Utility of second-look ultrasound in the management of incidental enhancing lesions detected by breast MR imaging

Purpose

To assess the utility of second-look ultrasound (US) for identifying and characterising incidental enhancing lesions detected by breast magnetic resonance imaging (MRI).

Materials and methods

From among 655 consecutive breast MRI studies, 62 lesions (MRI visible, nonpalpable, occult at first-look US and mammography) were recommended for second-look US. MRI enhancement of lesions was mass-like in 59 cases (95%) and non-mass-like in three (5%). Forty-two lesions (68%) were ??10 mm; only three lesions (5%) were >20 mm. Of all lesions, the Breast Imaging Reporting and Data System (BI-RADS) MRI category was highly suggestive of malignancy in six cases (10%), suspicious abnormality in 33 (53%) and probably benign in 23 (37%). The correlation between MRI lesion appearance, lesion size, histopathology findings and detection rate at second-look US were analysed. The reference standard was histopathology and/or follow-up (range 18?C24 months). Statistical analysis was performed with the Fisher exact test.

Results

Second-look US identified 44 out of 62 (71%) lesions depicted at MRI. The detection rate at second-look US was higher for mass-like MRI lesions (75%) than nonmass-like lesions (0%), for lesion size >10mm (90%) and for BI-RADS 4 lesions (88%). Second-look US-guided biopsy detected 12 out of 17 (71%) malignant lesions. There was no correlation between the likelihood of carcinoma and the presence of a sonographic correlate.

Conclusions

Second-look US is a reliable problemsolving tool in identifying and characterising most incidental MRI findings. It contributes to accurately selecting the cases in which MRI-guided biopsy is required.     

Characterisation of indeterminate focal breast lesions on grey-scale ultrasound: role of ultrasound elastography

Purpose

This study was undertaken to evaluate the role of ultrasound (US) elastography in characterising focal breast lesions classified as indeterminate on B-mode US.

Materials and methods

Eighty-four focal breast lesions, 64 benign and 20 malignant (mean diameter, 15.1 mm), detected but not characterised on B-mode US in 72 women, Breast Imaging Reporting and Data System (BI-RADS) US category 3 (n=56) or category 4 (n=28), were studied with US elastography and classified in consensus by two radiologists according to a five-point colour scale. Sensitivity, specificity and positive and negative predictive values (PPV and NPV) of US elastography compared with conventional US were calculated in relation to microhistology (n=67) and cytology (n=17), which were used as the reference standard.

Results

A total of 65/84 (77.4%) lesions were correctly classified as benign or malignant using US elastography, whereas the remaining 19/84 (22.6%) were incorrectly assessed. There were no statistically significant differences between US elastography and B-mode US with regard to sensitivity (70% vs. 68.4%), specificity (79.6% vs. 78.5%), PPV (51.8% vs. 48.1%) and NPV 89% vs. 89.5% (p>0.5). By contrast, a statistically significant difference was noted in the evaluation of BI-RADS 3 lesions, in which US elastography had 50% sensitivity, 86% specificity, 30% PPV and 93.5% NPV compared with BI-RADS 4 lesions (78.6%, 57.1%, 64.7% and 72.7%) (p<0.5).

Conclusions

The high NPV of US elastography may help reduce the use of biopsy in BI-RADS 3 lesions, but its low PPV in BI-RADS 4 lesions does not allow avoidance of biopsy on the basis of the US elastographic score alone in this group of lesions.     

Magnetic resonance imaging of primary breast lymphoma

Purpose

Primary lymphomas of the breast (PBNHL) are uncommon. Magnetic resonance imaging (MRI) features of these malignancies can be relevant in establishing the extent of disease and planning the appropriate therapeutic strategy, usually represented by chemo- and radiotherapy, rather than surgery. The purpose of this study was to assess MRI features of PBNHL.

Materials and methods

MRI examinations performed on seven patients with known PBNHL were retrospectively evaluated. Lesions were analysed for both morphology and kinetics and classified according to the Breast Imaging Reporting and Data System (BI-RADS) categories.

Results

The mean MRI maximum diameter was 44 mm (range 12–69). Six lesions showed a mass-like enhancement; one lesion showed a non-mass-like enhancement. For mass-like lesions, kinetic curve assessment of initial rise showed slow enhancement in one lesion, rapid enhancement in four lesions and medium enhancement in one lesion. Assessment of delayed enhancement showed plateau in five lesions and washout in one lesion. MRI BI-RADS categories were distributed as follows: one BI-RADS II, one BI-RADS III, three BI-RADS IV and two BI-RADS V.

Conclusions

MRI features of primary breast lymphomas in this study cohort suggest that the occurrence of a PBNHL should be considered in the presence of large enhancing lesions of the breast, especially if associated with skin thickening. MRI may also have an important role in the assessment of response to therapy and diagnosis of recurrence.     

Probability of malignancy for lesions detected on breast MRI: a predictive model incorporating BI-RADS imaging features and patient characteristics

Objectives

To predict the probability of malignancy for MRI-detected breast lesions with a multivariate model incorporating patient and lesion characteristics.

Methods

Retrospective review of 2565 breast MR examinations from 1/03?C11/06. BI-RADS 3, 4 and 5 lesions initially detected on MRI for new cancer or high-risk screening were included and outcomes determined by imaging, biopsy or tumor registry linkage. Variables were indication for MRI, age, lesion size, BI-RADS lesion type and kinetics. Associations with malignancy were assessed using generalized estimating equations and lesion probabilities of malignancy were calculated.

Results

855 lesions (155 malignant, 700 benign) were included. Strongest associations with malignancy were for kinetics (washout versus persistent; OR 4.2, 95% CI 2.5?C7.1) and clinical indication (new cancer versus high-risk screening; OR 3.0, 95% CI 1.7?C5.1). Also significant were age >?=?50?years, size >?=?10?mm and lesion-type mass. The most predictive model (AUC 0.70) incorporated indication, size and kinetics. The highest probability of malignancy (41.1%) was for lesions on MRI for new cancer, >?=?10?mm with washout. The lowest (1.2%) was for lesions on high-risk screening, <10?mm with persistent kinetics.

Conclusions

A multivariate model shows promise as a decision support tool in predicting malignancy for MRI-detected breast lesions.     

BI-RADS categorisation of 2708 consecutive nonpalpable breast lesions in patients referred to a dedicated breast care unit

Objectives

To determine the malignancy rate of nonpalpable breast lesions, categorised according to the Breast Imaging Reporting and Data System (BI-RADS) classification in the setting of a Breast Care Unit.

Methods

All nonpalpable breast lesions from consecutive patients referred to a dedicated Breast Care Unit were prospectively reviewed and classified into 5 BI-RADS assessment categories (0, 2, 3, 4, and 5).

Results

A total of 2708 lesions were diagnosed by mammography (71.6%), ultrasound (8.7%), mammography and ultrasound (19.5%), or MRI (0.2%). The distribution of the lesions by BI-RADS category was: 152 in category 0 (5.6%), 56 in category 2 (2.1%), 742 in category 3 (27.4%), 1523 in category 4 (56.2%) and 235 in category 5 (8.7%). Histology revealed 570 malignant lesions (32.9%), 152 high-risk lesions (8.8%), and 1010 benign lesions (58.3%). Malignancy was detected in 17 (2.3%) category 3 lesions, 364 (23.9%) category 4 lesions and 185 (78.7%) category 5 lesions. Median follow-up was 36.9?months.

Conclusion

This pragmatic study reflects the assessment and management of breast impalpable abnormalities referred for care to a specialized Breast Unit. Multidisciplinary evaluation with BI-RADS classification accurately predicts malignancy, and reflects the quality of management. This assessment should be encouraged in community practice appraisal.     

Real-time virtual sonography (RVS)-guided vacuum-assisted breast biopsy for lesions initially detected with breast MRI

Purpose

To report on our initial experiences with a new method of real-time virtual sonography (RVS)-guided 11-gauge vacuum-assisted breast biopsy for lesions that were initially detected with breast MRI.

Materials and methods

RVS-guided 11-gauge vacuum-assisted biopsy is performed when a lesion with suspicious characteristics is initially detected with breast MRI and is occult on mammography, sonography, and physical examination. Live sonographic images were co-registered to the previously loaded second-look spine contrast-enhanced breast MRI volume data to correlate the sonography and MR images.

Results

Six lesions were examined in six consecutive patients scheduled to undergo RVS-guided 11-gauge vacuum-assisted biopsy. One patient was removed from the study because of non-visualization of the lesion in the second-look spine contrast-enhanced breast MRI. Five patients with non-mass enhancement lesions were biopsied. The lesions ranged in size from 9 to 13 mm (mean 11 mm). The average procedural time, including the sonography and MR image co-registration time, was 25 min. All biopsies resulted in tissue retrieval. One was fibroadenomatous nodules, and those of four were fibrocystic changes. There were no complications during or after the procedures.

Conclusion

RVS-guided 11-gauge vacuum-assisted breast biopsies provide a safe and effective method for the examination of suspicious lesions initially detected with MRI.     

Identification of occult breast lesions detected by magnetic resonance imaging with targeted ultrasound: A prospective study

Objective

To verify the capacity of targeted ultrasound (US) to identify additional lesions detected on breast magnetic resonance imaging (MRI), but occult to initial mammography, US and clinical examinations.

Methods

This prospective study included 68 additional relevant breast lesions identified on MRI of 49 patients. As an inclusion criterion, breast US and mammography were required and performed up to six months before MRI. These lesions were then subjected to targeted “second-look” US up to 2 weeks after MRI, performed by one or two radiologists with expertise on breast imaging. Lesions were evaluated according to the established Breast Imaging Report and Data System (BI-RADS) lexicon.

Results

Targeted US identified 46/68 (67.6%) lesions revealed by MRI. No significant associations were observed between US identification and the type of lesion, dimensions, morphological characteristics and enhancement pattern according to MRI findings. Targeted US identified 100% of BI-RADS category 5 lesions, 90% of category 4 lesions, and just over 50% of category 3 lesions (p < 0.05). There was significant agreement (p < 0.001) between MRI and US BI-RADS classification for all three categories.

Conclusion

Targeted US can identify a large proportion of the lesions detected by breast MRI, especially those at high risk of malignancy, when performed by a professional with experience in both breast US and MRI.     

The role of second-look ultrasound of BIRADS-3 mammary lesions detected by breast MR imaging

Objective

To asses the value of second-look ultrasound (US) for identifying BIRADS 3 (Breast Imaging Reporting Data System) mammary lesions detected by breast Magnetic Resonance imaging (MRI).

Materials and methods

From April 2008 to May 2009 330 breast MRI were performed of which 60 patients are classified as BIRADS 3. 84 lesions underwent second-look US and percutaneous vacuum biopsy Vacora system US-guided. Statistical analysis: lesions were stratified into two groups: visible on US (Group 1) and not visible on US (Group 2).The clinical impact of second-look US was studied in terms of negative predictive value (NPV).

Results

The positive predictive value (PPV) of category 3 BIRADS MRI was found to be 89%. Second look-US results detected lesions in 51% of the MRI enhancing lesions. The second look-US showed a NPV of 97%. The NPV of second look-US was significantly greater than the NPV of MRI BIRADS 3 (97% vs 89%, p < 0.05). The logistic regression analysis showed a higher number of malignant lesions in group 1 than in group 2 (7vs 2, OR 3.7, p < 0.05).

Conclusions

The second-look US permitted the correct management of subcentimetric MRI BIRADS 3 lesions not visible with conventional imaging tecniques.     

Management for BI-RADS category 3 lesions detected in preoperative breast MR imaging of breast cancer patients

Objective

To retrospectively evaluate characteristics of and determine appropriate follow-up recommendations for BI-RADS category 3 lesions detected in preoperative MRI of breast cancer patients.

Methods

BI-RADS category 3 assessments were identified from the breast MRI database for 5,110 consecutive breast cancer patients who had undergone preoperative MRI and surgery. Patient and lesion characteristics, malignancy rate, and interval between lesion detection and cancer diagnosis were analysed. Histopathological results or imaging at or after 2-year follow-up were used as reference standards.

Results

Of the 626 lesions, morphological features included a single focus in 26.5% (n?=?166), multiple foci in 47.1% (n?=?295), mass in 21.7% (n?=?136) and non-mass enhancement in 4.6% (n?=?29). Cancer was found in 0.8% (5/626) at a median interval of 50 months (range, 29–66 months). Malignancy rate according to morphological feature was: 1.8% (3/166) in a single focus, 0.7% (1/136) in mass and 3.4% (1/29) in non-mass enhancement. All detected cancers were stage 0 or IA.

Conclusions

Annual follow-up might be adequate for BI-RADS category 3 lesions detected at preoperative MRI because of the 0.8% (5/626) malignancy rate, long interval between lesion detection and cancer diagnosis, and early stage of diagnosed cancers.

Key Points

? BI-RADS category 3 lesions on preoperative MRI had 0.8% malignancy rate. ? All cancer diagnoses from BI-RADS 3 occurred after 24-month follow-up. ? Annual follow-up might be adequate for BI-RADS 3 detected on preoperative MRI.

     

Contrast-enhanced breast MR imaging of claustrophobic or oversized patients using an open low-field magnet

Purpose

A number of women who should undergo magnetic resonance (MR) imaging of the breast cannot use this diagnostic tool due to claustrophobia or excessive body size for the restricted confines of standard closed MR systems. Our aim was to evaluate the performance of open low-field magnet breast MR imaging in such patients using a high-relaxivity contrast agent.

Materials and methods

Of 397 consecutive patients undergoing breast MR imaging, 379 (95.5%) were studied at 1.5 T. Due to claustrophobia (n=15) or large body size (n=3), 18 patients (4.5%) were studied on a 0.2-T open magnet using a body coil. A 3D dynamic T1-weighted gradient-echo 94-s sequence was acquired with intravenous injection of gadobenate dimeglumine (0.1 mmol/kg). The standard of reference was pathological examination for 16 lesions classified with a maximal Breast Imaging Reporting and Data System (BI-RADS) score from 3 to 5, fine-needle aspiration cytology and ?2-year follow-up for two lesions classified as BI-RADS 3, and ?2-years follow-up for five lesions classified as BI-RADS 2.

Results

Diagnostic MR image quality was achieved for 20/23 lesions in 15/18 patients. Three lesions (two invasive cancers and a cyst) were not assessed due to patient movement and considered as two false negatives and one false positive. Thus, an 86% sensitivity [13/15; 95% confidence interval (CI): 70%–100%], an 87% specificity (7/8; 95% CI: 65%–100%) and an 87% accuracy (20/23; 95% CI: 73%–100%) were obtained. The intraclass correlation coefficient between MR and pathologic lesion size was 0.845.

Conclusion

In claustrophobic or oversized patients, open low-field breast MR with gadobenate dimeglumine yields good diagnostic performance.     

3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography

Objective

To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography.

Methods

Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3–5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound.

Results

At pathology, 40/123 (33 %) lesions proved malignant; 28 (70 %) DCIS and 12 (30 %) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79 % (observer 1) and 86 % (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95 % CI 0.56–0.79) to 0.79 (95 % CI 0.70–0.88, observer 1) and to 0.80 (95 % CI 0.71–0.89, observer 2), respectively.

Conclusions

3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography.

Key points

? 3-T MRI is increasingly used for breast imaging in clinical practice. ? On 3-T breast MRI up to 86 % of DCIS lesions are detected. ? 3-T MRI increases the diagnostic value in patients with mammographically detected microcalcifications.     

US-guided diffuse optical tomography for breast lesions: the reliability of clinical experience

Purpose

To prospectively assess the reliability of US-guided diffuse optical tomography (US-DOT) using interobserver agreement for the diagnosis of breast lesions with individual real-time imaging and to assess the interobserver agreement of conventional sonography (US) combined with US-DOT for differentiation between benignity and malignancy breast lesions.

Materials and Methods

An Institutional Review Board approved this study, and all subjects provided written informed consent. 122 breast lesions in 111 patients evaluated with US-guided core biopsy were included. Assessments with US and US-DOT for cases subjected to biopsy were obtained by two radiologists using individual real-time imaging prior to biopsy and were prospectively recorded by each performer. With DOT, the total haemoglobin concentration (THC) for each breast lesion was measured. Histopathological results from US-guided biopsies were used as a reference standard. To assess measurement interobserver agreement, the intraclass correlation coefficient (ICC) and the Bland-Altman plot were used for THC in US-DOT and the kappa values and ROC analysis were used to evaluate the diagnostic performances of the US BI-RADS final assessment in US and combined US and US-DOT.

Results

Of 122 US-guided core biopsied lesions, 83 (68.0%) were diagnosed as benign, and 39 (32.0%) as malignant. Excellent correlation was seen in the THC in US-DOT (ICC score 0.796; 95% confidence interval, 0.708?C0.857). The interobserver agreement in BI-RADS final assessment with US and US-DOT (almost perfect; ???=?0.8618) was improved compared with that of US (substantial agreement, ???=?0.6574). However, the overall areas under the ROC curve did not show significant differences between US and combined US and US-DOT, 0.8894 and 0.8975, respectively (P?=?0.981).

Conclusions

The reliability of THC in US-DOT showed excellent correlation in overall real-time performance. Although the inter-observer agreement for BI-RADS final assessment of US was improved by using US-DOT, the performances of radiologists with respect to the characterization of breast masses as benign or malignant were not significantly improved with US-DOT.     

Real-time MRI navigated US: Role in diagnosis and guided biopsy of incidental breast lesions and axillary lymph nodes detected on breast MRI but not on second look US

Objectives

To prospectively evaluate the accuracy of real-time ultrasound combined with supine-MRI using volume navigation technique (RtMR-US) in diagnosis and biopsy of incidental breast lesions (ILSM) and axillary lymph nodes (LNSM) suspicious of malignancy on contrast enhanced magnetic resonance imaging (CE-MRI).

Materials and methods

Five hundred and seventy-seven women were examined using breast CE-MRI. Those with incidental breast lesions not identified after second-look ultrasound (US) were recruited for RtMR-US. Biopsy was performed in ILSM. Breast lesions were categorized with BI-RADS system and Fisher’ exact test. Axillary lymph nodes morphology was described. To assess efficacy of RtMR-US, diagnostic accuracy, sensitivity, specificity, detection rate and Kappa index of conventional-US and RtMR-US were calculated.

Results

Forty-three lesions were detected on CE-MRI before navigation. Eighteen were carcinomas and 25 ILSM. Of these, 21 underwent a RtMR-US. Detection rate on RtMR-US (90.7%) was higher than on conventional-US (43%) (p < 0.001). Agreement between both techniques was low (k = 0.138). Twenty ILSM and 2 LNSM were biopsied. Sixty-five percent were benign (100% of BI-RADS3 and 56% of BI-RADS4-5). Diagnostic performance of RtMR-US identifying malignant nodules for overall lesions and for the subgroup of ILSM was respectively: sensitivity 96.3% and 100%, specificity 18.8% and 30.7%, positive predictive value 66.7% and 43.7%, negative predictive value 75% and 100%. In addition RtMR-US enabled biopsy of 2 metastatic lymph nodes.

Conclusions

Real time-US with supine-MRI using a volume navigation technique increases the detection of ILSM. RtMR-US may be used to detect occult breast carcinomas and to assess cancer extension, preventing unnecessary MRI-guided biopsies and sentinel lymph node biopsies. Incidental lesions BI-RADS 3 non-detected on conventional-US are probably benign.     

Combined contrast-enhanced magnetic resonance and diffusion-weighted imaging reading adapted to the “Breast Imaging Reporting and Data System” for multiparametric 3-T imaging of breast lesions

Objective

To develop and assess a combined reading for contrast-enhanced magnetic resonance (CE-MRI) and diffusion weighted imaging (DWI) adapted to the BI-RADS for multiparametric MRI of the breast at 3 T.

Methods

A total of 247 patients with histopathologically verified breast lesions were included in this IRB-approved prospective study. All patients underwent CE-MR and DWI at 3 T. MRIs were classified according to BI-RADS and assessed for apparent diffusion coefficient (ADC) values. A reading method that adapted ADC thresholds to the assigned BI-RADS classification was developed. Sensitivity, specificity, diagnostic accuracy and the area under the curve were calculated. BI-RADS-adapted reading was compared with previously published reading methods in the same population. Inter- and intra-reader variability was assessed.

Results

Sensitivity of BI-RADS-adapted reading was not different from the high sensitivity of CE-MRI (P?=?0.4). BI-RADS-adapted reading maximised specificity (89.4 %), which was significantly higher compared with CE-MRI (P?<?0.001). Previous reading methods did not perform as well as the BI-RADS method except for a logistic regression model. BI-RADS-adapted reading was more sensitive in non-mass-like enhancements (NMLE) and was more robust to inter- and intra-reader variability.

Conclusion

Multiparametric 3-T MRI of the breast using a BI-RADS-adapted reading is fast, simple to use and significantly improves the diagnostic accuracy of breast MRI.

Keypoints

? Multiparametric breast 3-T MRI with BI-RADS-adapted reading improves diagnostic accuracy. ? BI-RADS-adapted reading of CE-MRI and DWI is based on established reporting guidelines. ? BI-RADS-adapted reading is fast and easy to use in routine clinical practice. ? BI-RADS-adapted reading is robust to intra- and inter-reader variability.     

Breast lesions classified as probably benign (BI-RADS 3) on magnetic resonance imaging: a systematic review and meta-analysis

Purpose

To investigate prevalence, malignancy rates, imaging features, and follow-up intervals for probably benign (BI-RADS 3) lesions on breast magnetic resonance imaging (MRI).

Methods

A systematic database-review of articles published through 22/06/2016 was performed. Eligible studies reported BI-RADS 3 lesions on breast MRI. Two independent reviewers performed a literature review and data extraction. Data collection included study characteristics, number/type of BI-RADS 3 lesions, final diagnosis (histopathology and/or follow-up). Sources of bias (QUADAS-2) were assessed. Meta-analysis included data-pooling, heterogeneity testing, and meta-regression.

Results

Fifteen studies were included. Prevalence was reported in 11 studies (range: 1.2-24.3%). Malignancy rates ranged between 0.5-10.1% (pooled 61/2814, 1.6%, 95%-CI:0.9-2.3% (random-effects-model), I²=53%, P=0.007). In a subgroup of 11 studies (2183 lesions), highest malignancy rates were observed in non-mass lesions (pooled 25/714, 2.3%, 95%-CI:0.8-3.9%, I²=52%, P=0.021) followed by mass lesions (pooled 15/771, 1.5%, 95%-CI:0.7-2.4%, I²=0%, P=0.929), and foci (pooled 10/698, 1%, 95%-CI:0.3-1.7%, I²=0%, P=0.800). There was non-significant negative association between prevalence and malignancy rates (P=0.077). Malignant lesions were diagnosed at all follow-up time points.

Conclusion

While prevalence of MRI BI-RADS 3 lesions was strongly heterogeneous, pooled malignancy rates met BI-RADS benchmarks (<2%). Malignancy rates varied, exceeding 2% in non-mass lesions. Twenty-four-month surveillance is required to detect all malignant lesions.

Key points

? Probably benign (BI-RADS 3) lesions showed a pooled malignancy-rate of 1.6% (95%-CI:0.9-2.3%). ? Malignancy rates differ and are highest in non-mass lesions (2.3%, 95%-CI:0.8-3.9%). ? The prevalence of BI-RADS 3 lesions on breast MRI ranged from 1.2-24.3%. ? Malignant lesions were diagnosed at follow-up time points up to 24 months.

     

Study of quantitative elastography with supersonic shear imaging in the diagnosis of breast tumours

Purpose

This study was undertaken to evaluate the value of quantitative elastography in the diagnosis of breast tumours.

Materials and methods

Conventional ultrasound (US) and quantitative elastography were performed in 108 women with 114 breast lesions by two experienced radiologists, and pathological results were available in all cases. For each lesion, the maximum, mean, and minimum (min) elasticity and elasticity ratio between lesions and surrounding tissue were measured. The Breast Imaging Reporting and Data System (BI-RADS) categories were assessed with conventional US in all lesions.

Results

Malignant lesions exhibited significantly higher maximum and mean elasticity (111.57±69.29 kPa and 54.49±33.70 kPa) than did benign lesions (59.00±45.3 kPa and 36.64±26.18 kPa) (p<0.01). For maximum elasticity versus BI-RADS, performance results were sensitivity 60.9 % vs. 78.3%, specificity 85.3% vs. 98.5%, positive predictive value (PPV) 73.7% vs. 97.3 %, negative predictive value (NPV) 76.3% vs. 87.0 % and accuracy 75.4% vs. 90.3%. BI-RADS had significantly better accuracy than maximum elasticity (p<0.01). Maximum and mean elasticity of invasive ductal carcinoma (IDC) were significantly higher than those of fibroadenoma (p<0.01), whereas the difference was not statistically significant with fibroadenosis, papilloma and inflammation (p>0.01). Maximum and mean elasticity and elasticity ratio of BI-RADS 5 were all significantly higher than those of BI-RADS 3 (p<0.01). Reliability for maximum and mean elasticity were almost perfect [intraclass correlation coefficients (ICC)=0.87 and 0.79].

Conclusions

Shear-wave elastography gives quantitative elasticity information that could potentially help in breast-lesion characterisation, although it cannot replace conventional BI-RADS in the differentiation of breast lesions.     

Incidentally detected enhancing lesions found in breast MRI: analysis of apparent diffusion coefficient and T2 signal intensity significantly improves specificity

Objectives

To evaluate the value of adding T2- and diffusion-weighted imaging (DWI) to the BI-RADS® classification in MRI-detected lesions.

Methods

This retrospective study included 112 consecutive patients who underwent 3.0T structural breast MRI with T2- and DWI on the basis of EUSOMA recommendations. Morphological and kinetic features, T2 signal intensity (T2 SI) and apparent diffusion coefficient (ADC) findings were assessed.

Results

Thirty-three (29.5 %) patients (mean age 57.0?±?12.7 years) had 36 primarily MRI-detected incidental lesions of which 16 (44.4 %) proved to be malignant. No single morphological or kinetic feature was associated with malignancy. Both low T2 SI (P?=?0.009) and low ADC values (≤0.87?×?10^?3 mm²s^?1, P?<?0.001) yielded high specificity (80.0 %/80.0 %). The BI-RADS classification supplemented with information from DWI and T2-WI improved the diagnostic performance of the BI-RADS classification as sensitivity remained 100 % and specificity improved from 30 % to 65.0 %. The numbers of false positive lesions declined from 39 % (N?=?14) to 19 % (N?=?7).

Conclusion

MRI-detected incidental lesions may be challenging to characterize as they have few specific malignancy indicating features. The specificity of MRI can be improved by incorporating T2 SI and ADC values into the BI-RADS assessment.

Key Points

? MRI-detected incidental lesions have few specific malignancy indicating features. ? ≥ 1 suspicious morphologic or kinetic feature may warrant biopsy. ? T2 signal intensity and DWI assessment are feasible in primarily MRI-detected lesions. ? T2 SI and DWI assessment improve the BI-RADS specificity in MRI-detected lesions.

     

A survey by the European Society of Breast Imaging on the utilisation of breast MRI in clinical practice

Objectives

While magnetic resonance imaging (MRI) is considered a helpful diagnostic tool in breast imaging, discussions are ongoing about appropriate protocols and indications. The European Society of Breast Imaging (EUSOBI) launched a survey to evaluate the utilisation of breast MRI in clinical practice.

Methods

An online survey reviewed by the EUSOBI board and committees was distributed amongst members. The questions encompassed: training and experience; annual breast MRI and MRI-guided-intervention workload; examination protocols; indications; reporting habits and preferences. Data were summarised and subgroups compared using χ² test.

Results

Of 647 EUSOBI members, 177 (27.4%) answered the survey. The majority were radiologists (90.5%), half of them based in academic centres (51.9%). Common indications for MRI included cancer staging, treatment monitoring, high-risk screening and problem-solving, and differed significantly between countries (p≤0.03). Structured reporting and BI-RADS were mostly used. Breast radiologists with ≤10 years of experience preferred inclusion of additional techniques, such as T2/STIR (p=0.03) and DWI (p=0.08) in the scan protocol. MRI-guided interventions were performed by a minority of participants (35.4%).

Conclusions

The utilisation of breast MRI in clinical practice is generally in line with international recommendations. There are substantial differences between countries. MRI-guided interventions and functional MRI parameters are not widely available.

Key points

? MRI is commonly used for the detection and characterisation of breast lesions. ? Clinical practice standards are generally in line with current recommendations. ? Standardised criteria and diagnostic categories (mainly BI-RADS) are widely adopted. ? Younger radiologists value additional techniques, such as T2/STIR and DWI. ? MRI-guided breast biopsy is not widely available.

     

Dynamic contrast-enhanced and ultra-high-resolution breast MRI at 7.0 Tesla

Objective

To assess the feasibility of 7-T contrast-enhanced breast MRI in patients with suspicious masses.

Methods

Twenty patients with 23 suspicious breast masses on conventional imaging (mean size 13 mm, range 5–27 mm) were examined at 7 T. The MRI protocol included a dynamic series with injection of 0.1 mmol/kg gadobutrol (seven consecutive 3D T1-weighted gradient echo sequences, resolution 1?×?1?×?2 mm³, temporal resolution 63 s) and ultra-high-resolution imaging (T1-weighted 3D gradient echo sequence, resolution 0.45?×?0.57?×?0.45 mm³). Two observers (R1 and R2) independently judged the examinations on image quality and classified lesions according to BI-RADS. The added value of ultra-high-resolution imaging was assessed.

Results

The image quality was deemed excellent in 1 and 0, good in 10 and 12, sufficient in 8 and 8, and insufficient in 1 and 0 for R1 and R2 respectively. Twenty of the 23 lesions were identified at 7-T MRI by both observers. All histopathologically proven malignant lesions (n?=?19) were identified and classified as BI-RADS-MRI 4 or 5. Ultra-high-resolution imaging increased reader confidence in 88 % (R1) and 59 % (R2) of acquisitions.

Conclusion

The study shows the feasibility of dynamic contrast-enhanced 7-T breast MRI, where all malignant mass lesions were identified by two observers.

Key Points

? Magnetic resonance imaging is important in the evaluation of breast cancer. ? Recently, 7-T MRI has become available. ? The 7-T dynamic contrast-enhanced breast MRI is feasible in patients. ? The 7-T breast examinations are amenable to evaluation according to BI-RADS.     

Role of sonographic elastography in the differential diagnosis of papillary lesions in breast

Purpose

The purpose of this study was to compare the diagnostic performance of elastography, conventional ultrasonography (US) and combined conventional US and elastography for differentiation of papillary breast lesions.

Materials and methods

A total of 95 papillary lesions (69 benign, 20 atypical and 6 malignant) in 87 patients were examined with conventional US and elastography. We evaluated conventional US images according to the Breast Imaging Reporting and Data System and internal composition (solid vs. cystic) and elastographic images according to elasticity scores. We compared diagnostic performances of elastography, conventional US and the combined method.

Results

Areas under the receiver-operating curve were 0.794 for elastography, 0.875 for conventional US and 0.787 for the combined method. When the elasticity score cutoff was between 2 and 3, the sensitivity, specificity, positive predictive value and negative predictive value were 100, 55.1, 13 and 100?%, respectively. The combined method showed similar sensitivity (100 vs. 100?%) to and higher specificity (57.3 vs. 5.6?%) than conventional US alone. No significant difference was found in the elasticity scores of cystic papillary lesions according to pathology.

Conclusion

Elastography improved the specificity of conventional US in differentiating between benign or atypical and malignant papillary breast lesions when it was combined with conventional US.