Intravenous Line Phase-Wrap Artifact at Bilateral Axial 3-T Breast MRI: Identification, Analysis, and Solution

Purpose

To understand and remove the source of a phase-wrap artifact produced by residual contrast agent in the intravenous line during acquisition of bilateral axial 3-T dynamic contrast material-enhanced (DCE) breast MRI.

Materials and Methods

A two-part study involved a phantom experiment, followed by an institutional review board approved clinical intervention, to evaluate the phase-wrap artifact at MRI. A phantom model evaluated artifact production by using an intravenous line filled with fluids with varying concentrations of gadolinium-based contrast agent (0, 0.4, 0.8, 1.2, 1.6, and 2 mmol/mL) and by positioning the simulated intravenous line within several fields of view (FOV) at 3-T MRI in breast coils. Next, a clinical assessment was performed with a total of 400 patients (control group:interventional group, 200:200) to determine the effect of taping the intravenous line to the patients' backs. Breast MR images were assessed blindly for the presence of the artifact. Software was used for statistical analysis with a P value of less than .05 considered a significant difference.

Results

In the phantom model, the artifact was produced only with a 0.4 mmol/mL gadolinium concentration and when the tubing was either close to the edge or within a FOV of 350-450 mm. In the clinical experiment, the artifact was more prevalent in the retrospective control group than in the prospective intervention group (52.5% [105 of 200] vs 22% [44 of 200]; P < .005).

Conclusion

The presence of phase-wrap artifacts can be reduced by moving the contrast agent intravenous line out of the FOV during acquisition by taping it to a patient's back during bilateral axial 3-T DCE breast MRI.Keywords: Breast, MR-Imaging, Phantom Studies© RSNA, 2020.

BRCA-associated Cancers: Role of Imaging in Screening, Diagnosis, and Management

Harmful mutations of the BRCA tumor suppressor genes result in a greater lifetime risk for malignancy-breast and ovarian cancers in particular. An increased risk for male breast, fallopian tube, primary peritoneal, pancreatic, prostate, and colon cancers also has been reported. The BRCA gene is inherited in an autosomal dominant pattern and tends to be highly penetrant; thus, there is an increased incidence of these cancers in affected families. Compared with sporadic tumors, BRCA-associated malignancies have unique manifestations, clinical features, and pathologic profiles. Manifestation at an early patient age, high-grade tumors, and an aggressive clinical course are common features of BRCA-associated malignancies. Understanding the behavior of these cancers aids in identification of affected individuals and families, who can then make informed decisions regarding their future health. Enhanced screening, prophylactic surgery, and chemoprevention are options for managing cancer risk factors in these individuals. Imaging has an important role in the screening, evaluation, staging, and follow-up of BRCA-associated malignancies. Supplemental screening of BRCA mutation carriers often begins at an early age and is critical for early and accurate cancer diagnoses. The authors review the etiopathogenesis and imaging features of BRCA-associated malignancies, the importance of a multidisciplinary approach to determining the diagnosis, and the treatment of patients who have these mutations to improve their outcomes. ^© RSNA, 2017.

Breast cancer detection and tumor characteristics in BRCA1 and BRCA2 mutation carriers

PURPOSE

To describe imaging findings, detection rates, and tumor characteristics of breast cancers in a large series of patients with BRCA1 and BRCA2 mutations to potentially streamline screening strategies.

METHODS

An IRB-approved, HIPAA-compliant retrospective analysis of 496 BRCA mutation carriers diagnosed with breast carcinoma from 1999 to 2013 was performed. Institutional database and electronic medical records were reviewed for mammography and MRI imaging. Patient and tumor characteristics including age at diagnosis, tumor histology, grade, receptor, and nodal status were recorded.

RESULTS

Tumors in BRCA1 mutation carriers were associated exhibited significantly higher nuclear and histological grade compared to BRCA2 (p < 0.001). Triple-negative tumors were more frequent in BRCA1 mutation carriers, whereas hormone receptor-positive tumors were more frequent in BRCA2 mutation carriers (p < 0.001). BRCA2 mutation carriers more frequently presented with ductal carcinoma in situ (DCIS) alone 14% (35/246) and cancers more frequently exhibiting calcifications (p < 0.001). Mammography detected fewer cancers in BRCA1 mutation carriers compared to BRCA2 (p = 0.04): 81% (186/231) BRCA1 versus 89% (212/237) BRCA2. MRI detected 99% cancers in each group. Mammography detected cancer in two patients with false-negative MRI (1 invasive cancer, 1 DCIS). Detection rates on both mammography and MRI did not significantly differ for women over 40 years and women below 40 years.

CONCLUSIONS

Breast cancers in BRCA1 mutation carriers are associated with more aggressive tumor characteristics compared to BRCA2 and are less well seen on mammography. Mammography rarely identified cancers not visible on MRI. Thus, the omission of mammography in BRCA1 mutation carriers screened with MRI can be considered.

PPV(3) of suspicious breast MRI findings

RATIONALE AND OBJECTIVES

Magnetic resonance imaging (MRI) characteristics of Breast Imaging Reporting and Data System (BI-RADS) 4 and 5 lesions were evaluated to identify characteristics that may improve the positive predictive value (PPV) of a biopsy.

MATERIALS AND METHODS

MRI BI-RADS 4 or 5 breast findings in 101 women who underwent biopsy leading to a diagnosis of cancer within 1 year (PPV3; n = 115 cases) were reviewed. Patient history, lesion morphology, enhancement pattern and kinetics, and T2 characteristics were examined.

RESULTS

The PPV3 of all BI-RADS 4 and 5 breast lesions seen on MRI was 22.6% (26 of 115). Excluding lesions with second-look imaging correlates decreased the PPV3 to 11.8% (6/51). Of the MRI-guided biopsies, 20.9% (24 of 115) yielded a high-risk lesion, altering surgical management. MRI lesion type did not significantly affect the PPV3: the PPV3 was 26.3% (15 of 57) for masses, 21.4% (9 of 42) for non mass enhancement (NME) and 12.5% (2 of 16) for suspicious foci. The PPV3 for lesions found on diagnostic MRI in women with newly diagnosed cancer was 30.8% (20 of 65) which was statistically significantly greater compared to a PPV3 of 11.9% (5 of 42) for lesions identified on high-risk screening MRI.

CONCLUSIONS

Suspicious MRI findings identified on a second-look examination are more likely malignant than those seen only on MRI. Suspicious MRI findings discovered in patients with concurrent malignancy have a greater PPV3 than those detected on high-risk screening MRIs. However, the type of MRI finding (mass vs. NME vs. foci) does not significantly affect the PPV3 and should not be used as a discriminator for determining biopsy threshold.

Breast carcinomas: variations in sonoelastographic appearance

Background

This study assessed factors influencing the sonoelastographic presentation of breast carcinoma.

Methods

A prospective collaborative study was conducted by the Santa Casa de São Paulo and CTC-Center, on 540 breast lesions in women referred for percutaneous breast biopsy. Eighty-four carcinomas showing lesions on ultrasonography were included. These lesions were classified into four sonoelastographic scores, where scores of 1, 2, and 3 were considered false-negative, and a score of 4 was considered true-positive. Scores were compared against histopathologic results, which were divided into two groups, ie, soft lesions (group 1) and hard lesions (group 2). False-negative and true-positive results were also assessed for variation according to patient age and mean lesion diameter.

Results

Of the 84 lesions studied, nine yielded false-negative results on sonoelastography and 75 yielded true-positive results. In terms of histopathologic classification, eight were assigned to group 1 and 76 to group 2. The chi-squared test showed a correlation between sonoelastographic scores and histopathologic lesion type. No statistically significant differences were observed according to patient age or largest lesion diameter.

Conclusion

Our results revealed an association between sonoelastographic presentation of breast lesions and histology. False-negative results on sonoelastography were influenced by histologic type of lesion and not by lesion size or patient age.

Magnetic resonance imaging of the breast for cancer diagnosis and staging

Gadolinium-enhanced breast magnetic resonance imaging (MRI) is optimally suited for the diagnosis and assessment of breast cancer. The complete breast MRI examination, which includes select nonenhanced sequences, yields abundant information about the nature and stage of disease. In this article, we will explore cancer diagnosis by examining the main imaging features of breast malignancy as well as the assessment of surrounding structures. We will then discuss current ideas in the use of breast MRI in breast cancer, including high-risk screening, evaluation of extent of disease, role in surgical planning, and the use of MRI in the patient receiving neoadjuvant chemotherapy. Breast MRI plays an important role in the assessment of patients with breast malignancy-a role that is yet to be fully defined and used. By understanding the strengths and weakness of this imaging method in cancer evaluation, we hope to highlight the appropriate uses of the technique.

Outcome of long term active surveillance for estrogen receptor-positive ductal carcinoma in situ

INTRODUCTION

An option for active surveillance is not currently offered to patients with ductal carcinoma in situ (DCIS); however a small number of women decline standard surgical treatment for noninvasive cancer. The purpose of this study was to assess outcomes in a cohort of 14 well-informed women who elected non-surgical active surveillance with endocrine treatment alone for estrogen receptor-positive DCIS.

METHODS

Retrospective review of 14 women, 12 of whom were enrolled in an IRB-approved single-arm study of 3 months of neoadjuvant endocrine therapy prior to definitive surgical management. The patients in this report withdrew from the parent study opting instead for active surveillance with endocrine treatment and imaging.

RESULTS

8 women had surgery at a median follow up of 28.3 months (range 10.1-70 months), 5 had stage I IDC at surgical excision, and 3 had DCIS alone. 6 women remain on surveillance without evidence of invasive disease for a median of 31.8 months (range 11.8-80.8 months).

CONCLUSION

Long-term active surveillance for DCIS is feasible in a well-informed patient population, but is associated with risk of invasive cancer at surgical excision.