THE IMPACT OF MAGNETIC RESONANCE IMAGING ON BI-RADS CLASSIFICATION AND MALIGNANCY PREDICTION IN ULTRASOUND-DETECTED NON-MASS BREAST LESION

Abstract

Objective: To assess the contribution of magnetic resonance imaging to Breast Imaging Reporting and Data System (BI-RADS) reclassification and biopsy decision making in patients with non-mass breast lesions identified on ultrasound. Material and Methods: This retrospective study included 392 patients who underwent breast magnetic resonance imaging following the identification of non-mass breast lesions on ultrasound; 135 had histopathologic verification and were analyzed. BI-RADS categories on ultrasound and magnetic resonance imaging were compared, and reclassification patterns were defined as upgrade (ultrasound <4 to magnetic resonance imaging ≥4), downgrade (ultrasound ≥4 to magnetic resonance imaging <4), or stable. Diagnostic accuracy metrics were calculated using BI-RADS ≥4 as the threshold for clinically significant disease. Results: Among 135 patients with pathology, of the lesions 64.4% were benign, 5.9% were high-risk, and 29.6% were malignant. Using BI-RADS ≥4, magnetic resonance imaging demonstrated higher sensitivity and negative predictive value (95.5% and 90.0%) than ultrasound (61.4% and 77.9%) but substantially reduced specificity (21.2% vs. 70.6%). Magnetic resonance imaging upgraded 48.8% of lesions and downgraded 4.7%. High-risk/malignant disease was detected in 23.8% of upgraded lesions, while all downgraded lesions were benign. Conclusion: Magnetic resonance imaging meaningfully influences BI-RADS reclassification in non-mass breast lesions by improving lesion exclusion confidence but at the cost of lower specificity and reduced biopsy yield. Magnetic resonance imaging -driven downgrade appears safe and may help avoid unnecessary biopsies in selected cases.

Keywords

• Non-mass breast lesion
• BI-RADS
• magnetic resonance imaging
• ultrasound
• reclassification

Supporting Institution

No financial support was received from any institution or person.

Ethical Statement

This retrospective study was conducted with the approval of the Ethics Committee of Ankara Bilkent City Hospital (decision number: TABED 2/1683/2025; date: 10.12.2025).

Thanks

No financial support was received from any institution or person.

Ultrasonografide Saptanan Kitlesel Olmayan Meme Lezyonlarında Manyetik Rezonans Görüntülemenin BI-RADS Sınıflandırmasına Etkisi ve Malignite Öngörüsüne Katkısı

Abstract

Amaç: Ultrasonografide kitlesel olmayan meme lezyonu saptanan hastalarda manyetik rezonans görüntülemenin Breast Imaging Reporting and Data System (BI-RADS) yeniden sınıflandırma sürecine ve biyopsi gerekliliğine etkisini değerlendirmek. Gereç ve Yöntemler: Ultrasonografide kitlesel olmayan lezyon saptanan ve ardından manyetik rezonans görüntüleme yapılan toplam 392 hasta incelendi; histopatolojik doğrulaması bulunan 135 hasta analize dahil edildi. Ultrason ve manyetik rezonans görüntüleme (BI-RADS) kategorileri karşılaştırıldı ve yeniden sınıflandırma (kategori yükselmesi, kategori düşmesi veya stabil olarak) yapıldı. BI-RADS ≥4 klinik anlamlı hastalık eşiği olarak kabul edilerek tanısal doğruluk ölçütleri hesaplandı. Bulgular: Patoloji doğrulaması olan hastalarda lezyonların %64,4’ü benign, %5,9’u yüksek riskli ve %29,6’sı malign bulundu. BI-RADS ≥4 eşik değeri kullanıldığında manyetik rezonans görüntüleme duyarlılık ve negatif prediktif değer açısından ultrasondan daha yüksek performans gösterdi (%95,5 ve %90,0), ancak özgüllük belirgin şekilde düşüktü (%21,2). Manyetik rezonans görüntüleme, olguların %48,8’inin kategorisini yükseltirken, %4,7’sini düşürdü. Kategorisi yükselen olguların %23,8’i yüksek riskli/malign iken, kategorisi düşürülen tüm olgular benign idi. Sonuç: Manyetik rezonans görüntüleme, kitlesel olmayan lezyonlarda BI-RADS yeniden sınıflandırmayı anlamlı ölçüde etkilemekte ve maligniteyi dışlamada yüksek tanısal güven sağlamaktadır. Bununla birlikte, spesifitedeki düşüş nedeniyle biyopsi veriminde belirgin iyileşme sağlamamakta; kategorisi düşen olgularda gereksiz biyopsileri güvenle azaltma potansiyeli sunmaktadır.

Keywords

• Kitlesel olmayan lezyon
• BI-RADS
• manyetik rezonans görüntüleme
• ultrasonografi
• yeniden sınıflandırma

Supporting Institution

Bu çalışma için herhangi bir kurum veya kişiden finansal destek alınmamıştır.

Ethical Statement

Bu retrospektif çalışma, Ankara Bilkent Şehir Hastanesi Etik Kurulu’nun onayı alınarak yürütülmüştür (karar no: TABED 2/1683/2025; 10.12.2025).

Thanks

Bu çalışma için herhangi bir kurum veya kişiden finansal destek alınmamıştır.

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