Outcome of breast lesions detected at screening ultrasonography

Objective

To assess the final outcome of breast lesions detected during screening ultrasonography (US) and categorized by BI-RADS final assessment.

Materials and methods

During a 1-year period, 3817 consecutive asymptomatic women with negative findings at both clinical breast examinations and mammography underwent bilateral whole breast US and BI-RADS categories were provided for US-detected breast lesions. The reference standard was a combination of histology and US follow-up (≥12 months), and the final outcomes of 1192 US-detected lesions were analyzed.

Results

Of 904 category 2 lesions, 890 remained stable for 12–60 months. Biopsies of 14 lesions revealed no malignancies (NPV = 100%). Of 247 category 3 lesions, 232 remained stable for 12–60 months. Biopsies of 15 lesions revealed 2 malignancies, which were diagnosed within 6 months of the index examination and were node negative (NPV = 99.2%). Of 41 category 4 lesions, biopsies of 38 lesions revealed 5 malignancies (PPV = 12.2%), and 3 remained stable for 37–51 months. No US-detected lesion was classified as category 5.

Conclusion

The rates of malignancy for US-detected BI-RADS categories 2, 3, and 4 lesions were 0%, 0.8%, and 12.2%, respectively. The final assessment of US BI-RADS categorization showed it to be an appropriate predictor of malignancy for screening US-detected breast lesions.     

Elastography ultrasound and questionable breast lesions: Does it count?

Objective

To check possible additional value of using elastography ultrasound in the specification of questionable breast lesions.

Subjects and methods

Questionable breast lesions on gray scale ultrasound examination had been further evaluated by elastography ultrasound in 97 cases with median age of 42 years. The studied lesions were pathologically proven (58 benign and 39 malignant) using true cut tissue/surgical excision biopsy that was considered the gold standard of reference.

Results

Conventional ultrasound categorization before biopsy included: category 3 (probably benign) in 42.3% (n = 41), category 4a (low suspicion of malignancy) in 13.4% (n = 13), category 4b (intermediate suspicion of malignancy) in 16.5% (n = 16) and category 4c (moderate suspicion of malignancy) in 27.8% (n = 27). We had evaluated elastography ultrasound regarding elastography strain scoring and quantitative strain ratio.Sensitivity, specificity and accuracy were 89.7%, 86.2% and 87.6% for conventional ultrasound, 92.3%, 74.1% and 81.4% for elastogram 5-point scoring method and 87.1%, 89.6% and 88.6% for the calculated strain ratios respectively in the assessment of the examined breast lesions.

Conclusion

Ultrasound elastography, using both qualitative and quantitative methods can improve the performance of conventional B-mode ultrasound and enhance its specificity and accuracy in the diagnosis of questionable (BI-RADS categories 3 and 4) breast lesions.     

Imaging findings in phyllodes tumors of the breast

Purpose

To study the radiological appearance and pathological features of breast phyllodes tumors (PTs), and to enhance the recognition of the tumor.

Materials and methods

Clinical and imaging findings were retrospectively reviewed in 24 women with PTs confirmed by surgical pathology. All of the 24 patients had preoperative MRI and sonography, and 10 had preoperative mammography.

Results

The histologic findings were benign, borderline and malignant PTs in 16.7% (4/24), 45.8% (11/24) and 37.5% (9/24) of cases, respectively. The tumor size (p = 0.001), irregular shape on sonographic imaging (p = 0.039), internal non-enhanced septations (p = 0.009), silt-like changes in enhanced images (p = 0.006) and signal changes from T2-weighted to enhanced images on MRI (p = 0.001) correlated significantly with the histologic grade; the BI-RADS category of the MRI could reflect the PT's histologic grade with a correlation coefficient of 0.440 (p = 0.031). If the category BI-RADS ≥4a was considered to be a suspicious malignant lesion, the diagnostic accuracy of mammography, US and MRI would be 70% (7/10), 62.5% (15/24) and 95.8% (23/24), respectively.

Conclusion

The tumor size and several US and MRI findings can be used to help preoperatively determine the histologic grade of breast PTs. When a patient presents with a progressively enlarging, painless breast mass, MRI should be recommended first.     

Power Doppler sonography: Anything to add to BI-RADS US in solid breast masses?

Objective

To evaluate the contribution of power Doppler ultrasonography (PDUS) to breast imaging reporting and data system ultrasonography (BI-RADS US) categorization of solid breast masses.

Materials and methods

Totally 94 solid lesions with histopathological results in 49 patients were included in the study. US features of the lesions were classified according to American College of Radiologists (ACR) BI-RADS US lexicon. Lesions were evaluated qualitatively according to their PDUS properties and quantitatively with spectral analysis. Hypervascularity, penetration of vessels into the mass or branching-disordered course and resistivity index values higher than 0.85 were accepted as probable malignant criteria.

Results

Fifty-five of 94 lesions were benign (58.5%), while 39 (41.5%) were malignant histopathologically. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US and PDUS in the diagnosis of malignant lesions were 100%, 58.2%, 62.9%, 100% and 71.8%, 81.8%, 73.7%, 80.4%, respectively. Criteria used for the distinction of malignant and benign lesions like number of vessels (p < 0.05), distribution of tumoral vessels, morphology of vessels and resistivity index values higher than 0.85 showed statistically significant difference (p < 0.001). When sonographic findings were combined with PDUS and spectral analysis findings, sensitivity, specificity, PPV and NPV were 100%, 52.7%, 60% and 100%, respectively.

Conclusion

PDUS and spectral analysis have no contribution to BI-RADS US. For the spectral analysis, when RI value is one or greater, malignancy risk significantly increases.     

Clinical impact of BI-RADS classification in Taiwanese breast cancer patients: BI-RADS 5 versus BI-RADS 0-4

Objective

The aim of this study was to analyze and determine the prognostic value of the Breast Imaging Reporting and Data System (BI-RADS) classification in Taiwanese patients with breast cancer.

Patients and methods

Nine hundred ninety-eight patients with breast cancer were diagnosed between January 1, 1999, and August 31, 2005, and 491 (49%) of them were classified as BI-RADS 5. Overall survival and disease-free survival were estimated with the Kaplan–Meier method and compared across the two groups (BI-RADS 5 versus BI-RADS 0–4) using the log-rank test. Univariate and multivariate analyses were used to identify the prognostic factors.

Results

The median follow-up time was 81.8 months. Kaplan–Meier analysis showed a significant difference between the two subgroups in five-year overall survival (P = 0.001) and five-year disease-free survival (P < 0.0001). On univariate analysis, the mammographic findings (BI-RADS 5 versus BI-RADS 0–4) were statistically significantly associated with five-year overall survival and disease-free survival, as were tumor size, lymph-node status, tumor grade, estrogen-receptor status, progesterone-receptor status, and HER-2 status. On multivariate analysis, only the mammographic findings, lymph-node status, HER-2 status, and tumor grade were significant factors related to five-year overall survival and disease-free survival.

Conclusion

The BI-RADS classification is a reliable prognostic and predictive factor. Patients with BI-RADS 5 breast cancer showed a worse pattern of relapse than that of BI-RADS 0–4 breast cancer patients.     

MRI of fat necrosis of the breast: the "black hole" sign at short tau inversion recovery

Objective

To describe MRI features of fat necrosis of the breast.

Materials and methods

Twenty-five lesions in 16 patients were retrospectively analyzed. MRI was performed due to equivocal findings at conventional imaging after surgical treatment of cancer (n = 14) or during anticoagulant therapy (n = 1), after focal mastitis treated with ductal resection (n = 1). In the 15 patients with previous surgery MRI was performed after a median interval of 24 months, using short tau inversion recovery (STIR) and contrast-enhanced dynamic T1-weighted sequences. Signal-to-noise ratio (SNR) inside the lesion and surrounding healthy fat was calculated on both STIR and unenhanced T1-weighted images. Maximal lesion diameter was measured on STIR images. All lesions had final clinical and imaging assessment in favor of fat necrosis and negative clinical and imaging follow-up (21–40 months; median 24 months).

Results

At STIR sequence, fat necrosis appeared as a “black hole”, being markedly hypointense (median SNR = 29) compared with surrounding fat (median SNR = 95) (P < 0.001), while no significant difference was found at unenhanced T1-weighted sequence. No significant correlation with time from treatment was found. Of 25 lesions, 15 showed ring enhancement, with continuous increase (n = 10), plateau (n = 2), or wash-out curve (n = 3). The 11 enhancing lesions in the 8 patients with previous radiation therapy showed an initial enhancement higher than that of the 4 enhancing lesions in the 2 patients who did not, although the difference was not significant (P = 0.104).

Conclusion

Fat necrosis of the breast exhibits a “black hole” sign on STIR images, allowing for an easier diagnosis in clinical practice.     

Could ultrasonic elastography help the diagnosis of small (≤2 cm) breast cancer with the usage of sonographic BI-RADS classification?

Objectives

To evaluate the additive value of ultrasound strain elastography (USE) to BI-RADS for the differentiation of benign and malignant breast small lesions.

Methods

Breast masses (≤2 cm) with histological diagnosis examined by ultrasonography and USE in our department from April 2004 to December 2009 were reviewed. Conventional B-mode ultrasound findings were classified according to the BI-RADS classification. USE findings were classified according to the 5-point scale. Histological diagnosis was used as the reference standard.

Results

401 (246 benign (61.3%), 155 malignant (38.7%)) from 370 consecutive patients were included in the study. Sensitivity and specificity were 90.3%, 68.3% for BI-RADS; 72.3%, 91.9% for USE. The sensitivity of BI-RADS was better than that of USE (P < 0.05), while the specificity of USE was better than that of BI-RADS (P < 0.05). A revised BI-RADS combined with USE results was proposed in this study. Sensitivity and specificity were 83.9% and 87.8% for revised BI-RADS. The diagnostic performance of revised BI-RADS was better than BI-RADS (P < 0.05).

Conclusions

USE could give BI-RADS some help in the differentiation of benign and malignant breast small lesions. The addition of elastography to BI-RADS could improve the diagnostic performance in <2 cm lesions.     

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.     

Percutaneous excisional biopsy of clinically benign breast lesions with vacuum-assisted system: comparison of three devices

Purpose

The aim of this study was to compare three devices in percutaneous excisional biopsy of clinically benign breast lesions in terms of complete excision rate, duration of procedure and complications.

Materials and methods

In a retrospective study from March 2005 to May 2009, 983 lesions underwent ultrasound-guided excisional biopsy with three vacuum-assisted systems, respectively. The lesions were category 3 lesions as determined by ultrasound imaging according to Breast Imaging Reporting and Data System (BI-RADS) (n = 951) or had been confirmed as benign by a previous core needle biopsy (n = 32). The completely excision rate, duration of procedure and complications (hematoma, pain and ecchymosis) were recorded.

Results

99.7% (980/983) lesions were demonstrated to be benign by pathology after percutaneous excisional biopsy. The overall complete excision rate was 94.8% (932/983). In lesions whose largest diameter equal to or larger than 1.5 cm, the complete excision rates of EnCor^® group (97.8%, 348/356) and Mammotome^® group (97.2%, 139/143) were significantly higher than that of Vacora^® group (91.9%, 445/484) (P < 0.05). The EnCor^® group (6.6 ± 6.5 min) had a significant less duration than Mammotome^® (10.6 ± 9.3 min) and Vacora^® group (25.6 ± 23.3 min) (P < 0.05). Hematoma occurred more in EnCor^® group and Mammotome^® group than in Vacora^® group (P < 0.05).

Conclusions

All these three vacuum-assisted systems are highly successful for excisional biopsy of benign breast lesions.     

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.     

Analysis of eighty-one cases with breast lesions using automated breast volume scanner and comparison with handheld ultrasound

Objectives

This study aims to evaluate the clinical utility of automated breast volume scanner (ABVS) against handheld ultrasound in detecting and diagnosing breast lesions.

Methods

Eighty-one patients were subjected to both automated breast volume scanner and handheld ultrasound examination in the supine position. The number of lesions detected and the average scanning time (both device-specific and user-specific) for each device were compared. The diagnostic accuracy, sensitivity and specificity were calculated for each method. The maximum diameters of the lesions based on handheld ultrasound and ABVS were compared with the final pathological sizes.

Results

Of the 81 patients, both automated breast volume scanner and handheld ultrasound detected 95 breast lesions. Compared with the pathological diagnosis in 35 lesions, both ABVS and handheld ultrasound exhibited high sensitivity (both 100%) and high specificity (95.0%, and 85.0%, respectively). In addition, ABVS had a higher diagnostic accuracy (97.1%) than handheld ultrasound (91.4%) for breast neoplasms. More importantly, ABVS was capable of displaying the retraction phenomenon in coronal plane. All the invasive ductal carcinomas (12 lesions) presented the retraction phenomenon. In contrast, intraductal carcinomas (3 lesions) and benign lesions did not display such features. Thus, retraction phenomenon had a high specificity (100.0%) and high sensitivity (80.0%) in detecting breast cancer while it also had high accuracy (91.4%) in determining malignant from benign lesions. There was no significant difference in maximum diameters of pathology, 2D and ABVS (p > 0.05), however the correlation coefficient revealed that ABVS had better correlation with pathology (r = 0.616) than 2D (r = 0.468). The user scanning time for the ABVS demonstrated no difference between two examiners (11.7 ± 1.3 min and 12.1 ± 1.4 min; p > 0.05). However, device-specific scanning time was longer for ABVS than handheld ultrasound (11.9 ± 1.4 min vs. 6.8 ± 1.1 min, respectively; p < 0.01).

Conclusions

Automated breast volume scanner provides advantages of high diagnostic accuracy, better lesion size prediction, operator-independence and visualization of the whole breast. It is a promising modality in breast imaging.     

Evaluation of breast lesions by contrast enhanced ultrasound: qualitative and quantitative analysis

Objective

To evaluate and compare the diagnostic performance of qualitative, quantitative and combined analysis for characterization of breast lesions in contrast enhanced ultrasound (CEUS), with histological results used as the reference standard.

Methods

Ninety-one patients with 91 breast lesions BI-RADS 3–5 at US or mammography underwent CEUS. All lesions underwent qualitative and quantitative enhancement evaluation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of different analytical method for discrimination between benign and malignant breast lesions.

Results

Histopathologic analysis of the 91 lesions revealed 44 benign and 47 malignant. For qualitative analysis, benign and malignant lesions differ significantly in enhancement patterns (p < 0.05). Malignant lesions more often showed heterogeneous and centripetal enhancement, whereas benign lesions mainly showed homogeneous and centrifugal enhancement. The detectable rate of peripheral radial or penetrating vessels was significantly higher in malignant lesions than in benign ones (p < 0.001). For quantitative analysis, malignant lesions showed significantly higher (p = 0.031) and faster enhancement (p = 0.025) than benign ones, and its time to peak was significantly shorter (p = 0.002). The areas under the ROC curve for qualitative, quantitative and combined analysis were 0.910 (A_z1), 0.768 (A_z2) and 0.926(A_z3) respectively. The values of A_z1 and A_z3 were significantly higher than that for A_z2 (p = 0.024 and p = 0.008, respectively). But there was no significant difference between the values of A_z1 and A_z3 (p = 0.625).

Conclusions

The diagnostic performance of qualitative and combined analysis was significantly higher than that for quantitative analysis. Although quantitative analysis has the potential to differentiate benign from malignant lesions, it has not yet improved the final diagnostic accuracy.     

Malignant spiculated breast masses: dynamic contrast enhanced MR (DCE-MR) imaging enhancement characteristics and histopathological correlation

Aim

Spiculation of breast masses is usually the result of significant desmoplastic reaction. Diminished neovascularization is expected due to sparsely dispersed tumor cells within the lesion. This feature can cause differences in enhancement patterns which can cause pitfalls while evaluating MR images as well. Aim of this study is to explore the enhancement characteristics of malignant spiculated masses and to correlate these findings with histopathological features.

Materials and methods

Eighteen spiculated and seventeen non-spiculated masses depicted with mammography were included in the study. MR imaging was performed with 1.5 T magnet with breast coil. In MR imaging, T2-weighted turbo spin echo (TSE) with fat suppression sequence followed by pre- and post-contrast T1-weighted 3D-fast low angle shot (FLASH) sequences were used. Lesions were evaluated according to enhancement characteristics: early phase enhancement (first 2 min; less than 50%, 50–100% and more than 100%), late phase enhancement (2–6 min; persistent, plateau and washout) and inner enhancement pattern (homogenous, heterogenous and rim). Desmoplasia and lymphocyte infiltration was classified as mild, moderate and severe. MR images and histopathological findings (desmoplasia, lymphocyte infiltration and grade) of both groups were compared.

Results

Mean ages of patients in spiculated and non-spiculated-mass groups were 55.07 (41–71) and 47.35 (31–62), respectively. Mean diameter of lesions was 17.3 mm (10–31 mm) for spiculated masses while non spiculated masses were 15.8 mm (6–40 mm). There were statistically significant differences between late phase enhancement, persistent enhancement, plateau and washout (p < 0.05). Intergroup comparison of desmoplasia revealed significant difference between severe versus and mild, moderate (p < 0.05).

Conclusion

Spiculated malignant lesions are supposed to contain intense desmoplastic reaction. On DCE-MR images they can show persistent enhancement pattern more often than non-spiculated lesions.     

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.     

Differentiating benign from malignant solid breast lesions: Combined utility of conventional ultrasound and contrast-enhanced ultrasound in comparison with magnetic resonance imaging

Objective

To prospectively evaluate the diagnostic efficacy of conventional ultrasound (US), contrast-enhanced US (CEUS), the combined use of two modalities, and magnetic resonance imaging (MRI) in the differentiation of focal solid breast lesions.

Materials and methods

61 patients with BI-RADS category 3–5 breast lesions detected at conventional US underwent CEUS and MRI. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of conventional US, CEUS, combination of two modalities and MRI for discrimination between benign and malignant breast lesions.

Results

Tissue specimens of 61 breast lesions were obtained either from surgical resection (n = 46) or from needle biopsy (n = 15). Histopathologic diagnosis revealed 28 benign and 33 malignant lesions. The diagnostic performance of conventional US and CEUS in differentiating benign from malignant breast lesions showed no significant difference (P = 0.741). The combination of two modalities significantly improved the diagnostic accuracy compared with either conventional US or CEUS alone (P = 0.031 and P = 0.012, respectively). The area under the ROC curve (A_z) value for the combined use of two modalities for discrimination between benign and malignant breast lesions was 0.94, and that for MRI was 0.91, whereas no statistical difference was found between them (P = 0.296).

Conclusion

The combined use of conventional US and CEUS has a better diagnostic performance than either method alone and displays good agreement with MRI in the differentiation capability for benign and malignant breast lesions.     

A new, preoperative, MRI-based scoring system for diagnosing malignant axillary lymph nodes in women evaluated for breast cancer

Objective

Malignant axillary lymph nodes are an important predictor for breast cancer recurrence, but invasive dissection or biopsy is required for the diagnosis. We determined whether and how malignant nodes could be diagnosed preoperatively with magnetic resonance (MR) imaging.

Materials and methods

We obtained MR images of all women evaluated for breast cancer at the Sun Yat-Sen University Cancer Center in 2010 and correlated the image characteristics of each axillary node with the pathologic diagnosis of the same node.

Results

We analyzed 251 nodes (117 benign; 134 malignant) from 136 women (mean age, 44 years; range, 20–67). Mean diameter of the nodes was 18 mm (range, 5–58 mm). With pathologic diagnosis as the reference standard, MRI-based interpretations were 66.4% sensitive, 94% specific, and 79% accurate. Diameter, pathologic type, apparent diffusion coefficient value (ADC, b = 500 and 800), time-intensity curve (TIC) type of breast tumors correlated with node metastasis; ADC value (b = 500 and 800), TIC type, early enhancement rate, long-axis, short-axis, shape, margin and the location of nodes correlated with node metastasis (P < 0.001 for all). Tumor immunohistochemistry results for estrogen receptors, progesterone receptors, c-erbB-2, vascular endothelial growth factor, and Ki67 were not. An MRI-based lymph node scoring system based on these correlations had a specificity of 91%, a sensitivity of 93%, and an area under the ROC curve of 0.95 (P < 0.001).

Conclusion

Metastatic axillary lymph nodes can be accurately diagnosed by MR in women with early breast cancer preoperatively and non-invasively. The scoring system appears to be superior to current methods.     

Breast cancer with low FDG uptake: characterization by means of dual-time point FDG-PET/CT

Background

Malignant breast lesions usually are differentiated by FDG-PET with a semiquantitative FDG standardized uptake value (SUV) of 2.5. However, the frequency of breast cancer with an SUV of less than or equal to 2.5 is noteworthy, and often present diagnostic challenges. This study was undertaken to evaluate the accuracy of dual-time point FDG-PET/CT with FDG standardized uptake value (SUV) calculation in the characterization of such breast tumors.

Methods

Forty-nine female patients with newly diagnosed breast cancer were found to have primary breast cancer with minimally increased FDG uptake and met the criteria for inclusion in this study by having borderline levels of increased FDG uptake (SUVmax less than or equal to 2.5) in the initial FDG-PET/CT images. Consequently, they underwent further delayed phase FDG-PET/CT scan for better evaluation of the disease.

Results

Of the 49 cancer lesions; the majority were found to have rising or unvarying dual-time changes in SUVmax (75.5%). The median value of SUVmax increases by 25% between the early and delayed scan. The means ± S.D. of the SUVmax1, the SUVmax2, and the ΔSUVmax% were 1.2 ± 0.6%, 1.3 ± 0.9%, and 5.1 ± 22.4%, respectively. The receiver-operating-characteristic (ROC) analysis proved that the highest accuracy for characterization of malignant breast lesions was obtained when a ΔSUVmax% cut-off value 0.0% was used as criteria for malignant FDG uptake-change over time with sensitivity 75.5%, and false-positive rate 20.4%.

Conclusion

These results suggested that dual-time FDG-PET/CT imaging with standardized uptake value (SUV) estimation can improve the accuracy of the test in the evaluation of breast cancer with low FDG uptake.     

Contralateral lesions detected by preoperative MRI in patients with recently diagnosed breast cancer: application of MR CAD in differentiation of benign and malignant lesions

Objectives

To retrospectively investigate the added value of kinetic features measured by computer-aided diagnosis (CAD) for differentiating benign and malignant contralateral breast lesions detected by preoperative MRI in breast cancer patients.

Methods

This study was approved by our institutional review board, and the requirement for informed consent was waived. Fifty-two breast MR images and their CAD kinetic features were obtained for 52 consecutive breast cancer patients with contralateral breast lesions detected by preoperative MRI and confirmed by excision (23 cancers and 29 benign lesions). Three experienced radiologists independently reviewed the MR images without CAD information and assessed probabilities of malignancy. Four weeks later, these probabilities were reanalyzed using stored CAD data. Diagnostic performances and detection rates of delayed washout components were compared between interpretations without and with CAD for each reader.

Results

Use of MR CAD increased detection of washout component by 2.4- to 3.7-fold than visual assessment for enhancing contralateral lesions, which increased sensitivity (91% vs. 87% in reader 1; 96% vs. 74% in reader 2; 91% vs. 70% in reader 3) and decreased specificity, but statistical significance was only found for decreased specificity in one reader (52% vs. 28%, P = 0.039), and overall performance (areas under ROC curves 0.672 vs. 0.616 in reader 1; 0.624 vs. 0.603 in reader 2; 0.706 vs. 0.590 in reader 3) remained unimproved.

Conclusion

Addition of MR CAD increased sensitivity and decreased specificity than radiologist's assessment alone for differentiating benign and malignant contralateral lesions in breast cancer patients and overall performance remained unimproved.     

Histologic work-up of non-palpable breast lesions classified as probably benign at initial mammography and/or ultrasound (BI-RADS category 3)

Purpose

To determine the accuracy of a probably benign assessment of non-palpable breast lesions (BI-RADS category 3) at mammography and/or ultrasound with immediate histological work-up.

Materials and methods

Stereotactic or ultrasound guided core needle breast biopsy (NBB) was performed to evaluate 288 lesions, which were prospectively assessed as BI-RADS category 3. Imaging findings included 195 masses, 73 calcification cases, 16 focal asymmetries, and four architectural distortion cases. After NBB, patients underwent either open surgical biopsy (OSB) (n = 204) or mammographic follow-up (n = 84) for at least 24 months. Histological results of NBB were compared with those of OSB.

Results

Three of the 288 lesions (1.0%) proved to be malignant at histological work-up, two of them were ductal carcinoma in situ (DCIS) and one of them was an invasive carcinoma. NBB revealed invasive carcinoma in 1/288 (0.35%) and atypical ductal hyperplasia (ADH) in 13/288 (4.5%) lesions. OSB revealed DCIS in 2/204 (1%) and invasive carcinoma in 1/204 (0.5%) lesions. The two DCIS were underestimated as ADH by NBB. The remaining 285 (99%) lesions proved to be benign at OSB or remained stable during follow-up.

Conclusion

Confirmed by tissue diagnosis, the low likelihood of malignancy of prospectively assessed probably benign lesions is below the 2% threshold established for BI-RADS category 3. Imaging follow-up is a safe and effective alternative to immediate histological work-up for such lesions.