Video

Principle. Low-dose x-ray of compressed breast (DM); DBT acquires multiple low-dose projections to reconstruct thin slices, reducing tissue overlap.

Indications.

• Population screening and diagnostic work-up (first-line)
   
• Post-treatment surveillance (per institutional protocols)
   
• Problem solving in calcifications and architectural distortion
   

Advantages.

• Only modality proven to reduce mortality in population screening
   
• Detects microcalcifications optimally (DCIS)
   
• DBT improves lesion conspicuity and reduces recalls vs DM alone
   

Limitations.

• Sensitivity decreases with increasing breast density; DBT mitigates but doesn’t eliminate the effect.
   
• Overlap/structural noise (largely addressed by DBT)
   
• Ionizing radiation (low; DBT similar to or slightly above DM depending on vendor/protocol)
   

Performance.

• In comparative meta-analyses and cohort data, DBT shows higher sensitivity than DM (≈86% vs 80%) with similar specificity (~96% each); recall rates often lower with DBT.
   
• Dense-breast sensitivity for mammography is reduced relative to nondense tissue (ACR Appropriateness Criteria).
   

Patient perspective.

• Brief exam; compression can be uncomfortable.
   
• Radiation is low and within screening safety norms.
   

Impact on management.

• First gate for screening/diagnostics; defines need for adjunct imaging (US, MRI).
   
• Calcification-driven pathways (stereotactic biopsy).
   
• DBT lowers recalls and may reduce benign biopsies in many programs. 

Principle: High-frequency B-mode imaging (7–15 MHz) with real-time assessment of lesion morphology, echotexture, margins, and vascularity.

Indications:

• Palpable lumps not visible on mammography
   
• Characterization of mammographic abnormalities (solid vs cystic)
   
• Screening adjunct in dense breasts
   
• Image-guided biopsy and aspiration
   
• Axillary lymph node assessment
   

Advantages:

• Radiation-free, cost-effective, portable, real-time evaluation
   
• Excellent for differentiating cystic from solid lesions
   
• Facilitates interventional procedures
   

Limitations:

• Operator-dependent
   
• Limited sensitivity for microcalcifications and small deep lesions
   
• Low specificity for atypical benign lesions
   

Diagnostic Performance:

• Sensitivity: 75–92% for solid lesions (>5 mm)
   
• Specificity: 70–90% depending on lesion morphology and BI-RADS criteria
   
• False negatives: small, isoechoic, or posteriorly located lesions
   

Role in Management:

• Primary tool for lesion characterization
   
• Guides biopsy planning and follow-up
   
• Critical for axillary node assessment

Purpose: Focused evaluation of a region of interest identified on mammography, MRI, or physical exam.

Advantages:

• High spatial correlation with other modalities
   
• Allows real-time lesion confirmation and biopsy under one setting
   

Limitations:

• Region-specific — may miss additional foci if used in isolation
   

Use Cases:

• Correlation of MRI enhancement or mammographic density
   
• Confirmation of sonographic correlate prior to percutaneous biopsy

Principle: Functional imaging using Tc-99m sestamibi or similar radiopharmaceuticals; uptake reflects mitochondrial density and blood flow in tumor cells.

Indications:

• Dense breasts where mammography/USG are inconclusive
   
• MRI contraindicated or unavailable
   
• Problem-solving for indeterminate lesions
   

Advantages:

• Functional evaluation independent of breast density
   
• High specificity for invasive lesions
   
• Alternative to MRI in claustrophobic or renal-compromised patients
   

Limitations:

• Radiation exposure (~6–8 mSv per exam)
   
• Limited spatial resolution for lesions <5 mm
   
• False negatives in low-grade or hypovascular tumors
   

Performance:

• Sensitivity: 80–90%
   
• Specificity: 70–85%
   
• Comparable detection to MRI in dense-breast cohorts
   

Clinical Value:

• Complementary to structural imaging
   
• Improves diagnostic confidence when MRI not feasible

Principle: Peritumoral or subareolar injection of Tc-99m sulfur/nanocolloid to map lymphatic drainage and locate the sentinel lymph node.

Indications:

• Preoperative localization of sentinel nodes in early-stage breast cancer
   
• Axillary staging in clinically node-negative disease
   

Advantages:

• Minimally invasive mapping technique
   
• Reduces need for full axillary dissection and associated morbidity
   

Limitations:

• Possible non-visualization (obesity, lymphatic blockage)
   
• Limited anatomical detail; pathology confirmation still required
   

Performance:

• SLN identification rate: >95%
   
• False-negative rate: <5–10%
   
• Concordance with blue dye mapping: >90%
   

Clinical Impact:

• Determines extent of axillary surgery
   
• Reduces lymphedema risk and surgical morbidity

Principle: ^18F-FDG accumulates in metabolically active tumor tissue; fused PET–CT provides metabolic and anatomical correlation.

Indications:

• Staging of locally advanced or metastatic breast cancer
   
• Evaluation of recurrence and therapy response
   
• Assessment of equivocal findings on conventional imaging
   

Advantages:

• Whole-body evaluation in a single session
   
• Detects distant metastases, including bone marrow and soft tissue
   
• Quantitative (SUV-based) therapy response assessment
   

Limitations:

• Limited sensitivity for small (<5 mm), low-grade, or lobular lesions
   
• Radiation exposure (7–10 mSv typical)
   
• False positives with infection/inflammation
   

Performance:

• Sensitivity: 80–90% (for metastases)
   
• Specificity: 85–90%
   
• Outperforms CT/bone scan in detecting bone and soft-tissue metastases
   

Clinical Value:

• Alters staging and management in ~30% of patients
   
• Monitors treatment efficacy via metabolic response
   
• Guides early switch of ineffective systemic therapy

Principle: Combines T1/T2-weighted sequences, DWI/ADC mapping, and dynamic contrast-enhanced imaging to evaluate vascularity and permeability (Ktrans).

Indications:

• High-risk screening (BRCA1/2, strong family history)
   
• Preoperative staging and mapping of multifocal/multicentric disease
   
• Problem-solving for inconclusive mammogram/USG findings
   
• Assessment of residual disease post-neoadjuvant chemotherapy
   
• Implant evaluation (silicone leakage, rupture)
   

Advantages:

• Highest soft-tissue contrast and 3D anatomical resolution
   
• High sensitivity for invasive carcinoma (especially lobular)
   
• No radiation exposure
   

Limitations:

• Requires gadolinium-based contrast (contraindicated in severe renal dysfunction)
   
• False positives due to benign proliferative lesions
   
• Cost, time, and access limitations
   

Performance:

• Sensitivity: 83–94%
   
• Specificity: 71–95% (variable)
   
• NPV: >95% for exclusion of residual disease
   

Clinical Role:

• Alters surgical planning in up to 25–30% of cases
   
• Detects contralateral or multifocal lesions in 3–6% of patients
   
• Superior for invasive lobular carcinoma and post-treatment assessment

Principle: Combines metabolic information (PET) with superior soft-tissue contrast of MRI; simultaneous acquisition minimizes misregistration.

Advantages:

• Reduced radiation dose vs PET–CT
   
• Better lesion characterization (especially in liver, bone, and breast)
   
• Multiparametric functional assessment (DWI, DCE + PET)
   

Limitations:

• High cost, limited availability
   
• Longer acquisition times
   
• MRI contraindications apply
   

Performance:

• Sensitivity: ~86–90% for nodal metastases
   
• Specificity: ~94–99%
   
• Superior to MRI or PET–CT alone for detecting liver and bone metastases
   

Clinical Role:

• Comprehensive one-stop staging
   
• Excellent for assessing treatment response
   
• Valuable in recurrent/metastatic disease mapping

Principle: Radiolabeled estradiol analog binds to estrogen receptors (ER), enabling in vivo mapping of ER expression.

Indications:

• Assess receptor heterogeneity across metastases
   
• Guide endocrine therapy decisions
   
• Identify ER-positive lesions inaccessible for biopsy
   

Advantages:

• Functional “whole-body biopsy” of ER status
   
• Non-invasive alternative to tissue sampling
   
• Can predict endocrine therapy responsiveness
   

Limitations:

• Availability limited to specialized centers
   
• Minimal radiation (~6 mSv)
   
• Not suitable for ER-negative tumors
   

Performance:

• Sensitivity: 84–90%
   
• Specificity: 80–95%
   
• Correlation with immunohistochemistry >85% in major trials
   

Clinical Impact:

• Refines treatment planning in metastatic settings
   
• Avoids futile endocrine therapy in ER-negative metastases
   
• Potential companion diagnostic for theranostics