Breast MRI is a cutting-edge technology in the diagnosis and intervention of breast abnormalities. Over the last decade, breast MRI has evolved from a research field to a clinical field. Radiologists should understand the indications, how to obtain adequate images, and how to interpret and report their findings. Breast MRI is now used in the differentiation of benign from malignant mass, preoperative staging of breast cancer patients, assessment of tumor response to neoadjuvant chemotherapy, and evaluation of women with breast implants. It can also be used as a supplemental screening modality for high-risk women. Qualified radiologists and adequate MRI technique are crucial for the success of these purposes. This review is focused on the indication, standardized use of lexicon and categorization of breast MRI.
Breast ; Breast Implants ; Breast Neoplasms ; Female ; Humans ; Mass Screening

Characterization of breast cancer molecular subtypes has been the standard of care for breast cancer management. We aimed to provide a review of imaging features of breast cancer molecular subtypes for the field of precision medicine. We also provide an update on the recent progress in precision medicine for breast cancer, implications for imaging, and recent observations in longitudinal functional imaging with radiomics.

Breast MRI is the most accurate adjunctive to the mammography for the screening of breast cancer. Despite lack of randomized controlled trials on the effectiveness of MRI screening, it is now recommended for the women at high risk for breast cancer by the American Cancer Society and the National Comprehensive Cancer Network based on several prospective observational studies. In Korea, a retrospective study reported that preoperative MRI screening of the contralateral breast in women with unilateral breast cancer was associated with reduced metachronous cancer incidence. To introduce breast MRI as a supplemental modality to screening mammography in Korea, standardization and education of interpretation, establishment of MR-guided biopsy and adequate indication, and evaluation of cost-effectiveness and should be preceded.
American Cancer Society ; Biopsy ; Breast ; Breast Neoplasms ; Female ; Humans ; Incidence ; Korea ; Mammography ; Mass Screening

PURPOSE: To evaluate the characteristic color Doppler imaging of vertebral artery flow in the subclavian steal phenomenon. MATERIALS AND METHODS: The study group consisted of eight patients with reversed vertebral artery flow proved by color Doppler imaging. We classified this flow into two groups : (1) complete reversal ; (2)partial reversal, as shown by Doppler velocity waveform. Vertebral angiography was performed in six of eight patients ; color Doppler imaging and angiographic findings were compared. RESULTS: On color Doppler imaging, all eight cases with reversed vertebral artery flow showed no signal at the proximal subclavian or brachiocephalic artery. We confirmed shunting of six cases by performing angiography from the contralateral verterbral and basilar artery to the ipsilateral vertebral artery. On the Doppler spectrum, six cases showed complete reversal and two partial reversal. On angiography, one partial reversal case showed complete occlusion of the subclavian artery with abundant collateral circulation of muscular branches of the vertebral artery. CONCLUSION: On color Doppler imaging, a reversed vertebral artery suggests the subclavian steal phenomenon. In particular, partial reversal waveform may reflect collateral circulation.
Angiography ; Arteries ; Basilar Artery ; Collateral Circulation ; Humans ; Subclavian Artery ; Subclavian Steal Syndrome* ; Vertebral Artery

Breast ultrasound is a valuable adjunctive to mammography for the identification and characterization of palpable and nonpalpable abnormalities. With the advances of ultrasound techniques over the past 10 years, the role of ultrasound has evolved from differentiation of benign from malignant masses, evaluation of mammmographic abnormalities, and guidance modality of interventional procedure to preoperative evaluation of lesion extent, follow-up after operation, and screening method for high-risk women. It can also be used as a supplemental modality of a physical examination and mammography to increase diagnostic accuracy and to reduce unnecessary surgical biopsy. This article is to review the indication of breast ultrasound examinations as well as merits and limitations compared to mammmography.
Biopsy ; Breast ; Breast Neoplasms ; Female ; Follow-Up Studies ; Humans ; Mammography ; Mass Screening ; Physical Examination

During the last 15 years, traditional breast cancer classifications based on histopathology have been reorganized into the luminal A, luminal B, human epidermal growth factor receptor 2 (HER2), and basal-like subtypes based on gene expression profiling. Each molecular subtype has shown varying risk for progression, response to treatment, and survival outcomes. Research linking the imaging phenotype with the molecular subtype has revealed that non-calcified, relatively circumscribed masses with posterior acoustic enhancement are common in the basal-like subtype, spiculated masses with a poorly circumscribed margin and posterior acoustic shadowing in the luminal subtype, and pleomorphic calcifications in the HER2-enriched subtype. Understanding the clinical implications of the molecular subtypes and imaging phenotypes could help radiologists guide precision medicine, tailoring medical treatment to patients and their tumor characteristics.
Acoustics ; Breast Neoplasms* ; Breast* ; Classification ; Diagnosis ; Gene Expression Profiling ; Humans ; Phenobarbital ; Phenotype* ; Precision Medicine ; Receptor, Epidermal Growth Factor ; Shadowing (Histology) ; Ultrasonography

This work reviews the evidence on breast imaging for screening (surveillance) in women with a history of breast cancer (BC). Early detection of second BCs in these women improves their prognosis based on studies using mammography (usually with clinical examinations) for surveillance. Cohort studies have estimated that mammography surveillance has moderate sensitivity (65.4%) and good specificity (98.3%), and have shown that these women are at a higher risk of interval BC than age- and breast density-matched women without a history of BC. Studies of adjunct imaging (ultrasound, magnetic resonance imaging) for surveillance that have reported detection and accuracy measures have generally shown that adjunct imaging detected more second BCs than mammography and added substantially to the amount of false-positive results; however, little evidence exists regarding screening efficacy of adjunct imaging as part of routine surveillance.
Breast Neoplasms* ; Breast* ; Cohort Studies ; Female ; Humans ; Mammography ; Mass Screening* ; Prognosis ; Sensitivity and Specificity

Despite the high sensitivity and widespread use of preoperative magnetic resonance imaging (MRI), the American Cancer Society and the National Comprehensive Cancer Network guidelines do not recommend the routine use of preoperative MRI owing to the conflicting results and lack of clear benefit to the surgical outcome (reoperation and mastectomy) and long-term clinical outcomes (local recurrence and metachronous contralateral breast cancer).Preoperative MRI detects additional cancers that are occult at mammography and ultrasound but increases the rate of mastectomy. Concerns about overdiagnosis and overtreatment of preoperative MRI might be mitigated by adjusting the confounding factors when conducting studies, using the state-of-the-art image-guided biopsy technique, applying the radiologists’ cumulative experiences in interpreting MRI findings, and performing multiple lumpectomies in patients with multicentric cancer. Among the various imaging methods, dynamic contrastenhanced MRI has the highest accuracy in predicting pathologic complete response after neoadjuvant chemotherapy. Prospective trials aimed at applying the MRI information to the de-escalation of surgical or radiation treatments are underway. In this review, current studies on the clinical outcomes of preoperative breast MRI are updated, and circumstances in which MRI may be useful for surgical planning are discussed.

PURPOSE: To compare the galactographic findings of malignant and benign disease in patients with pathologic nipple discharge and to analyze the features suggesting malignancy. MATERIALS AND METHODS: In 24 patients in whom pathologic nipple discharge had occurred, the findings of preoperative galactography were correlated with those of pathology. RESULTS: Nine of the 24 cases were malignant and the other 15 were benign. Intraductal calcification occurred in five malignant cases (56%) and two (13%) which were benign. Seven malignant cases (78%) involved the segmental ducts, and in eight (89%), the peripheral ducts below the subsegmental duct were involved. Five benign cases (33%) involved the lactiferous sinus, seven (47%) the segmental duct, and two (13%) the subsegmental duct. Distal duct dilatation occurred in four benign cases (27%), while ductal stenosis was noted in six cases (67%) and ductal distortion in seven (78%). A malignant tumor appeared as a multiple (n=5, 56%) or irregular (n=5, 56%) filling defect, and a benign tumor as a single (n=12, 80%), oval (n=6, 40%) or lobular (n=4, 27%) filling defect. CONCLUSION: At galactography, a malignant tumor frequently appeared as an irregular multiple intraductal filling defect in a peripheral duct. A benign tumor, on the other hand, appeared as an oval or lobular single lesion. The presence of ductal stenosis, distortion and intraductal microcalcifications not opacified by contrast material suggest possible malignancy.
Constriction, Pathologic ; Dilatation ; Hand ; Humans ; Nipples* ; Pathology

Ultrasound (US) elastography is a tool that indicates the hardness of a lesion. Recent studies using elastography with freehand compression have shown similar diagnostic performance to conventional US in differentiating benign lesions from malignant breast masses. On the other hand, the acquired information is not quantitative, and the reliability of the imaging technique to correctly compress the tissue depends on the skill of the operator, resulting in substantial interobserver variability during data acquisition and interpretation. To overcome this, shear wave elastography was developed to provide quantitative information on the tissue elasticity. The system works by remotely inducing mechanical vibrations through the acoustic radiation force created by a focused US beam. This review discusses the principles and examination techniques of the two types of elastography systems and provides practical points to reduce the interobserver variability or errors during data acquisition and interpretation.
Acoustics ; Breast ; Breast Neoplasms ; Elastic Modulus ; Elasticity ; Elasticity Imaging Techniques ; Hand ; Hardness ; Observer Variation ; Vibration