MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

Relationship Between Breast Ultrasound Background Echotexture and Magnetic Resonance Imaging Background Parenchymal Enhancement and the Effect of Hormonal Status Thereon

We studied the relationship between breast ultrasound background echotexture (BET) and magnetic resonance imaging (MRI) background parenchymal enhancement (BPE) and whether this relationship varied with hormonal status and amount of fibroglandular tissue (FGT) on MRI. Two hundred eighty-three Korean women (52.1 years; range = 27-79 years) with newly diagnosed primary breast cancer who underwent preoperative breast ultrasound and MRI were retrospectively studied. Background echotexture, BPE, and FGT were classified into 4 categories, and age, menopausal status, menstrual cycle regularity, and menstrual cycle stage at MRI were recorded. Background echotexture and BPE relationship was assessed overall, and in menopausal, FGT, menstrual cycle regularity, and menstrual cycle stage subgroups. Background echotexture and BPE correlated in women overall, and menopausal, FGT, and menstrual cycle subgroups and those in the first half of the cycle (all P < 0.001). Background echotexture reflects BPE, regardless of menopausal status, menstrual cycle regularity, and FGT and may be a biomarker of breast cancer risk.

Pure Fibrocystic Change Diagnosed at MRI-guided Vacuum-assisted Breast Biopsy: Imaging Features and Follow-up Outcomes

OBJECTIVE

Fibrocystic change (FCC) is considered one of the most common benign findings in the breast and may be commonly seen on breast MRI. We performed this study to identify MRI characteristics of pure FCC on MRI-guided vacuum-assisted breast biopsy (VABB) without other associated pathologies and describe the findings on MRI follow-up and outcomes.

METHODS

A retrospective review was performed for 598 lesions undergoing 9-gauge MRI-guided VABB at our institution from January 2015 to April 2018, identifying 49 pure FCC lesions in 43 patients. The associations between variables and lesion changes on follow-up MRI were analyzed using exact Mann-Whitney tests and Fisher's exact tests.

RESULTS

MRI features of pure FCC are predominantly clumped nonmass enhancement (19/49, 39%) or irregular masses with initial fast/late washout kinetics (9/49, 18%). There was no upgrade to high-risk or cancerous lesions among the 11 patients (25.6%) who underwent surgery. There were 22 pure FCC lesions in 19 (44.2%) patients who had follow-up MRI (mean 18.0 months, range 11-41 months) showing regression (13, 59%), stability (8, 36%), or progression (1, 5%) of the lesion size, and no cancers were found on follow-up at the site of the MRI biopsy for fibrocystic changes. No patient demographics or lesion features were associated with lesion regression or stability (P > 0.05).

CONCLUSION

Our study shows that MRI features of VABB-proven FCC lesions may mimic malignancy. After VABB of pure FCC, given that adequate sampling has been performed, a 12-month follow-up MRI may be reasonable.

Imaging and Clinical Features of an Unusual Unilateral Breast Enlargement Diagnosed as Fibrocystic Change: A Case Report

Patient: Female, 38

Final Diagnosis: Fibrocystic change

Symptoms: Breast swelling

Medication: —

Clinical Procedure: Breast biopsy

Specialty: Radiology

Diagnostic efficacy and safety of gadoteric acid MR mammography in 1537 patients

OBJECTIVES

To perform a large-scale multicenter post-marketing surveillance study for analyzing diagnostic effectiveness and safety of intravenous (IV) gadoteric acid (Dotarem^®) in magnetic resonance (MR) mammography under daily practice conditions.

MATERIALS AND METHODS

Patients underwent high-resolution MR mammography with gadoteric acid in 15 German centers. Radiologists used a standardized questionnaire to report data including patient demographics and medical history, characteristics of MR examination and results in terms of diagnosis and safety for the patient.

RESULTS

A total of 1537 patients were examined. In 99.2% of all patients, a diagnosis was established. In 91.6% of all patients, image quality was excellent or good. Histopathological examinations were performed for 232 of 1537 patients (15.1%) with invasive ductal carcinoma being the most frequent diagnosis (109 patients, 47.0%). Based on histopathology as the standard of reference, IV gadoteric acid-enhanced MR mammography confirmed diagnoses of invasive ductal carcinoma in 93.5% of the patients. Adverse drug reactions occurred in 5 of 1537 patients (0.3%) and were classified as serious in one case (tachycardia, dysphagia, urticaria, rash). All patients with adverse drug reactions fully recovered after the examination.

CONCLUSION

This noninterventional surveillance study shows IV gadoteric acid to be a safe and effective contrast agent for use in MR mammography.

Correlation of endogenous hormonal levels, fibroglandular tissue volume and percent density measured using 3D MRI during one menstrual cycle

BACKGROUND

We measured breast density (BD) on MRI and correlated with endogenous hormonal levels.

PATIENTS AND METHODS

Twenty-four premenopausal women received four weekly breast MRI. A blood sample was collected on the same day of MRI. BD was measured using a computer-based algorithm. The generalized estimation equation method was applied to model mean fibroglandular tissue volume (FV) and mean percent density (PD) from predictor variables including estradiol, progesterone, and week during a cycle.

RESULTS

In week 3, a borderline significant correlation between estradiol and PD (r = 0.43, P = 0.04), estradiol and FV (r = 0.40, P = 0.05) and between progesterone and FV (r = 0.42, P = 0.04) was noted. The FV and PD measured in weeks 4 and 1 were higher than in weeks 2 and 3, adjusted for variation in endogenous estradiol and progesterone, indicating that the hormone change could not account for the changes in density. No lag effect of endogenous hormone on the change of FV or PD was noted (all P-values > 0.05).

CONCLUSIONS

Our results showed that BD is not strongly associated with the endogenous hormone. Their association with breast cancer risk was likely coming from different mechanisms, and they should be considered as independent risk factors.

Background parenchymal enhancement on breast MRI: influence of menstrual cycle and breast composition

PURPOSE

To evaluate the menstrual cycle and breast composition influence on background parenchymal enhancement of breast magnetic resonance imaging (MRI) and to investigate the optimal time for breast MR examinations.

MATERIALS AND METHODS

We evaluated the dynamic contrast-enhanced breast MR images of 238 women who had completed a questionnaire survey about menstrual status. On MRI, the degree of enhancement (DE) of normal parenchyma was measured in the images 2 minutes and 6 minutes after contrast injection. A comparison between premenopausal and postmenopausal women and a separate comparison between dense breasts and fatty breasts were analyzed according to the premenopausal women's menstrual cycle.

RESULTS

Premenopausal women showed significantly higher DE than the postmenopausal women (P<0.001). In premenopausal women, overall DE of fatty breasts and dense breasts was not different. However, fatty breasts showed the highest DE in the 4th week and lowest DE in the 2nd week, while dense breasts showed the highest DE in the 3rd week and the lowest DE in the 4th week of menstrual cycle.

CONCLUSION

The influence of menstrual cycle on the enhancement of breast parenchyma is different according to the breast composition. The optimal time for breast MRI could be different for dense and fatty breasts.

Effect of the menstrual cycle on background parenchymal enhancement in breast MR imaging

PURPOSE

We assessed the influence of the menstrual cycle on background parenchymal enhancement (BPE) of the breast in the early and delayed phases of dynamic magnetic resonance (MR) imaging and the optimal timing of MR imaging of the breast in Japanese women.

MATERIAL AND METHODS

We reviewed dynamic MR images of 165 consecutive women with regular menstrual cycles and divided the women into 4 groups by week of the menstrual cycle: 32 in Week One (Days 1 through 4 of the menstrual cycle); 46 in Week 2 (Days 5 through 12); 49 in Week 3 (Days 13 through 20); and 38 in Week 4 (Days 21 through 30). We qualitatively evaluated BPE of the whole breast in the early and delayed phases of MR imaging; categorized enhancement as minimal, mild, moderate, or marked; and calculated the rate at which signal intensity increased (=SI post-SI pre/SI pre) in regions of interest in from the early and delayed phase to the before contrast administration phase to assess BPE quantitatively.

RESULTS

In both the early and delayed dynamic MR phases, BPE was significantly more extensive and stronger in Week 4 than Week 2 (P<0.01). Throughout the menstrual cycle, BPE was significantly stronger in the delayed phase than in the early phase in both qualitative (Week One, P=0.0002; Weeks 2 through 4, P<0.0001) and quantitative (Weeks One through 4, P<0.0001) assessments.

CONCLUSION

The optimal time to perform dynamic breast MR imaging in premenopausal Japanese women was during Days 5 through 12 of the menstrual cycle.

Normal breast parenchyma: contrast enhancement kinetics at dynamic MR mammography--influence of anthropometric measures and menopausal status

PURPOSE

To study T1 baseline signal intensity (SI) and contrast material enhancement kinetics of normal breast parenchyma by using dynamic contrast-enhanced (DCE) magnetic resonance (MR) mammography and to determine the influence of anthropometric measures and menopausal status on the variability of these features.

MATERIALS AND METHODS

Institutional review board approval and written informed consent were obtained. Between June 2008 and September 2011, 345 women (age range, 26-81 years; mean age, 51.3 years ± 11.6 [standard deviation]) underwent DCE MR mammography, with T1-weighted three-dimensional MR images (repetition time msec/echo time msec, 8.86/4.51; flip angle, 25°) acquired with a 1.5-T whole-body MR unit before and 1, 2, 3, 4, and 5 minutes after a gadobutrol bolus injection of 0.1 mmol per kilogram of body weight. Regions of interest were traced manually, and T1 SI of parenchyma was recorded. The influence of different predictors of T1 baseline SI and contrast enhancement was studied by using random-effects models.

RESULTS

T1 baseline SI varied considerably between women, with a mean of 167.7 ± 49.2 (71.4-424.7 [range]) and 175.9 ± 48.9 (51.8-458.3) in the right and the left breast, respectively (P < .01). T1 baseline SI increased linearly with age (P < .0001) and body weight (P < .0001). After contrast material delivery, relative percentage of enhancement was 8.1%, 13.8%, 18.2%, 22.1%, and 24.6% at 1, 2, 3, 4, and 5 minutes, respectively, but varied considerably between women. Contrast enhancement was 9.3% in the lowest quintile and 47.4% in the highest. Contrast enhancement increased with body weight (P < .01) but decreased in postmenopausal women (P < .01). Women with higher baseline T1 SI tended to have a higher contrast enhancement slope.

CONCLUSION

Anthropometric measures and menopausal status contribute to a large variability in contrast enhancement of normal breast parenchyma. This might influence the interpretation of contrast enhancement kinetics of breast lesions and current strategies for determining contrast medium dose for breast MR imaging.

Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy

OBJECTIVES

To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM).

METHODS

A total of 459 female volunteers (mean age 49.1 ± 12.5 years) underwent T1-weighted 3D MRM 1-5 min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n = 69) and HT (n = 24) on CE was studied using random effects models.

RESULTS

Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P < 0.001). CE decreased significantly with the use of OC (P = 0.01), while HT had negligible effects (P = 0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P < 0.0001), but was similar in OC users and non-OC users (P = 0.61) as well as HT users and non-HT users (P = 0.77).

CONCLUSIONS

Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use.

KEY POINTS

Breast parenchymal enhancement at MR mammography is stronger in premenopausal than postmenopausal women. The prevalence of strong enhancing non-mass-like areas is greater before menopause. Such enhancing non-mass-like areas may impair lesion detection in premenopausal women. Breast parenchymal enhancement is only marginally affected by hormone use. Discontinuation of hormone use before MR mammography may be unnecessary.

Magnetic resonance imaging (MRI) and dynamic MRI evaluation of extranodal non-Hodgkin lymphoma in oral and maxillofacial regions

OBJECTIVE

The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI), especially dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), in extranodal non-Hodgkin lymphoma (NHL) of oral and maxillofacial regions.

STUDY DESIGN

Thirteen cases with extranodal NHL were examined using MRI. T1-weighted images (T1WI) and T2-weighted images (T2WI) or short TI inversion recovery (STIR) images were obtained in all cases. Contrast-enhanced images and DCE-MRI were acquired in 10 and 7 cases, respectively. On DCE-MRIs, we analyzed the parameters as follows: contrast index at maximal contrast enhancement (CImax), maximum contrast index (CI) gain/CImax ratio, and washout ratios (WR(300), WR(600), and WR(900)) at 300, 600, and 900 seconds after contrast medium injection.

RESULTS

The signal intensity of all lesions was hypointense to isointense on T1WIs and showed variable contrast enhancement patterns. On T2WIs and STIR images, the signal intensity was isointense to hyperintense in almost all cases. Analysis of DCE-MRI parameters in extranodal NHLs resulted in the identification of 4 types of CI curves according to CImax and WR: (1) CImax greater than 2.0 and WR(900) greater than 40%, (2) CImax greater than 2.0 and WR(900) less than 40%, (3) CImax less than 1.5 and WR(900) greater than 40%, and (4) CImax less than 1.5 and WR(900) greater than 40%.

CONCLUSIONS

The signal intensities on MRI were not specific to extranodal NHL and resembled those of other tumor types. When CImax was less than 1.5 or WR900 was less than 40%, these parameters contributed to diagnosis in extranodal NHLs.

Menstrual cycle-related fluctuations in breast density measured by using three-dimensional MR imaging

PURPOSE

To investigate the fluctuation of fibroglandular tissue volume (FV) and percentage of breast density (PD) during the menstrual cycle and compare with postmenopausal women by using three-dimensional magnetic resonance (MR)-based segmentation methods.

MATERIALS AND METHODS

This study was approved by the Institutional Review Board and was HIPAA compliant. Written informed consent was obtained. Thirty healthy female subjects, 24 premenopausal and six postmenopausal, were recruited. All subjects underwent MR imaging examination each week for 4 consecutive weeks. The breast volume (BV), FV, and PD were measured by two operators to evaluate interoperator variation. The fluctuation of each parameter measured over the course of the four examinations was evaluated on the basis of the coefficient of variation (CV).

RESULTS

The results from two operators showed a high Pearson correlation for BV (R(2) = 0.99), FV (R(2) = 0.98), and PD (R(2) = 0.96). The interoperator variation was 3% for BV and around 5%-6% for FV and PD. In the respective premenopausal and postmenopausal groups, the mean CV was 5.0% and 5.6% for BV, 7.6% and 4.2% for FV, and 7.1% and 6.0% for PD. The difference between premenopausal and postmenopausal groups was not significant (all P values > .05).

CONCLUSION

The fluctuation of breast density measured at MR imaging during a menstrual cycle was around 7%. The results may help the design and interpretation of future studies by using the change of breast density as a surrogate marker to evaluate the efficacy of hormone-modifying drugs for cancer treatment or cancer prevention.

Diagnosis of breast cancer: MDCT versus MRI

In Japan, helical CT has been applied to breast cancers for the accurate determination of cancer extent before surgery. In recent years, multidetector CT (MDCT) has become commercially available. Compared with mammography and ultrasonography, MDCT of the breast is thought to be useful for preoperative assessment of breast-conserving surgery. In contrast, magnetic resonance imaging (MRI) is extremely accurate in the diagnosis of intraductal carcinoma and multicentricity of breast cancer. A real problem related to the use of CT is X-ray exposure. Therefore, it is controversial whether the use of CT for the patients with breast cancer is appropriate or not. Recent studies that compared the use of MDCT and MRI in the same patients concluded that MRI was more accurate for the detection and evaluation of the extent of intraductal carcinoma. We should consider the pitfalls and limitations of CT for assessing the breast cancer extent.

Inflammatory breast carcinoma in magnetic resonance imaging: a comparison with locally advanced breast cancer

RATIONALE AND OBJECTIVES

Although inflammatory breast carcinoma (IBC) accounts for 1%-4% of all breast cancer cases, the appearance of this highly malignant tumor in magnetic resonance imaging (MRI) is still not well characterized. The aim of this study was to identify typical imaging features of IBC in comparison with noninflammatory locally advanced breast carcinoma (LABC).

MATERIALS AND METHODS

MRIs of 48 patients with IBC were compared with an equivalent cohort of 52 subjects with LABC. Age and histopathologic subtype were equivalent between the two groups. To delineate characteristic features, a multitude of dynamic and morphologic parameters were evaluated using T1- and T2-weighted sequences.

RESULTS

No significant differences of prevalences could be found for the following criteria: dynamic tumor signal characteristics, prominent vessels, perifocal edema, axillary lymph node involvement, morphology of focal masses, and morphologic pattern of non-mass like enhancement. Otherwise, the quantity of focal masses and the spatial distribution of the tumoral infiltration significantly differed between the two cancer groups. The following parameters occurred more frequently in the IBC cases: edema (cutaneous/subcutaneous 81.3%, perimamillar 70.8%, diffuse 89.6%, prepectoral 72.9%, intramuscular pectoral 41.7%), thickening (75.0%) and pathologic enhancement (60.4%) of Cooper's ligaments, skin thickening (83.3%), punched-out sign (initially strong, focal increase of some dermal or subcutaneous parts followed by slow-continuous enhancement of the surrounding skin; 56.3%).

CONCLUSIONS

Inflammatory breast carcinoma seems to represent a specific biological entity resulting in typical MRI characteristics. Some of the parameters are supposed to visualize the characteristic extensive lymphovascular infiltration and therefore may improve the diagnosis of IBC.

Signal intensity of normal breast tissue at MR mammography on midfield: applying a random coefficient model evaluating the effect of doubling the contrast dose

PURPOSE

To prospectively investigate the effect on signal intensity (SI) of healthy breast parenchyma on magnetic resonance mammography (MRM) when doubling the contrast dose from 0.1 to 0.2 mmol/kg bodyweight.

MATERIALS AND METHODS

Informed consent and institutional review board approval were obtained. Twenty-five healthy female volunteers (median age: 24 years (range: 21-37 years) and median bodyweight: 65 kg (51-80 kg)) completed two dynamic MRM examinations on a 0.6T open scanner. The inter-examination time was 24 h (23.5-25 h). The following sequences were applied: axial T2W TSE and an axial dynamic T1W FFED, with a total of seven frames. At day 1, an i.v. gadolinium (Gd) bolus injection of 0.1 mmol/kg bodyweight (Omniscan) (low) was administered. On day 2, the contrast dose was increased to 0.2 mmol/kg (high). Injection rate was 2 mL/s (day 1) and 4 mL/s (day 2). Any use of estrogen containing oral contraceptives (ECOC) was recorded. Post-processing with automated subtraction, manually traced ROI (region of interest) and recording of the SI was performed. A random coefficient model was applied.

RESULTS

We found an SI increase of 24.2% and 40% following the low and high dose, respectively (P<0.0001); corresponding to a 65% (95% CI: 37-99%) SI increase, indicating a moderate saturation. Although not statistically significant (P=0.06), the results indicated a tendency, towards lower maximal SI in the breast parenchyma of ECOC users compared to non-ECOC users.

CONCLUSION

We conclude that the contrast dose can be increased from 0.1 to 0.2 mmol/kg bodyweight, if a better contrast/noise relation is desired but increasing the contrast dose above 0.2 mmol/kg bodyweight is not likely to improve the enhancement substantially due to the moderate saturation observed. Further research is needed to determine the impact of ECOC on the relative enhancement ratio, and further studies are needed to determine if a possible use of ECOC should be considered a compromising factor, if an MRM is indicated in a young woman.

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.

Further Signs in the Evaluation of Magnetic Resonance Mammography

PURPOSE

To increase accuracy and reliability of magnetic resonance breast imaging, a new evaluation method might be helpful. The recently suggested evaluation method (Fischer U, et al) resulted in a relevant number of equivocal cases (3 or 4 points). Additional morphologic and dynamic signs as an extension of this score were evaluated.

METHOD AND MATERIALS

One hundred thirty-two histologically verified lesions were evaluated by 3 radiologists double-blinded using 2 evaluation methods: 1) method 1 (according to Fischer, et al): 2pt: initial signal increase >100%, washout, centripetal enhancement, 1pt: initial signal increase 50-100%, plateau phenomenon, centrifugal inhomogeneous enhancement, irregular borders, linear, stellar or dendritic structure; and 2) method 2 (according to Malich, et al): 3pt: hook sign (sign of pectoral invasion), 2pt: unifocal edema, blooming. 1pt: hypointensity in T2, lymph nodes >10 mm, skin thickening, adjacent vessels, a lesion's distorted inner architecture, disruption of the mamillary edge; -1pt: isointensity in T2, no edema, enhancing septations; -3pt: hyperintensity in T2, non enhancing septations. Method 1 judged a lesion to be malignant if 5 or more points were given and benign if 2 or less points were given, respectively. Method 2 (mean value of 3 radiologists) was tested in those cases in which a clear possible decision using method 1 was not sufficiently possible.

RESULTS

Method 1 alone resulted in a negative predictive value of 96.8% and a positive predictive value of 90.8% (without carcinoma in situ), a sensitivity of 83.1%, a specificity of 58.8%, and revealed uncertain results (3 and 4 points) in 29 cases (out of 132; 22%). Adding the new scoring system in these 29 equivocal cases and an increase of 2 or more points by using method 2 is supposed to be a sign of malignancy; findings suggest a sensitivity of 90.9% and a specificity of 60% if an increase of maximum 1 is observed in benign lesions. In conclusion, our results show that Göttingen score alone has a sensitivity of 83.1%, a specificity of 58.8%; the second evaluation method reveals a sensitivity of 90.9% and a specificity of 60% in equivocal cases of Göttingen score. Göttingen score then reaches in all cases and second, adding the second evaluation method in equivocal cases, a sensitivity of 97% and a specificity of 76.5%.

CONCLUSION

The application of a second evaluation method in those cases remaining unclear in Göttingen score can lead to a decrease of uncertainty and a higher sensitivity and specificity of diagnosis in MR mammography. In this study, Göttingen score reaches a sensitivity of 83.1% and a specificity of 58.8%, increasing to a sensitivity of 97% and a specificity of 76.5% when being extended by a second evaluation method in unclear cases.

Magnetic Resonance Imaging Characteristics of Fibrocystic Change of the Breast

OBJECTIVE

The objective of this study was to identify magnetic resonance imaging (MRI) characteristics of fibrocystic change (FCC) of the breast.

MATERIALS AND METHODS

Fourteen patients with a histopathologic diagnosis of solitary FCC of the breast underwent x-ray mammography and MRI of the breast. Three experienced breast imaging radiologists retrospectively reviewed the MRI findings and categorized the lesions on morphologic and kinetic criteria according to the ACR BI-RADS-MRI Lexicon.

RESULTS

The most striking morphologic feature of fibrocystic change was nonmass-like regional enhancement found in 6 of 14 (43%) FCC lesions. Based on morphologic criteria alone, 12 of 14 (86%) lesions were correctly classified as benign. According to analysis of the time-intensity curves, 10 of 14 (71%) FCC lesions were correctly classified as benign.

CONCLUSION

Although FCC has a wide spectrum of morphologic and kinetic features on MRI, it most often presents as a mass or a nonmass-like regional enhancing lesion with benign enhancement kinetics.

Changes in magnetic resonance mammography due to hormone replacement therapy

Background

The aim of the present article is to investigate effects of hormone replacement therapy (HRT) on contrast medium enhancement patterns in postmenopausal patients during magnetic resonance mammography (MRM).

Materials and methods

Two hundred and fifteen patients receiving hormonal medication were divided into four groups: 150 patients with 1 MRM during HRT (group A), 13 patients with 2 MRMs under HRT (group B), 30 patients with 1 MRM during HRT and 1 MRM after HRT withdrawal (group C), and 22 women with 1 MRM after HRT withdrawal (group D). Dynamic MRM was performed at 1.5 Tesla. Signal intensity changes were characterized by five time curves: minimal enhancement (type I), weak continuous enhancement (type II), strong continuous enhancement (type III), and a steep initial slope followed by a plateau phenomenon (type IV) or a washout effect (type V).

Results

Of all 193 patients under HRT (group A + group B + group C), 60 patients (31.1%) showed curve type I, 88 patients (45.6%) showed type II and 45 patients (23.3%) showed type III. There were significant differences to 52 patients after HRT withdrawal (group C + group D) (P < 0.0001), with 42 patients (80.8%) for curve type I, 8 patients (15.4%) for type II, and 2 patients (3.8%) for type III. In both MRM sessions in group B, 69% of the patients showed identical curve types without significant differences (P = 0.375). In group C, 28 of 30 patients (93%) dropped to lower curve types with significant differences in curve types during and after HRT (P < 0.0001).

Conclusion

The majority of patients receiving postmenopausal HRT showed bilateral symmetrical, continuous enhancement without evidence of a plateau phenomenon or a washout effect due to HRT in MRM. Hormonal effects could be proven and were reproducible and reversible.

MR imaging: breast cancer staging and screening

This review describes the current knowledge and challenges of breast cancer staging and screening with MRI of the breast. Assessment of local disease extent, including tumor size, multicentricity, and chest wall invasion, can be obtained more accurately with MRI than with mammography. Moreover, international experts have established standardized reporting of MRI staging results, taking into account tumor size measurements and the number of breast quadrants involved. Results from MRI assessment of the axilla and skin are promising, but need further refinement. Preliminary results of the use of breast MRI in patients at high risk for breast cancer demonstrated a superiority of breast MRI over the combined use of mammography and high-frequency ultrasound. The role of MRI in this subset of patients may be confirmed by ongoing larger multicenter trials. Strict protocol conditions are mandatory to maintain a high standard of quality. Confirming the nature of "MRI-only" lesions with MRI-guided biopsy systems will allow changes in treatment planning. More accurate tumor diagnosis and tumor volume evaluation may allow minimally invasive treatment strategies.