Breast imaging questions cluster around BI-RADS assessment, mammography, MRI, and ultrasound. These free samples from the RadioQBank published set include full explanations, exam pearls, and references across screening and diagnostic scenarios.
Question 1 · Breast Cancer Staging · easy
A 45-year-old woman with newly diagnosed left breast IDC (ER+/PR+/HER2−) is counselled regarding surgical options. MRI shows unifocal disease (2.5 cm), no multicentricity, no skin or chest wall involvement, and the patient is willing to undergo radiation. Which statement BEST reflects current evidence regarding BCS vs mastectomy?
- a. Mastectomy provides a survival benefit over BCS + radiation for tumours >2 cm
- b. BCS + radiation is oncologically equivalent to mastectomy for appropriately selected patients, with comparable overall survival
- c. MRI-guided surgical planning for BCS increases the rate of re-excision compared to mammography-guided surgery
- d. Bilateral prophylactic mastectomy is recommended for all patients with Luminal A breast cancer
Answer: B. Multiple randomised trials (Milan trial, NSABP B-06, EORTC 10801) and subsequent meta-analyses have demonstrated that BCS followed by whole-breast radiation provides equivalent overall survival and disease-specific survival to total mastectomy for appropriately selected early-stage patients. BCS preserves the breast with equivalent oncological outcomes. Selection criteria include unifocal disease, achievable negative margins, willingness for radiation, and no contraindications.
Exam pearl: BCS + RT = mastectomy in OS for early breast cancer. Milan + NSABP B-06 + EORTC 10801 all confirm equivalence.
Veronesi U Milan trial, NEJM 2002; Fisher B NSABP B-06, NEJM 2002; Grainger & Allison 7th ed
Question 2 · BI-RADS · easy
BI-RADS category 0 on mammography — which of the following best defines this assessment category?
- a. Negative mammogram with no abnormality — routine annual screening recommended
- b. Incomplete assessment — additional imaging evaluation needed (prior films, additional views, ultrasound)
- c. Probably benign finding — short-interval follow-up in 6 months recommended
- d. Highly suspicious finding — biopsy recommended
Answer: B. ACR BI-RADS Category 0 is defined as an INCOMPLETE assessment — the mammographic evaluation cannot be definitively completed without additional information. It is used when: comparison with prior mammograms is needed; additional diagnostic views are required (magnification, spot compression); or ultrasound is needed to characterise a finding seen on mammography. BI-RADS 0 is appropriate only in the screening setting — in a diagnostic setting, the workup should be completed before issuing a final category. When a BI-RADS 0 is issued, the patient must return for additional evaluation to assign a final category (1–6).
Exam pearl: BI-RADS 0 = Incomplete. Used in screening only. Needs: prior films / additional views / US before final category. Not used in diagnostic setting.
ACR BI-RADS Atlas 5th ed; Grainger & Allison 7th ed — Breast; Radiographics 2014
Question 3 · Breast Ultrasound · moderate
Regarding the sonographic evaluation of breast vascularity with Doppler ultrasound, which of the following is MOST accurate?
- a. Absence of flow on Doppler confirms a benign lesion
- b. Increased internal vascularity on Doppler is a reliable indicator of malignancy
- c. Doppler findings are supplementary and should not be used in isolation to determine BI-RADS category
- d. All fibroadenomas are avascular on Doppler
Answer: C. Doppler vascularity findings are supplementary descriptors in breast ultrasound and cannot independently determine the BI-RADS category. Both benign and malignant lesions may show internal vascularity. Malignant tumours often demonstrate increased internal vascularity (tumour neovascularity) with high-velocity, low-resistance arterial flow, but these features overlap significantly with benign lesions. The BI-RADS category is assigned based primarily on B-mode morphology (shape, margins, orientation, echo pattern) with Doppler as supporting information.
Exam pearl: Doppler vascularity in breast US is supplementary only — BI-RADS category is based on B-mode morphology, not flow alone.
ACR BI-RADS Atlas 5th ed; Stavros AT — Breast Ultrasound textbook
Question 4 · Molecular Subtypes · moderate
All of the following are TRUE regarding Ki67 in breast cancer molecular classification EXCEPT:
- a. Ki67 is a nuclear antigen expressed in all phases of the cell cycle except G0
- b. A Ki67 threshold of 14% is used by St. Gallen 2013 consensus to distinguish Luminal A from Luminal B (HER2−)
- c. High Ki67 (>20%) is associated with better response to chemotherapy
- d. Ki67 is the most reproducible and standardised biomarker for proliferation across laboratories
Answer: D. Ki67 is the LEAST reproducible biomarker in breast cancer pathology — inter-laboratory variation is substantial (up to 25%), and there is no standardised cut-off globally accepted, with thresholds ranging from 14% to 20% across different guidelines. This is a known limitation. Ki67 expression (active in G1, S, G2, M phases but NOT G0) does provide prognostic and predictive information, and high Ki67 does correlate with chemo-sensitivity.
Exam pearl: Ki67 threshold 14% (St. Gallen): <14% = Luminal A, ≥14% = Luminal B; but Ki67 has poor inter-lab reproducibility.
Goldhirsch A et al St. Gallen 2013; Dowsett M, J Clin Oncol 2011; AIIMS-MAMC-PGI guide
Question 5 · Breast MRI · hard
Which of the following is the correct definition of 'functional tumour volume' (FTV) as used in breast MRI NACT response assessment?
- a. The maximum diameter of the tumour on the most enhancing post-contrast sequence
- b. The volume of tissue within the tumour that shows a minimum percentage enhancement above a defined threshold (usually >70%) on early post-contrast subtracted images
- c. The ratio of tumour ADC at cycle 2 compared to baseline DWI
- d. The total BPE-normalised enhancement of the tumour on T1 post-contrast images
Answer: B. Functional tumour volume (FTV) is defined as the volume of tissue that enhances above a specified threshold — typically ≥70% signal enhancement above pre-contrast baseline — measured on early phase subtracted DCE-MRI images. FTV integrates both the size and enhancement intensity of the tumour mass, making it more sensitive to early treatment response than linear measurements (RECIST). The ACRIN 6698 trial demonstrated FTV is a superior predictor of pCR over longest diameter.
Exam pearl: FTV = volume with ≥70% enhancement threshold on early subtracted DCE-MRI; validated by ACRIN 6698.
Hylton NM, Lancet Oncol 2016; ACRIN 6698 trial; Radiographics 2021
Question 6 · BI-RADS · hard
A 40-year-old female undergoes breast ultrasound showing a well-defined hypoechoic mass with increased shear wave elastography (SWE) stiffness of 180 kPa. Mammography shows a partially obscured mass without calcifications. BI-RADS assessment should be:
- a. BI-RADS 3 — Probably benign
- b. BI-RADS 4A — Low suspicion
- c. BI-RADS 4B — Moderate suspicion
- d. BI-RADS 4C — High suspicion
Answer: C. A mass that appears benign on B-mode ultrasound but shows significantly elevated SWE stiffness (>160 kPa) warrants upgrading the BI-RADS category. Normal breast tissue has SWE values of 3-30 kPa; benign lesions typically <80 kPa; and malignant lesions often >100 kPa. An SWE value of 180 kPa in a lesion with otherwise benign morphology creates a discordant finding that should be classified as BI-RADS 4B (moderate suspicion) to ensure tissue sampling.
Exam pearl: SWE cutoff: <80 kPa likely benign, >160 kPa suspicious. SWE can UPGRADE BI-RADS but should not DOWNGRADE morphologically suspicious lesions.
ACR BI-RADS Atlas 5th Ed, 2013; J Ultrasound Med 2015;34(12):2127-2137; The Breast 2021