The Adjacent Vessel Sign on Breast MRI: New Data and a Subgroup Analysis for 1,084 Histologically Verified Cases

OBJECTIVE: The adjacent vessel sign (AVS) is a descriptor for differentiating malignant from benign breast lesions on breast MRI (bMRI). This investigation was designed to verify the previous reports on the diagnostic accuracy of AVS and to assess correlation between AVS, histopathological diagnosis, lesion size and lesion grade. MATERIALS AND METHODS: This study was approved by the local ethical committee. Experienced radiologists evaluated 1,084 lesions. The exclusion criteria were no histological verification after bMRI and breast interventions that were done up to one year before bMRI (surgery, core biopsy, chemo- or radiation therapy). The native and dynamic contrast-enhanced T1-weighted series were acquired using standardized protocols. The AVS was rated positive if a vessel leading to a lesion could be visualized. Prevalence of an AVS was correlated with the lesions' size, grade and histology using Chi-square-tests. RESULTS: The AVS was significantly associated with malignancy (p 2 cm more often presented with an AVS than did those malignant lesions < 2 cm (p < 0.0001; sensitivity: 65%, PPV: 90%). There was no correlation of the AVS with the tumor grade. The prevalence of an AVS didn't significantly differ between invasive lobular carcinomas versus ductal carcinomas. In situ cancers were less frequently associated with an AVS (p < 0.001). CONCLUSION: The adjacent vessel sign was significantly associated with malignancy. Thus, it can be used to accurately assess breast lesions on bMRI. In this study, the AVS was particularly associated with advanced and invasive carcinomas.

Correlation between High Resolution Dynamic MR Features and Prognostic Factors in Breast Cancer

OBJECTIVE: To correlate high resolution dynamic MR features with prognostic factors in breast cancer. MATERIALS AND METHODS: One hundred and ninety-four women with invasive ductal carcinomas underwent dynamic MR imaging using T1-weighted three-dimensional fast low-angle shot (3D-FLASH) sequence within two weeks prior to surgery. Morphological and kinetic MR features were determined based on the breast imaging and reporting data system (BI-RADS) MR imaging lexicon. Histological specimens were analyzed for tumor size, axillary lymph node status, histological grade, expression of estrogen receptor (ER), expression of progesterone receptor (PR), and expression of p53, c-erbB-2, and Ki-67. Correlations between the MR features and prognostic factors were determined using the Pearson chi-square test, linear-by-linear association, and logistic regression analysis. RESULTS: By multivariate analysis, a spiculated margin was a significant, independent predictor of a lower histological grade (p < 0.001), and lower expression of Ki-67 (p = 0.007). Rim enhancement was significant, independent predictor of a higher histological grade (p < 0.001), negative expression of ER (p = 0.001), negative expression of PR (p < 0.001) and a larger tumor size (p = 0.006). A washout curve may predict a higher level of Ki-67 (p = 0.05). Most of the parameters of the initial enhancement phase cannot predict the status of the prognostic factors. Only the enhancement ratio may predict a larger tumor size (p = 0.05). CONCLUSION: Of the BI-RADS-MR features, a spiculated margin may predict favorable prognosis, whereas rim enhancement or washout may predict unfavorable prognosis of breast cancer.

Breast MRI for Evaluating Patients with Metastatic Axillary Lymph Node and Initially Negative Mammography and Sonography

OBJECTIVE: We wanted to investigate the ability of breast MR imaging to identify the primary malignancy in patients with axillary lymph node metastases and initially negative mammography and sonography, and we correlated those results with the conventional imaging. MATERIALS AND METHODS: From September 2001 to April 2006, 12 patients with axillary lymph node metastases and initially negative mammography and sonography underwent breast MR imaging to identify occult breast carcinoma. We analyzed the findings of the MR imaging, the MR-correlated mammography and the second-look sonography. We followed up both the MR-positive and MR-negative patients. RESULTS: MR imaging detected occult breast carcinoma in 10 of 12 (83%) patients. Two MR-negative patients were free of carcinoma in the ipsilateral breast during their follow-up period (39 and 44 months, respectively). In nine out of 10 patients, the MR-correlated mammography and second-look sonography localized lesions that were not detected on the initial exam. All the non-MR-correlated sonographic abnormalities were benign. CONCLUSION: Breast MR imaging can identify otherwise occult breast cancer in patients with metastatic axillary lymph nodes. Localization of the lesions through MR-correlated mammography and second-look sonography is practically feasible in most cases.

The Role of Diffusion-Weighted Imaging and the Apparent Diffusion Coefficient (ADC) Values for Breast Tumors

OBJECTIVE: We wanted to evaluate the role of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for detecting breast tumors, as compared with the T1- and T2-weighted images. MATERIALS AND METHODS: Forty-one female patients underwent breast MRI, and this included the T1-, T2-, DWI and dynamic contrast-enhanced images. Sixty-five enhancing lesions were detected on the dynamic contrast-enhanced images and we used this as a reference image for detecting tumor. Fifty-six breast lesions were detected on DWI and the histological diagnoses were as follows: 43 invasive ductal carcinomas, one mucinous carcinoma, one mixed infiltrative and mucinous carcinoma, seven ductal carcinomas in situ (DCIS), and four benign tumors. First, we compared the detectability of breast lesions on DWI with that of the T1- and T2-weighted images. We then compared the ADCs of the malignant and benign breast lesions to the ADCs of the normal fibroglandular tissue. RESULTS: Fifty-six lesions were detected via DWI (detectability of 86.2%). The detectabilities of breast lesions on the T1- and T2-weighted imaging were 61.5% (40/65) and 75.4% (49/65), respectively. The mean ADCs of the invasive ductal carcinoma (0.89 +/- 0.18x10(-3)mm2/second) and DCIS (1.17 +/- 0.18x10(-3)mm2/ second) are significantly lower than those of the benign lesions (1.41 +/- 0.56x10(-3)mm2/second) and the normal fibroglandular tissue (1.51 +/- 0.29x10(-3)mm2/ second). CONCLUSION: DWI has a high sensitivity for detecting breast tumors, and especially for detecting malignant breast tumors. DWI was an effective imaging technique for detecting breast lesions, as compared to using the T1- and T2-weighted images.

Intracystic Papillary Carcinoma with Extensive Hemorrhage of the Breast: Sonographic and Advanced MR Findings: A Case Report

Intracystic papillary carcinoma (IPC) of the breast is very rare, and it has a much better prognosis than the other types of breast carcinoma. We experienced a case of intracystic papillary carcinoma that we diagnosed in an 83-year-old-woman. MR imaging of the IPC shows a multicystic appearance with a subacute or chronic stage of intracystic hemorrhage. The contrast-enhanced MR imaging demonstrates enhancement of the cyst wall and mural nodules, and this modality proved to be successful for making an accurate preoperative diagnosis.

Contrast Enhanced MRI Findings of Ductal Carcinoma in Situ

PURPOSE: The purpose of this study is to describe characteristic contrast enhanced MR mammographic findings of ductal carcinoma in situ (DCIS) and also DCIS with microinvasion. MATERIALS AND METHODS: From January 2000 to July 2005, 32 women with 33 lesions affected by DCIS or DCIS with microinvasion underwent contrast enhanced MRI, and they were then retrospectively evaluated. All the patients had previously undergone mammography and ultrasonography. All the findings of mammography, ultrasonography (US), and MRI were analyzed by using an ACR BI-RADS lexicon. RESULTS: All 33 cases were enhanced on the enhanced MR images. A smooth margined homogeneous enhanced mass was seen in the two (2/33) cases, and nonmass enhancement was seen in 31 (31/33) cases. Among the non-mass enhancement, focal enhancement (7/31), ductal enhancement (5/31), segmental enhancement (9/31), and regional enhancement (10/31) were observed. On the kinetic study, a wash-out pattern (10/33), a plateau pattern (20/33), and a persistent pattern (3/33) were demonstrated. No significant differences were noted between the pure and microinvasive DCIS. CONCLUSION: There is no significant difference between pure and microinvasive DCIS. However, contrast enhanced MR images can demonstrate occult foci, multifocal lesion and the tumor extent of DCIS on mammogram or ultrasonogram.

Granular Cell Tumor Simulating Breast Malignancy: A Case Report

Granular cell tumor is a rare and usually benign tumor that occasionally involves the breast. The physical examination, the mammographic and ultrasonographic findings and the pathologic findings are often suggestive of carcinoma. We report here a rare case of granular cell tumor of the breast that mimicked carcinoma on the mammography, ultrasonography and MR imaging.

Sequential Change in the Findings of Fat Necrosis on US, MRI and Tissue Specimen Radiogram Correlating with Histopathologic Findings: Experimental Study in Pigs

PURPOSE: This study compared the sequential findings of ultrasound, MRI and tissue specimen radiograms of experimentally induced fat necrosis in pigs with the histopathology findings. MATERIALS AND METHODS: Fat necrosis was induced in five experimental groups containing three pigs per group (3-day, 2-week, 4-week, 6-week and 8-week groups), which were divided according to the amount of time after inducing fat necrosis until when the tissue specimen was obtained. Ultrasound (US) and MRI (T1 weighted images, T2 weighted images, STIR sequence, T1 fat-suppressed contrast enhanced images) were obtained. X-ray tissue specimen radiograms were obtained after sacrificing the pigs. The changes in the findings of these imaging modalities were compared with the histopathology findings. RESULTS: Ultrasound showed the lipase-induced masses of fat necrosis to be isoechoic (47%) and mixed echoic (42%) masses in 3-day group, mixed (56%, 41%) and hypoechoic (42% and 59%) masses in the 2-week and 4-week groups respectively, and hypoechoic (67% and 56%) masses in the 6-week and 8-week groups. MRI showed the T1 weighted images to have significantly high rate of isosignal intensity in the 3-day, 2, 4 and 6-week groups, but the isosignal intensity lesions decreased gradually while the low signal intensity lesions increased with time. The T2 weighted images showed that the high signal intensity lesions were the main type of lesion in the early stage but the isosignal intensity lesions increased markedly in the late stage. The STIR (short tau inversion recovery) sequence showed that all the masses of fat necrosis were observed to have high signal intensity in the 3-day group, and the high signal intensity lesions decreased while the isosignal intensity lesions increased significantly during the follow-up period between 2 weeks to 8 weeks. All the masses of fat necrosis were enhanced on the fat-suppressed contrast-enhanced T1 weighted images. Among the total 45 cases X-ray tissue specimen radiograms, fat necrosis was observed as a radiopaque mass in 28 cases (62%). Among these 28 cases, calcifications within the masses were observed in 4 cases from the 8-week group and 1 case from 6-week group. Two cases from 2-week group were observed as spiculated masses. The histopathology findings of fat necrosis were acute inflammatory cell infiltration, edema and hemorrhage in the 3-day group, the proliferation of fibroblasts, connective tissue and capillaries around the fat necrosis in the 2-week group. However, the number of vessels decreased gradually and the fibrosis had progressed further in the 4, 6 and 8-week groups. CONCLUSION: The sequential findings of fat necrosis on US, MRI and tissue specimen radiogram were correlated with the histopathology findings. These results may be helpful for the differentiating fat necrosis from more ominous breast masses.

Breast MR Imaging: Correlation of High Resolution Dynamic MR Findings with Prognostic Factors

PURPOSE: We wanted to correlate the kinetic and morphologic MR findings of invasive breast cancer with the classical and molecular prognostic factors. MATERIALS AND METHODS: Eighty-seven patients with invasive ductal carcinoma NOS underwent dynamic MR imaging at 1.5 T, and with using the T1-weighted 3D FLASH technique. The morphologic findings (shape, margin, internal enhancement of the mass or the enhancement distribution and the internal enhancement of any non-mass lesion) and the kinetic findings (the initial phase and the delayed phase of the time-signal Intensity curve) were interpreted using a ACR BI-RADS(R)174;-MRI lexicon. We correlate MR findings with histopathologic prognostic factors (tumor size, lymph node status and tumor grade) and the immunohistochemically detected biomarkers (ER, PR, p53, c-erbB-2, EGFR and Ki-67). Univariate and multivariate statistical analyses were then performed. RESULTS: Among the MR findings, a spiculated margin, rim enhancement and washout were significantly correlated with the prognostic factors. A spiculated margin was independently associated with the established predictors of a good prognosis (a lower histologic and nuclear grade, positive ER and PR) and rim enhancement was associated with a poor prognosis (a higher histologic and nuclear grade, negative ER and PR). Wash out was a independent predictor of Ki-67 activity. CONCLUSION: Some of the findings of high resolution dynamic MR imaging were associated with the prognostic factors, and these findings may predict the prognosis of breast cancer.

Correlation of Contrast-Enhanced MR Findings and Tumor Microvessel Density of Breast Masses

PURPOSE: To compare the contrast-enhanced dynamic MR findings of solid breast masses with their histopathologic tumor angiogenesis. MATERIALS AND METHODS: Thirty-two cases of pathologically proved breast lesions (8 benign and 24 malignant lesions) examined with contrast-enhanced MRI were retrospectively reviewed, focusing on the tumor size, the maximum amount of contrast enhancement (% Signal Intensity Change, SIC), the time to peak (early or late peak) and the type of time-signal intensity curve (TSC). We compared the characteristic MR findings of breast cancer with the microscopic maximum microvessel density (MVD). RESULTS: Among the total of 11 small lesions ( or = 20). On the other hand, among the 21 large lesions (> 2 cm, 15 malignant and 6 benign), only two cases of malignant and five cases of benign lesions showed high MVD. More than 100% SIC was observed in a total of 11 malignant and two benign lesions, but 8 of these 11 malignant lesions showed low MVD (< 20), whereas the two benign lesions showed high MVD. Early time to peak (< or = 3 min) was observed in 18 (17 malignant and 1 benign) lesions, and 11 of these 17 malignant lesions showed low MVD. An early high peak and early or slow wash-out pattern, which is typical of the malignant type, was seen in 18 (17 malignant and 1 benign) lesions, but 12 of these 17 malignant lesions showed low MVD. There is no statistically significant correlation between the characteristic MR findings of breast cancer and the MVD. CONCLUSION: Although high MVD indicated malignancy in the case of the small lesions, the histopathologic MVD was not significantly correlated with either the increased amount of enhancement, early time-to peak or the malignant pattern of the TSC.

Magnetic Resonance Findings of Breast Diseases / 한국유방암학회지

Contrast-enhanced magnetic resonance imaging (MRI) of the breast is probably the most sensitive method for the detection of the pathology of the breast. It is an emerging technology that may revolutionize the management of women with known or suspected breast cancer. Recently, breast MRI has proven most useful in patients with proven breast cancer for the assessment of a multifocal/multicentric disease, chest wall involvement, chemotherapy response, or tumor recurrence or to identify the primary site in patients with occult breast cancer. False positive findings can pose a significance problem in the interpretation of a breast MRI. MRI examinations should be interpreted with an awareness of the pitfalls, false positive breast lesions, and artifacts that can affect on the image evaluation.

MR Findings of Siliconoma in Interstitial Silicone Injection Mammoplasty Patients

PURPOSE: To assess the MR findings of siliconomas (silicone granulomas) in patients with interstitial silicone injection mammoplasty. MATERIALS AND METHODS: Women with interstitial silicone injection mammoplasty were referred for this study on the basis of clinical findings of palpable mass. Nine patients with 18 augmentated breasts underwent axial and sagittal MR imaging, and the results were analysed in terms of their size, shape, margin, signal intensity, enhancement pattern, distribution and adjacent parenchymal distortion. We undertook in-vitro MR imaging of silicone, paraffin, fat, and water, and then compared their signal intensities at each sequence. RESULTS: Siliconomas were seen as well-defined low-signal-intensity nodules at T1WI and high-signal-intensity nodules at T2WI. There was no demonstrable contrast enhancement. Where there was breast cancer in which heterogeneous signal intensity was observed at T1 -and T2WI, together with heterogeneous enhancement, siliconomas were well differentiated from the tumor mass. At in-vitro MR imaging of silicone, paraffin, fat and water, paraffin showed a very low signal intensitiy at all pulse sequences but silicone showed low signal intensity at T1-fat-suppressed T1WI and high signal intensity at T2-and water-suppressed T2WI. CONCLUSION: MRI allows clear differentiation of siliconoma from fat and fibroglandular tissue, and can therefore, reveal anatomical details and detect lesions in patients with interstitial silicone injection mammoplasty.

Comparison of Imaging Diagnosis of Pyo genic Abscess and Inflammatory Cancer in the Breast: Focused on MRI

PURPOSE: To compare the radiologic findings of pyogenic abscess(PA) and inflammatory cancer(IC) of the breast, as seen on mammograms, US, and MR images and to evaluate the usefulness of the differential diagnostic findings of MRI for differentiation of PA and IC of the breast. MATERIALS AND METHODS: We retrospectively analyzed the mammographic, US and MR findings of nine histopathologically proven cases of PA and four cases of IC of the breast. Parenchymal density, mass density, skin thickening and calcification were evaluated by mammography, and the extent of lesion and its morphologic characteristics and changes of dermal lymphatics by US and MRI. The latter was also used to analyse signal intensity and enhancement pattern. RESULTS: Mammographic findings for both lesions were nonspecific. US showed that the pyogenic abscess was a hypoechoic and anechoic complex lesion with posterior acoustic enhancement, while inflammatory cancer was a spiculated lesion with a heterogeneous hypoechoic echotexture. On 3D-GRE dynamic enhanced M-RI, PA was shown in six cases(66.7 %) to be a lesion with superficial periareolar involvement, in contrast to the deep parenchymal spread seen in all cases of IC. A central non- enhanced portion with an irregular thick peripheral enhanced rim was seen in eight cases of PA(88.9 %) , and in all cases of IC an inhomogeneously enhanced spiculated lesion in parenchyma and a diffusely enhanced dermal and subcutaneous layer was apparent. An MRI time-intensity curve showed that the enhancement pattern was slow in five cases of PA(55.6 % ) and irregular in four(44.4 %), while for IC it was rapid in three cases(33.3 %) and irregular in one(11.1 % ). CONCLUSION: As compared with mammography and US, 3D-GRE dynamic MRI was a useful method for the differential diagnosis of PA and IC of the breast. The characteristic MR findings of PA were a central non-enhanced portion with an irregularly thick peripheral enhanced rim, located mainly in the superficial periareloar area and spreading into the parenchymal layer. An inhomogeneously enhanced spiculated solid mass in the parenchyma associated with diffuse dermal thickening and lymphatic dilatation was more suggestive of IC.

MRI of Breast Implant-related Complications

PURPOSE: To assess the usefulness of MRI in the preoperative diagnosis of breast implant-relatedcomplications. MATERIALS AND METHODS: Thirty four breast implants in 17 patients were examined. Eight breasts hada history of repeated surgery due to rupture and in eight others, simultaneous interstitial silicone injection hadbeen performed. MR images of the 34 implants were prospectively analyzed for implant-related complications,without prior clinical information, and the findings were compared with the results of surgery. RESULTS: Theimplant-related complications seen on MRI were infections in three cases, seromas in two, and implant malpositionin two. The linguine sign was seen in eight cases and intraparenchymal silicone in 17. Among the 32 removedimplants, rupture was genuine in ten cases (nine, extracapsular; one, intracapsular). In evaluating the MRfindings of implant rupture, the linguine sign showed 80% sensitivity, 100% specificity and 93.8% accuracy.Intraparenchymal silicon also revealed high sensitivity (90%), but relatively low specificity and accuracy (63.7%and 71.9%, respectively); this was due to the difficulty of differentiating granulomas still present after aprevious rupture from injected silicone material. MRI was useful for visualization of implant migration, thedirect relationship of extended or extruded silicone in extracapsular rupture and the localization of siliconegranulomas, as seen on multiplanar images. The extent of infection was clearly demonstrated on contrast enhancedscan. There was relatively good correlation between the degree of contracture seen on physical examination andthat seen on MRI. CONCLUSION: MRI was an effective and useful method for the preoperative evaluation ofimplant-related complications; degree of contracture was successfully predicted.

Diagnostic Value of 3D-Gradient Echo Dynamic Contrast Enhanced MRI in Breast Cancer

PURPOSE: To assess the usefulness of 3D-gradient echo dynamic contrast enhanced MRI (3D-DMRI) in the diagnosis of breast cancer and to determine the most useful parameter for this diagnosis. MATERIALS AND METHODS: Using a 1.0T MR unit, (Magnetom, Siemens, Erlaugen, Germany), 3D-DMRI (TR/TE=30/12) with Gd-DTPA was performed in 38 cases of breast cancer, 22 of fibroadenoma, and in three normal volunteers. We retrospectively evaluated the findings according to the speed on dynamic study and maximal amount of contrast enhancement during the delayed phase; we calculated the contrast index and morphology of the cancers and compared diagnostic accuracy among these three diagnostic parameters. RESULTS: On conventional spin-echo T1- and T2-weighted images, there was no significant difference of signal intensity between benign fibroadenoma and breast carcinoma. Rapid contrast enhancement (within one minute) was noted in 35 breast cancer lesions (92.1%), but relatively low and slow contrast enhancement (after five minutes) was noted in three such lesions (7.9%). Gradual contrast enhancement was noted in 21 lesions of fibroadenoma (95.5%), but a moderate degree of rapid contrast enhancement (from three to five minutes) was noted in the other case (7.9%). of On the delayed enhanced phase of 3D-DMRI, the maximal amountof contrast enhancement showed no significant difference between fibroadenoma and cancer. On 3D-DMRI, an irregular, spiculated border, with high contrast enhancement was noted in all cases of breast cancer, in particular, irregular thick peripheral contrast enhancement with central necrosis was noted 11 cases (28.9%). CONCLUSION: For the diagnosis of breast cancer, 3D-DMRI is a useful technique. Among the diagnostic criteria of speed, maximal amount of contrast enhancement and morphology, morphologic change after contrast enhancement study was the most useful diagnostic parameter.