERIALS AND METHODS: The study had ethics committee approval; all patients provided written informed consent. One hundred eighteen consecutive women (mean age, 52 years) with unilateral breast cancer or high-risk lesions and negative findings in the contralateral breast at physical examination, ultrasonography, and conventional mammography underwent gadobenate dimeglumine-enhanced 1.5-T MR mammography. Transverse three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 minutes after gadobenate dimeglumine administration (0.1 mmol per kilogram body weight). Breast Imaging Reporting and Data System (BI-RADS) was used to categorize breast density and the level of suspicion for malignant contralateral breast lesions. Results were compared with histologic findings. Sensitivity, specificity, accuracy, and positive and negative predictive values for contrast-enhanced MR mammography were evaluated. RESULTS: Contrast-enhanced MR mammography revealed contralateral lesions in 28 (24%) of 118 patients. Twenty-four lesions were detected in patients with dense breasts (BI-RADS breast density category III or IV). Lesions in eight (29%) of 28 patients were BI-RADS category 4; patients underwent biopsy. Lesions in 20 (71%) patients were BI-RADS category 5; patients underwent surgery. At histologic analysis, 22 lesions were confirmed as malignant; six lesions were fibroadenomas. No false-negative lesions were detected; none of the fibroadenomas were BI-RADS category 5. The sensitivity, specificity, accuracy, and positive and negative predictive values of contrast-enhanced MR mammography for depiction of malignant or high-risk contralateral lesions were 100%, 94%, 95%, 79%, and 100%, respectively. Follow-up findings (12-24 months) confirmed absence of contralateral lesions in 90 of 118 patients with negative contrast-enhanced MR mammographic findings in the contralateral breast. CONCLUSION: Contrast-enhanced MR mammography is accurate for detection of synchronous contralateral cancer or high-risk lesions in patients with newly diagnosed breast cancer or high-risk lesions.     

Multicompartment analysis of gadolinium chelate kinetics: blood-tissue exchange in mammary tumors as monitored by dynamic MR imaging.

The blood-tissue exchange kinetics of gadopentetate were studied in 49 malignant and benign mammary tumors. Signal enhancement was monitored simultaneously in the aorta and in tumor for 10.5 minutes after the beginning of a 1 minute i.v. infusion of the contrast medium (CM). Kinetic analysis was based on a model with two compartments for systemic pharmacokinetics and up to three kinetically distinct compartments for tumor. Kinetic heterogeneity, ie, two or more compartments with different exchange rate constants in a given tumor, was found in 85% of carcinomas, 38% of fibroadenomas, and 14% of mastopathic tumors. The within-tumor average of CM exchange rates was 1.22 (0.62-1.65) min(-1) in carcinomas, 0.38 (0.26-0.60) min(-1) in fibroadenomas, and 0.16 (0. 12-0.20) min(-1) in mastopathies (median and interquartile distances). The area under the signal enhancement-time curve of the aorta varied 4.5-fold between individuals. It is concluded that individual CM kinetics in arterial blood should be taken into account when CM exchange rates between blood and tumor are to be determined and that a kinetic model for potentially malignant tumors should allow for kinetic heterogeneity.     

Contrast-enhanced color Doppler sonography for evaluation of enlarged cervical lymph nodes in head and neck tumors

OBJECTIVE: We determined whether contrast-enhanced color Doppler sonography can differentiate benign from malignant enlarged cervical lymph nodes in head and neck tumors. SUBJECTS AND METHODS: Ninety-four enlarged lymph nodes in 39 adult patients (32 men and seven women; age range, 30-81 years) were examined with B-mode sonography and with unenhanced and contrast-enhanced color Doppler sonography. All patients had carcinoma of the oral cavity. Histologically, lymphadenitis was found in 57 nodes and metastases in 37 nodes. Geometric dimension, texture, and margin of the node and detection and location of vessels were noted. Histology and imaging findings were correlated. RESULTS: The transverse-to-longitudinal diameter ratio in combination with texture and margin analysis resulted in a correct diagnosis in only approximately 79% of the nodes. With contrast-enhanced color Doppler sonography, 86% of nodes showed vessels, and 28% of nodes showed vessels with this technique exclusively. Characteristic configurations were identified: hilar vessels with branching indicated lymphadenitis (sensitivity, 98%; specificity, 100%), and predominantly peripheral vessels indicated metastases (100%, 98%). These findings changed the diagnosis in 13 nodes, changed the therapy in four patients, and led to an incorrect diagnosis in one patient. CONCLUSION: Enlarged lymph nodes can be characterized as metastatic or inflammatory with high diagnostic accuracy on the basis of their vascular architecture as seen on contrast-enhanced color Doppler sonography.